By Dan Larson
Last month, I discussed the minimum nutritional needs for bull development. Most often, the concern however, is purchasing overfed bulls that "melt" on pasture. The same bull customers who complain about fat bulls, however, will generally pay more for a highly conditioned, well-muscled bull. So, how do we reconcile these conflicting demands?
We do it by creating a bull development system that allows adequate gain testing and development up to sale day, with a period of hardening prior to breeding. Gain testing is most economical between weaning and 10 to 12 months of age. Conveniently, this is also prior to most production sales and leaves enough time to harden prior to turnout.
The biggest challenges in gain testing and bull development are acidosis, the resulting founder and fat-insulated testicles. Acidosis can be prevented by using high-fiber feedstuffs, such as distillers’ grains or gluten feed, and by accurate feedbunk management. Bulls that experience even one bout of acidosis in their lifetime will experience more foot and leg problems for the rest of their life.
Roughage is essential in managing rumen health. Forage-free diets, while minimally adequate for finishing cattle, are not appropriate for developing bulls. Using Rumensin or Bovatec will help manage acidosis and bloat, as well as improve feed efficiency.
Fed right to perform. Regardless of how you choose to develop bulls, reducing body fat will improve semen quality and longevity. Research shows that reducing bull weight from May to June increased the percentage of motile sperm and normal sperm and reduced aged acrosomes, which improved sperm viability (Pruitt and Corah, 1985).
The caveat is that fatter bulls have a larger scrotal circumference—but how much of that increase is fat? A 60-day period of feeding a high-roughage diet will improve serving capacity and reduce the chance that a young bull will fall apart during his first breeding season. It is critical to maintain adequate vitamin and trace mineral nutrition prior to breeding in order to ensure high-quality sperm and breeding capability.
Perhaps the most neglected animal on the farm is a bull after the breeding season. It is all too easy to put a bull out of sight and out of mind. As seedstock producers, we have limited influence on how bulls are managed during and after breeding. Work with your customers to ensure that
young bulls are fed to gain after breeding in order to improve their longevity. This will ultimately create return customers.
Bulls do not reach maturity until three years of age or older and require slightly enhanced nutrition to prepare for the next breeding season. For example, 3 lb. to 5 lb. of dry distillers’ grain per day with moderate-quality hay will allow the young bull to regain condition and continue to grow. In cold climates, remember to provide adequate bedding to avoid frozen testicles. Allow plenty of exercise to keep bulls athletic and ready to breed.
It is essential to have a professional attitude toward bull development. Know your clientele and their needs to create a system that ensures your bulls work for them. Work with your nutritionist to develop a well designed program—it can become an integral part of your marketing strategy.
Dan Larson is a ruminant nutritionist at Great Plains Livestock Consulting, Inc. His experience in both cow–calf and feedlot cattle operations offers a unique perspective on the beef industry.
- November 2011