Genetic and Environmental Influences on Age at First Calving of the Kenya Sahiwal Cattle

Abstract

To increase the reproductive life of cattle, heifers should be raised properly so that they reach puberty and a safe calving size at an early age (Tanner et al., 1995). Early calvers may have an advantage in lifetime milk production and produce more calves than heifers that calve first at later age. The age at first calving of Bos indicus cattle is 38-48 months (Alim, 1960; Mahadevan and Marples, 1961; Bhat et al., 1978; Trail and Gregory, 1981; Mrodc and Akinokun, 1986). To reduce the interval from birth to first calving and minimise the rearing cost it is important to identify the genetic and environmental factors affecting age at first calving.