Abstract:
Proc. Aust. Soc. Anim. P&,(1978) 12: 233 PATTERN OF GROWTH AND CARCASS CHARACTERISTICS OF STEERS J.H.L. MORGAN* and A.J. CLARK* Supplementary feeding can be used to reduce the seasonal variation in the growth rate of grazing steers and, hence, allow slaughter at a younger age. Any possible effects on carcass characteristics must be considered in evaluating the benefits of earlier slaughter. In February 1974, three groups of seven Hereford weaner steers were allocated to separate areas of pasture and stocked at 3.1 ha-l. Groups 1 and 2 were then supplemented with hay and oats in an attempt to maintain mean growth rates of 0.8 and 0.4 kg day-l, respectively. Supplementation ceased in September and Group 1 was slaughtered in January at a mean live weight of 450 kg at 19 months of age. From January onwards Groups 2 and 3 were grazed together at 1.8 ha-' until they attained the mean slaughter weight of 450 kg which they did in June and August at 25 and 27 months of age, respectively. The results are presented in Table 1. The carcases of Group 1 steers were shorter and fatter than those of steers from Groups 2 and 3. Similar results have been reported by Palsson and Verges (1952) in sheep and by Lalande and Fahmy (1975) in cattle. Such results are of particular importance in view of the ' emphasis given to conf'ormation and fat cover by the meat trade and the inclusion of carcass length and depth of fat cover in the Australian carcass classification scheme. It cannot be determined from this experiment whether the treatment effect on carcass fatness was due to the pattern of growth or to the feeding of grain. However, the results of a subsequent experiment (Sully and Morgan 1978) indicate that both factors can influence carcass fatness. LALANDE, G. and FAHMY, M.H. (1975). Anim. Prod. 21:81. PALSSON, H. and VERGES, J.B. (1952). #J. agric. Sz. Camb. 42:l. SULLY, R.J. and MORGAN, J.H.L. (1978). Proc. Aust. SOC. Anz. Prod. = 12: * PastoralResearch Institute, P.O. Box 180, Hamilton, Vic. 3300. 233.