Selk Compares Weaning Dates For Fall-Calving Cows

By Glenn Selk, Oklahoma State University Emeritus Extension Animal Scientist

Oklahoma State University animal scientists evaluated weaning dates of 158 Angus fall-calving cows over a 4 year period. Cows were allowed to nurse their calves for about 210 days (April Weaning) or 300 days (July-Wean). All cows calved in September or October and were weaned in mid-April (April-Wean) or mid-July (July-Wean). April-weaned young cows had greater re-breeding percentages (98.4% versus 89.3%) than July-weaned young cows. Young cows were defined as the two and three year old cows.

However, there was no advantage in the re-breeding performance of April-weaned mature cows compared to July-weaned mature cows (90.2% versus 96.7%).    Mature cows were defined as cows that were 4 years of age and older. April-weaned cows were heavier and fleshier at calving than July-weaned cows.

Calves weaned in July were 90 days older and 204 pounds heavier (642 lb versus 438 lb) when weaned than were the April-weaned calves. The April-weaned calves were allowed to graze native pasture after weaning and weighed 607 pounds in mid July.