Winter bull management

Reconditioning bulls to ensure a success breeding season is critical to beef herd performance. Lance Kennington, an animal nutrition specialist with CHS, shares tips for winter bull management.

“Bulls that are too thin or too fat have a tough time breeding cows,” Kennington says. “The ideal body condition score at breeding time is six, although five is acceptable. This will ensure they will be able to pass a breeding soundness exam and have enough energy to last through the breeding season.”

Conditioning considerations

After being out on pasture for the summer, many bulls enter fall and winter with too little condition and poorly prepared to handle the strenuous breeding season. But bulls that are overconditioned – with body condition score is greater than six – may have reduced ability to keep up with cows.

“If bulls are overconditioned, cut back their energy intake by reducing the amount of concentrate being fed,” Kennington explains. “Remember to maintain the levels of the other nutrients in the diets. They’ll still need the same amount of protein, minerals and vitamins as before.”

Kennington adds cold weather management for bulls requires extra protection from the wind to keep them healthy and to avoid frostbite.

Nutrition strategies

Kennington recommends the following steps when developing a nutrition program for bulls.

1. Ensure good quality forage. Make sure forages are free of mold. Mold can produce microtoxins that interfere with reproductive health.
2. Formulate diets to meet bulls’ needs. Make sure nutrition plans include the proper energy, protein, vitamin and mineral requirements. All these nutrients must be present at the required amounts to ensure successful breeding.
3. Provide clean water. Sulfates or other harmful minerals can cause problems with bull development.
4. Limit starch intake. Use high-quality forages and highly digestible fiber sources like corn coproducts, wheat middlings and soy hulls to limit starch in bull diets. Starch can cause acidosis in the rumen, leading to bloat and damaging feet.
5. Feed flax oil. Research has shown that feeding flax oil through supplements such as FlaxLic^® tubs or Payback^® Power Booster Bull Challenger^® can improve semen quality and improve reproductive rates. Begin feeding flax oil at least 60 days before the breeding soundness exam, since sperm cells take 60 days to reach maturity.
6. Tailor diets to age. Young bulls are still growing and adding muscle and bone, so they need more energy and protein in their diets than mature bulls. He recommends separating bulls into groups so they can be fed according to the group’s needs.