Laster et al. (1976) reported weights of heifers (550
d) from Cycle I. Their ranking of breed groups was
similar, but the magnitudes of the differences were less
than in the present study, as was expected from weights
at an earlier age. The only important differences in the
two studies were for heifers with Limousin sires, which
had weights that were almost the same (−1 kg) as thosefor HA females, and for heifers from Simmental sires
that were slightly (5 kg) heavier than the F1 females
from Charolais sires. Gregory et al. (1992; 1995) reported
weights of purebred and crossbred cows from
the GPU program. In their analyses, mean weights of
purebred cows from 2 to 7+ yr of age were greater than
those in the present study, which ranged from 428 to
579 kg (Hereford) and 423 to 557 kg (Angus). Hereford
cows were heavier than Angus cows at each age, as was
the case in this study, and the differences, ranging from
5 (2 yr) to 22 kg (7+ yr), were not statistically significant
(P > 0.05).
Table