An intensive beef production system: evaluation of different strategies for the winter feeding of replacement heifers.
In an experiment carried out in Brazil between June and December 1994, 318 Hereford and Aberdeen-Angus heifers were weaned in autumn then placed (1) on improved natural pasture, (2) on improved pasture and given energy and protein supplements, or (3) in a feedlot and fed hay and concentrates. For heifers in the 3 groups, daily gain averaged 786, 615 and 744 g respectively in winter and 474, 501 and 351 g in spring, the differences between groups being significant. Body weight at the beginning of the insemination period (on 12 July) averaged 230.3, 215.1 and 216.1 kg respectively (P<0.05) and height at withers 154.5, 153.6 and 154.5 cm. There were no significant differences between the 3 groups in the percentage of cycling females on 7 December (27, 24 and 24% respectively).