EARLY WEANING OF FALL-BORN BEEF-CALVES .2. POSTWEANING PERFORMANCE OF EARLY-WEANED AND NORMAL-WEANED CALVES

A 5-yr study was conducted to compare the effects of early weaning at approximately 110 d of age with normal weaning at approximately 220 d in fall-born beef calves (Bos taurus). Differences in postweaning performance of steer and heifer calves that were early- or normal-weaned are reported in this paper. One hundred fifty-two Shorthorn x Angus x Hereford steers were used to study the effects of early weaning on feedlot performance and carcass cutability. Slaughter date was determined by using a combination of visual apprasial and sonoray measurements to slaughter steers at a relatively constant fat thickness. Early-weaned steers were 31 lb heavier (P = 0.02) at slaughter than normal-weaned steers. Early-weaned steers had greater (P < 0.05) daily gain from normal weaning to slaughter and were 11 d younger (P < 0.01) at slaughter than normal-weaned steers. Forty-seven heifer calves that were either early-or normal-weaned in 1982, 1983, or 1984 were returned to the breeding herds. Reproductive performance was not different.