Effect of weaning age and post-weaning nutrition on the growth of calves and the liveweight of their dams

Abstract

A factorial grazing experiment conducted during 1970,1971 and 1972 at the Pastoral Research Station, Hamilton, Victoria, studied two major management factors in beef production. Post weaning liveweight changes of calves and their dams were measured to compare the effects of either an eight or ten month weaning age and differing nutritional regimes applied from 8 to 12 months post calving. The cows stocked at the higher rate (1.7 cow ha -1) post weaning lost less weight or gained more weight during the test period in three out of four occasions than the cows stocked at the lower rate (1.5 cow ha-1). The results from this experiment confirm the finding of Bailey and Bishop 1972 and show that on perennial pastures in southern Australia, calves weaned at ten months old from autumn calving Hereford cows are likely to be heavier at 12 months old than are calves weaned at eight months onto dry pasture. However, weaning calves at eight months onto hay aftermath would be an effective alternative to ten month weaning. This would also reduce the risk of weight loss by the cow due to later weaning.