Kris Ringwall, NDSU Extension Service, Published May 14 2012
Beef Talk: Don't take bull fertility for grantedLate May and early June are prime bull turnout times in the beef business, so the final check needs to be done now to make sure every bull is ready to go.
The beef business depends on buying fertile, productive bulls that pass on the desired genetics to their offspring and meet the consumers' demand for beef.
This spring, many producers have purchased a bull that is in the $3,000 to
$5,000 range. It's a good investment, but good investments need to be cared for and maintained properly. One of the keys to a successful breeding season is a bull that breeds cows. That seems like such a logical thought, but it is not.
There are three major considerations when evaluating bulls as the breeding season approaches. The first and the simplest is the breeding soundness exam. The exam tends to get the most publicity, and constant reminders are given to have the bulls fertility tested. These tests need to be done six to eight weeks prior to bull turnout because the bulls are expected to be producing viable sperm in advance of the breeding season.
If for some reason a bull fails the breeding soundness exam, the bull should be re-evaluated now. If he fails again, the bull needs to be culled. Keep in mind that many yearling bulls are fertility tested prior to selling and are screened adequately at sale time. However, if the opportunity presents itself, re- evaluating the new bulls when the older bulls are evaluated certainly does not compromise management.
Now the second point of consideration: Although often part of the breeding soundness exam, general bull thriftiness and structure need to be evaluated. A bull often may cover up a weakness when being worked with other bulls, so unsoundness may be overlooked. The back legs and hips are the working machines that allow a bull to breed. Any defect needs to be evaluated very critically. Once out on the pasture, the opportunity to evaluate adequately, along with the added difficulty of gathering the bulls, makes second decisions very difficult.
Bulls that have lost condition prior to bull turnout certainly are candidates for poor fertility. As with the cows, a condition score of 5 or 6 means the bull is in good breeding shape. However, losing condition prior to breeding is not advisable. Much like breeding soundness exams, bull nutrition needs to be correct two months before bull turnout because making changes prior to breeding is ill-advised.
The third important criterion is bull behavior, or aggressiveness and breeding desire. Some bulls may be too aggressive and even place the producer and ranch hands in the pecking order as they work to dominate all living things. Although certainly ready to be turned out, these bulls should be noted and politely excused when an opportunity comes to sell them.
It may be difficult, but it is true that calves from aggressive, hyperactive bulls are not desirable. Just as important, producers need to make sure the bull or bulls have a desire to mate. Not all bulls breed cows. Assuming such can bring long and disappointing looks as the cows are pregnancy-checked in the fall. Although there is no quick check, keeping an eye on all the bulls prior to and after turnout is critical. Make sure every bull is breeding cows. That is not an easy task, but it needs to be done.
The consequence is open cows, so check and recheck your cows and bulls. Ask
yourself: "In the last seven days, how many times did I check the cows and how many times did I check the bulls?"
Once calving is complete, cows should be cycling. In fact, a quick check of the cows can be made by remembering that the average estrous cycle of a cow is 21 days. If all the cows are cycling, about 5 percent should be expressing "heat" each day (one day divided by 21 days). Assuming a herd of 100 cows, an average of five cows should be in heat or estrus on any given day.
I realize that not all the cows calve the first 21 days of the calving season. In fact, only 63 percent of the cows calve the first 21 days of the calving season. However, it is not unreasonable to expect at least one cow should be in heat every day early in the breeding season, even if a producer only exposes a mature bull to 30 cows.
If calf gain is 2.5 pounds per day while nursing, every time a bull misses a cow in heat, it costs the producer more than 50 pounds of calf. Most producers do not argue the value of the bull, but the magnitude of that value often is underestimated.
Evaluate the bulls now to make sure the starting lineup is ready. It also never hurts to look at the bull bench to make sure you have some depth on the team.
May you find all your ear tags.
Your comments are always welcome at http://www.BeefTalk.com.
Ringwall is a North Dakota State University Extension Service livestock specialist and the Dickinson Research Extension Center director.