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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.

2016

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

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