Finishing strategies for steers based on pasture or silage plus grain and time on feed and their effects on beef quality

Abstract

The aims of the present study were to compare the quality of grainfed and pasture-fed beef and to assess the effects of two feeding periods on grain for finishing steers. A group of 75 steers were fed one of 5 finishing diets (n = 15 per diet): pasture for 90 d (P), oat grain plus pasture silage for 35 d (SO), oat grain plus pasture silage for 75 d (LO), wheat grain plus pasture silage for 35 d (SW), and wheat grain plus pasture silage for 75 d (LW). The physicochemical and sensory attributes and the fatty acid composition of the longissimus lumborum muscle were determined. The beef from pasture-fed animals tended to be tenderer, darker, less red, and with yellower fat than the beef from grain-fed steers. The beef from steers fed wheat plus silage for 75 d had lower tenderness scores than beef from steers fed for 35 d on grain plus silage. The beef from pasture-fed steers had higher levels of conjugated linoleic acid c-9 t-11 and n-3 fatty acids and a lower n-6:n-3 fatty acid ratio than the beef from grain-fed steers. The time fed on grain plus silage had a significant effect on the fatty acid composition of the beef from steers fed wheat, but no similar effect was observed in beef from steers fed oats. However, the n-6:n-3 ratio of beef was more favorable when steers were fed grain (wheat or oats) plus silage for 35 d than for 75 d.