Feeding strategy during pregnancy for ewes with a large litter size. 1. Effect of quantity and composition of concentrates on intake and reproductive performance.
AbstractIn 6 trials, 40 Ile de France X Finnish Landrace ewes 2 to 8 years old were given during pregnancy diets containing 40% energy from concentrates and crude protein (CP) 196 or 91 g/kg or 60% energy from concentrates and CP 189 or 240 g/kg. Mean litter size was 3.26. The sum of the birth weights of lambs was affected by the treatment where a higher protein concentration was combined with a lower degradability of the protein. Net body weight gain was affected by litter size, ketosis and treatment. Metabolizable energy (ME) intake was lower than expected. Treatments with 60% of energy from concentrates showed a higher ME intake than treatments with 40% of energy originating from concentrates. CP intake was higher where a higher protein level was combined with a lower degradability. DM intake in the last 2 months of pregnancy was affected by litter size, age of the ewes, ketosis and feeding treatment. DM intake decreased in the last weeks of pregnancy and was related to litter size, The possible reasons for this effect are discussed. Substitution rates of concentrates to forage depended also on the litter size. The effect of the ketosis on the intake pattern is described. (Abstract retrieved from CAB Abstracts by CABI’s permission)