Published online by Cambridge University Press: 02 September 2010
Three randomized-block experiments involving 87 British Friesian, 18 Simmental × Friesian and 18 Hereford × Friesian, artificially reared calves (mean initial live weight 47 kg and age 9 days), were carried out to examine the effects of the quantity of milk substitute consumed on the lifetime performance of beef cattle. The three treatments were (1) 400 g milk powder per head daily, weaned at 42 days of age (2) ad libitum intake of milk powder, weaned at 42 days and (3) ad libitum intake of milk powder, weaned at 60 days. All calves were individually penned and fed until after weaning; those on treatment 1 were bucket fed twice daily, while those on treatments 2 and 3 sucked the milk from 25·1 containers through artificial teats. They were offered a pelleted, barley/soya-bean meal concentrate (197 g crude protein per kg dry matter (DM)) ad libitum from purchase until intake reached a maximum of 2·7 kg per head daily, and well preserved grass silage ad libitum from 6 weeks of age. Three commercial, skimmed milk-based, acidified milk substitutes (242 and 187 g crude protein and oil per kg respectively) were used. Intakes of milk substitute, concentrate DM and silage DM per calf to 12 weeks of age for treatments 1 to 3 respectively were as follows: 13·0, 39·7 and 54·8 (s.e. 1·67) kg; 88, 73 and 58 (s.e. 1·5) kg and 9·4, 10·6 and 11·2 (s.e. 0·23) kg. Live-weight gains to 12 weeks of age and carcass weights adjusted to 19 months of age were 0·71, 0·82 and 0·84 (s.e. 0·026) kg/day and 335, 340 and 341 (s.e. 3·8) kg. It is concluded that increasing the input of milk substitute above 400 g per head daily until 6 weeks of age produced only a small and uneconomic increase in the lifetime performance of beef cattle.