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Beef Cattle Yearling Bull Management
Have you considered marketing bulls as long yearlings instead of holding them to
two years of age and incurring additional development costs and risks. Because
of the additional development costs associated with holding younger bulls until
two years of age, there may be opportunities to offer yearling bulls with
desirable genetics for less cost than purchasing more mature bulls with similar
genetics.
However, special management considerations come into play when yearling bulls
are used as herd sires.
Proper post-weaning development of beef bulls is important for future
effectiveness as herd sires. Bulls should be separated and managed according to
age groups (weanling bull calves, yearling bulls, highly-fitted or gain-tested
bulls, 2-year old bulls, mature bulls). ~
Separating younger and older bulls can be particularly important in preventing
injuries.
Dividing bulls into management groups also allows the different nutritional
needs of the different groups to be better met.
Yearling bulls still have lots of growth and development ahead of them and
should be managed differently than older bulls.
As bulls mature, their nutritional requirements change. Younger bulls require
less quantity but higher quality diets.
For example, daily nutrient requirements for a 700 pound bull gaining two lbs.
per day are approximately 16 lbs. of dry matter intake with 11.4% crude protein
and 65% total digestible nutrients (TDN) on a dry matter basis, while a 1,500
pound bull gaining two lbs. per day needs approximately 34.5 lbs. of dry matter
intake with 6.1% crude protein and 63% TDN on a dry matter basis. While daily
dry matter intake generally increases with increasing body weight, a bull's
crude protein requirement declines as a percentage of dry matter intake with
advancing age and body size. Younger bulls require higher protein percentages
for the rapid lean muscle growth that is occurring during early development.
Increased physical activity of bulls during the breeding season can result in
body condition loss. Adequate bull body condition is important for effective
breeding performance.
Since it can often be difficult to supplement bulls separately from the
remainder of the breeding herd, bulls should be fed to go into the breeding
season in at least good body condition without being excessively fat. A body
condition score of 6, where 1=extremely thin and 9=obese, is a good goal for
bulls at the start of breeding.
Yearling bulls can lose significant amounts of weight during their first
breeding season. They must gain this weight back and continue to grow before the
next breeding season to remain effective herd sires.
It is important to observe growing bulls closely for changes in body condition.
Adjustments to bull feeding programs can then be made in a timely manner. A good
target is for a 2-year old bull to weigh approximately 75% of his expected
mature weight. For example, if a bull's expected mature weight is 2,000 lbs.
then he should weigh approximately 1,500 lbs. (2000 x .75 = 1,500) at two years
of age.
Bull power is another particularly important consideration when using yearling
bulls. The number of females a bull can effectively service depends upon bull
maturity, body condition, paddock size, fertility, libido, length of the
breeding season, and structural soundness. The number of females a young bull
can successfully cover during a breeding season is typically much less than that
of a mature bull. Cow-calf producers should limit the exposure of young bulls to
about 15 to 18 head of females in a controlled breeding season.
With many well developed yearling bulls with desirable genetics available, it is
important to consider the level of management needed for successful use of these
young bulls in herd breeding programs. Cow calf producers can then look at the
advantages of using young bulls in breeding programs and decide whether or not
yearling bulls are a good fit for their programs. No matter what the age of the
bull, well planned and implemented bull development and management practices are
worthwhile.
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