PREWEANING PERFORMANCE OF CALVES FROM FIRST-CROSS AND RECIPROCAL BACKCROSS COWS

Abstract

Preweaning performance was evaluated for calves out of first-cross and reciprocal back-cross cows maintained under two contrasting environments. All cows were bred to Limousin bulls and the calves were born between 1982 and 1986, inclusive, at Brandon, Manitoba (semi-intensive management) and Manyberries, Alberta (extensive range management). Dam cross comparisons revealed that calves out of Hereford × Angus dams were inferior to calves out of European continental × British dams for all preweaning traits at both locations. Comparisons between calves out of F1 dams and calves out of backcross (1/4 or 3/4 European continental) dams generally favored the calves out of F1 females. Specific and nonspecific comparisons between the reciprocal backcrosses demonstrated that calves out of dams with 3/4 European continental breeding were heavier and grew faster than calves out of dams with 1/4 European continental breeding. Male calves exceeded female calves for all preweaning traits and calves born at Manyberries were heavier and grew faster than calves born at Brandon. Key words: Beef cattle, preweaning growth, crossbreeding, backcrosses