Håvard Steinshamn

Seniorforskar

(+47) 906 82 643
havard.steinshamn@nibio.no

Sted
Tingvoll

Besøksadresse
Gunnars vei 6, 6630 Tingvoll

Biografi

Eg er forskar på fôrdyrking, fôrutnytting og produksjon av mjølk og kjøtt hos drøvtyggjarar. Eg har hatt spesielt fokus på utfordringar i økologisk produksjon. I seinare tid har eg arbeidd med prosjekt innan fôrdyrking, sett på samanhengen mellom eigenskapar hos fôr og produksjon og kvalitet av mjølk, på utnytting av beite og produksjon av mjølk og kjøtt på beite, på å finne erstatningar for syntetiske vitamin, på bruk av tang og tare som fôr og fôrtilskot, og på alternative tiltak mot parasittar hos sau.

Les mer

Sammendrag

Lokal verdiskaping basert på utmarka i verdsarvområda Vestlandsk fjordlandskap kan ikkje sjåast isolert, men er tett knytt til heile samfunnsutviklinga på desse stadene. Det tradisjonelle landbruket i desse områda har skapt verdfulle naturgode som biologisk mangfald, opne turområde med høg rekreasjonsverdi, turstiar og anna. Fleire av desse naturgoda er viktige for reiselivsnæringa. Kulturlandskapet er også viktig for verdsarvstatusen i seg sjølv, ettersom dette er ein viktig del av kjerneverdiane til området (OUV). Utviklinga i landbruket gjer at tungdrivne areal også i verdsarvområda går ut av bruk. Opphøyr eller låg bruksintensitet går spesielt ut over utmarksressursane og dei seminaturlege naturtypane. Utmarka i Geirangerfjordområdet er særleg trua, da tradisjonell bruk med beiting, slått og hausting no i stor grad har teke slutt, og naturtypane gror att med buskar og kratt. Gjengroing fører til tap avvariasjon, artar og økologiske funksjonar. Intensivering av landbruket vil også forringe naturverdiane og landskapskvalitetane. For at landbruket ikkje berre skal vere eit «kulisselandbruk», men vere del av eit berekraftig driftssystem, må tilgjengelege arealressursar på innmark og utmark nyttast til matproduksjon og andre livsviktige økosystemtenester. Gjeldande landbrukspolitikk, med mål om stordrift og effektivisering av matproduksjonen, er ei sterkare drivkraft enn dei tiltaka som er sett inn for å bremse og motverke at tungdrivne areal går ut av bruk i verdsarvområda. Den lokale turist- og reiselivsnæringa kan også hamne i noko av same marginaliserte situasjonen som landbruksnæringa fordi dei ikkje lenger er dei mest sentrale aktørane. Eksterne aktørar representert ved cruiseindustri, turbussar og storskala reisearrangørar er ofte i enda større grad premissleverandørar. Det trengs ei heilskapleg tilnærming for å løyse utfordringane. Ein prosess som forskyv maktbalansen frå eksterne aktørar innan masseturisme og i retning lokalt næringsliv og verdiskaping og som inkluderer innbyggjarane, krev nytenking, utvikling av nye forretningsmodellar og evne til gjennomføring gjennom demokratiske planprosessar. Av ulike konkrete verkemiddel som kan prøvast ut, men da helst som element i ein større endringsprosess, vil vi peike på særskilde landbrukspolitiske verkemiddel i retning sveitsisk modell, turistskatt, anna betaling for fellesgode og bygdeutviklingsprosjekt som kan gi auka tilflytting og ny næringsaktivitet. Dialog og partnarskapsbygging kan fremme ansvarleg medverknad.Forskingsbehova for verdsarvområda og tilsvarande område med store og unytta ressursar i utmarka er mange, og arbeidsgruppa si vurdering er summert og konkretisert i denne rapporten

Til dokument Til datasett

Sammendrag

Dairy products are often considered challenging for health due to their saturated fatty acid content, yet they also provide beneficial nutrients, some unique to ruminants. The degree of fat saturation is influenced by cows’ diets; grazing pasture enhances unsaturated fatty acids in milk compared with conserved forages. These benefits can be partially mimicked by feeding oilseeds and here we consider the impact on milk composition in a 2 × 2 trial, feeding rapeseed to both conventional and organic cows, finding very differing lipid metabolism in the 4 experimental groups. For milk fat, benefits of organic rather than conventional management (+39% PUFA, +24% long chain omega-3 and +12% conjugated linoleic acid (CLA)) appear complementary to those from feeding rape (+43% MUFA, +10% PUFA, +40% CLA), combining to produce milk 16% lower SFA and higher in MUFA (43%), PUFA (55%) and CLA (59%). Organic and rape feeding provide less omega-3 PUFA than the conventional and control diets, yet contrary to expectations, together they almost doubled (+94%) the omega-3 concentration in milk, implying a 3.8 fold increase in net transfer from diet into milk. Organic and rape feeding also gave lower trace-elements and antioxidants in milk. Greater understanding of these phenomena might enhance the sustainability of dairying.

Til dokument Til datasett

Sammendrag

In this study, a brown macroalgae species, Saccharina latissima, processed to increase its protein concentration, and a red macroalgae species, Porphyra spp., were used to evaluate their in vivo digestibility, rumen fermentation and blood amino acid concentrations. Four castrated rams were used, whose diets were supplemented with a protein-rich fraction of S. latissima, a commercial Porphyra spp. and soybean meal (SBM). Our results show that the protein digestibility of a diet with S. latissima extract was lower (0.55) than those with Porphyra spp. (0.64) and SBM (0.66). In spite of the higher nitrogen (N) intake of diets containing Porphyra spp. and SBM (20.9 and 19.8 g N/day, respectively) than that with S. latissima (18.6 g N/day), the ratio of N excreted in faeces to total N intake was significantly higher in the diet with S. latissima than those with Porphyra spp. and SBM. This reflects that the utilization of protein in S. latissima was impaired, possibly due to reduced microbial activity. The latter statement is corroborated by lower volatile fatty acid composition (25.6, 54.8 and 100 mmol/l for S. latissima, Porphyra spp. and SBM, respectively) and a non-significant tendency for lower ammonia concentration observed in diets with S. latissima and Porphyra spp. compared to SBM. It is important to note that the S. latissima used in this trial was rinsed during processing to remove salt. This process potentially also removes other water-soluble compounds, such as free amino acids, and may have increased the relative fraction of protein resistant to rumen degradation and intestinal absorption. Furthermore, the phlorotannins present in macroalgae may have formed complexes with protein and fibre, further limiting their degradability in rumen and absorption in small intestines. We recommend that further studies explore the extent to which processing of macroalgae affects its nutritive properties and rumen degradability, in addition to studies to measure the intestinal absorption of these macroalgae species

Til dokument

Sammendrag

Two short-term grazing experiments were conducted with Norwegian Red cows. In Exp 1, 24 cows were randomly assigned to one of the following three pasture allocation methods (PAM): weekly pasture allowance (7RG), grazing 1/7 of 7RG each day (1SG), or grazing as 1SG but had access to grazed part of the paddock within one week (1FG). In Exp 2, 7RG was shortened to 5 days (5RG). We hypothesized that PAM will affect sward quality, quantity, intake and production differently. Pasture chemical composition changed with advancing grazing days but were not different between treatments. Pasture intake, milk yield, and methane emission were not affected by PAM. In Exp 1, 7RG cows spent less time on grazing, whereas in Exp 2, 1FG cows spent longer on grazing than others. Patterns observed in sward quality, and behavioural and physiological adaptations of cows to short-term changes in nutrient supply may explain the observed effects.

Sammendrag

•Blandingseng med rødkløver og gras høsta to ganger i sesongen gir lavere grovfôrkostnader sammenlignet med tre slåtter per år i blandingseng eller timoteibasert eng som høstes to eller tre ganger. •Blandingsenga slått to ganger per sesong gir også lavest total fôrkostnad (grovfôr + kraftfôr) selv om treslåttsystemene reduserte behovet for kraftfôr. • Sjøl om en kan bruke mindre og billigere kraftfôr ved tre slåtter, greier en ikke å dekke inn de høyere dyrkings- og høstekostnadene. • Femårig engomløp kommer generelt bedre ut økonomisk enn treårig, selv om avlingsnivået er litt lavere. Avlingsøkninga kompenserer ikke for de økte dyrkingskostnadene. • Blandingseng med kløver, som er moderat gjødsla og høsta to ganger per år, gir lavest kostnad, totalt for grovfôr + kraftfôr, og er mest arealeffektivt med dagens kraftfôrpris

Sammendrag

The objective of this paper was to examine how cutting frequency, silage fermentation patterns and clover performance in grass-clover swards influence the use of inputs and profitability in an organic dairy system. A linear programming model was developed to compare a three-cut and a two-cut system for a model farm in Central Norway, either with restricted or extensive silage fermentation at low or high red clover (Trifolium pratense L.) proportion in the sward, giving 8 different silage types in all. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway as well as a silage fermentation experiment, and with feed intakes and milk yields from simulations with the ‘TINE Optifôr’ feed ration planner in the Norfor feed evaluation system. The model maximized total gross margin of farms with 260,000 l milk quota and housing capacity for 45 cows, with separate model versions for each of the 8 silage types. Farmland availability varied from 30 to 70 ha with 40 ha as the basis. Our results suggested that farmland availability and marginal return of a competing barley crop profoundly influenced the profitability of the different silage types. A high clover proportion increased dry matter (DM) yields and was far more important for profitability than the score on the other factors considered at restricted land availabilities. Profits with the three-cut systems were always greater than those with the two-cut systems, the former being associated with greater silage intakes and improved dairy cow performances but lower DM forage yields. Three-cut systems were further favoured as land availability increased and also by a lower marginal return of barley. Although use of an acidifying silage additive improved feed intakes and milk production per cow, the practice reduced total milk production and depressed profit compared to untreated, extensively fermented silage at restrictive land availabilities. With more land available, and in particular at a low marginal return of barley, use of a silage additive was profitable.

Til dokument Til datasett

Sammendrag

Utilisable crude protein (uCP), methane (CH4) production and other fermentation parameters were analysed in vitro for a diet in which grass silage was replaced by different levels of seaweed protein fractions prepared from three seaweed species: Saccharina latissima, Alaria esculenta and Palmaria palmata. Ten fractions from these three species in which the protein content had been increased and the salt content reduced by simple processing were tested, with inclusion levels in the diet based on the nitrogen content of the fractions. Following an extraction procedure, four fractions from Saccharina latissima, three from Alaria esculenta and one from Palmaria palmata, were gradually included in the diet by replacing high quality silage with approximately 0, 0.15, 0.30 and 0.45 g/g DM, while two high-protein fractions of Palmaria palmata were tested at replacement levels of 0, 0.075, 0.15 and 0.225 g/g DM. To estimate fermentation parameters, 500 mg of each diet were incubated in bottles with 60 mL buffered rumen fluid. Estimated uCP increased linearly with increasing replacement rate of grass silage with seaweed protein fractions (from 158 g/kg DM to 206 g/kg DM on average for all fractions). Increasing protein fraction from the brown seaweed Saccharina latissima in the diet significantly increased true organic matter digestibility (OMD) (from on average 0.786 to 0.821). Organic matter digestibility decreased with increasing level of Alaria esculenta fractions (from on average 0.785 to 0.733), which also gave a linear decrease in CH4 production (from on average 45.3 to 38.5 mL/g organic matter). As a result of decreased CH4 production and OMD, total volatile fatty acid concentration decreased with increasing level of Alaria esculenta fractions (from on average 69.5 to 63.0 mmol/L). Thus, positive and species-specific effects of seaweed on estimated uCP and fermentation parameters were observed in vitro when protein fractions remaining after an extraction procedure on seaweed partly replaced grass silage in the feed ration.

Til dokument

Sammendrag

Red clover (Trifolium pratense) grown in mixtures with grasses often constitutes a lower proportion of total yield in spring than in summer growth. A more even red clover proportion between the harvests would benefit forage quality and management at feeding. We investigated whether inclusion of early versus late‐maturing red clover varieties could reduce this disproportionality. In a two‐year field trial harvested three times per season, each of six red clover varieties was grown in two grass mixtures. Rate of phenological development did not differ during spring growth, but did so in regrowth after first and second cuts. Here, the earliest varieties constituted the highest proportion. At all harvests, the early varieties had lower crude protein concentrations and a higher content of neutral detergent fibre (NDF) and indigestible NDF than the late varieties. Clover proportion was higher in swards with a mixture of timothy and meadow fescue than in swards with perennial ryegrass during the first year and lower in the second year. It is concluded that developmental rate should be explored further as a key character for red clover competiveness in spring growth of rapidly elongating grasses.

Sammendrag

Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmlandmay have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1) No grazing, (2) grazing with heifers, and (3) grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1) Common farm procedure with summer range pasturing, (2) spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3) spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d) compared to common farm practice (228 g/d) and spring and summer grazing on the abandoned grassland (203 g/d), and carcass value was 14% higher in lambs on extended spring grazing compared to common farm practice. In autumn, sheep preferred to graze areas grazed by sheep during summer. Re-introduction of grazing stimulated forage production, and extended spring grazing improved performance in lambs. This study has quantified the value of abandoned grassland as a feed resource.

