The effect of short‐term grain feeding on liveweight gain and beef quality

Abstract

Two serial slaughter experiments were conducted to compare the liveweight gain and carcass quality of 3‐year‐old Angus steers finished on concentrate‐based rations with steers finished on high quality spring pasture in New Zealand. Experiment 1 used a feedlot ration of 70% maize grain and 30% pasture silage and Experiment 2 used barley instead of maize. In both experiments, steers were adjusted to the concentrate ration prior to being fed ad libitum for 12 weeks. Finishing regime led to a significant difference in carcass weight in Experiment 1 (363 and 407 kg for pasture and grain, respectively). There was no significant difference in final carcass weight in Experiment 2. There was no significant effect of feeding regime on marbling in either experiment. Although grain‐finishing significantly affected pH in Experiment 1, there were no treatment effects on tenderness in either experiment, and resident New Zealand panellists were unable to detect sensory differences between beef from the two feeding regimes when comparisons were made at the same slaughter time. In both experiments, steers fed the concentrate diet had brighter and redder meat, but this may have been related to the reduced level of exercise of the feedlot group rather than diet per se. Diet had no effect on carcass fat colour in Experiment 1 but steers fed the feedlot ration in Experiment 2 had significantly whiter fat colour. In these experiments the effects of short‐term grain finishing on meat quality were minor. It was concluded that, provided a high growth rate and adequate level of finish could be achieved, beef produced from pasture finishing was similar in tenderness and taste to beef finished for up to 100 days on a feedlot.