However, if an effort is made to properly adapt and care for new bulls, that investment per calf sired can be reduced through improved bull longevity.
One aspect that impacts the bull’s first season, and lifetime success, is how they are managed once you take possession of them.
Communicate with the seller
Determine previous plane of nutrition
Every operation likely has a unique program for developing bulls. There is no reason to be critical of any type of development program, but it is important to note that bulls “tested” to achieve an average daily gain of 3.5 pounds or more will need to reduce energy intake.
This will require a transition to a ration balanced to meet the nutrient requirements of still-growing bulls.
Herd health
Bulls should be well vaccinated and treated for parasites prior to taking possession. They will require booster vaccinations on an annual basis for IBR, BVD, PI3 and BRSV (respiratory viruses).
They should also be vaccinated for reproductive diseases like vibriosis and leptospirosis prior to annual turnout. Purchasing virgin bulls eliminates the risk of bringing a sexually transmitted disease like trichomoniasis into the herd. Visit with your veterinarian for details specific to your herd.
Breeding soundness exam
Know the policy of your genetic provider regarding fertility testing. Bulls may be fertility-checked prior to the sale, following the sale by the breeder, or it may be your responsibility once you have the bull.
In any case, it is important to make sure your bull is fertile and sound at least 45 to 60 days prior to the breeding season. This will allow time for you to work with the breeder or another provider to get a suitable replacement should a problem arise.
Taking possession of bulls
Placing bulls on the operation
There are a few considerations to make when determining where your new bulls should go. First, and most typically, this decision can be limited by available space. Giving them enough room not only allows them to keep their distance from dominant bulls, but exercise is an important part of the “hardening” process in preparation for the breeding season.
Plans should be made to ensure bulls achieve a body condition score of 6 to complement both fertility and libido. If an individual bull is segregated, make sure other cattle are visible to him to reduce agitation and stress.
Nutritional adaptation
If you receive the bulls immediately off of test, it is critical we don’t turn them out on dormant forage with a group of bulls. Maintaining high levels of fertility requires that you meet the bull’s nutrient requirements for protein, energy, vitamins and trace minerals. Considering that, start by offering them about 70 percent of the concentrate they were previously on.
Working with your nutritionist, determine what ration would achieve a 2-pound average daily gain to accommodate the still-growing animal. Also consider a pre-breeding vitamin and trace mineral program like your cows are receiving through that period.
Turnout management
Observe yearling bulls
Even if your bulls are fertile, we must make sure they can complete the process. While managing yearling bulls’ nutrition and body condition will help with things like libido and activity among the cow herd, we must also make sure they have the physical ability to mount and breed the cow.
It is good to note what cows are being bred and observe again in 19 to 23 days to make sure she does not return to estrus.
Manage the breeding season
When you consider the activity level of yearling bulls and the declining forage quality available later in the grazing season, it is important we don’t allow them to get run down.
After a defined breeding season, it is in the bull’s best interest to remove him from the cows and place him where he can recover and re-condition for the next season.
Socialization
No matter what group of bulls are turned out, there will be some level of dominance established. One way to manage this is by running yearling and mature bulls separately. Mature bulls will obviously intimidate the young sires and hinder their interest in breeding.
Some producers will run mature bulls to start the season and replace them with younger bulls later on to manage the socialization and nutrition and allow young bulls to further mature.
Review
Bulls require a significant investment, and this should be matched by our effort to ensure their success. In review of the detailed points above, consider the following:
- Communicate with the breeder regarding the bulls’ most recent diet, herd health program and fertility tests.
- New yearling bulls should be given plenty of space to avoid mature bulls and to allow for exercise.
- Slowly reduce the energy intake of performance-tested yearling bulls to reduce gains to a 2-pound average daily gain and achieve a body condition score 6 at turnout.
- Observe your yearling bull for libido, activity, estrus detection and ability to breed cows.
- Manage the breeding season of yearling bulls to prevent them from becoming run down.
Management does not stop after the bull’s first season. We should continually be attentive to body condition, structure, foot integrity and health.
Bulls should be permitted the same attention the cow herd has regarding balanced nutrition and offering high-quality vitamin and trace mineral programs that improve fertility and immune function. The bottom line depends on it. 
PHOTO: Plans should be made to ensure bulls achieve a body condition score 6 to complement both fertility and libido. Staff photo.
Tyler Melroe is a beef nutritionist with Hubbard Feeds. Email Tyler Melroe.