Til dokument

Sammendrag

Det er økende interesse hos forbrukere for mjølk og mjølkeprodukt som er produsert uten bruk av kraftfôr med bare beite og konservert gras i fôrrasjonen. Rørosmeieriet AS, som foredler økologisk produsert mjølk, er interessert i å etablere egen produksjonslinje for mjølkeprodukt fra kyr produsert uten kraftfôr. For mjølkeprodusenten kan det å kutte ut kraftfôr i fôrrasjonen få store konsekvenser for mjølkeytelse og dermed økonomi. Formålet med dette arbeidet var å vurdere hva en kan forvente seg av mjølkeytelse og mjølkekvalitet ved å kutte ut kraftfôr i rasjonen. Helse og fruktbarhet hos dyra, næringsstofforsyning til gården og totaløkonomien vil sannsynligvis også påvirkes, og det var et mål å beregne hva mjølkeprodusenten må ha i merpris for mjølka for å opprettholde dekningsbidraget. Arbeidet er gjennomført som en litteraturstudie og som en egen analyse der vi brukte data fra fire økologiske mjølkeproduksjonsbruk i Rørosområdet, som leverer mjølk til Rørosmeieriet. For de fire bruka gjorde vi en scenarioanalyse der vi estimerte mjølkeproduksjon og fôrforbruk uten kraftfôr i beitetida, men med kraftfôr i innefôringstida, og helt uten kraftfôr i rasjonene. Data generert fra scenarioanalysen blei sammenlignet med dagens tilstand med hensyn på mjølkeytelse, næringsstoffbalanse og økonomi. Vi tok også ut mjølkeprøver fra tanken før beiteslipp og i beitetida for å analysere kvaliteten av mjølk..............

Til dokument

Sammendrag

The effects of a commercial seaweed (SW) product and extracts collected from wild SWs in the Northern Norway on cultivable commensal intestinal bacterial groups isolated from Norwegian White sheep ewes were studied in vivo and in vitro. Bacterial counts from faeces from the ewes fed with supplement which contained SW meal throughout the entire indoor winter period had significantly lower lactic acid bacteria (LAB) counts (P ≈ .05). The screening of extracts from red and brown SWs showed that a number of the organic extracts had an inhibitory effect on the growth of the two Enterococcus sp. isolates. The results indicate that Ascophyllum nodosum supplementation reduces LAB counts in the ewes and the lambs, and that extracts from this SW have an inhibitory effect on the growth of Enterococcus sp. isolates.

Sammendrag

The 2015-2018 PROMAC (Energy efficient Processing of Macroalgae in blue-green value chains) is financed by the Norwegian Research Council. The PROMAC consortium is led by Møreforsking AS and consists of both Norwegian (SINTEF, NIBIO, NTNU, NMBU) and European (CEVA, MATIS, SLU)research institutes, as well as industrial partners (TafjordKraftvarme, FelleskjøpetFôrutvikling, Firmenich, LegaseaBiomarine Cluster, The Northern Company, Orkla Foods, Hortimare, Marinox).An advisory panel with public authority and interest groups from the marine, energy and agricultural sectors, also oversee the 4,5Mill EUR project’s relevance in a societal context.The current approaches to meeting the demands for meat and other protein-rich food sources are often associated with damage to natural resources and negative effects on climate, air quality, soils and fresh water availability. Therefore, the PROMAC project (http://promac.no/) investigates an alternative approach for providing food and sources of proteins and energy in animal feed, and health benefits in human food through cultivation of macroalgae. The project focuses on the three macroalgaespecies Alariaesculenta, Saccharinalatissima andPalmariapalmata.The research project (i) assesses variation of raw material composition and quality from both harvested and cultured macroalgae, (ii) develops primary processing methods enhancing desired raw material properties, (iii) establishes fractionation and extraction methods best suited to enrich beneficial proteins or remove undesirable anti-nutrients and (iv) evaluates nutritional and health values of processed macroalgal ingredients for various animal groups and in relation to their distinct digestive systems.PROMAC assesses the costs and benefits of macroalgal products from a value chain perspective (from raw material to primary market) through process-based Life Cycle Assessment (LCA), Material and Energy Flow Analysis (MEFA) and business models. To reduce the substantial energy required for primary processing of macroalgae - organisms characterized by ahigh-water content - PROMAC includes a case study utilizing excess heat from a waste incinerator for primary drying and processing of macroalgae biomass. This case study is integrated into both environmental and economic models.Initialresults identifyingmacroalgae food and feed products (ingredients)and associatedprocessing methods most relevant for commercial applications, will be presented integrated across work packages and subject fields.

Til dokument

Sammendrag

Prosjektet «BeiteRessurs» har vært ledet av Norsk Institutt for Bioøkonomi (NIBIO). Norsk senter for økologisk landbruk (NORSØK) og Senter for bygdeforskning har vært samarbeidsparter. Prosjektet ble gjennomført 2013-2016. Hovedmålet var å teste mulighetene for å ta i bruk marginale jordbruksområder som har ligget brakk, til beite for sau. Denne rapporten tar for seg de økonomiske konsekvensene av å ta i bruk et nedlagt innmarksbeite til vår- og høstbeite på sauegarder i Midt-Norge. De fleste undersøkelsene i prosjektet ble gjort på et nedlagt fellesbeite på 220 daa i Møre og Romsdal. Dette arealet ble dyrket opp rundt 1980, og var i bruk som fellesbeite for melkekyr frem til sommeren 2001. I 2013 ble det ryddet en gjerdetrasé og arealet ble gjerdet inn med fire-tråders strømgjerde. Sommeren 2013 ble arealet beitet av sau og hest. I 2014 og 2015 ble det gjennomført et forsøk med en sauebesetning som ble inndelt i tre like store forsøksgrupper. Den ene gruppen ble sluppet direkte til fjells rett fra garden etter lamming. Gruppe to fikk utvidet vårbeiteperiode med fire uker på hele innmarksarealet før de ble sluppet til fjells. Den tredje gruppen fikk også utvidet vårbeiteperiode med fire uker på hele innmarksarealet før de beita resten av sommeren på ca 1/3 del av arealet. Innmarksarealet hadde fire uker uten beiting i august/september og på høsten ble hele arealet beita med sau og påsettlam i fire uker. Alle kostnader ved bruk av innmarksbeite er delt inn i etableringskostnader og driftskostnader. Disse kostandene ble brukt som grunnlag for å sammenligne dekningsbidrag for to «eksempelgarder» i Midt-Norge: En middels stor sauegard (82 vinerfôra sauer (vfs)) og en stor sauegard (175 vfs) med og utenbruk av nedlagte innmaksbeiter. Ved å ta i bruk nedlagte beiteområder frigis arealer hjemme på garden. Tilleggsarealet kan gi grunnlag for flere vfs, bedre grovfôrkvalitet ved at slåtten kan tas tidligere, redusert bruk av kraftfôr, eller salg av rundballer. I rapporten har vi beregnet dekningsbidrag ved ulike alternativer for bruk av det frigitte arealet. Rydding og inngjerding av innmarksbeite på 220 daa ga en etableringskostnad på 87 kr/løpemeter gjerde. Årlige driftskostnader ble beregnet til 14,45 kr/løpemeter gjerde. Total kostnad inkludert alt utstyr og arbeid med etablering og årlig drift ble beregnet til 20,20 kr/løpemeter gjerde eller 190 kr/daa innmarksbeite når levetid på gjerdet ble satt til 15 år. Ved levetid på 20 år var kostanden 177 kr/daa innmarksbeite. Det høyeste dekningsbidraget oppnås ved at frigjort areal hjemme brukes til å øke besetningen. Ved å øke antall vfs viste resultatene våre at ved å ta i bruk det nedlagte arealet til vårbeite før dyra dro til fjells og som høstbeite for livsauene, så økte dekningsbidraget med 26 % for gjennomsnittsgarden og 24 % for den store garden. Hvis antallet vfs ikke kan økes, er det mer lønnsomt å produsere grovfôr med god kvalitet og redusere kraftfôrandelen enn å produsere rundballer på frigitt areal. Dersom vi hadde lagt inn lengre levetid på gjerdet enn 15 år og høyere lammevekter på grunn av fire uker forlenget vårbeite ville dekningsbidraget blitt enda bedre. Tilskuddet til innmarksbeite er en viktig faktor for at det kan bli lønnsomt å ta i bruk nedlagte innmarksbeiter for å øke arealressursene på sauegarder. Prosjektet har vist at det kan være fordelaktig for sauebønder å ta i bruk nedlagte arealer til beite både med hensyn til tilgang på godt vårbeite, tilvekst på lammene, bedre grunnlag for godt vinterfôr og økonomisk resultat.

Til dokument

Sammendrag

Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectively. However, for these and many other composition parameters, for which meta-analyses found significant differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Evidence from controlled experimental studies indicates that the high grazing/forage-based diets prescribed under organic farming standards may be the main reason for differences in FA profiles. Further studies are required to enable meta-analyses for a wider range of parameters (e.g. antioxidant, vitamin and mineral concentrations) and to improve both precision and consistency of results for FA profiles for all species. Potential impacts of composition differences on human health are discussed.

Til dokument

Sammendrag

There are differences in grass-clover proportions and chemical composition between herbage from primary growth (PG) and regrowth (RG) in grass-clover leys. Mixing silages made from PG and RG may provide a more optimal diet to dairy cows than when fed separately. We tested the hypotheses that increasing dietary proportions of grass-clover silage made from RG compared with PG would increase digestion rate of potentially degradable NDF (pdNDF), and increase ruminal accumulation of indigestible NDF (iNDF). Eight rumen cannulated Norwegian Red cows were used in two replicated 4 × 4 Latin squares with 21-day periods. Silages were prepared from PG and RG of an organically cultivated ley, where PG and RG silages were fed ad libitum in treatments with RG replacing PG in ratios of 0, 0.33, 0.67 and 1 on dry matter basis in addition to 8 kg concentrate. We evaluated the effect of the four diets with emphasis on rumen- and total tract fiber digestibility. Increasing RG proportions decreased silage intake by 7%. Omasal flow of pdNDF decreased, whereas iNDF flow increased with increasing RG proportions. Increasing RG proportions decreased rumen pool sizes of NDF and pdNDF, whereas pool sizes of iNDF and CP increased. Increasing RG proportions increased digestion rate of NDF, which resulted in greater total tract digestion of NDF. Pure PG diet had the highest calculated energy intake, but the improved rumen digestion of NDF by cows offered 0.33 and 0.67 of RG leveled out milk fat and protein yields among the three PG containing diets.

Til dokument

Sammendrag

Under Norwegian conditions, diets based on primary growth (PG) silage typically increase milk yield compared to silage prepared from the regrowth (RG). Organic PG, dominated by immature grasses, is often high in energy and low in crude protein (CP), whereas the opposite is the case for organic RG harvests, dominated by clover. Here, we tested the hypotheses that increasing proportions of RG will reduce the total supply of metabolizable energy, but increase the CP intake, and that there is a dietary optimal mix of PG and RG to meet requirements for optimal milk production. Sixteen Norwegian Red cows were used in an experiment designed with four balanced 4 × 4 Latin squares with 21-day periods to evaluate the effect of incremental replacement of PG with RG on feed intake, nutrient digestion, and milk production. Silages were prepared from PG and RG of an organically managed grassland. Treatments comprised silages fed ad libitum with RG replacing PG in ratios of 0, 0.33, 0.67, and 1 on dry matter (DM) basis. Additionally, concentrate was offered with 8 kg for pluriparous and 7 kg for primiparous cows. The PG had higher content metabolizable energy (ME), potentially degradable neutral detergent fiber (NDF), and water-soluble carbohydrates, while RG contained more CP and indigestible NDF. The already mentioned characteristics led to higher intakes of DM, organic matter, NDF, and ME and lower intakes of CP and indigestible NDF with increasing proportions of PG in the diet. Milk yield tended to be higher when PG and RG were offered as a mixture than when fed alone. The milk fat concentration decreased linearly with increasing proportions of RG proportion, while protein concentration was unaffected by diet. This led to a similar production of energy-corrected milk among cows fed diets containing PG while cows fed pure RG diet produced 0.9 kg less daily. Silage energy concentration and energy intake influenced milk production more than CP supply.

Til dokument

Sammendrag

Clover proportions, and thereby chemical composition of herbage, differ between primary growth (PG) and regrowth (RG) in organic managed grass-clover fields. The characteristics of PG and RG silages suggest different supplementary feeding strategies to sustain an efficient milk production in dairy cows. Silage made of the RG generally offers more crude protein (CP) in the diet than silage made of the PG because of an increasing proportion of clover later in the season. Additionally, grass and clover have different amino acid (AA) profiles. His has been suggested to be the first limiting AA in grass silage, while Met has been suggested to be the primarily limiting AA in red clover silage. Eight rumen cannulated Norwegian Red cows were used in two replicated 4 × 4 Latin squares with 21-days periods. Organic PG and RG silages were fed ad libitum in four diets with RG replacing PG silage in ratios of 0, 0.33, 0.67 and 1 on dry matter (DM) basis. Changing RG silage proportions from 0 to 1 increased daily CP intake from 2.90 to 3.08 kg and rumen NH3-concentrations from 4.9 to 8.4 mmol/L, but did not promote a better protein supply. Neither total ruminal outflow of AA nor the AA profile in the small intestine differed between dietary treatments. Met and His were probably the most limiting AA for a higher milk production. Limitations by His may be more related to diets based on PG, while production by cows fed diets based on more RG herbage were more likely limited by Met.

