It is common practice this time of year to evaluate cows to make culling decisions, but this is also a good time to evaluate bulls to determine which sires will be fed through the winter and which have come to the end of their genetic contribution to the operation.
Like cows, bulls can live 10 to 12 years. Most bulls will remain active in the herd for closer to four or five years before they experience feet and leg, structural, and fertility problems; temperament concerns; or injuries. The decision to cull bulls often happens in the spring after the animal fails a breeding soundness exam. However, producers can save input costs by culling bulls in the fall if they or their offspring have any undesirable characteristics that would make them unsuitable for the next breeding season. Six months’ worth of decent quality hay for a mature bull will cost about $600, based on current prices.
Most mature breeding bulls can maintain condition with the same winter management as the cow herd. However, since mature bulls tend to weigh more than the average cow, you can expect their per-head dry matter intake to be more, as well. If we assume a bull will consume roughly 2% of its body weight in dry matter per day and that a mature bull weighs about 1,800 pounds, it will consume about 36 pounds of dry matter daily for the nine months that it is not actively breeding cows. If you know a bull has a problem, cull it sooner rather than later, instead of sinking more input costs into it.
Attitude problems and feet and leg issues are two reasons why bulls should be culled sooner rather than later. If a bull is aggressive, it may be in the best interest of your operation and the safety of yourself, employees and other livestock to cull that animal. It is important to understand that docility is a heritable trait. As a bull matures and gains weight, it may develop feet and structural issues that limit its ability to effectively breed cows. It may be advantageous to cull those bulls now instead of waiting to see how they pull through the winter season.
Culling bulls with undesirable traits allows producers to invest in genetics that will improve the cow herd. The bull contributes to 90% of the gene pool, and has more of a genetic contribution to the herd in one year than a cow will have in her lifetime. There is a thought process among some producers that “the bull is paid for, and regardless of his issues, I am going to continue to use him.” The problem with this thinking is that every year the bull is allowed to contribute genetics to the herd, it is passing along negative traits as well. Buying a new bull has the potential to be more profitable if the new bull possesses the genetics to improve reproductive performance, growth rate or carcass traits, to name a few.
Culling bulls that have reached the end of their genetic contribution to the operation this fall not only has a positive impact on this year’s income, but also can lead to long-term profitability in the cow herd.
Cauffman is the Extension agriculture educator in Grant County, Wis. This column is provided by the University of Wisconsin Division of Extension Livestock Team.