INFLUENCE OF BISON PERCENTAGE ON PRE- AND POSTWEANING TRAITS OF CATTALO CALVES

Abstract

Lower birth weights of cattalo calves (averaging 16.5% bison–83.5% domestic) from cattalo dams (averaging 24.0% bison–76.0% domestic) were associated with higher percentage bison of calf or dam. Calf losses at birth or shortly after birth were 13.9% of the total number of cattalo calves (749) born during 1951–1963. Among the dead calves, birth weights were lower by 1.00 and 0.45 kg for each unit increase in percentage of bison (kg/B-%) of the calf and the calf’s dam. Corresponding birth weights of calves surviving to weaning were lower by 0.34 and 0.20 kg/B-%. Average daily gain to weaning and weaning weight were not significantly affected by increases in percentage bison. Postweaning traits tended to be affected more by percentage bison of the calf’s dam than by percentage bison of the calf. Higher percentage bison of the dam significantly reduced final feedlot weight of calves born in 1958–1963 (b = −0.81 kg/B-%), liveweight before slaughter (b = −1.87 kg/B-%), and weight of left-rear quarter of calves born in 1963 (b = −0.26 kg/B-%). Percentage bison in the calf and calf’s dam significantly reduced 18-mo weight (b = −1.37 kg/B-% and b = −0.69 kg/B-%) of cattalo calves restricted to pasture.