Getting heifers bred can be difficult, especially if you don’t have facilities that allow you to easily lock them up for breeding. However, that doesn’t mean after one or two tries at artificial insemination you should just turn them over to the bull, says Joe Dalton, extension dairy specialist, University of Idaho. Here are six reasons why you should not use clean-up bulls with heifers.
1. Clean-up bulls do not deliver the genetic advancement that AI bulls can. In addition, issues such as calving ease are unknown with clean-up bulls.
2. First-lactation heifers represent the greatest potential contribution to your herd’s genetics.
3. Heifers that remain open after one or two insemination attempts are victims of chance. If you achieve a 55 percent conception rate in heifers, only 80 percent will be pregnant after two services.
4. When you add up the purchase price, feed, health cost and lost productivity in offspring, clean-up bulls cost more than you think.
5. Clean-up bulls can introduce venereal disease into your herd.
6. Bulls can be dangerous and unpredictable. That poses a risk to you and your employees.