Bull Management For Yearling Bulls
Spring is most every cattle rancher's preferred or primary bull buying
season. If you are like most of us, right or wrong, the yearling bulls seem to fit in better.This always seems
to pose a need to learn the necessities of Bull Management For Yearling Bulls.
You will need to spend time studying
performance information, pedigrees and other pertinent information as sire selection is the most important
tool for making genetic progress in your herd. Of equal importance is the care and management of the newly
acquired bull. Proper management and nutrition are essential for the bull to perform satisfactorily during
the breeding season. With most new herd sires purchased as yearling bulls, management prior to, during,
and after the first breeding season is particularly important.
Management Prior to the Breeding Season
Many newly purchased yearling bulls will have been provided a high plane of nutrition. The energy level of
the diet should gradually be reduced to prevent excessive fat deposition. The reduction in energy may be
accomplished through restricting intake of high energy grain supplements, in conjunction with supplying a total
diet lower in energy content (primarily forage). Young bulls should be managed to be a body condition score 6 at
turn out. This will give the bull adequate reserves of energy for use during the breeding season.
Yearling bulls can be expected to lose 100 pounds or more during the course of the breeding season.
Acquiring a new yearling bull at least 60 to 90 days prior to the breeding season is critical from
several aspects. First, this leaves ample time for the new bull to get adjusted to the feed and environment
of his new home. Secondly, adequate exercise, in combination with a proper nutritional program, is essential
to “harden” him up prior to the breeding season. A facility for the newly acquired bull that allows for ample
exercise will help create bulls that are physically fit for the breeding season. The nutrition of the bull
will be dependent on body condition. Yearling bulls are still growing and developing, and should be targeted
to gain 2.0 to 2.5 pounds per day from a year of age through the breeding season. Bulls weighing
approximately 1200 pounds will consume 25 to 30 pounds of dry matter per day. This intake may consist of high
quality pasture plus 12 lbs corn, grass legume hay plus 12 lbs corn, or 80 lbs corn silage plus 2 lbs protein
supplement. Provide adequate clean water, and a complete mineral free choice.
Prior to the breeding season, all bulls should receive breeding soundness exams (BSE) to assure
fertility. All bulls that are to be used should have a BSE annually. Because a variety of factors may affect
bull fertility, it may be advisable to re-test young bulls before the breeding season even if it has only been a
few months since their pre sale BSE.
Management During the Breeding Season
The breeding season should be kept to a maximum of 60 days for young bulls. This will prevent over-use of the
bull, severe weight loss and reduced libido. Severe weight loss may impair future growth and development of
the young bull, and reduce his lifetime usefulness. When practical, supplementary feeding young bulls during
the breeding season will reduce excessive weight loss.
In single sire situations, young bulls can normally be expected to breed a number of females
approximately equal to their age in months. Using this rule of thumb, a newly purchased bull that is 18
months of age could be placed with 18 cows or heifers. Bulls used together in multiple sire breeding pastures
should be of similar age and size. Young bulls cannot compete with older bulls in the same breeding
pasture. A common practice is to rotate bulls among different breeding pastures every 21 to 28 days.
This practice decreases the breeding pressure on a single bull. Some producers use older bulls early in the
breeding season, and then replace them with young bulls. The appropriate bull to female ratio will vary from one
operation to the next based on bull age, condition, fertility, and libido, as well as size of the breeding pasture,
available forage supply, length of the breeding season and number of bulls with a group of cows.
All bulls should be observed closely to monitor their breeding behavior and libido to ensure they
are servicing and settling cows. Additionally, observe the cowherd to monitor their estrous cycles.
Many females coming back into heat may be the result of an infertile or subfertile bull. All bulls should be
monitored for injury or lameness that may compromise their breeding capability.
Management After the Breeding Season
Young bulls require a relatively high plane of nutrition following the breeding season to replenish body condition
and meet demands for continued growth. Yearling bulls should be maintained in a separate lot from mature
bulls, so these additional nutritional requirements can be provided. Body condition and projected mature size
of the bull will determine his nutrient requirements during the months following the breeding season and until next
breeding season. Bulls should be kept away from cows in an isolated facility or pasture after the breeding
season. In the winter months, provide cover from extreme weather that may cause frostbite to the scrotum
resulting in decreased fertility.
All herd bulls should receive breeding soundness exams (BSE) to assure fertility on an annual
basis. Assess the bull battery well in advance of the breeding season, so that new herd sires can be acquired
in a timely fashion.