Kl. Barkhouse et al., PREDICTION OF BREEDING VALUES FOR TENDERNESS OF MARKET ANIMALS FROM MEASUREMENTS ON BULLS, Journal of animal science, 74(11), 1996, pp. 2612-2621
Data were tenderness measures on steaks from 231 bulls (Group II) slau
ghtered after producing freezable semen and on 1,431 related steers an
d heifers (market animals, Group I) from Angus, Hereford, Pinzgauer, B
rahman, and Sahiwal crosses from the Germ Plasm Evaluation project at
the U.S. Meat Animal Research Center. Tenderness was assessed through
Warner-Bratzler Shear Force (SF), taste panel tenderness (TPT), marbli
ng score (MS), and myofibrillar fragmentation index (MFI). For all tra
its, as fraction Bos indicus inheritance increased, implied tenderness
decreased. Heritability estimates were generally not significantly di
fferent from zero. Genetic correlations generally indicated favorable
associations among the traits. The range in predicted breeding values
of bulls for market animal tenderness was small and from -.34 to .32 k
g for market animal shear force. Because of low estimates of heritabil
ity for SF or TPT, results from this experiment indicate that selectio
n based on tenderness of steaks sampled from intact or late castrate m
ales slaughtered following collection of freezable quality semen would
not be very effective in improving average tenderness of steaks from
steers or heifer progeny. If a mean of heritability estimates reported
in the literature of .27 for shear value was assumed for market steer
and heifer progeny instead of .02 as found in the present study, then
selection based on estimates of shear force in young bulls would be r
elatively more effective in improving shear force of market progeny.