In order to evaluate the effect of source and amount of milk delivered to lambs on their performance, thirty newborn Shall male lambs (4.76 ± 0.31 kg) were randomly assigned to one of three treatments: 1) conventional whole milk feeding program at 10% of body weight (CWM); 2) conventional milk replacer feeding at 10% of body weight and 17.1% milk solid (MRC); 3) accelerated milk replacer feeding program at 20% of body weight and 21% milk solid (MRA). Lambs were weaned at 56 d of age and the experiment finished 2 week after weaning. Milk and solid feed intakes were individually recorded on a daily basis. As the experiment advanced, the solid feed consumption (P < 0.01) and average daily gain (ADG; P < 0.01) increased, but MRC fed lambs had a decreased ADG compared to CWM or MRA groups in the pre-weaning (94 g/day vs. 140 and 155 g/day, respectively), but not in post-weaning, phase. The accelerated program led to decreased solid feed intake in the MRA group while the other lambs had similar starter intake, though total dry matter intake was greater in MRA compared with others. The CWM group had the best gain:feed ratio, resulting in similar final body weights as the MRA group and greater body weights compared with MRC lambs. Circulating β-hydroxy butyric acid was decreased (P < 0.01) in MRA lambs compared with lambs on the traditional program during pre-weaning, but not post-, weaning period. In conclusion, it appears that lambs can be artificially reared on very low fat MRA program with greatly improved ADG during the first month of life, but, without altering final performance.
