Effect of early weaning age on growth performance, nutrient digestibility, and serum parameters of lambs

Abstract

To determine the effect of a weaning program on growth performance, nutrient digestibility, and serum parameters in Hu lambs, 48 newly born twin lambs (2.53 ± 0.13 kg; 24 male and 24 female) were randomly divided into four treatments: ewe reared (ER) or weaned at 10, 20, or 30 days post birth (EW10, EW20, and EW30) and fed milk replacer (MR). All liquid feed were eliminated at 60 days of age. Creep feed was offered ad libitum to all lambs from 15 to 90 days of age. The results indicated that lambs fed MR had higher liveweight, average daily gain, and creep feed intake (P < 0.001) than those in the ER group. There were no differences between treatments in the apparent digestibility of dry matter, organic matter, nitrogen or phosphorus (P > 0.05) from 50 to 60 days of age. The apparent digestibility of dry matter, organic matter, nitrogen and phosphorus of EW20 and EW30 groups were significantly higher (P < 0.05) than that of EW10 and ER groups from 80 to 90 days of age. Lambs in the EW10 group had higher concentration of albumin, serum urea nitrogen, and immunoglobulin G levels than those of other groups (P < 0.05). In conclusion, early weaning could improve creep intake, growth performance, and nutrient utilisation of Hu lambs. Early weaning age had a significant effect on the growth of lambs.