The effects of supplementary feeding, pattern of growth and slaughter age on the carcass characteristics of Hereford steers

Summary Three groups (1, 2 and 3) of weaned Hereford steers were grazed separately on pasture. Groups 1 and 2 were supplemented with hay and oats during autumn and winter in an attempt to maintain two rates of live-weight gain, namely 0·8 and 0·4 kg/day, respectively. Group 3 was not supplemented and gained at zero and 0·11 kg/day during corresponding periods in the 2 years in which the experiment was repeated (years 1 and 2). Supplementation ceased at the end of winter (September). Group 1 steers were slaughtered at the end of the growing season (January) when their mean live weight was 420 and 450 kg in years 1 and 2 at 19 months of age. Thereafter, groups 2 and 3 were removed from the plots and grazed together on another pasture at a reduced stocking rate until they attained the slaughter live weights of group 1 when they were slaughtered at 25 and 27 months of age, respectively. Mean depth of fat cover over the eye muscle at the 10–11th rib in groups 1, 2 and 3 were 8, 6 and 4 mm in year 1, and 12, 5 and 6 mm in year 2, respectively. Group 1 carcasses had shorter skeletal dimensions, contained more fat and graded better than the carcasses of groups 2 and 3. The Longissimus dorsi muscles from group 1 were found to be the most tender in year 1 but no treatment effects were detected in year 2.