Chemical, Fatty Acid, and Tenderness Characteristics of Beef from Three Biological Types of Cattle Grazing Cool-Season Forages Supplemented with Soyhulls

摘要

Over two consecutive years, the effects of allocating large-, medium-, or small-framed cattle, all of intermediate rate of maturing (n = 107), to fescue without supplementation (Control), or fescue or orchardgrass pasture with soyhull supplementationon shear, chemical, and fatty acid characteristics were investigated. There were no differences (P > 0.05) in shear force between dietary treatments. Cattle from the two supplemented treatments produced beef that had increased (P < 0.05) percentage lipidand decreased (P < 0.05) proportions of polyunsaturated (PUFA) and n-3 fatty acids (those fatty acids with the first double bond at the third carbon from the carbonyl end of the fatty acid) compared to the Control. However, supplementation did not decrease proportions of conjugated linoleic acid (CLA) present in the longissimus, which can commonly occur when forage-fed cattle are supplemented concentrates. Additionally, even though the proportion of n-3 fatty acids was reduced with supplementation, then-6-3 ratio (n-6 fatty acids are those unsaturated fatty acids with the first double bond at the sixth carbon from the carbonyl end of the fatty acid molecule) was below five in all three treatments, which could potentially aid in reduced atherosclerosis and inflammation. Biological type did not appear to be a significant source of variation for most traits analyzed in this study. These results suggest that supplementation of soyhulls to cattle grazing forage may not decrease CLA proportions, and although it might elicit a reduction in proportions of PUFA and n-3 fatty acids present in the longissimus, the n-6-3 ratio still may be maintained below the recommended ratio of four to five.