Intake, feed efficiency, carcass traits, muscle colour and sensory characteristics of beef from steers offered grass silage and barley-based supplementary concentrates with increasing levels of dry corn gluten feed

Abstract

Increasing awareness of feed-food competition means the inclusion of human-inedible by-product feed ingredients rather than cereals in concentrate feedstuffs for beef cattle is now preferred. The objective of the present experiment was to evaluate the complete replacement of soya bean meal and partial replacement of rolled barley with increasing levels of dry corn gluten feed (DCGF) in the concentrate supplement to grass silage on intake, growth, carcass traits and meat quality attributes of finishing beef cattle. The control concentrate (DCGF-0) was based on rolled barley (865 g/kg fresh weight) and soya bean meal (60 g/kg fresh weight). In three other concentrates, barley and all the soya bean meal was replaced with either 250 g/kg (DCGF-250), 500 g/kg (DCGF-500) or 750 g/kg (DCGF-750) fresh weight of DCGF. Forty-eight late-maturing breed suckler steers were individually offered Lolium perenne dominant grass silage ad libitum supplemented with 4.0 kg dry matter (DM) of the respective concentrates daily, for 124 days. Inclusion of DCGF in the concentrate had no effect on silage DM intake, daily live weight gain, feed conversion ratio, pre-slaughter weight, ultrasonic measures of body fat, carcass weight, estimated carcass gain, kill-out proportion, carcass conformation score, carcass fat score, carcass fat depth or on subcutaneous fat redness, yellowness and saturation. There was a linear increase (P < 0.01) in subcutaneous fat lightness and hue as DCGF inclusion level increased. Inclusion of DCGF in the concentrate had no effect on ultimate pH, temperature, drip loss, colour or meat sensory characteristics of the M. Longissimus dorsi muscle. Under the conditions of this experiment, DCGF had a feeding value comparable to that of rolled barley (+ soya bean meal) with little effect on meat quality, when included at up to 750 g/kg fresh weight in a concentrate supplement to grass silage. The overall implication of these findings is that the human-edible food-feed efficiency of beef production can be enhanced further by the use of DCGF.