Sammendrag

Large areas of cultivated grasslands have been abandoned in Norway and are no longer used for production. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, this study aims at testing the effect of introducing abandoned farmland into sheep production. One sheep €ock with 83(88) ewes (lambs) in 2014 and 77 (106) ewes (lambs) in 2015 was each year assigned to three treatments: (1) control; common farm procedure with a short spring grazing period before summer grazing on range pasture; (2) spring extended; a four-week extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture; (3) whole season grazing on abandoned cultivated grassland. Weight gain from spring to autumn, slaughter weight and carcass value were signicantly (P<0.05) higher in lambs assigned to treatment 2, with four weeks extended spring grazing period (255 g day-1, 15.7 kg, 699 NOK), compared to treatment 1 (229 g day-1, 14.3 kg, 615 NOK) and treatment 3 (206 g day-1, 13.2 kg, 548 NOK). !e use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight, while whole season grazing on abandoned grassland was the least productive option tested.

Sammendrag

Large areas of cultivated grasslands have been abandoned in Norway and are no longer used for production. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, this study aims at testing the effect of introducing abandoned farmland into sheep production. One sheep €ock with 83(88) ewes (lambs) in 2014 and 77 (106) ewes (lambs) in 2015 was each year assigned to three treatments: (1) control; common farm procedure with a short spring grazing period before summer grazing on range pasture; (2) spring extended; a four-week extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture; (3) whole season grazing on abandoned cultivated grassland. Weight gain from spring to autumn, slaughter weight and carcass value were signicantly (P<0.05) higher in lambs assigned to treatment 2, with four weeks extended spring grazing period (255 g day-1, 15.7 kg, 699 NOK), compared to treatment 1 (229 g day-1, 14.3 kg, 615 NOK) and treatment 3 (206 g day-1, 13.2 kg, 548 NOK). !e use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight, while whole season grazing on abandoned grassland was the least productive option tested.

Sammendrag

Large areas of cultivated grasslands are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, we tested the effect of grazing abandoned grassland on sheep production. We also assessed herbage production by looking at plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers. The experiment was run for two consecutive years; 2014 and 2015. The sheep production was assessed by studying one sheep flock with 83(88) ewes(lambs) in 2014 and 77(106) ewes(lambs) in 2015, which was assigned each year with respect to age of ewe and number of lambs born to three treatments: 1) control; common farm procedure with short spring grazing period before summer grazing on range pasture, 2) spring extended; 4 weeks extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture, 3) whole season grazing on abandoned grassland. Assessment of herbage production was done by sheep grazing the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: a) control with no management, b) grazing heifers and c) grazing sheep with offspring. The stocking rate was 1.8 LU/ha, in both b and c, for a duration of one month. Pasture production and herbage intake was estimated using grazing exclosure cages. Weight gain from birth to autumn as well as slaughter weight were significantly (P<0.05) higher in lambs assigned to treatment 2 with four weeks extended spring grazing period (259 g/day and 15.7 kg) compared to treatment 1 (238 g/day and 14.3 kg) and treatment 3 (216 g/day and 13.2 kg). Herbage consumed during the summer period was on average 211 g DM/m2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM/m2 and 62% in the grazed treatments and 28 g DM/m2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. There was no difference between the grazed treatments on annual herbage production, herbage intake or pasture utilization. The use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight of lambs. Further, grazing stimulated herbage production

Sammendrag

Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with off€spring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no diff€erence between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.

Sammendrag

We assessed milk production with 24 mid-lactation Norwegian Red dairy cows on a spring pasture dominated by timothy (Phleum pratense) for a period of 21 days using three pasture allocation techniques (n=8). Cows received weekly allowances at once (7 day-set-paddocking; 7SP), grazed 1/7 of 7SP allowance each day (daily-strip-grazing; 1SG), or grazed like 1SG but also had access to the previously grazed part of the paddock (daily-forward-grazing; 1FG). We hypothesized that 7SP would deteriorate sward quality and quantity over the grazing days whilst the other two treatments would provide balanced pasture quality and intake. These changes were expected to result in differences in milk yield and its components. However, changes in sward chemical composition (e.g. neutral netergent fiber, crude protein) over the grazing days in each week were not different among treatments (treatment × grazing day; P>0.05). Furthermore, no effect of treatments on milk yield and its components was observed. Nonetheless, the effects of grazing days over a week on milk yield and components were different among treatments (treatment × grazing day; P<0.05). These treatment by grazing day interaction effects, in the absence main effect of treatment, could be due to fluctuations in daily DMI among treatments over the grazing days in each week.

Sammendrag

We assessed milk production with 24 mid-lactation Norwegian Red dairy cows on a spring pasture dominated by timothy (Phleum pratense) for a period of 21 days using three pasture allocation techniques (n=8). Cows received weekly allowances at once (7 day-set-paddocking; 7SP), grazed 1/7 of 7SP allowance each day (daily-strip-grazing; 1SG), or grazed like 1SG but also had access to the previously grazed part of the paddock (daily-forward-grazing; 1FG). We hypothesized that 7SP would deteriorate sward quality and quantity over the grazing days whilst the other two treatments would provide balanced pasture quality and intake. These changes were expected to result in differences in milk yield and its components. However, changes in sward chemical composition (e.g. neutral netergent fiber, crude protein) over the grazing days in each week were not different among treatments (treatment × grazing day; P>0.05). Furthermore, no effect of treatments on milk yield and its components was observed. Nonetheless, the effects of grazing days over a week on milk yield and components were different among treatments (treatment × grazing day; P<0.05). These treatment by grazing day interaction effects, in the absence main effect of treatment, could be due to fluctuations in daily DMI among treatments over the grazing days in each week.

Sammendrag

Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with off€spring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no diff€erence between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.

Sammendrag

Grassland and the associated ruminant livestock production is the backbone of Norwegian agriculture, as ruminant products contribute nearly 50% of the gross income of the agricultural sector. About 2/3 of the agricultural area is used for temporary and permanent grassland, and a large proportion (40%) of the arable land is used for producing cereals that are included in concentrate mixtures fed to ruminants. The huge variation in climatic conditions, caused by the wide range in both latitude and altitude as well as in the distance to the coast, determines the land use and choice of species and varieties used in grassland. However, the dominating ley grassland species used in in almost all parts of the country are timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.). The use of perennial ryegrass (Lolium perenne L.) is increasing, particularly in the southwestern parts of the country. The grassland yields and forage feed quality have remained very much the same during the last decade, while the intensity in ruminant production, e.g. milk yield per cow, has increased considerably. Factors that have contributed to grassland yield stagnation are probably the increasing proportion of rented farmland by larger farm units, the increasing price ratio between livestock products and feed concentrates and the increasing cost of producing forage relative to the price of concentrates

Sammendrag

Grassland and the associated ruminant livestock production is the backbone of Norwegian agriculture, as ruminant products contribute nearly 50% of the gross income of the agricultural sector. About 2/3 of the agricultural area is used for temporary and permanent grassland, and a large proportion (40%) of the arable land is used for producing cereals that are included in concentrate mixtures fed to ruminants. The huge variation in climatic conditions, caused by the wide range in both latitude and altitude as well as in the distance to the coast, determines the land use and choice of species and varieties used in grassland. However, the dominating ley grassland species used in in almost all parts of the country are timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.). The use of perennial ryegrass (Lolium perenne L.) is increasing, particularly in the southwestern parts of the country. The grassland yields and forage feed quality have remained very much the same during the last decade, while the intensity in ruminant production, e.g. milk yield per cow, has increased considerably. Factors that have contributed to grassland yield stagnation are probably the increasing proportion of rented farmland by larger farm units, the increasing price ratio between livestock products and feed concentrates and the increasing cost of producing forage relative to the price of concentrates

Til dokument

Sammendrag

Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. However, there is still considerable uncertainty over whether the use of organic production standards affects milk quality. Here we report results of meta-analyses based on 170 published studies comparing the nutrient content of organic and conventional bovine milk. There were no significant differences in total SFA and MUFA concentrations between organic and conventional milk. However, concentrations of total PUFA and n-3 PUFA were significantly higher in organic milk, by an estimated 7 (95 % CI −1, 15) % and 56 (95 % CI 38, 74) %, respectively. Concentrations of α-linolenic acid (ALA), very long-chain n-3 fatty acids (EPA+DPA+DHA) and conjugated linoleic acid were also significantly higher in organic milk, by an 69 (95 % CI 53, 84) %, 57 (95 % CI 27, 87) % and 41 (95 % CI 14, 68) %, respectively. As there were no significant differences in total n-6 PUFA and linoleic acid (LA) concentrations, the n-6:n-3 and LA:ALA ratios were lower in organic milk, by an estimated 71 (95 % CI −122, −20) % and 93 (95 % CI −116, −70) %. It is concluded that organic bovine milk has a more desirable fatty acid composition than conventional milk. Meta-analyses also showed that organic milk has significantly higher α-tocopherol and Fe, but lower I and Se concentrations. Redundancy analysis of data from a large cross-European milk quality survey indicates that the higher grazing/conserved forage intakes in organic systems were the main reason for milk composition differences.

Til dokument

Sammendrag

Effects of wilting rate and fermentation stimulators and inhibitors on protein characteristics of forages typ- ical for organic production were assessed using tradi- tional analytical methods and a gas production in vitro assay. The hypotheses were that the proportion of the crude protein (CP) fraction that was soluble would be lowest, and the protein feed value highest, under rapid wilting and restricted fermentation. The solubil- ity of the CP fraction varied according to treatments and between a first and a second cut, with moderate and high content of clover respectively. It was, how- ever, of minor importance for the protein value, both calculated as amino acids absorbed in the small intes- tine (AAT 20 ) and estimated as effective utilizable crude protein (uCP 04 ) by the in vitro assay. In ensiled her- bage, AAT 20 was highest in rapidly wilted and restrict- edly fermented silages made from a first cut dominated by highly digestible grasses. Silages from the second cut dominated by red clover were far lower in AAT 20 . The in vitro assay did not separate silages according to herbage composition or wilting rate, but ranked restrictedly fermented above extensively fer- mented with regard to protein supply. The assay might still have caught the characteristics that determine the true protein value in vivo.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

A meta-analysis based on experiments in organically cultivated grasslands in Norway was conducted to quantify the effects of management factors on herbage yield and feed quality. A dataset was collected that included 496 treatment means from experiments in five studies carried out at eight locations with the latitude range of 58.8 to 69.6 N between 1993 and 2010. We tested the effect of harvesting system (two vs. Three cuts annually), plant developmental stage at the first cut, growth period (temperature sum) and the herbage clover proportion. Plant maturity at the first cut and herbage clover proportion explained to a large extent herbage yield and quality of the first cut and annual yield. The timing of the first cut influenced also the yield and herbage quality of the second cut. The analysis confirmed the importance of legumes performance for herbage yield and quality from grasslands in organic production. Estimated annual herbage DM yield harvested at standardized plant development stage and at average clover proportion was 9%higher in the two—compared to the three-cut system. The crude protein concentration and in vitro dry matter digestibility was 17 and 3 % higher and the NDF concentration 7 % lower in the annual herbage from the three-cut than from the twocut system, respectively. The empirical equations developed in this study may be applied to explore different options for grassland management as basis for ration and production planning and in scenario analysis of economic performance of individual and model farms. The equations do also reveal in numeric terms the tradeoffs in management practice between high yields, yield digestibility, NDF and crude protein content in organic forage production relying on red clover N2 fixation as the engine in the system.

Til dokument

Sammendrag

Globalt representere husdyrproduksjon 14,5 % av antropogene klimagassutslipp, mens landbruket i Norge står for tilsvarende 9 %. Innenfor husdyrproduksjon kommer den største andelen av klimagassutslippene fra metanutslipp hos melkekyr. Dette skyldes den mikrobielle fermenteringen i vomma, som medfører et overskudd av hydrogen. Metanogene bakterier bruker hydrogen som et substrat, og sluttproduktet er metan. Mengde frie hydrogenmolekyl er styrt gjennom produksjonen av eddiksyre, smørsyre og propionsyre. Hensikten med denne oppgaven var å undersøke om tre ulike beitemetoder hadde en påvirkning på metanutslipp og fôropptak hos melkekyr. Metanproduksjonen ble målt ved hjelp av SF6 metoden. Metoden går ut på at du bruker en kapsel med kjent frigjøringsrate som en referanse for å beregne metanproduksjonene. Prosjektet hadde to perioder, en om våren og en om sensommeren. Hypotesen om at stripebeiting vil føre til mindre metanutslipp ble ikke bekreftet. Selv om min studie ikke fikk påvist at ulike beitemetoder påvirker metanutslipp, kan det likevel ikke utelukkes da resultatene for beregnet metanproduksjon var varierende og upresise. Metanutslippet variert fra 263 g/dag til 315 g/dag gjennom forsøket. Melkeproduksjonen var høyest om våren og gikk ned med noen kilo til sensommeren, generelt sett fulgte også fôropptaket denne trenden. Det ble heller ikke påvist at de ulike beitemetodene hadde en effekt på melkeproduksjonen og fôropptaket. Det har i tidligere studier blitt vist at SF6 metoden gir store variasjoner i beregning av metanutslipp og at den er noe upresis, noe som denne studien også fant. Det har blitt antatt at firgjøringsrate av SF6 er konstant, men nyere studier har påvist at dette er feil.

