Effect of pre-weaning nutrition on dairy heifer calf performance during the first season at pasture

摘要

Post-weaning, pasture-based systems can provide a cost effective method of rearing heifer calves. To improve efficiency of such systems, pre-weaning nutrition must promote good performance at pasture. The aim of this experiment was to investigate theeffect of different milk replacer (MR) feeding regimes on performance at pasture. Immediately after birth calves were weighed and received colostrum at 8.5% of birth body weight (BW). Calves were then assigned to a treatment group, receiving, 6 litres per day of: (1) 26% crude protein (CP) MR at 125 gl~(-1); (2) 26% CP MR at 200 gl~(-1); (3) 20% CP MR at 125 gl~(-1); or (4) 20% CP MR at 200 gl~(-1). Live weight was recorded weekly pre-weaning and weaning occurred at 18% of mature BW. Post-weaning, calves were turned out to pasture, as single group, where live weight was recorded fortnightly. Grass was allocated ad libitum, with fresh grass allocated when calves had grazed to a post grazing residual of 4cm. Using a 26% CP MR at 200 gl~(-1) allowed earlier weaning to be achieved when compared with 20% CP MR at a rate of 125 gl~(-1). No difference was observed in weight gain at pasture between the groups.