The BW, half-carcass, and leg weight showed a similar,
continuous growth in all 4 breeds from 3 to 9 mo of
gestation (Tables 2 and 3). The increase of body weight
from 6 to 9 mo is about 3-fold greater than the increase
from 3 to 6 mo. Previously, Prior and Laster (1979) reported
that the growth of normally developing cattle fetus follows
an exponential equation with a BW gain of 25 g/d up to 4
mo of gestation, and the maximal rate of BW gain of 352
g/d by 7.6 mo. The profound increases in fetal size and
weight occur during the third trimester in cattle (Ferell,
1991; Orourke et al., 1991). McPherson et al. (2004)
demonstrated that the growth of porcine fetuses and fetal
tissues occurs at different rates during the gestation. Porcine
fetus growth accelerates during late gestation. A similar
result is also shown in ovine fetal growth by Osgerby et al.
(2002).