REARING OF DAIRY CALVES ON PASTURE WITH OR WITHOUT WHOLE OATS

Abstract

Three groups of 10 Ayrshire bull calves born in May and June, 1963 were placed on pasture at 2 weeks of age, after weaning at 55 kg body weight, or at 15 weeks of age. Half the calves in each group also received whole oats while on pasture to a maximum of 1.4 kg/day. Prior to going on pasture, calves were fed a starter ration and timothy hay. The calves were removed from pasture at 21 weeks of age and fed hay and grain until 52 weeks of age. There were no differences between groups in rate of gain from 1 week of age to weaning, the average growth rate for all calves being 427 g/day. Calves put on pasture after weaning gained 223 g/day from weaning to 15 weeks of age, and calves put on pasture at 15 weeks of age gained only 177 g/day from 15 to 21 weeks of age. Weight gains during these same two periods for calves put on pasture at 2 weeks of age were 432 and 500 g/day, respectively. Feeding oats to calves on pasture did not increase growth rates to weaning or to 15 weeks of age. Average body weights at 52 weeks of age were 251, 228, and 242 kg, respectively for calves started on pasture at 2 weeks of age, after weaning, and at 15 weeks of age.