A comparison of growth rates and carcass quality of steers receiving maize silage as a supplement to annual pasture or as a component of a feedlot ration

Abstract

Summary. We tested the hypothesis that liveweight gain per hectare could be doubled in beef steers grazing irrigated annual pastures by increasing stocking rate from 2.5 to 5.0 steers/ha and supplementing the heavier stocked treatments with maize silage offered at either 2.4 or 5.6 kg dry matter/steer. day to replicated groups of 4 steers. During an average period on feed of 172 days, liveweight gain was substantially increased, from 245 kg/ha to either 464 or 576 kg/ha, when maize silage was fed to steers at 2064 or 4816 kg dry matter/ha, in association with an increase in stocking rate from 2.5 to 5.0 steers/ha. However, such production systems increased the chance of feed shortages, particularly in exceptionally wet winters such as the one experienced in the experiment. Increasing the rate of supplementary feeding without increasing stocking rate may not be economically viable. Other strategies, such as lot feeding steers, were also tested. Diets where maize silage constituted either 46% dry matter (with the balance of the diet comprising wheat grain, cottonseed meal, urea, bentonite, vitamins and minerals) or 97% dry matter (with the balance of the diet comprising urea, vitamins and minerals) led to steers achieving liveweight gain of 1.34 and 0.93 kg/steer. day respectively. Carcasses from steers eating maize silage fed at pasture or maize silage as a component of lot-fed diets had at least as adequate fat cover and as good eating quality as carcasses from steers grazing at 2.5 steers/ha.