beef cow, weaning date, nutrition, reproduction
Records from 92 mature crossbred cows calving in March and April were used to determine the effect of weaning calves 40 days earlier than the traditional weaning time on cow weight change, body condition, and reproductive performance. When calves were weaned early (September 14 versus October 231, their dams gained more weight from September 14 to early December and had higher body condition scores in December than the dams of later weaned calves. The two nutritional treaments imposed after calving were important in explaining the effects of earlier weaning on cow reproductive performance. For cows that were fed grass hay at 75% of NRC energy requirements in drylot after calving, the advantage of higher weight change and body condition scores from early weaning persisted until the following May. This resulted in a higher percentage conceiving during the first 21 days of the breeding season. For cows on Moderate postcalving nutrition, the advantages of weaning early on weight change and body condition were gone by early May, resulting in no difference in reproductive performance. For spring calving cows with access to abundant forage for at least 30 days prior to the breeding season to compensate for undernutrition during the winter, weaning calves earlier than the traditional weaning time may only be beneficial to reproductive performance when winter nutrition is severely limited.
Number of Pages
South Dakota State University
Copyright © 1994 South Dakota State University.
Pruitt, R. J. and Momont, P. A., "Effect of Weaning Date on Performance of Beef Cows" (1994). South Dakota Beef Report, 1994. 12.