Til dokument

Sammendrag

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON)farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of ertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that Production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans.

Sammendrag

Seaweeds have been used as supplementary feed for livestock in Norway for centuries. Research activities on the use of seaweed as feed started early last century and continued until the late 1960s. The results were elusive, partly because the design of the experiments were imperfect. However, a long term experiment in the 1960’s demonstrated 6% higher milk production by cows supplemented mineral fortified Ascophyllum nodosum meal than in cows offered standard mineral supplement. The authors suggested that seaweed compounds might have had benficial effect on the rumen microflora. Seaweeds are a rich source of Se and antioxidants such as substituted phenols, polyphenols, vitamins, and vitamin precursors. Results from research last 10-20 years suggests that dietary supplementation with A. nodosum meal has positive effects on ruminant product quality and stress tolerance. Alginates have been documented to be non-specific immunostimulants. A. nodosum is currently commersially harvested and processed and sold as a feed supplement. Winter fed sheep and cattle in Norway needs to be given extra fat soluble vitamins and minerals, particularly vitamin E and Se, in order to ensure good animal health and production. Based on the aquired knowledge from international reseach on A. nodosum and its possible beneficial health effect, we tested if A. nodosum has immunestimulating effect and can be used as a substitute for synthetic vitamin E in sheep and cattle. Our hypothesis were that supplementing the diet with seaweed to sheep and lactating dairy cows would produce better adaptive immune response following immunization compared to no supplementation and similar to animals given extra vitamin E. Two feeding experiments were conducted, one continous with 40 pregnant ewes and one with 24 lactating dairy cows in a replicated Latin square design. The four supplement treatments applied were: A. Nodosum meal (SW), Natural vitamin E, Synthetic vitamin E, or Control. The average daily rate of A. Nodosum meal per ewe and cow in SW was 80 and 200 g DM, respectively. The ewes and their newborn lambs were monitored the entire indoor feeding period, from mating until pasture let out (200 d). In the ewes, supplementation with SW had no health effects compared to the other treatments, and serum IgG concentrations were reduced in the SW group.The adaptive immunity of the lambs was not affected by supplementation, and seaweed reduced the counts of different intestinal bacterial groups. However, seaweed interferred with the lambs passive immunity resulting in a mortality rate of 35 %, compared with 10% in Control. All cows responded well to immunization, but there were no significant effects of the diet on the immune response measured. The immunesupression observed in newborn lambs from ewes offered SW was likely du to impaired Ig absorption from colostrum, and we conclude that ruminants should not be supplemented with seaweed during peripartum. More research is needed on the identification of bioactive components in seaweed, their effects in animal health, the mechanisms related to their effects on the animal health and testing before seaweed should be used as a feed supplement to ruminants.

Sammendrag

Lønnsemd, uttrykt som dekningsbidrag per årsku, auka med årsavdråtten (kg EKM/årsku) hos økologiske mjølkeprodusentar i Trøndelag. Det var ingen samanheng mellom kraftfôrnivå (FEm/årsku) og lønnsemd, men lønnsemda auka med aukande grovfôropptak

Sammendrag

The spring and the summer growth of an organic grass-clover sward were preserved as extensively and restrictedly fermented silages in laboratory silos.The aim was to develop and test the hypothesis that such crops contribute complementary energy and protein qualities that can be exploited in mixed rations. The summer growth, containing 76% red clover, contributed more, and more stable crude protein than the spring growth, which was dominated by grasses. Nevertheless, when preserved as silage, summer growth supplied less metabolizable protein and net energy lactation because of its lower digestibility. Lower feed value remains to be validated in feeding experiments, and the quality of regrowth silages may also be improved by more frequent or appropriate timing of harvests. Restricted fermentation obtained by application of formic acid improved energy and protein preservation.

Sammendrag

The spring and the summer growth of an organic grass-clover sward were preserved as extensively and restrictedly fermented silages in laboratory silos.The aim was to develop and test the hypothesis that such crops contribute complementary energy and protein qualities that can be exploited in mixed rations. The summer growth, containing 76% red clover, contributed more, and more stable crude protein than the spring growth, which was dominated by grasses. Nevertheless, when preserved as silage, summer growth supplied less metabolizable protein and net energy lactation because of its lower digestibility. Lower feed value remains to be validated in feeding experiments, and the quality of regrowth silages may also be improved by more frequent or appropriate timing of harvests. Restricted fermentation obtained by application of formic acid improved energy and protein preservation.

Til dokument

Sammendrag

This study compared the forage quality of Festulolium entries of festucoid (Hykor) and loloid attributes (Felopa and Norwegian candivars) with major cultivars of the parent species perennial ryegrass and meadow fescue, and with timothy. Forage NDF, iNDF, kdNDF and DDM were analysed at vegetative stage, early heading, heading and anthesis during spring growth (SG) and two subsequent regrowths over two production years at two locations in Norway. NDF and iNDF increased and kdNDF and DDM decreased with advancing maturity, mostly expressed in SG, with negative correlations between DDM and NDF and iNDF and ADL and strong positive correlations with kdNDF. In SG, across years and locations, the content of NDF at heading stage was 30% higher and iNDF 400% higher in stems than in leaves, while stem kdNDF was about 50% of that in leaves. In general, timothy cv. Grindstad and Festulolium cv. Hykor had the highest NDF and iNDF and the lowest kdNDF values. Loloid entries of Festulolium were quite similar to perennial ryegrass, although the tetraploid entry proved better than the others with respect to forage quality. Regarding nutritive value, the festucoid and loloid types of Festulolium should be considered separate groups. The effect of year was more pronounced than that of location, for which the ranking of entries was quite similar. Loloid Festulolium is prone to winter damage and, although it has higher nutritive value than the parent species, its use will depend on the conditions for winter survival.

Til dokument

Sammendrag

Dietary phytoestrogens are metabolized or converted in the gastrointestinal tract of ruminants, only limited knowledge exists on the extent and location of this conversion in vivo. The objective of this study was to quantify the gastro-intestinal metabolism of phytoestrogens in lactating dairy cows fed silages with different botanical composition. Four lactating rumen cannulated Norwegian Red cattle were assigned to a 4 × 4 Latin square with 1 cow per treatment period of 3 wk. The 4 treatment silages were prepared from grasslands with different botanical compositions: organically managed short-term timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) ley (2 yr old: ORG-SG); organically managed long-term grassland with a high proportion of unsown species (6 yr old; ORG-LG); conventionally managed perennial ryegrass (Lolium perenne L.) ley (CON-PR); and conventionally managed timothy ley (CON-TI). The herbages were cut, wilted, and preserved with additive in round bales, fed as a mix of the first and third cut at 90% of ad libitum intake, and contributed to 70% of the total dry matter intake. Milk, feed, omasal digesta, urine, and feces were collected at the end of each period and analyzed for the concentrations of phytoestrogens by using a liquid chromatography–tandem mass spectrometry technique. Concentration of total isoflavones was highest in ORG-SG and lowest in CON-TI silage, whereas the content of total lignans was highest in the grass silages. The isoflavones were extensively metabolized in the rumen on all diets, and the recovery of formononetin and daidzein in omasum, mainly as equol, averaged 0.11 mg/mg. The apparent intestinal metabolism was less severe as, on average, 0.29 mg/mg of the omasal flow was recovered in feces. The plant lignans were also strongly degraded in the rumen. However, the flow of lignans to omasum and excretion in feces were, on average, 7.2- and 5.2-fold higher, respectively, than the intake of the plant lignans matairesinol and secoisolariciresinol, known as precursors of mammalian lignans. Thus, excretion to milk could not be directly related to intake, implying that plant lignans other than matairesinol and secoisolariciresinol in forage are precursors for enterolactone production in the rumen and for its content in milk. Equol followed mainly the flow of large particles out of the rumen, whereas the mammalian lignans were distributed between phases proportional to dry matter flow. The main metabolism of phytoestrogens occurred in the rumen and the main route of excretion was through feces and urine, with only a small part being excreted in milk. The concentration of phytoestrogens in milk can be manipulated through intake but the intermediate transfer capacity to milk appears to be limited by saturation

Til dokument

Sammendrag

We report results from trials on chicory growth (experiment 1) and lamb growth on chicory (experiment 2). In experiment 1, we assessed yield and chemical composition on swards established under organic conditions as perennial ryegrass/red clover, perennial ryegrass/chicory, chicory/red clover (CHRC), pure perennial ryegrass (RG-alone) and pure chicory (CHalone) over two years. Chicory/red clover and CH-alone showed improved crude protein, Ca, Mg, P, Cu and net energy contents compared to other mixtures. However, dry matter yield was the lowest for CHRC and CH-alone compared to others. In experiment 2, 48 weaned lambs grazed swards sown as chicory alone (CHA), chicory–grass–clover mix (CGC) or grass–clover mix (GCM) for 45 days. Lamb body weight (BW) gain and final BW were higher on CHA and CGC than on GCM. The results suggest that chicory can complement conventional grass/clover swards especially in macro- and micronutrients for improved lamb growth with a proper grazing management in place

Sammendrag

Store område med godt beite går ut av produksjon i Norge. Samtidig viser prognosene til Nortura at vi har for lite norsk lammekjøtt og storfekjøtt. Kva skal til for at vårt moderne landbruk igjen tar i bruk areala som ligg brakk? Det undersøker forskarane ved Bioforsk Økologisk i prosjektet BeiteRessurs.

Til dokument

Sammendrag

Phyto-oestrogens are a group of secondary plant metabolites that may bind to oestrogen receptors and exert oestrogenic or anti-oestrogenic effects in humans and can protect against cancer diseases. When ingested by dairy cows, phyto-oestrogens can be metabolised and transferred to the milk. The objective of this study was to assess the effects of grazing a recently established pasture containing red clover (Trifolium pratense L.) and an older pasture containing a variety of sown and unsown plant species on milk concentrations of phyto-oestrogens. Sixteen Norwegian Red dairy cows [mean (standard deviation); body weight 599 (45.1) kg, stage of lactation 73 (15.0) d in milk, milk yield 29.9 (2.90) kg/d at the start of the experiment] were divided into two groups and grazed either a short-term pasture (SP) or a long-term pasture (LP). The SP was representative of organically managed leys in Norway, which are frequently, approximately every third year, renewed by soil tillage and seeding, whereas LP was representative of organically managed grasslands that are less frequently renewed. The SP contained meadow fescue (Festuca pratensis Huds.) (mean 34%), timothy (Phleum pratense L.) (mean 19%), red clover (mean 28%), shepherd׳s-purse (Capsella bursa-pastoris (L.) Medik.) (mean 6%), pineappleweed (Matricaria matricarioides Porter ex Britton) (mean 5%) and scentless mayweed (Tripleurospermum perforatum (Mérat) Laínz) (mean 4%), and LP contained mainly white clover (Trifolium repens L.) (mean 21%), smooth meadowgrass (Poa pratensis L.) (mean 19%), timothy (mean 17%), meadow fescue (mean 15%), perennial ryegrass (Lolium perenne L.) (mean 6%), tufted hairgrass (Deschampsia cespitosa (L.) P. Beauv.) (mean 5%), northern dock (Rumex longifolius DC.) (mean 4%), common couch (Elytrigia repens (L.) Desv. Ex Nevski) (mean 4%), red clover (mean 3%) and dandelion (Taraxacum spp.) (mean 3%). In addition to a daily pasture allowance of 20 kg dry matter per cow, supplements of 3.0 kg barley (Hordeum vulgare L.) concentrate were fed. Herbage, concentrates and milk was sampled during the last week of three experimental periods and analysed for phyto-oestrogens using LC-MS/MS technology. Herbage from SP had 19 times higher concentration of isoflavones than herbage from LP, whereas only small differences were found for lignans. Milk produced on SP had 14 times higher concentrations of the mammalian isoflavonoid equol, and the concentrations of equol were higher than found in most other studies. This study confirms that grazing pastures containing red clover increases concentrations of isoflavones and especially equol in bovine milk compared to grazing pastures with other botanical composition. The higher milk concentrations of the lignan metabolite enterodiol in milk from SP compared to LP could not be related to differences in intake of the analysed lignans and may therefore be related to unidentified lignans.

