So, if we assume that the average weaning weight of calves from the sub-fertile bull is 500 lbs., rather than the 525-lb. weaning weight of calves from the fertile bull, then we would have 25 lbs./head fewer to market. If that 500-lb. calf brought $200/cwt., then each calf would be worth $1,000. A total of 24 calves worth $1,000/head results in total revenue of $24,000. Meanwhile, 27 calves worth $1,018.50/head results in total revenue of $27,499.50. Thus, the fertile bull returned nearly $3,500 more than the sub-fertile bull.
In addition, the use of a sub-fertile bull could result in a much lower calf crop percentage than used in this example, which would cost a producer even more. So the question is: "can a producer afford not to have a BSE performed on the bull?"
The economic benefits associated with the decision to have the bull tested before the start of the breeding season seems to be fairly straightforward for producers with a defined breeding season. But how do producers with a continuous breeding season evaluate this decision? The answer is to transition the herd to a defined breeding and calving season.
Many factors can influence a bull's ability to breed, and it can be difficult to keep an eye on the bull for 365 days/year. When the cows are exposed to the bull year-round, it becomes difficult to determine if the reproductive inefficiency is with the cow or if it’s with the bull. Producers can have the bull tested at a certain time every year, but his fertility may be impacted in some manner during the year, which renders him unable to settle cows.
Of course, producers would recognize this inability at some point. However, the producer with a continuous breeding season would have to determine if it’s the bull or the cow that has the reproductive inefficiency. An inefficiency associated with a bull would likely be recognized more quickly in a herd with a defined breeding season.
Thus, the moral of the story is to have a BSE performed on all bulls before every breeding season, and work to establish a defined breeding season if one is not currently in place.
Andrew P. Griffith is an assistant professor in the University of Tennessee’s Department of Agricultural and Resource Economics.