Sixty-four 8-too-old steers, produced from 7/8 Simrnental sires mated to crossbred dams,
averaged 265 kg initial weight. Forty-eight steers were assigned to an Accelerated (ACC) production
system, while 16 steers were assigned to a Conventional (CONV) production system. Steers on the
ACC system were fed an 85% concentrate diet; steers on the CONV system were backgrounded for
110 d on a high silage diet and then finished on an 85% concentrate diet. The ACC steers were
slaughtered in three groups at average weights of 438, 492 and 554 kg; CONV steers were slaughtered
at 591 kg. Days-on-feed were 139 (ACC-I), 174 (ACC-II), 2,0,.2 (ACC-III) and 284 (CONV),
respectively. At slaughter, one side of the carcass was pulse-electrically stimulated (ES) with 400 V
at 45 min postmortem and the other side served as a nonelectrically stimulated control (C). Semimembranosus
(SM) and longissimus (LD) C and ES steaks were removed at 48 and 24 h postmortem,
respectively, vacuum packaged, aged 6 d at 2 C, frozen and later thawed for trained
sensory panel and Warner-Bratzler shear (WBS) evaluations. Overall average daily gains were not
different among slaughter groups, but CONV steers gained faster (P<.05) during the finishing phase
than ACC steers. Metabolizable energy:gain ratios were not different among treatments, but dry
matter:gain ratios were higher (P<.05) for CONV steers than for ACC-I and ACC-II steers. The
CONV steers had lower (P<.05) dressing percentages than ACC-II and ACC-III steers. Lipid of the
9-10-11th rib section was higher (P<.05) and protein and water were lower (P<.05) for ACC-III
than for ACC-I and ACC-II steers, but not different (P>.O5) from CONV steers. Electrical stimulation
decreased (P<.05) 2-, 4- and 6-h pH readings. The LD steaks from ACC-II and ACC-III steers
were at least equal in all sensory traits, except juiciness, to those from CONV steers. The SM steaks
from CONV steers had the highest WBS force and lowest sensory scores. Electrical stimulation
decreased (P<.0$) LD myofibrillar and overall tenderness scores, but had no effect on SM palatability.