Til dokument

Sammendrag

Store område med godt beite går ut av produksjon i Norge. Samtidig viser prognosene til Nortura at vi har vi for lite norsk lammekjøtt og storfekjøtt. Kva skal til for at vårt moderne landbruk tar i bruk desse areala igjen? Det undersøker forskarane ved Bioforsk Økologisk i prosjektet BeiteRessurs.

Sammendrag

Råproteininnhaldet var høgare og proteinet var meir stabilt under konservering i raudkløverdominert gjenvekst enn i grasdominert vårvekst. Likevel vart proteinverdien lågare i gjenvekstsurfôret, spesielt dersom ein la til rette for sterk gjæring. Tilsetjing av maursyrehaldige ensileringsmiddel for å hemme nedbryting av lettomsetjelege karbohydrat vil vere eit godt tiltak for god proteinkonservering. både i vårvekst og gjenvekst.

Sammendrag

The objective of the present study was to examine the effect of grazing on different pasture types and hay feeding on dairy goat’s milk casein composition in early and late grazing season. Eighty goats were grouped according to genotype at the αS1-casein locus and number of lactations and randomly divided into two groups (Early and Late) with approximately 8 weeks difference in kidding dates. Goats within each of the two groups were further allocated to four forage treatment groups accounting for genotype and lactation number: R, forest rangeland pasture; C, cultivated pasture; HH, high quality hay; HL, low quality hay. The goats in Early were subjected to forage treatments in early grazing season, while the goats in Late received the forage treatments 8 weeks later. There was a strong effect of genotype but no genotype by diet interaction on casein content and composition. Goats grazing R yielded less milk (1.6 vs. 2.2 kg/d, P<0.001) with higher milk fat content (48 vs. 38 g/kg, P<0.001) than goats on C. Pasture type had no effect on total protein or casein content. However, milk from goats on R compared to C had lower content of αs1-casein (2.57 vs. 3.82 g/L, P<0.01) and κ-casein (4.51 vs. 5.22 g/L, P<0.05) but higher content of β-casein (13.1 vs. 11.7 g/L, P<0.001). Grazing compared to hay gave similar milk yield with higher content of total casein (24.2 vs. 21.0 g/kg, P<0.001), αs2-casein (3.48 vs. 3.04 g/L, P<0.001) and β-casein (12.4 vs. 11.7 g/L, P<0.01). Grazing compared to hay feeding improved the milk casein composition important for cheese making, while cultivated pasture were superior to rangeland.

Til dokument

Sammendrag

Bulk tank milk from 28 dairy farms was sampled every second month for 2 yr to assess the effects of grassland management, production system and season on milk fatty acid (FA) composition, concentrations of fat-soluble vitamins, Se, and milk sensory quality. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Within ORG farms, SG farms differed from LG farms in herbage botanical composition, but not in concentrate FA concentrations, dry matter intake, or milk yield. Within CON farms, herbage composition, concentrate FA concentrations, dry matter intake, and milk yield showed no or insignificant variations. The ORG farms differed from CON farms in herbage botanical composition, concentrate FA concentrations, concentrate intake, and milk yield. Compared with ORG-LG farms, ORG-SG farms produced milk fat with higher proportions of C10:0 and C12:0 associated with higher herbage proportions of legumes (Fabaceae) and lower proportions of other dicotyledon families. Compared with milk from CON farms, milk fat from ORG farms had higher proportions of most saturated FA and all n-3 FA, but lower proportions of C18:0 and C18:1 cis-9 associated with higher forage proportion and differences in concentrations of FA in concentrates. Compared with the outdoor-feeding periods, the indoor feeding periods yielded milk fat with higher proportions of most short-chain and medium-chain FA and lower proportions of most C18-FA associated with grazing and higher forage proportions. Milk concentrations of α-tocopherol and β-carotene were lower during the grazing periods. Inclusion of fishmeal in organic concentrates may explain higher Se concentrations in organically produced milk. Milk sensory quality was not affected in this study. In conclusion, grassland management had minor effects on milk composition, and differences between ORG farms and CON farms may be explained by differences in concentrate intake and concentrate FA concentrations. Milk produced on ORG farms versus CON farms and milk produced during the outdoor versus indoor feeding periods had potential health benefits due to FA composition. In contrast, the higher milk-fat proportions of saturated FA in milk from ORG farms may be perceived as negative for human health.

Til dokument

Sammendrag

Ruminal biohydrogenation and transfer of fatty acids (FA) to milk were determined for 4 silages with different botanical compositions using 4 multiparous Norwegian Red dairy cows [(mean ± SD) 118±40.9d in milk, 22.5±2.72kg of milk/d, 631±3.3kg of body weight, 3.3±0.40 points on body condition score at the start of the experiment] fitted with rumen cannulas. Treatments consisted of 4 experimental silages: a mix of the first and third cut of organically managed short-term grassland with timothy (Phleum pratense L.) and red clover (Trifolium pratense L.; 2 yr old; ORG-SG); organically managed long-term grassland with a high proportion of unsown species (6 yr old; ORG-LG); conventionally managed ley with perennial ryegrass (Lolium perenne L.; CON-PR); and conventionally managed ley with timothy (CON-TI). The herbages were cut, wilted, and preserved with additive in round bales and fed at 0.90 of ad libitum intake. A barley (Hordeum vulgare L.) concentrate constituted 300g/kg of dry matter of the total feed offered. A Latin square design (4×4) with 3-wk periods and the last week in each period used for sampling was implemented. Omasal flows of FA were measured using Yb acetate, Cr-EDTA, and the indigestible neutral detergent fiber fraction as indigestible markers. The composition of FA was analyzed in feed, omasal digesta, and milk. Compared with ORG-LG, ORG-SG had a higher herbage proportion of red clover (0.36 vs. 0.01) and lower proportions of timothy (0.42 vs. 0.18), smooth meadowgrass (Poa pratensis L.), meadow fescue (Festuca pratensis Huds.), white clover (Trifolium repens L.), dandelion (Taraxacum spp.), and creeping buttercup (Ranunculus repens L.). The silages were well preserved. The concentration of neutral detergent fiber was higher and the concentration of Kjeldahl-N was lower for CON-TI than for the other silages. Silage type had no effect on dry matter intake, but milk yield was lower for CON-TI than for the other silages. Apparent biohydrogenation of C18:3n-3 was lower for ORG-SG (932g/kg) than for ORG-LG (956g/kg), CON-PR (959g/kg), and CON-TI (958g/kg). Compared with the grass-based silages, ORG-SG and ORG-LG resulted in higher omasal flows of C18:1 trans FA and higher milk fat proportions of C18:1 trans FA and C18:2 cis-9,trans-11. Apparent recovery of C18:3n-3 in milk was higher for ORG-SG (61g/kg) than for ORG-LG (33g/kg), CON-PR (34g/kg), and CON-TI (38g/kg), and milk fat proportion of C18:3n-3 was higher for ORG-SG than for CON-TI. Milk fat proportions of C16:0 were lower for ORG-SG and ORG-LG compared with those for CON-PR and CON-TI. It was concluded that high proportions of red clover and other dicotyledons in the silages affected ruminal biohydrogenation and increased milk fat proportions of beneficial FA.

Til dokument

Sammendrag

Previous research has shown that grazing pastures compared to feeding preserved forages has large impact on milk fatty acid (FA) composition, but differences between grazing red clover (Trifolium pratense L.) or white clover (Trifolium repens L.) are small, whereas the herbage proportions of dicotyledon botanical families is positively correlated with the milk-fat proportions of total polyunsaturated FA when grazing pastures in the Alps. The objective of the present study was to investigate the influence of botanically different pastures on bovine milk composition and milk susceptibility to oxidation. Two groups of 8 multiparous Norwegian Red dairy cows [mean (standard deviation); 599 (45.1)kg body weight, 73 (15.0)d in milk, 29.9 (2.90)kg milk/d at experiment start] grazed either a short-term pasture (SP) or a long-term pasture (LP). Both pastures were organically managed, meaning that no artificial fertilizers or herbicides were applied. The SP was representative for pastures, which are frequently, i.e. at least every third year, renewed by soil tillage and seeding, whereas LP was representative for pastures, which are less frequently renewed. The SP contained mainly meadow fescue (Festuca pratensis Huds.), timothy (Phleum pratense L.) and red clover and LP contained smooth meadow grass (Poa pratensis L.), white clover and a variety of unsown species. Sixteen cows were blocked according to milk yield, days in milk and sire, and randomly within block allocated to the 2 dietary treatments with a daily pasture allowance of 15–20kg dry matter per cow, supplemented with 3.0kg barley (Hordeum vulgare L.) concentrate. Milk was sampled during the last week of 3 experimental periods and analysed for FA composition by gas chromatography, concentrations of fat-soluble vitamins by high performance liquid chromatography, and oxidative stability in a light-exposure experiment by measuring the formation of hydroperoxides and by front-face fluorescence spectroscopy. Pasture type had no effect on milk yield, milk gross composition, and only minor effects on milk FA composition. Milk from SP had higher concentration of α-tocopherol than LP. The formation of hydroperoxides in milk was lower for SP than LP after 24h light exposure, but no differences were found after 48h. Front-face fluorescence spectroscopy revealed slightly higher formation of components in the area of 409–480nm wavelength for SP than LP, which may be related to milk-lipid oxidation. The experimental pastures differed mainly in herbage proportions of red clover and white clover and less in proportions of non-legume dicotyledons. This explains small differences in milk FA composition and milk susceptibility to oxidation.

Sammendrag

Traditionally, Norwegian dairy goats graze on diverse forest or alpine rangeland during summer, and these pastures are important both as a feed source, and for keeping the traditional image of goat milk being produced on local “natural” resources. Simultaneously, the grazing goats keep the landscape open. The quality of goat milk often declines during summer, with increased problems with free fatty acids (FFA) in the milk. This seems to coincide with the latter part of the grazing season, when goats generally also are in a later lactation stage, which also can cause problems with FFA. To elucidate the effects of pasture quality on milk production and quality we conducted an experiment where we grouped eighty goats according to genotype and lactation. They were randomly divided into two groups with approximately 8 weeks difference in kidding date and start of feeding experiment in Early (beginning of July) and Late (end of August) grazing season on improved cultivated pasture (PC) or rangeland (PR). Grazing was compared with hay of high (HH) or low (HL) quality. We used n-alkanes and long chained alcohols found in plant waxes as markers to estimate diet composition, and dosed the animals with the even-chained alkane C32 to estimate intake. Grazed plants were analysed also for feed quality. The forage intake was generally high, on average 1.2, 1.9, 2.1 and 1.6 kg DM day-1 per goat for PC, PR, HH and HL, respectively. The intake in the cultivated pasture the diet was predominantly timothy (Phleum pratense) in early season, while meadow fescue (Festuca pratensis) and couch grass (Elytrigia repens) dominated in 2nd period. In the rangeland, the diet was diverse and consisted of ferns, sedges, blueberry (Vaccinium myrtillis) and birch (Betula pubescens) in early summer. In late summer the diet was particularly diverse, coinciding with a general decline in plant quality. R yielded less milk (1.6 vs. 2.2 kg d-1) and lower milk protein content (32 vs. 33 g kg-1), but higher milk fat (48 vs. 38 g kg-1) and DM content (122 vs. 114 g kg-1) than C. Milk content of free fatty acids (FFA) was not affected by pasture type. The effect of pasture type on milk yield and milk constituents were similar in early and late grazing season. Grazing resulted in similar milk yield but higher milk fat (43 vs. 35 g kg-1), protein (32 vs. 30 g kg-1) and DM (118 vs. 107 g kg-1) content and lower content of FFA (0.25 vs. 0.31 mEq L-1) than hay feeding.

Sammendrag

Geitene på utmark på Gibostad i Troms spiste en variert diett med mye halvgras, gras, busker og trær, både tidlig og seint i beiteperioden. På innmarksbeite tok geitene opp mest timotei tidlig i beitesesongen, mens engsvingel og kveke var hoveddiett seint i august. Valget av beiteplanter reflekterte både det som til enhver tid var tilgjengelig, men også næringsverdien til beiteplantene.

