Comparative weights of dairy calves at 4, 8, 12 and 16 weeks of ag at Moor Plantation, Ibadan, Nigeria

Abstract

SUMMARYIn a comparative study of some factors that influence the body weights of 36 Friesian, 54 Holstein, 22 Holstein-Friesian, 24 Jersey and 17 Brown Swiss calves born during 1964–9 at the Moor Plantation dairy herd, Ibadan, breeds differed significantly (P <0·01) at all ages. Highly significant sex differences (P <0·01) existed at 4 and 8 weeks of age. The season of birth significantly influenced the weight at 4 and 8 (P < 0·05) and at 12 weeks (P < 0·01). The season × sex and season × breed interactions significantly affected the weights at virtually all ages but the sex × breed interaction did not. The birth weight exerted a highly significant influence (P < 0·01) on all other body weights. It reduced the residual variation as well as the differences and interactions between the main effects. After adjusting for birth-weight differences, body weight was significantly (P < 0·05) influenced at various ages by breed of calf, season of birth, sex × breed and season × breed interactions. The sex and season × sex interaction effects on adjusted body weights at all ages were negligible (P > 0·05).