Twenty of 40 Angus bulls were implanted
(I) five times with 36 mg of Ralgro| at average
intervals of 106 d, beginning near birth. All
bulls and their dams were on bluestem pasture
initially and, at an average age of 320 d bulls
were fed a concentrate diet until they were
slaughtered, weighing either 454 or 499 kg. One
side of each carcass was electrically stimulated.
Average daily gain and feed efficiency of I
bulls improved 6.5 to 10.4% and 7.9 to 8.1%,
respectively, depending upon the end point
comparison with nonimplanted (NI) bulls. Implanted
bulls attained their slaughter weights 42
d sooner than did NI bulls. Implantation
decreased (P<.05) penis weight and length,
testicle weight, volume and density, but did not
affect (P>.05) seminal vesicle and pituitary
weights. Carcasses from I bulls had more
(P<.05) skeletal ossification and were fatter
than carcasses from NI bulls. Marbling scores,
quality grades and longissimus cooking losses
and juiciness scores were not affected (P>.05)
by implantation. Taste panel flavor intensity
and detectable connective tissue scores were
higher (P<.05) for steaks from I bulls than
from NI bulls. Longissimus steak tenderness
evaluations were higher (P<.05) for both I
slaughter groups than for the NI light-weight group and were higher (P<.05) for the I lightweight
group than for the NI heavy-weight
group. Longissimus tenderness tended (P = .11)
to be higher for steaks from the I heavy-weight
group than those from the NI heavy-weight
group. Electrical stimulation produced (P<.05)
a softer, coarser textured lean, but it did not
affect lean color, marbling or quality grade.
Steaks from electrically stimulated sides tended
to have higher (P = .09) myofibrillar tenderness
scores and lower (P = .06) flavor scores than
steaks from nonstimulated sides.