Sammendrag

Forskjell i biotilgjengelighet av vitamin E i tilskuddsfôr med tangmel, naturlig vitamin E og syntetisk vitamin E ble undersøkt i fôringsforsøk med 24 kyr av rasen Norsk Rødt Fe (NRF) i midt- og seinlaktasjon. Analyse av forsøksblandingene viste et lavt innhold av vitamin E i forsøksblandingen med tangmel og derfor kunne ikke biotilgjengelighet av vitamin E i tangmel fastsettes ut i fra dette forsøket. Innhold av vitamin E i forsøksblandingene med naturlig- og syntetisk vitamin E ble kraftig redusert ved pelletering, trolig på grunn av en blokkering av pelletpressa som førte til høy temperatur under prosessering. Vi kunne likevel beregne forskjell i biotilgjengelighet mellom naturlig- og syntetisk vitamin E. Forskjellen var større enn det som til nå er generelt akseptert, noe som samsvarer med andre nylig utførte studier på melkekyr. Tangmel innholder naturlig vitamin E, men likevel er innholdet for lavt til at tangmel kan brukes som tilskuddsfôr for dyr med stort behov for vitamin E. Med antagelse om at vitamin E i tangmel er like tilgjengelig som andre kilder til naturlig vitamin E må det tilføres ca. 3,5 kg tangmel daglig for å dekke anbefalingene fra National Research Council, USA på 20 mg/kg tørrstoffopptak, dersom tangmel er eneste kilde til vitamin E i rasjonen. Siden tangmel har et lavt energiinnhold vil en så stor mengde tangmel redusere det totale energiopptaket og dermed også melkeproduksjonen. Ferskt gras har et høyt innhold av vitamin E og vil kunne dekke behovet for vitamin E til melkekyr. Surfôr er også en viktig kilde til vitamin E, men det kvantitative innholdet er svært variabelt. Dersom surfôret har et betydelig innhold av vitamin E og grovfôropptaket er høyt vil det ikke være nødvendig å gi tilskudd av vitamin E til kyr i midt- og seinlaktasjon. Likevel er det vanskelig å estimere innholdet av vitamin E i surfôr, og analysering er per i dag kostbart og krevende å utføre. Det bør derfor gis tilskudd av vitamin E til melkekyr i innefôringssesongen, særlig i perioden rundt kalving da behovet er størst. Dersom det er mulig å gi tilskudd av naturlig vitamin E vil dette være positivt for økologisk melkeproduksjon, der det er et mål om å bruke minst mulig syntetiske tilsetningsmidler. Tilskudd av naturlig vitamin E vil også føre til et lavere kvantitativt behov på grunn av større biotilgjengelighet. Ut fra resultatene fra dette forsøket vil det kreves 3 ganger mer syntetisk vitamin E, enn naturlig vitamin E for å dekke samme behov. Dermed kan bruk av naturlig vitamin E bidra til å redusere forbruket av tilskuddsfôr i melkeproduksjonen. Dersom naturlig vitamin E skal brukes som tilskudd i økologisk melkeproduksjon, bør produksjonsmetodene være i tråd med prinsippene innen økologisk produksjon.

Til dokument

Sammendrag

There is increasing concern that the intensification of dairy production reduces the concentrations of nutritionally desirable compounds in milk. In this study we therefore compared important quality parameters (protein and fatty acid profiles, α-tocopherol and carotenoid concentrations) in milk from four dairy systems with contrasting production intensities (in terms of feeding regimes and milking systems). The concentrations of several nutritionally desirable compounds (β-lactoglobulin, omega-3 fatty acids, omega-3/omega-6 ratio, conjugated linoleic acid c9t11 and/or carotenoids) decreased with increasing feeding intensity (organic outdoor ≥ conventional outdoor ≥ conventional indoors). Milking system intensification (use of robotic milking parlours) had a more limited effect on milk composition, but increased mastitis incidence. Multivariate analyses indicated that differences in milk quality were mainly linked to contrasting feeding regimes, and that milking system and breed choice also contributed to differences in milk composition between production systems.

Til dokument

Sammendrag

Two feeding experiments were performed to study the effects of silage botanical composition, regrowth interval and α-tocopherol supplementation on the fatty acid (FA) composition and α-tocopherol, β-carotene and retinol concentrations of milk. In Exp. 1, 24 Swedish Red dairy cows were fed two- or three-cut red clover–grass silages (R2 and R3, respectively) or two-cut birdsfoot trefoil–grass silage (B2). In Exp. 2, 16 Norwegian Red dairy cows were fed short-term ley silage with red clover (S3) or long-term ley silage with white clover (L3) in combination with the supplementation of RRR-α-tocopheryl acetate (1600 mg/day). The FA proportions in the milk and the recoveries of C18:2n-6 and C18:3n-3 were higher on the red clover diets R2 and S3 than on B2 and L3, respectively, and the n-6/n-3 FA ratio was also higher on the red clover diets. Shorter regrowth interval increased both the concentrations of FA in silage and the proportions of unsaturated FA in milk. Intakes of α-tocopherol, β-carotene and lutein were higher on B2 than on R2 due to higher silage intake on B2. However, the highest intake was seen on diet R3 due to the higher concentrations in the silage mixture. In Exp. 2, intakes of α-tocopherol, β-carotene and lutein were higher on L3. However, not all of these differences affected the milk, since the only significant differences related to silage diet in the two experiments were a higher milk α-tocopherol concentration on L3 than on S3 and a slightly lower β-carotene concentration on B2 than on R2. Supplementation with α-tocopherol increased milk α-tocopherol concentrations from 0.77 to 1.05 and from 1.07 to 1.24 mg/kg milk for S3 and L3, respectively, but did not affect milk FA composition. A higher concentration of antioxidants in the feed could be beneficial as a larger proportion of the animal's vitamin requirements would be met by the forage and the need for supplementation might decrease.

Sammendrag

The objective of the present study was to examine the effect of grazing on different pasture types and hay feeding on dairy goat milk fatty acid (FA) composition in early and late grazing season. Eighty goats were grouped according to genotype and lactation, and randomly divided into two groups (Early and Late) with approximately 8 weeks difference in mating and kidding dates. Goats within each of the two groups were further allocated to four forage treatment groups: R, forest rangeland pasture; C, cultivated pasture; HH, high quality hay; HL, low quality hay. The goats in Early were subjected to forage treatments in early grazing season, while the goats in Late received the forage treatments 8 weeks later. The most abundant FAs were C16:0 and C18:1c9 followed by C14:0 and C18:0. The milk proportion of the short and medium chained fatty acids (C6:0-C14:0) and C16:0 was higher (P < 0.0001) in Late than in Early grazing season, whilst the proportion of long chained FAs (C18:0, C18:1c9, C18:1t11, C18:2c9, 12, C18:2c9t11 and C18:3c9, 12, 15) were lower (P < 0.001). Goats grazing R yielded less milk (1.5 vs. 2.0 kg/d, P < 0.001) but with higher milk fat content (46 vs. 37 g/kg, P < 0.001) than C. The milk from goats on R had lower (P < 0.01) proportion of medium chained FAs (C10:0-C14:0) and C18:2c9, t11 but higher (P < 0.05) proportion of C18:0, C18:2c9,12 and C20:0 than C. Grazing compared to hay gave milk with lower proportion of medium chained FAs (C12:0-C14:0) and C16:0 but higher proportion of the long chained FAs C18:0, C18:1t11, C18:3c9, 12, C18:2c9, t11, C18:3c9, 12, 15, C20:0 than hay feeding. Higher supply of energy may explain higher proportion of de novo synthesised low and medium chained FA and lower proportion of long chained FA on C than on R, whilst higher supply of FA from mobilized fat may explain higher milk proportion of long chain FA in Early than in late season. Moreover, goats on pasture had likely higher supply of FA from dietary fat, which explain higher milk proportion of the long chained FA than on hay.

Sammendrag

Norwegian goat milk production is based on summer grazing on diverse forest or alpine rangeland, and the quality of these pastures is important for milk quantity and quality. We used n-alkanes and long chained alcohols found in plant wax as markers to estimate diet composition in goats grazing on a heterogeneous rangeland during two periods in summer; early (beginning of July) and late (end of August). The goats were fitted with GPS collars that recorded their position. Preliminary results show a diverse diet, where ferns, sedges, blueberry (Vaccinium myrtillis) and birch were preferred in early summer. In late summer the diet was particularly diverse, coinciding with a general decline in plant quality.

Sammendrag

The objective was to examine the effect of pasture type, and of grazing compared with hay feeding, on milk production and quality from dairy goats in early and late grazing season. Eighty goats were grouped according to genotype and lactation, and randomly divided into two groups with approximately 8 weeks difference in kidding date and start of feeding experiment, in Early and Late grazing season. At the start of the feeding experiment the goats were divided into 4 forage-treatment groups: R,forest rangeland pasture; C, cultivated pasture; HH, high quality hay; HL, low quality hay. Group R yielded less milk (1.5 vs. 2.0 kg d–1) and lower milk protein content (32 vs. 33 g kg–1), but higher milk fat (46 vs. 37 g kg–1) and DM content (120 vs. 113 g kg–1) than group C. Free fatty acids (FFA) content in milk was not affected by pasture type. The effects of pasture type on milk yield and milk constituents were similar in early and late grazing season. Grazing resulted in similar milk yield but higher milk fat (42 vs. 34 g kg–1), protein (32 vs. 30 g kg–1) and DM (117 vs. 106 g kg–1) content, and lower content of FFA (0.22 vs. 0.34 mEq L–1) than hay feeding

Til dokument

Sammendrag

Phytoestrogens are hormone-like substances in plants that can substantially influence human health (positively or negatively), and when fed to dairy cows are transferred to their milk. The aim of this study was to investigate effects of varying the botanical composition and regrowth interval of legume-grass silage on silage and phytoestrogen intake and milk phytoestrogen concentrations. In one experiment, 15 Swedish Red dairy cows were fed two- or three-cut red clover-grass silage (designated R2 and R3, respectively), or two-cut birdsfoot trefoil-grass silage (B2). In a second experiment, 16 Norwegian Red dairy cows were fed short-term ley silage with red clover (S3) or long-term ley silage with white clover (L3), and the effects of supplementation with α-tocopherol were also tested. There were high concentrations of formononetin and biochanin A in all silage mixtures with red clover (R2, R3, and S3). The milk concentration of equol was highest on diet R2 (1,494 μg/kg milk). Due to metabolism of biochanin A, genistein and prunetin, their concentrations in milk and the apparent recovery were low. Coumestrol was only detected in silage mixtures S3 and L3, and its milk concentration was low. Concentrations of secoisolariciresinol and matairesinol were higher in silage mixtures B2 and L3, those with legume species other than red clover and the highest grass proportions. B2 also resulted in higher enterolactone concentration than the other diets (226 μg/kg milk). Lengthening the regrowth interval increased the intake of secoisolariciresinol and decreased recovery of lignans. Feeding long-term ley silage resulted in higher lignan milk concentrations, but lower isoflavone milk concentrations than feeding short-term ley silage. The apparent recovery of all phytoestrogens except prunetin was highest on B2, indicating that condensed tannins (present in the birdsfoot trefoil) affect rumen metabolism. There was no effect of α-tocopherol supplementation on milk concentrations of any of the measured phytoestrogens. There were variations in milk concentrations of phytoestrogens, especially of equol, among cows, which could not be explained by variations in diet composition or phytoestrogen intake. The results show that milk phytoestrogen concentration is strongly influenced by silage botanical composition and management, but questions regarding phytoestrogen metabolism remain to be answered.

Sammendrag

Geiter på utmark produserte mindre mjølk med lavere innhold av protein enn geit på innmarksbeite, men utmarksbeite gav ellers ikke redusert mjølkekvalitet. Beite gav mjølk med høyere innhold av fett, protein og tørrstoff, og lavere innhold av urea og frie fettsyrer sammenligna med høyfôring. Utmarksbeite fører ikke nødvendigvis til mjølk med høyt innhold av frie fettsyrer eller til økt innhold av frie fettsyrer utover i beitesesongen.

Sammendrag

Norwegian goat milk production is based on summer grazing on diverse forest or alpine rangeland, and the quality of these pastures is important for milk quantity and quality. We used n-alkanes and long chained alcohols found in plant waxes as markers to estimate diet composition in goats grazing on a heterogeneous rangeland during two periods in summer; early (beginning of July) and late (end of August). Some of the goats were fitted with GPS collars that recorded their position. Preliminary results show a diverse diet, where ferns, sedges, blueberry (Vaccinium myrtillis) and birch (Betula pubescens) were preferred in early summer. In late summer the diet was particularly diverse, coinciding with a general decline in plant quality.

Sammendrag

In winter fed organic raised sheep inadequate plasma vitamin E levels is common and therefore supplementation is recommended. The objective of the present work was to test the supplementation of natural vitamin E and seaweed meal on the immune status of ewes and their offspring. Forty Norwegian White Sheep ewes were randomly allocated to three supplementation treatments: natural vitamin E, synthetic vitamin E, seaweed meal, and control. The feeding experiment lasted the entire indoor feeding period. Ewes and newborn lambs were vaccinated against different environmental microorganisms and pathogens. Different immunological parameters were measured. Supplementing the ewes with natural vitamin E had positive effect on immunity against Mycobacterium bovis in lambs. Seaweed, on the other hand, had negative effect on the passive transfer of maternal antibodies in lambs the first week after birth. The adaptive immunity was not affected by seaweed supplementation.

Sammendrag

The objective was to compare the effects of supplementing lactating dairy cows with synthetic (All-rac), natural (RRR) α-tocopheryl acetate or seaweed with a control on the concentration of α-tocopherol in blood and milk. Twenty four dairy cows in mid lactation, fed an organic feed ration, were randomly allocated to the four treatments in a replicated Latin square design. Plasma and milk α-tocopherol concentrations were higher in RRR and All-rac than in the other treatments and higher in RRR than in All-rac. RRR-α-tocopherol was the predominant steroisomer (> 86%), in both plasma and milk, whereas the remaining part was largely made up by the three synthetic 2R isomers. In cows fed the control, seaweed and RRR, the proportion of RRR-α-tocopherol in plasma and milk constituted more than 97% of the total α-tocopherol. The study demonstrated that dairy cows in mid and late lactation have preferential uptake of RRR-α-tocopherol compared to other stereoisomers.

