The effect of pre- and post-natal nutrition on the growth of beef cattle. 2. The effect of severe restriction in early post-natal life on growth and feed efficiency during recovery

Abstract

The growth of Hereford calves, from dams fed on either a submaintenance or an above-maintenance diet over the last trimester of pregnancy, was controlled from 4 to 200 days of age. During a subsequent period they were either held in yards on a high quality ration and fed to appetite or allowed to graze pasture. The influence of restricted growth commencing on the fourth day after birth on subsequent liveweight gain and feed efficiency was studied. Restricted nutrition for c. 200 days (mean gain 0.05 kg day-1) did not impair the capacity of the calf to resume normal growth when grazing or when fed on a high quality ration. Calves that had been restricted and allowed to recover in yards did not demonstrate compensatory growth, although they did exhibit growth rates (0.87 kgday-1) equivalent to those of the unrestricted controls (0.90 kg day-1). Calves that had been restricted and allowed to recover on pasture grew faster (0.50 kg day-1) than unrestricted controls also finished on pasture (0.36 kg day-1). During the recovery period, restricted calves were more efficient in converting food into liveweight gain than unrestricted calves. However, when compared over the same liveweight range, this trend was not apparent.