Effects of fasting and transport on liveweight loss and the prediction of hot carcase weight of cattle

Abstract

At the start of a 53 h pre-slaughter fast, 144 steers were subjected to either 0 (controls), 3 or 12 h of road transport to examine the precision of predicting hot carcase weight from liveweight and the effect of transport on liveweight loss and hot carcase weight. The mean rate of liveweight loss declined progressively with fasting, from 2.57 kg/h during the first 5.3 h to 0.71 kg/h during the final 23.6 h. The precision of predicting hot carcase weight from liveweight showed little improvement beyond 5.3 h of fasting. Transport tended to reduce the rate of liveweight loss during the first 24 h of fasting. Hot carcase weight decreased linearly (P < 0.01) with increasing transport length, after an adjustment was made to the same zero-hour liveweight and pre-trial liveweight gain. As a means of improving the precision of predicting hot carcase weight from liveweight, these results question the need for the current practice of fasting cattle overnight before weighing for sale.