Til dokument

Sammendrag

A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds Background: It has been questioned if the old native Norwegian sheep breed, Old Norse Sheep (also called Norwegian Feral Sheep), normally distributed on coastal areas where ticks are abundant, is more protected against tick-borne infections than other Norwegian breeds due to a continuously high selection pressure on pasture. The aim of the present study was to test this hypothesis in an experimental infection study. Methods: Five-months-old lambs of two Norwegian sheep breeds, Norwegian White (NW) sheep and Old Norse (ON) sheep, were experimentally infected with a 16S rRNA genetic variant of Anaplasma phagocytophilum (similar to GenBank accession number M73220). The experiment was repeated for two subsequent years, 2008 and 2009, with the use of 16 lambs of each breed annually. Ten lambs of each breed were inoculated intravenously each year with 0.4 ml A. phagocytophilum-infected blood containing approximately 0.5x106 infected neutrophils/ml. Six lambs of each breed were used as uninfected controls. Half of the primary inoculated lambs in each breed were re-challenged with the same infectious dose at nine (2008) and twelve (2009) weeks after the first challenge. The clinical, haematological and serological responses to A. phagocytophilum infection were compared in the two sheep breeds. Results: The present study indicates a difference in fever response and infection rate between breeds of Norwegian sheep after experimental infection with A. phagocytophilum. Conclusion: Although clinical response seems to be less in ON-lambs compared to NWlambs, further studies including more animals are needed to evaluate if the ON-breed is more protected against tick-borne infections than other Norwegian breeds.

Sammendrag

Fettsyresamensetning og innhold av vitaminer i melk ble i stor grad påvirket av sesong og produksjonssystem og i mindre grad av engalder. Beitesesongen hadde gunstig effekt på fettsyresammensetning sammenlignet med innefôringsperioden, mens økologisk driftsform hadde gunstige effekter som økt andel av C18:3c9,12,15 og negative effekter som økt andel mettede fettsyrer. Hovedfaktorene bak de observerte effektene antas å være fôrrasjonens andel av kraftfôr, beiteopptak, rødkløver og kraftfôrets innhold av lipider

Sammendrag

Fettsyresamensetning og innhold av vitaminer i melk ble i stor grad påvirket av sesong og produksjonssystem og i mindre grad av engalder. Beitesesongen hadde gunstig effekt på fettsyresammensetning sammenlignet med innefôringsperioden, mens økologisk driftsform hadde gunstige effekter som økt andel av C18:3c9,12,15 og negative effekter som økt andel mettede fettsyrer. Hovedfaktorene bak de observerte effektene antas å være fôrrasjonens andel av kraftfôr, beiteopptak, rødkløver og kraftfôrets innhold av lipider

Sammendrag

Surfôr fra kortvarig eng har gitt høyere andel av flerumettede fettsyrer i melk sammenlignet med surfôr fra langvarig eng men dette har ikke ført til at melka ble mer utsatt for lysindusert oksidasjon. Tilskudd av α-tokoferol økte innholdet av α-tokoferol i melka men hadde ingen effekt på melkas oksidative stabilitet. Surfôr fra kortvarig eng ga høyere innhold av isoflavoner og lavere innhold av lignaner i melk enn surfôr fra langvarig eng.

Sammendrag

Surfôr fra kortvarig eng har gitt høyere andel av flerumettede fettsyrer i melk sammenlignet med surfôr fra langvarig eng men dette har ikke ført til at melka ble mer utsatt for lysindusert oksidasjon. Tilskudd av α-tokoferol økte innholdet av α-tokoferol i melka men hadde ingen effekt på melkas oksidative stabilitet. Surfôr fra kortvarig eng ga høyere innhold av isoflavoner og lavere innhold av lignaner i melk enn surfôr fra langvarig eng.

Sammendrag

Den flåttbårne sjukdommen sjodogg forårsaket av bakterien Anaplasma phagocytophilum som er overført av flått (Ixodes ricinus) (Øverås 1972, Stuen 2003) er en av de største utfordringene for velferden hos sau i beiteperioden. Sjodogg gir høy feber og redusert immunitet. Det finnes få effektive forebyggende tiltak mot sjodogg. Lam får råmelk med immunglobuliner fra mor etter fødsel og denne passive immuniteten som overføres kan til en viss grad hjelpe lammet å handtere infeksjoner generelt, inntil lammet selv kan utvikle immunitet. Smitteforsøk har vist at svært unge lam er resistente mot sjodogg, men at det ikke skyldes antistoffene alene (Stuen et al. 1992). Formålet med dette arbeidet var å teste effekten av å eksponere lam for naturlig sjodogg-infeksjon i løpet av første leveuke på tilvekst og forekomst av sjukdom i feltforsøk.

Sammendrag

Tidlig beiteslipp av lam på flåttinfiserte beiter slik at lammene utsettes for smitte når de er unge (1-2 uker gamle) har en positiv effekt på tilvekst og kan anbefales som tiltak for å redusere tap i form av tilvekst på grunn av A. phagocytophilum infeksjon.

Sammendrag

E vitamin er nødvendig for drøvtyggere for å opprettholde et velfungerende immunsystem, høy reproduksjonsnivå, og god melk- og kjøttkvalitet. Innholdet av antioksidanter i råmelken påvirker absorpsjonen av antistoffer hos nyfødte kalver. Selen innholdet i jord og dermed hjemme dyrket grovfôr kan være fattig på selen. Hvis grovfôret også er fattig på E vitaminet, som samhandler sine biologiske effekter med selen, kan underforsyning lett oppstå. Derfor blir rasjonene til drøvtyggere supplert med syntetisk produsert E vitamin for å sikre tilstrekkelig inntak av E vitamin. Det er imidlertid kjent at syntetisk E vitamin består av 87,5 % molekyler med ikke-naturlig konfigurasjon og som biologiske ikke er like effektiv. Av denne grunn er det viktig å finne alternative naturlige vitamin- og antioksidantkilder som er billig, bærekraftig å utvinne og enkle å håndtere, spesielt med tanke på økologisk husdyrproduksjon, men også for tradisjonell husdyrproduksjon. Det ble derfor gjennomført et forsøk med drektige søyer for å teste tang og naturlig E vitamin som mulige kilder for E vitamintilskudd og deres effekt på dyrehelsen hos søyene og avkommene.  

Sammendrag

Surfôr fra kortvarig eng (KS) hadde lavere innhold av C18:3c9,12,15 enn surfôr fra langvarig eng og raigrassurfôr. Likevel ga KS høyest innhold av C18:3c9,12,15 i melk. årsaken var redusert hydrogenering i vomma. Dette gjaldt også summen av alle umettede C18-fettsyrer men ikke C18:1c9 eller C18:2c9,12. årsaken til redusert hydrogenering for KS kan være rødkløverens innhold av PPO

Sammendrag

Surfôr fra kortvarig eng (KS) hadde lavere innhold av C18:3c9,12,15 enn surfôr fra langvarig eng og raigrassurfôr. Likevel ga KS høyest innhold av C18:3c9,12,15 i melk. årsaken var redusert hydrogenering i vomma. Dette gjaldt også summen av alle umettede C18-fettsyrer men ikke C18:1c9 eller C18:2c9,12. årsaken til redusert hydrogenering for KS kan være rødkløverens innhold av PPO

Sammendrag

Planteøstrogena formononetin og daidzein blir i stor grad omsatt til equol og vidare til ukjende sambindingar i vomma. Nedbrytinga av planteøstrogena i vom var sterkare i surfôr laga på raigras og langvarig artsrik eng enn i surfôr laga av timoteieng eller kortvarig eng med raudkløver. Attfinninga av planteøstrogena var størst i gjødsel og minst i mjølk. Omsetjinga av equol i kroppen (intermediær) var avgrensa av fart (rate limiting) medan dette synest ikkje å vere tilfelle i vom og tarm.

Sammendrag

Planteøstrogena formononetin og daidzein blir i stor grad omsatt til equol og vidare til ukjende sambindingar i vomma. Nedbrytinga av planteøstrogena i vom var sterkare i surfôr laga på raigras og langvarig artsrik eng enn i surfôr laga av timoteieng eller kortvarig eng med raudkløver. Attfinninga av planteøstrogena var størst i gjødsel og minst i mjølk. Omsetjinga av equol i kroppen (intermediær) var avgrensa av fart (rate limiting) medan dette synest ikkje å vere tilfelle i vom og tarm.

Sammendrag

Utmarksbeite har sannsynlegvis ikkje skulda for dårleg geitemjølkekvalitet i beitesesongen. Kvaliteten var vel så god på utmark som på innmark, og innhaldet av FFS var lågt både tidleg og seint i beitesesongen på begge beitetypane. Ysteeigenskapar var derimot betre i tidleg beitesesong.

Sammendrag

The effect of cows" diets on milk composition is discussed, focusing on those components of particular interest for human health. First dietary sources of fatty acids and their digestion and metabolism are reviewed. Then feeding factors affecting milk fat content and fatty acid composition are discussed, with emphasis on those factors related to forage and fat supplements. The effects of diet on protein content and composition and milk content of minerals and vitamins are reviewed. Feeding strategies for improving the nutritional quality of milk are summarized.

Sammendrag

Literature data from experiments with lactating dairy cows offered silage-based diets was reviewed to evaluate the effects of the grassland legume species Trifolium repens (WC, white clover), Trifolium pratense (RC, red clover) and Medicago sativa (M, lucerne) on feed intake, milk production and milkquality. Seven data sets were created to compare grass silage (G) with grassland legumes in general (L), G with RC, G with WC, G with M, RC with WC, RC with M and different silage proportions of RC. Daily dry matter intake and milk yield were on average 1.6 and 1.6 kg, respectively, higher and milk fat content 1.2 g/kg milk lower on L than on G based diets. Similar differences were found when G was compared with RC or WC diets. Cows offered WC yielded 1.1 kg/d more milk than RC, and milk produced on WC and M contained 0.7 g more protein per kg than milk from RC diets. Increasing the silage diet RC proportion from 0.5 to 1.0 also decreased the milk protein content by 0.8 g/kg milk. RC increased the level of poly-unsaturated fatty acids, particularly C18:3n-3, and isoflavones, particularly equol, in milk. Effects are discussed in relation to plant cell wall characteristics, plant chemical constituents and changes in rumen digestion to explain the origin of the differences in intake, milk yield and milk composition.

Sammendrag

Milk samples from sixteen Norwegian Red dairy cows grazing mixed swards of either grass-red clover (GR) or mixed swards of sown and unsown species of grass, clover and other herbs (GCH) were collected during four periods. Both pastures were organically managed. Pasture botanical composition had no effect on milk fat, protein or vitamin concentration and only minor effects on fatty acid composition. Milk from GR had higher concentrations of the phytoestrogens equol, genistein and biochanin A than milk from GCH. Concentrations of equol in milk from GR were higher than concentrations reported from experiments with red clover silage. The oxidative stability of the milk lipids was not affected by pasture type

Sammendrag

Thirty-two dairy farms in Middle-Norway with different grassland systems (short-term (7 years) grassland (L)) and different production systems (organic (O) or conventional (C)) were compared in a field study in 2007. In a principal component analysis on variables including farm details, botanical composition and chemical forage composition the farms were separated into organic and conventional farms with exception of one farm. Amongst the organic farms most SO farms were distinguished from LO farms. Concentration of forage crude protein was positively correlated with proportion of grasses. Concentration of non-fibrous carbohydrates, in vitro digestibility and net energy lactation was positively correlated with proportion of legumes. Species diversity and cutting time at first cut was positively correlated with proportion of non-legume herbs

Til dokument

Sammendrag

The purpose of this study was to compare the effect of grazing on mountain (M) versus cultivated lowland pasture (C) on the performance and meat quality of suckling calves (Experiments 1 and 2). In addition, the effect of finishing on C after M on growth and meat quality was assessed (Experiment 2). Animals on C and M had on average similar live weight gain and carcass weight in the first experiment. However, the performance depended on year as gain and carcass weight was higher on C than on M in the first year and vice versa in the second year. In the second experiment the calves on M had lower gain and carcass weight than on C. Three weeks finishing on C after M compensated to some extent for the lower growth rate on M. Overall, the results indicate that mountain grazing may yield similar growth rates and slaughter weights as improved lowland pasture depending on year. There were only small effects of pasture type on carcass and meat quality traits like conformation, fatness, intramuscular fat and protein content, and fatty acid (FA) composition. The variation in FA composition could to a large extent be explained by difference in fatness with increase in monounsaturated and decrease in polyunsaturated FA with increasing intramuscular fat content, in turn varying between pasture type, experiment and year. There was a tendency that M led to higher proportion of C18:1n-9 and lower proportion of C18:1n-7 than C. which may be due to difference in milk and forage intake. Both pasture types resulted in meat with intramuscular fat with high nutritional value since the n-6/n-3 ratio was low. (C) 2010 Elsevier B.V. All rights reserved.

