Calf records on 621 West African Shorthorn (WASH) and 3 grades of Jersey x WASH crossbreds were analysed for the effects of the level of Jersey breeding and other factors on birth weight, 205-day weaning weight and average daily gain (ADG). Crossbred calves were significantly (P < 0.01) heavier at birth than purebred WASH and birth weights increased with increasing level of Jersey breeding. No significant differences were established for 205-day weaning weight, however ADG declined with increasing level of Jersey breeding suggesting possible problems of adaptation for calves of over 75% Jersey breeding. Age of dam effect was significant and linear (P < 0.0001) for birth weight and significant and quadratic (P < 0.01) for weaning weight and ADG, with values increasing from 3-year old dams to a peak in 7 year old dams.