Mj. Garber et al., DOSE-RESPONSE EFFECTS OF VITAMIN-E SUPPLEMENTATION ON GROWTH-PERFORMANCE AND MEAT CHARACTERISTICS IN BEEF AND DAIRY STEERS, Canadian journal of animal science, 76(1), 1996, pp. 63-72
This study examined dose-response effects of supplemental dietary dl-a
lpha-tocopheryl acetate (VE) on growth performance, immune response, a
nd carcass and meat sensory characteristics in two breeds of cattle. S
eventy-five crossbred beef steers (361 +/- 22 kg) were blocked by weig
ht, randomly assigned to one of five treatment groups, and fed a ratio
n supplemented with 0, 250, 500, 1000 or 2000 IU VE steer(-1) d(-1). S
ixty Holstein steers (366 +/- 22 kg)were similarly blocked and allocat
ed (no 250 IU treatment). Four days post-slaughter the left sirloin su
bprimal of each steer was removed and vacuum packaged. On day 13, smal
l cores were cut from the gluteus medius (GM) and packaged with O-2-pe
rmeable wrap; these were then displayed under 45-W natural white light
for up to 10 d at 4 degrees C. Serum alpha-tocopherol increased (P <
0.0001) with increasing VE in both breeds, although more so (P < 0.000
1) in beef steers. The GM alpha-tocopherol levels increased linearly (
P < 0.0001) with increasing VE, but more so (P < 0.0002) in beef steer
s. The levels of alpha-tocopherol in semimembranosus muscle, perirenal
and subcutaneous fat, and liver also increased linearly (P < 0.0001)
in both breeds. Growth performance of all steers and carcass character
istics of beef steers were not affected (P > 0.10) by VE. Dairy steers
receiving 1000 IU d(-1) had darker (P < 0.03) ribeyes. There were no
effects (P > 0.10) of VE on sensory attributes of frozen streaks. Surf
ace metmyoglobin formation was deterred by VE supplementation in meat
from beef (linear, P < 0.016) but not dairy (P > 0.10) steers. Lipid o
xidation was suppressed (linear, P < 0.0002) by VE but more so (P < 0.
0001) in beef than in dairy meat (72.9% vs. 40.0% suppression, respect
ively, at 2000 IU d(-1)). Immune response increased (P < 0.074) at hig
her levels of VE. In summary, VE supplementation improved immune respo
nse and increased serum and muscle alpha-tocopherol levels, resulting
in delayed metmyoglobin formation (beef) and lipid oxidation (beef and
dairy) in a dose-dependent manner. Supplemental VE was more effective
in meat from beef steers than in that from dairy steers.