Sammendrag

Increasing nitrogen-use efficiency in agriculture decreases N2O emissions.  We wanted to investigate whether intensification of animal production by use of imported feed might improve the nitrogen-use efficiency of agriculture. Based on a review of published surveys of dairy farms, we concluded that where production is based on the local feed production, N-use efficiency is very high. Farms that combine grazing with their own hay/silage production for the winter period are highly nitrogen efficient.

Sammendrag

Kyr med høg avdrått må få energirikt grovfôr frå eng som er tidleg og hyppig slått, og der gjenvekstar utgjer ein stor del av årsavlinga. Mellom vårvekst og gjenvekst vil det vere variasjon i proteininnhald og fiberkvalitet. Det trengst meir kunnskap om korleis ein kan balansere dei ulike kvalitetane i ei målretta fôring.Les/last ned PDF av artikkel og presentasjon under "Les meir" til høgre. 

Sammendrag

Mer beiting er den enkleste måten å øke innholdet av CLA fettsyrer i storfekjøtt. Genetikk, fôrsammensetning og høstemetoder er andre forhold som kan påvirke fettkvaliteten.

Sammendrag

I 2007-2008 ble det gjennomført et feltstudie med målsetningen å finne sammenheng mellom engdriftsystem, produksjonssystem og melkekvalitet. Ni gårder med økologisk melkeproduksjon basert på kortvarig eng (KØ) ble paret med 9 gårder med konvensjonell melkeproduksjon basert på kortvarig eng (KK) og 7 gårder med økologisk melkeproduksjon basert på langvarig eng (LØ) ble paret med 7 gårder med konvensjonell melkeproduksjon basert på langvarig eng (LK). Fôrprøver og melkeprøver ble samlet inn annenhver måned. Botanisk sammensetning ble estimert før første slått i 2007. I tillegg ble data fra kukontrollen analysert. Melkeprøvene ble blant annet analysert for fettsyresammensetning, innhold av vitaminer, innhold av selen og innhold av fytoøstrogener. På de konvensjonelle gårdene var det grasarter som dominerte. På de økologiske gårdene var det i tillegg til grasarter en betydelig andel belgvekster (KØ) og urter (LØ). Kvalitetsegenskapene hos melk ble i større grad påvirket av produksjonssystem (økologisk eller konvensjonelt) enn av engdyrkingssystem (kortvarig eller langvarig eng). Det antas at hovedfaktorene var kraftfôrmengde, kraftfôrets innhold av lipider og botanisk sammensetning av grovfôret.

Til dokument

Sammendrag

Progesterone profiles in Norwegian Red cows were categorized, and associations between the occurrence of irregularities in the profiles and the commencement of luteal activity were investigated. The cows were managed in 3 feeding trials from 1994 to 2001 and from 2005 to 2008 at the Norwegian University of Life Sciences. The cows were followed from calving, and the milk samples collected represented 502 lactations from 302 cows. Milk samples for progesterone analysis were taken 3 times weekly from 1994 throughout 1998 and from 2005 to 2008 and 2 times weekly from 1999 to 2001. Commencement of luteal activity was defined as the first day of 2 consecutive measurements of progesterone concentration >= 3 ng/mL not earlier than 10 d after calving. Delayed ovulation type I was defined as consistently low progesterone concentration, <3 ng/mL for >= 50 d postpartum. Delayed ovulation type II was defined as prolonged interluteal interval with milk progesterone measurements <3 ng/mL for >= 12 d between 2 luteal phases. Persistent corpus luteum (PCL) type I was defined as delayed luteolysis with milk progesterone >= 3 ng/mL for >= 19 d during the first estrous cycle postpartum. Persistent corpus luteum type II was defined as delayed luteolysis with milk progesterone >= 3 ng/mL for >= 19 d during subsequent estrous cycles before first artificial insemination. Delayed ovulation type I was present in 14.7%, delayed ovulation type II in 2.8%, PCL type I in 6.7%, and PCL type II in 3.3% of the profiles. Commencement of luteal activity was related to milk yield, parity, PCL type I, and the summated occurrence of PCL type I and II. The least squares means for the interval to commencement of luteal activity were 24.2 d when PCL type I and II were present and 29.5 d when PCL type I and II were absent. The likelihood of pregnancy to first service was not affected in cows with a history of PCL when artificial insemination was carried out at progesterone concentrations <3 ng/mL (i.e., during estrus); however, cows that had experienced PCL were more likely to be inseminated during a luteal phase. The occurrence of delayed ovulation and PCL in Norwegian Red cows was less than that reported in most other dairy populations.

Til dokument

Sammendrag

Relationships among commencement of luteal activity (C-LA), milk yield, and energy balance (EB) were investigated in 3 selection lines of Norwegian Red cows at the Norwegian University of Life Sciences from 1994 through 2001. The cows were selected for low genetic merit for milk yield (LMP), high genetic merit for milk yield (HMP), and a combination of high indices for milk yield and fertility (HI). Breeding values for fertility were based on 56-d nonreturn rate. The material included 268 lactations from 147 cows. Milk samples for progesterone analysis were drawn 3 times weekly from 1994 through 1998, and 2 times weekly from 1999 to 2001. Commencement of luteal activity was defined as the first 2 consecutive measurements of progesterone concentration > 3 ng/mL not earlier than 10 d after calving. Selection line was significantly related to C-LA, so that the least squares mean days from calving to C-LA were 22.5, 30.4, and 27.2 d for LMP, HMP, and HI cows, respectively. The HMP cows produced more milk than the LMP cows. The average milk yield in the sixth week of lactation was 24.0, 27.1, and 25.3 kg for LMP, HMP, and HI cows, respectively. The interval to C-LA decreased for the HMP and HI cows after phenotypic adjustment for EB in the model. Least squares means for the interval to C-LA were 23.2, 29.7, and 25.6 d for the LMP, HMP, and HI cows, respectively, in a model that included parity, selection lines, and EB as covariates. Cumulated EB during the first 4 wk of lactation, which itself differed between selection lines, did not fully account for differences in interval to C-LA between selection lines. Thus, the results of the present investigation indicate that selection for milk yield negatively affects C-LA over and above the effects caused by concurrent changes in EB. The increase in days to C-LA caused by selection for high yields can be reduced if selection for milk yield is combined with fertility in the breeding program.

Sammendrag

The review confirms that feeding legume silage leads to higher DMI and milk production than grass. White clover is superior to red clover and red clover to lucerne in milk yield relative to intake. Milk fat content is lower on red clover than on grass diets and red clover yield milk with lower protein content than white clover  and lucerne. Red clover yields milk with higher proportion of the fatty acids C18:2n-5 and C18:3n-3 than grass and higher content of equol than grass and white clover.

Sammendrag

Thirty-two dairy farms in Middle-Norway participated in a field study in 2007 and 2008. Nine organic farms with short-term grassland (SO) were paired with 9 conventional farms with short-term grassland (SC) and 7 organic farms with long-term grassland (LO) were paired with 7 conventional farms with long-term grassland (LC) with regard to proximity and calving pattern. Every second month feed and tanker milk samples were collected from each farm. Data from the Norwegian dairy herd recording system were collected and botanical composition before first cut in 2007 was analysed. Milk samples were analysed for chemical composition, fatty acid composition, vitamin concentration, selenium concentration and phytoestrogen concentration. In this paper results from 2007 are presented. Milk quality was more influenced by production system then grassland system. Higher proportions of SFA and lower proportion of oleic acid in milk from O compared to C may be a future challenge for adjusting feed ratios in organic farming in Norway. Red clover stands for the main botanical effect in this study with strong effect on equol concentrations. The potential health effects of equol should be investigated further.

Sammendrag

A continuous grazing experiment with three measurement periods, 3 weeks each, was conducted with 16 Norwegian Red dairy cows in mid lactation to compare milk quality when grazing red clover-grass (R) or botanical diverse pasture (D). The cows were offered either R or D from the start of grazing season in mid May until beginning of September 2008. Milk yield was measured and milk samples were collected in the last week in each period (end of June, beginning of August and end of August). Pasture type had no effect on milk yield and milk content of fat or protein. Cows grazing R had higher proportion of the fatty acids C18:0 (22.41 vs. 9.96, P

Sammendrag

A continuous grazing experiment with three measurement periods, 3 weeks each, was conducted with 16 Norwegian Red dairy cows in mid lactation to compare milk quality when grazing red clover-grass (R) or botanical diverse pasture (D). The cows were offered either R or D from the start of grazing season in mid May until beginning of September 2008. Milk yield was measured and milk samples were collected in the last week in each period (end of June, beginning of August and end of August). Pasture type had no effect on milk yield and milk content of fat or protein. Cows grazing R had higher proportion of the fatty acids C18:0 (22.41 vs. 9.96, P<0.05) and C18:1t11 (0.58 vs. 0.44 g/100g FAME, P<0.05) and lower proportion of C16:0 (27.83 vs. 30.92, P<0.05) in their milk fat than the cows grazing D. The milk content of ?-tocopherol was higher in milk from R than D (3.01 vs. 2.64 µg/ml, P<0.05). The oxidative stability of the milk lipids were only minor affected by pasture type.

Sammendrag

I 2007-2008 ble det gjennomført et feltstudie med målsetningen å finne sammenheng mellom engdriftsystem, produksjonssystem og melkekvalitet. Ni gårder med økologisk melkeproduksjon basert på kortvarig eng (KØ) ble paret med 9 gårder med konvensjonell melkeproduksjon basert på kortvarig eng (KK) og 7 gårder med økologisk melkeproduksjon basert på langvarig eng (LØ) ble paret med 7 gårder med konvensjonell melkeproduksjon basert på langvarig eng (LK). Fôrprøver og melkeprøver ble samlet inn annenhver måned. Botanisk sammensetning ble estimert før første slått i 2007. I tillegg ble data fra kukontrollen analysert. Melkeprøvene ble blant annet analysert for fettsyresammensetning, innhold av vitaminer, innhold av selen og innhold av fytoøstrogener. På de konvensjonelle gårdene var det grasarter som dominerte. På de økologiske gårdene var det i tillegg til grasarter en betydelig andel belgvekster (KØ) og urter (LØ). Kvalitetsegenskapene hos melk ble i større grad påvirket av produksjonssystem (økologisk eller konvensjonelt) enn av engdyrkingssystem (kortvarig eller langvarig eng). Det antas at hovedfaktorene var kraftfôrmengde, kraftfôrets innhold av lipider og botanisk sammensetning av grovfôret.

Sammendrag

Et kontinuerlig beiteforsøk med 3 perioder à 3 uker ble gjennomført med 16 NRF-kyr i midtlaktasjonen. Målsetningen var å sammenligne melkequalitet når kyrne beitet rødkløvergras (RB) eller botanisk allsidig beite (AB). beitetype hadde ingen effekt på ytelse, melkas fettinnhold eller proteininnhold. Kyr som beitet RB hadde en høyere andel av fettsyrene C18:0 (22.41 vs. 9.96, P

Sammendrag

Et kontinuerlig beiteforsøk med 3 perioder à 3 uker ble gjennomført med 16 NRF-kyr i midtlaktasjonen. Målsetningen var å sammenligne melkequalitet når kyrne beitet rødkløvergras (RB) eller botanisk allsidig beite (AB). beitetype hadde ingen effekt på ytelse, melkas fettinnhold eller proteininnhold. Kyr som beitet RB hadde en høyere andel av fettsyrene C18:0 (22.41 vs. 9.96, P<0.05) og C18:1t11 (0.58 vs. 0.44 g/100g FAME, P<0.05) og lavere andel C16:0 (27.83 vs. 30.92, P<0.05) i melkefettet sammenlignet med kyr som beitet AB. Innholdet av alfatokoferol var høyere i melk fra RB enn AB (3.01 vs. 2.64 µg/ml, P<0.05). Den oksidative stabiliteten av melkas lipider ble bare i mindre grad påvirket av beitetype.

Sammendrag

Dei totale fôrkostnadane utgjer om lag 80% og grovfôrkostnadane 60% av dei variable kostnadane i sjølvrekrutterande storkjøttproduksjonen (Nortura). Det kan derfor være mye å hente økonomisk dersom det er mulig å betre effektiviteten i fôrutnyttinga.

Sammendrag

Diekalvproduksjon på utmarksbeite kan gi like stor tilvekst og slaktevekt som tilsvarende produksjon på innmarksbeite. Begge beitetypene gav meget god kjøttkvalitet med kun små forskjeller i kvalitet mellom kjøtt produsert på inn- og utmark. Prosjektet er gjennomført av Nortura og Bioforsk med besetninger av forskjellige storferaser fra Lillehammer, Gausdal, Øyer og Ås.

Sammendrag

Prosjektets hovedmål er å etablere måleparametere for god kvalitet, og å kunne bruke disse opplysningene til å styre produksjonen på den enkelte gard. Kvaliteten kan forbedres gjennom riktigere fôring på kort sikt, og gjennom målrettet avlsarbeid på lengre sikt.