Normal growth and development up to one year of age of Sudanese cattle with special reference to the influence of Sex and sire

Abstract

Three years' data on a herd of Sudanese cattle were used to study the influence of sex and sire on their growth from birth to 1 year of age. The traits studied included body weights at birth, weaning and yearling ages, and body measurements at birth and weaning age. Analysis of variance indicated no significant sex by sire interactions. Male calves had significantly (P < 0-01) heavier birth, weaning and yearling weights and faster pre-weaning average daily gain than female calves. There were no statistically significant differences between sexes in post-weaning gain or body measurements. The sire effects were highly significant (P < 0-01) for birth and yearling weights and postweaning average daily gain, but not for weaning weight and pre-weaning average daily gain. Sire effects were also significant (P < 0-05) for height at withers and heart girth at birth and weaning age and for body length at weaning age. The heritability estimates of birth and yearling weights and post-weaning gain were relatively high, whereas the heritability estimates of weaning weight and pre-weaning gain were low. Heritability estimates of body measurements were also high.