Abstract
Angus (N = 25), Brahman (N = 25) and Brahman x Angus (N = 25) steer calves were fed a high-energy diet and five steers from each breed-type were slaughtered after 0, 56, 112, 168 and 224 days. Steaks from Angus and Angus x Brahman steers were more tender (P < 0.05) than steaks from Brahman steers in 27 of 50 comparisons and 14 of 50 comparisons, respectively. Tenderness of steaks from steers of the breed-types responded to time-on-feed (TOF) differently: steaks from Brahman steers improved in tenderness (P < 0.05) with increasing time-on-feed for all muscles except the psoas major; with the exception of the longissimus muscle, tenderness of steaks from Angus steers did not change as time-on-feed increased; and, for the Brahman x Angus steers, five of the ten muscles studied improved in tenderness with increasing time-on-feed. Breed-type differences (P < 0.05) did not exist for sarcomere length, however, very distinct TOF differences were observed--sarcomere lengths were significantly (P < 0.05) longer after 112 days of feeding. Collagen solubility and concentrations did not differ (P > 0.05) between breed-types or TOF periods. Multiple regression equations used to predict some of the palatability characteristics utilized collagen solubility, sarcomere length, 6 hr longissimus temperature, carcass maturity and marbling. These data indicate that TOF can be used to predict the tenderness of some of the major muscles of the carcass, that tenderness differences occur among some of the major muscles of different breed-types of cattle, and that numerous chemical, histological and/or carcass traits interact, resulting in the breed-type and TOF differences.
McKeith, Floyd Kenneth (1982). Tenderness comparisons of muscles among three breed-types of cattle at differing times-on-feed. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -361664.