Comparison on the growth characteristics between calves of two different Japanese beef breeds suckled by Japanese shorthorn dams

Abstract

The growth characteristics of five male Japanese black calves that were produced by embryo transfer to, born from, and nursed by Japanese Shorthorn surrogate dams (BS-group) were compared with those of five male Japanese Shorthorn calves that were delivered from dams of the same breed after natural mating (SS-group). The birth weights of the BS-group calves were lower (P < 0.01) than those of the SS-group calves. During the first two months, the daily weight gain of the SS-group calves was greater (P < 0.05) than that of the BS-group calves. However, between the third and fourth months, the daily weight gain of the BS-group calves was greater (P > 0.05). During the first two months, the chest girth was smaller (P< 0.05) in the BS-group calves than in the SS-group calves, but was similar in both groups by the age of four months.