Abstract:

This trial was conducted to study the effects of milk replacers with different protein concentrations on the intake of starter feeds, growth performance and nutriment digestion in early weaned lambs. Thirty six crossbred F1 lambs (Dorset×Thin-tailed Han sheep) were randomLy divided into 4 groups. A group of lambs suckling their ewe’s milk was used as control, the others were fed with three milk replacers containing 21%, 25% or 29% of protein, respectively. The body weight and size were measured on d 20, 40, 60, 80 and 90 after birth. Two digestion trials were undertaken during d 50-60 and 80-90 after birth. The milk replacers promoted the lambs to ingest the starter feeds earlier, and the intake of the starter feeds was decreased (P ＜0.05) as the protein level of milk replacers increased. The weight gains of lambs receiving three milk replacers containing 21%, 25% or 29% protein were 14.1, 14.6, 13.9 kg, respectively. Compared with control group, the weight gains of the latter groups above were increased by 7.6%, 11.5% or 6.1%, respectively (P ＞0.05). The tendency of body size changes was the same as body weight gains. The milk replacer containing 25% protein was the best. The crude protein level had no significant effects on the apparent digestibility of dry matter, organic matter, ether extract, calcium or phosphorus (P ＞0.05). The nitrogen retention was 73.5% for 29% protein group, which was significantly lower (P ＜0.05) than that of 21% protein (77.2%) and 25% protein (77.6%) groups during d 80-90. Conclusion: the intake of starter feeds was decreased with the increasing protein levels of the milk replacers. The growth performance and nutriment digestion in the lambs given the milk replacer of 25% protein were better than the others.