Effects of pasture and high‐concentrate diets on the performance of beef cattle, carcass composition at equal growth rates, and the fatty acid composition of beef

摘要

Abstract Two experiments were carried out to examine the effects of high quality pasture and high‐concentrate diets on liveweight and carcass gain of beef cattle, carcass composition at equal carcass gain, and the fatty acid composition of beef. Heifers of late‐maturing breed type (406 kg initial liveweight; Experiment 1) and steers of late‐maturing breed type (460 kg initial liveweight; Experiment 2) were finished on a ryegrass pasture or a high‐concentrate diet at either (1) ad libitum, (2) 85% of ad libitum intake or (3) 70% of ad libitum intake. The high‐concentrate diet consisted of 95% barley‐based concentrate and 5% barley straw. Carcass gain of the animals finished at pasture (648 g day?1) was 0.78 in Experiment 1 (P < 0.001) and 0.88 in Experiment 2 (P > 0.1) of that of the animals given the high‐concentrate diet ad libitum. Gains in lean meat were similar for animals finished at pasture and those given concentrates ad libitum, whereas daily fat gains were 39% lower for the animals finished at pa...