To evaluate the combined effects of time on
feed and diet energy density on the palatability
of beef longissimus muscle steaks, we randomly
allotted 112 Angus yearling steers to 14 nutritional
regimens (eight steers per treatment):
control group (C), submaintenance group (S)
and 12 groups fed either a low (L), medium (M)
or high (H) energy density diet (.771, .992 or
1.28 Meal NEp/kg, respectively) and slaughtered
after 56, 91, 119, 147 (M and H groups only)
or 175 (H group only) days on feed. Taste
panel evaluations, lnstron textural assessments
and sarcomere length measurements were
conducted on longissimus muscle samples
collected 7 days postmortem. Taste panel
muscle fiber tenderness, overall tenderness,
juiciness and flavor intensity scores were not
influenced (P>.05) by nutritional regimen.
Connective tissue was most detectable in steaks
from the S group, but the amount was similar
(P>.05) to that detected in the C, L-56 and
H-147 groups' steaks. In general, steaks from
cattle fed L diets for 91 or more days or M or H
diets for 56 or more days had the least amount
of detectable connective tissue. Values for peak
force and peak force minus initial-yield force
were affected (P<.05) by nutritional regimen;
however, there was no consistent pattern for
these variables. Steaks from cattle in the S
group had the shortest longissimus muscle
sarcomere lengths (1.73/am). C group sarcomere
lengths were shorter than those of all L, M and
H diet groups except M-56, but these differences
did not affect measurements of muscle fiber
tenderness.
