Too many open cows?
Seth asks, “I had some pretty high percentages of open cows this fall. I am having a hard time narrowing down a cause. A neighbor told me that I had too much condition on my cows at breeding time, is that possible?”
ISU Extension beef program specialist Byron Leu says the answer isn’t a simple yes or no.
“Determining a cause for lower conception rates can be challenging because a number of factors, including cow body condition score (BCS), bull ‘power’, environmental factors, and health issues, can impact reproduction rates.
“Regarding BCS, the reproductive indicators are highest from BCS 5 to 7+. There is a slight decline in projected conception rate for BCS 8 cows. When evaluating your cow herd, it’s recommended to maintain the majority of the cow herd at BCS 5-6 to control feed costs while supporting animal performance.
“It’s a good idea to have Breeding Soundness Evaluation completed on your bull(s) before the breeding season to remove questionable breeders. Also make sure you have adequate bull power for your beef enterprise. As a general recommendation, a yearling bull should be turned out with approximately 15 cows, and a mature bull should breed 25 cows. Of course, this range varies greatly but check to ensure that you are not short from a bull power perspective.
“Your conception rate also can be impacted by stress or other factors including high temperatures or other weather extremes during peak breeding period, poor quality and/or low quantity of forage, high levels of endophyte infected fescue, and bull injury.
“Be sure to check with your veterinarian to make sure health issues are not part of the problem. For more specifics, feel free to contact your ISU Extension Beef Program Specialist. Find the specialist for your area here ISU Extension Beef Program Specialist Map.”