The effect in an intensive production system of type of cereal and time of weaning on the performance of lambs

Abstract

SUMMARYTwo experiments were conducted to study the effect of type of cereal and time of weaning on the performance and voluntary intake of lambs.In the first experiment 20 early-weaned entire male lambs were given diets ad libitum during the fattening period from 15 to 40 kg live weight. The diets were based on either kibbled maize or rolled barley. A high feed efficiency and growth rate were achieved with both diets and differences between them were not statistically significant. The growth rates were 428 and 430 g/day. The cold carcass weights at 40 kg live weight were 19·0 and 19·9 kg and the conversion ratios of dry matter to live-weight gain were 2·33 and 2·22 for the rolled barley and kibbled maize diets respectively.In the second experiment a comparison was made of the performance of 36 sets of twin lambs, one of each set being weaned at either 6, 13 or 20 weeks of age and the other being left to suck the ewe outdoors. The lambs weaned at 6 weeks had better conversions of dry matter to live-weight gain than lambs weaned at 13 and 20 weeks. The respective conversions of dry matter to live-weight gain were 3·36, 5·64 and 5·52. The lambs weaned at either 13 or 20 weeks had a greater weight at weaning, a greater growth check at weaning and a lower rate of feed intake.