breeding season, cidr, beef cows, conceiving early
Cows that conceive earlier in the breeding season wean calves that are older and heavier at weaning. Therefore, the objective of this study was to determine the ability of a CIDR to increase the proportion of cows that conceived early during a natural service breeding season. Two hundred twenty-two postpartum beef cows were allotted to one of two treatments: 1) cows were treated with a CIDR for 7 days before bulls were introduced (n = 100), 2) cows were not treated and served as a control (n = 122). Seven days before bulls were introduced to the herd CIDRs were inserted into the CIDR treated cows, and were removed the day bulls were placed with the herd. The percentage of CIDR treated cows that conceived during the first 14 days of the breeding season tended (P = 0.08) to be greater compared to the control group. Beginning on day 21 of the breeding season a similar (P > 0.35) percentage of CIDR treated and control cows had conceived. In summary, a CIDR alone tended to increase the proportion of cows that conceived during the first 14 days of the breeding season.
Number of Pages
South Dakota State University
Copyright © 2005 South Dakota State University
Perry, George A., "Effect of Using CIDRs for Seven Days Before the Introduction of Bulls on the Proportion of Cows Conceiving Early in the Breeding Season" (2005). South Dakota Beef Report, 2005. 26.