FATTENING OF LAMBS ON SILAGE ALONE AND WITH TWO LEVELS OF CONCENTRATES IN BOTH INDOOR AND OUTDOOR INDIVIDUAL PENS

The responses obtained in Galway X Suffolk lambs of about 38.5 kg initial liveweight offered good quality silage alone ad lib and supplemented with 227 and 454 g concentrates per head per day under both indoor and outdoor individually penned conditions were measured during a 60-day period. Supplementation with 227 and 454 g concentrates increased (p < 0.01) total daily dry matter intake by about 22 and 42% and 20 and 39% during the final 53 days and total 60 days respectively. The corresponding reductions in daily silage dry matter intake were 1.4 and 3.3% and 2.1 and 4.5%. During the final 53 days and total 60 days, liveweight gains (kg) for silage only and silage + 227 and 454 g concentrates were 1.02, 4.54 and 6.84 and 0.85, 2.74 and 5.73 respectively and the corres ponding hot carcass weight gains (kg) for the total 60 days were 1.42, 3.05 and 4.35. No significant difference was recorded between indoor and outdoor locations with respect to any of the measure ments except that the indoor Iambs lost slightly more (p < 0.10) liveweight during the first 7 days. There were no significant interactions between diets and locations.