The results of the present study show breed differences
in body weight, organ, muscle, and body fat weight in the
second and third trimester of gestating cattle. Obviously, the
greatest increase in all tissues and organs occurred in the
third trimester. The weight to body weight ratios for organs
decreased, while these of body fat increased continuously
from 3 to 9 mo of gestation. Muscle weight to body weight
ratios increased in the second trimester and remained
constant during the third trimester. Cattle breeds with
postnatal different growth impetus and muscularity show
differences in fetal development, especially in muscle tissue
deposition and development. Fetuses from large framed
breeds had greater birth weights, which originated from
greater muscle development already at 3 mo of gestation.