Food Waste Products in Diets for Growing-finishing Pigs: Effect on Growth Performance,Carcass Characteristics and Meat Quality

With high variation in environmental conditions, especially during the extensive grazing season, genotype by environment interaction is potentially important to lamb production in Norway. Using breed as an indicator of genotype, the interaction between breed and environment, i.e. production level of farm and year calculated as solutions of a random farm*year variable, on 52 farms keeping both long-tailed Dala and short-tailed Spæl during 1989–98 was studied. The dataset included 48,946 Dala lambs and 38,299 Spæl lambs. The breed by environment interaction affected lamb autumn weights, and though Dala lambs were always heavier, the difference was substantially smaller at lower than at higher production levels: 1 kg increase in production level was related to Dala lambs’ weights increasing 0.09 kg more than the Spæl lambs’ weights. The results indicate that breed by environment interaction may be of importance, and potential bias in the data and need for further research is discussed.     

Indications of breed by environment interaction for lamb weights in Norwegian sheep breeds

With high variation in environmental conditions, especially during the extensive grazing season, genotype by environment interaction is potentially important to lamb production in Norway. Using breed as an indicator of genotype, the interaction between breed and environment, i.e. production level of farm and year calculated as solutions of a random farm*year variable, on 52 farms keeping both long-tailed Dala and short-tailed Spæl during 1989–98 was studied. The dataset included 48,946 Dala lambs and 38,299 Spæl lambs. The breed by environment interaction affected lamb autumn weights, and though Dala lambs were always heavier, the difference was substantially smaller at lower than at higher production levels: 1 kg increase in production level was related to Dala lambs’ weights increasing 0.09 kg more than the Spæl lambs’ weights. The results indicate that breed by environment interaction may be of importance, and potential bias in the data and need for further research is discussed.     

Differences in choice of diet between sheep breeds grazing mountain pastures in Norway

In the present study, the foraging behaviour of ewes from three common Norwegian sheep breeds; the long-tailed Dala sheep, and the two short-tailed breeds Spæl sheep and Norwegian Fur sheep was studied. Based on difference in body size and digestive anatomy, we expected the lighter short-tailed ewes to browse more on woody plants than the Dala ewes. The experiments were conducted during two consecutive summers within the flocks’ usual grazing areas, and we sampled the proportion of grazing time that ewes spent feeding on woody plant species. We tested the hypothesis by applying generalized linear mixed models to the feeding behaviour data. As predicted, the short-tailed ewes spent substantially more of their grazing time browsing on trees, bushes and heather compared to the Dala ewes. We discuss the results in the context of maintaining the, now threatened, pastoral landscapes of mountainous regions of Norway; short-tailed breeds should be more effective than the Dala breed in reducing tree and bush encroachment, but more detailed studies are needed to quantify the breed differences in this respect.