Beef Muscle Tenderness as Influenced by Days on Feed, Sex, Maturity and Anatomical Location

Abstract
Warner-Bratzler shear values were obtained on the triceps brachii, longissimus and semimembranosus muscles of 200 cattle slaughtered at 30-day intervals over a 270-day feeding period. Shear values of all muscles were lower (P<.05) at 150 and 180 days on feed than at all other periods. There was an apparent interaction between time on feed and animal age. The first 180 days on feed had a beneficial effect on tenderness. However, after 180 days, animal age appeared to exert a greater influence. Within treatment differences attributable to sex were small and insignificant. Muscle location had a significant effect on resistance to shear. The triceps brachii muscle had a consistently lower resistance to shearing and the longissimus a higher resistance. Within treatments, the triceps brachii was more tender (P<.05) than the longissimus at 0, 60, 90, 120, 240 and 270 days on feed. The semimembranosus was more tender (P<.05) than the longissimus at 60, 90 and 120 days on feed. No significant differences in tenderness within treatment were observed between the triceps brachii and semimembranosus. Copyright © 1970. American Society of Animal Science . Copyright 1970 by American Society of Animal Science