FEEDING STRATEGY DURING PREGNANCY FOR EWES WITH A LARGE LITTER SIZE .1. EFFECT OF QUANTITY AND COMPOSITION OF CONCENTRATES ON INTAKE AND REPRODUCTIVE-PERFORMANCE

In six feeding trials with pregnant crossbred ewes the effect of four different feeding regimes on intake (dry matter, energy and crude protein), reproductive performance and occurrence of acetonaemia were compared. The treatments differed in energy level, protein supply, protein degradability and the level of concentrates supplementation. Hay was used as roughage. The mean litter size was 3.26. The sum of the birth weights of lambs was positively affected by the treatment where a higher protein level was combined with a lower degradability of the protein. Net body weight gain was affected by litter size, occurrence of acetonaemia and treatment. The ME-intake was in general lower than the aimed levels. Treatments with 60% of energy originating from concentrates showed a higher ME intake then treatments with 40% of energy originating from concentrates. The crude protein intake was higher on the treatment where a higher protein level was combined with a lower degradability. Dry matter intake in the last two months of pregnancy was affected by litter size, age of the ewes, occurrence of acetonaemia and feeding treatment. Dry matter intake decreased in the last weeks of pregnancy. This decrease 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 acetonaemia on the intake pattern is described.