Before 6 mo of gestation, there
were no significant differences in half-carcass weight and
leg weight between Holstein Friesian and Belgian Blue, but
fetuses from Belgian Blue had the significantly greatest
half-carcass weight and leg weight among all investigated
breeds at 9 mo of gestation. This result suggests that muscle
tissue grew more rapidly in Belgian Blue than in the other
breeds after 6 mo of gestation.
Our results support the findings of Reynolds et al.
(1990), who reported that calves from large framed sire
breeds had heavier BW at 6.5 mo of gestation and at birth
than calves from medium-sized sire breeds. Also Ferrel
(1991) showed that fetal weight of Brahman cattle at 7.7 mo
was significantly smaller than Charolais. In contrast, Gore
et al. (1994) reported that the BW of Angus and Chianina
were not significantly different at 3.3 and 6.7 mo of
gestation, and 1 mo after birth. In our study, cattle breeds
with different postnatal growth impetus and muscularity
had significant differences in body traits as early as 3 mo of
gestation, and these differences were maintained at birth