Management of Young Bulls Before and After the Breeding Season
Yearling bulls should be in condition score 6 (1 = thin and emaciated; 9 = obese) before the start of the breeding season. This is usually not a problem as these bulls would be coming off of a growing/development ration.
Yearlings should be left with the cow herd for 60 days or less. Beyond that time their condition can fall off to such a degree that it could have long-range effects upon their growth.
After removal from the cow herd after the breeding season, yearlings should be kept separate from the older bulls if possible at least through their second winter. Yearlings need to be fed or grazed on a good quality forage or pasture.
For spring/summer breeding programs, this could be meadow regrowth or bromegrass pasture. Their supplemental feeding regime can be equated to the program for bred-yearling heifers. These bulls are growing rapidly, in addition to replacing the condition they lost during the breeding pasture.
Extra care and feed of yearling bulls after the breeding season should increase their longevity. These bulls should also have a Breeding Soundness Evaluation well before the start of the breeding season.
Get two-year-old bulls in condition or their working clothes well before the start of the breeding season. Start at least 100 days before the start of the breeding season to get these bulls in condition score 6. This may mean some grain or distillers may need to be fed to get them in condition. Starting early enough means that you will not need a lot of grain or distillers to get this accomplished.
Two-year-old bulls should have more of their mature size by breeding season as compared to yearling bulls. A 1,700 pound 2-year-old that is slightly under-conditioned will probably only need to gain 1 pound per day at this stage in his life. To do this, active bulls may need 40 pounds of feed or more on a dry matter basis, of which 5 to 7 pounds should be grain.
If body condition is well below the target, the amount of grain will need to be increased to near 0.5 to 1 pound or more per 100 pounds of body weight. Again, make any increases in grain intake gradually so that digestive disorders are unlikely.
The diet will need to be about 12% crude protein. Depending on the forage available this again may a require protein supplement.
Monitor the body condition of the bulls closely and make grain feeding adjustments to reach the body condition score of 6 before the next breeding season begins.
After this age of bull finishes the breeding season, good quality grass pasture should be adequate. Watch body condition and if they struggle to pick up condition by fall, they may need some supplement during the fall and winter.
These bulls should also have a Breeding Soundness Evaluation well before the start of the breeding season.
Dr. Rick Rasby
Professor of Animal Science
University of Nebraska–Lincoln