Effect of method of sale and various water regimens at saleyards on the liveweight, carcass traits and muscle properties of cattle

Abstract

In two experiments, we examined the effects on liveweight, carcass traits and muscle properties of (a) sending cattle to the abattoir either direct from a farm or via a saleyard, and (b) different curfew and sale procedures at a saleyard. During the 12 h curfew and 10 h sale periods, cattle were held with or without water, but always denied feed. In experiment 1, after a journey of 1320 km, 252 bullocks (mean liveweight 558 kg) were subjected to one of seven treatments. The groups transported direct to the abattoir were (1) denied water between arrival and slaughter (26 h), (2) offered water for 26 h, or (3) offered water and feed for 50 h and then water alone for 24 h. Those sent to the saleyard were given access to water (4) at all times, (5) only during the curfew and sale periods, (6) only before the curfew began, or (7) were denied water until after the sale, when all groups were offered water for 36 h until slaughter. Among the bullocks sent direct to the abattoir, the group with water for 26 h until slaughter had heavier (P< 0.0 1 ) carcasses than those denied water (331 kg vs 312 kg) and also a greater (P < 0.0 1) muscle water content, while the carcasses of the group slaughtered 2 d later were intermediate for both. Whether dressing percentages were calculated on liveweights at the start or end of the simulated sale for the four saleyard groups, the differences in mean dressing percentages between groups offered water (0.7 and 0.3 percentage units) were less than the differences between the means of the groups denied water (3.7 and 3.5 units). The increases in dressing percentage during the sale for groups with water (0.7 and 0.3 units) were less than those for the groups denied water (1.5 and 1.7 units). Differences in mean liveweights and mean muscle water contents between groups followed the same trends. Mean carcass weights did not differ significantly between saleyard groups (318-323 kg). In experiment 2, after a journey of 90 km, 152 cows (mean liveweight 323 kg) were subjected to one of four treatments. The group going direct to the abattoir was offered water for 4.5 h, fasted for 16 h and then slaughtered. For the other three groups, the saleyard treatments 4,6, or 7 of experiment 1were imposed, followed by 21 h on water and a 16 h pre-slaughter fast. Trends in dressing percentage and liveweight were similar to those recorded in experiment 1. Mean carcass weight varied (P<0. 05) between groups and tended to increase with muscle water content. Method of sale was important because it affected the time from mustering to slaughter, and thus, carcass weight. At saleyards, the practice of giving cattle continuous access to water reduced significantly the variation in liveweight, dressing percentage and muscle water content between groups with similar initial liveweights. This practice at abattoirs avoided dehydration of carcass tissues at slaughter