Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2012
Forfattere
Inger MartinussenSammendrag
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Forfattere
Inger MartinussenSammendrag
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Forfattere
Grete H. M. JørgensenSammendrag
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Forfattere
Grete H. M. JørgensenSammendrag
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Sammendrag
In Norway, most lambs are slaughtered at the end of the grazing season in September. An increased demand for fresh meat during the off-season may change this pattern. Castration of male lambs is not permitted, and off-season slaughtering may affect the acceptability of the meat. The objective of this study was to determine the effect of gender on meat quality from Norwegian White Sheep lambs slaughtered in September at the age of five months. Twenty-nine male lambs and 46 female lambs were included in the experiment. Loin samples of M. Longissimus dorsi were analysed for sensory profile. Meat from male lambs had higher scores for the less pleasant sensory attributes of cloying (P < 0.05) and rancid (P = 0.08) flavour, and lower scores for the more pleasant attributes of sour and sweet taste (P < 0.05 for both attributes) compared to meat from female lambs. The differences were more apparent between lambs grazing ryegrass than between lambs fed a concentrate and roughage diet. It is concluded that even at the normal slaughtering time in September, significant differences between genders may occur.
Sammendrag
Abstract: This paper reviews several studies of earthworms in agricultural soils in Norway. Crops and management significantly influence the earthworm fauna. Beneficial impacts of earthworms on plant growth are likely, but challenging to prove. Earthworm casts contain high amounts of extractable plant nutrients, which probably contribute to plant nutrient uptake. Geophagous (soil-eating) species such as Aporrectodea caliginosa and A.rosea dominate the earthworm fauna in our arable soils1. Lumbricus terrestris is also present and was found also in all-arable crop rotations with annual ploughing2. In southern Norway, L. rubellus and A. longa are also common. Earthworm populations, recorded in autumn, vary between 30 and 350 individuals m-2, with the lowest values found in all-arable systems2. The inclusion of leys in the crop rotation increases the abundance of channels, earthworm numbers and their biomass2. Since most earthworms prefer living in the upper soil layer, shallow ploughing (15 cm depth) might be expected to be detrimental. However we found that the number and biomass of earthworms was not lower with shallow than with deep ploughing (25 cm)1. In a study, green manure management affected the biomass, species and number of earthworms3. More worms were found in plots where the green manure was left on the field, compared with where it was removed. L. rubellus responded positively and rapidly to mulching, and so did A.caliginosa in clay soil. The use of biogas slurry from green manure in one season gave no effect on number and biomass of earthworms3. Long-term use of solid animal manure positively influenced some earthworm parameters, even three years after the last application1, compared to mineral fertilizer. Utilizing animal manure to produce biogas may reduce fossil fuel usage and emissions of greenhouse gases. However, there is limited information on how the recycling of digested manure as a fertilizer affects soil fertility in the long run. Reduced recycling of carbon to the soil, may harm soil fauna, including earthworms. In a newly started project on the organic research farm at Tingvoll, Norway, anaerobically digested manure is compared with undigested slurry in perennial ley and arable crops. Effects on crop yields, soil fauna, microbial communities, soil structure, organic matter and nutrient concentrations are being measured. Initial studies showed that several earthworm species were present (A.caliginosa, A.rosea, L.terrestris, L.rubellus, Octolasion cyaneum). Earthworm casts (excrements) from the detritivorous species L. terrestris (that feeds on plant residues) have been shown to be richer in nutrients than bulk soil, but little was known previously about the casts of geophagous species (that ingest mostly soil). Casts from two soil depths (13 and 25 cm) were collected by means of litter bags, to study whether such casts also contained more plant available nutrients than the bulk soil. A.caliginosa and A.rosea were the dominant species in these fields. The casts had considerably higher concentrations of plant nutrients than the bulk soil. The content of total-N was 28 % higher in casts, total-C was 37% higher, the contents of available P and K were 40-60%, whilst those of Ca and Mg were 10-20 % higher. On average for the two sites, these differences corresponded to the following amounts (kg ha-1 y-1): 5.6 for P, 8.9 for K, 5.3 for Mg, 144 for N and 2542 for C. With earthworm densities such as those found in farming systems incl. ley and animal manure (ca. 230 individuals m-2), about 220 tonnes of topsoil per hectare passes through the earthworm digestive tract each year. Our study indicated that earthworm casts are valuable sources of plant nutrients even in soils where the fauna is dominated by geophagous species.
Sammendrag
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Forfattere
Lampros LamprinakisSammendrag
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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.
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