Managing Bulls after the Breeding Season
Over the course of the breeding season, bulls can lose between 100 and
200 lbs. of weight. To achieve a tight calving pattern that will deliver
both a uniform crop of calves and a calf per cow per year requires a breeding
season of around 63 days. This means that for a mature bull running with
36 or more cows at any one time, there is little time available for feeding
and resting during this intensely active period. It's completely understandable
that after this level of exertion that post breeding recovery can take
between 4 and 8 months. A good recovery period is essential for bulls
to be fit and ready for next year's breeding season. Post breeding recovery
is important for all ages of bulls but special attention to this recovery
should be given to young bulls that are still growing (i.e. those less
than 36 months).
Mature bulls that are in good condition at the end of the breeding season
will easily recover any weight lost through access to good quality grazing
followed by good quality winter forage (i.e. hay) without the need for
grains or other supplementary feeding. Target hay quality of around 8%
to 10% crude protein. The aim is to get bulls into ideal body condition
score, i.e. 2.5 to 3, for the start of the breeding season but not fat.
Over-conditioned bulls at the start of the breeding season will have low
sperm counts and display lower breeding activity than a bull in ideal
condition. Bulls that are thin at the end of the breeding season may need
some supplementary grains to help with weight recovery - the amount of
grains will depend on the nutritional quality of grazing and other forages
available after the breeding season.
Young bulls are still growing so they need access to good quality grazing
after the breeding season. Grain supplementation may or may not be needed
depending on the quality and quantity of high-quality pasture available.
Body condition scoring and feed testing is important prior to the start
of the winterfeeding period. From those results a winter-feeding program
can be formulated so that the young bull can gain 1½ to 2 pounds
per day depending on the magnitude of weight loss during the breeding
season. Winter diets should target around 10 - 12% crude protein level.
Producers who run two calving seasons (spring and fall) often are in
the situation of double using their bulls. In this situation bulls must
recover their body condition in the short time between breeding seasons.
In these situations, its important producers plan for the post breeding
management of their bulls and ensure both high quality pasture and supplementary
grains are available to get those bulls back into shape as quickly as
possible. Young bulls may not be the best choice for this type of system
as they would potentially have to gain over 2½ lbs. per day to
recover body condition between breeding seasons, depending on the weight
Where bulls are maintained in a coral or indoors post breeding, adequate
space should be provided to allow the bull to get exercise. Daily exercise
is necessary so that the bull has built up the stamina to put in the distance
required during the next breeding season. Simply placing water and feed
at opposite sides of the barn or coral will force the bull to walk between
stations, thereby getting the necessary daily exercise. Be careful when
putting multiple bulls together after the breeding season - introductions
should be done slowly to avoid fighting.
It's critically important for a successful breeding season that the performance
of breeding bulls is examined closely while they are with the cows. Pay
close attention to herd estrus behavior; note cows that are mated and
if they show estrus again approximately 21 to 45 days later. Identifying
and rectifying a situation where a bull that may be infertile or have
sub-clinical fertility is critical to ensuring a good breeding season.
Such a situation may require the replacement of the bull with another
bull or using timed AI to save the current year's breeding season and
to avoid issues with subsequent breeding seasons.
There are several factors that must be considered when making decisions
around culling a beef bull. The main reason beef bulls are culled is for
reproductive failure, which, unfortunately, is sometimes only recognized
when cows are scanned. This can have a significant negative impact on
next year's calf crop and a significant negative economic outcome from
reduced calf sales. It is therefore imperative that the breeding herd
is watched for breeding repeats to quickly prevent a subclinical bull
becoming a breeding disaster.
Other culling decisions relate to issues of age. As bulls age they become
less active and their breeding performance declines. Health issues is
another common culling criterion, particularly related to feet and legs,
which should be examined after the breeding season. If injuries have occurred,
these should be treated, and it should be determined if they will heal
adequately enough to enable the bull to perform well next year. Where
treatment is not likely to be successful, this should be determined early
so decisions around next year's bull can be contemplated. The movement
of older bulls move should also be observed to determine if arthritis
is becoming a problem.
Where beef cow culling practices revolve around retaining home produced
heifers, bulls will need to be culled to prevent inbreeding. This necessity
is less of a problem on farms that run multiple bulls, but good breeding
records must be maintained to prevent inbreeding.
Producers should also note the degree of dystocia (calving difficulty)
that can be attributed to an individual bull. In some cases, this may
not be obvious initially but over time as the cow herd changes as new
breeding females with different genetics enter the herd, dystocia may
become a problem. The primary cause of dystocia is fetal-maternal mismatch,
i.e. the calf being too big at the time of calving to be born easily.
Birth weight, which determines size, is strongly genetically determined
by the male line.
The temperament of bulls can change and an initial quiet bull may become
aggressive and dangerous over time. No matter how good the quality of
calves or the number of calves that a bull produces, an aggressive and
dangerous bull must always be culled from the herd, and the sooner the
Finally, producers should also consider the quality of calves being produced.
Although a lot of emphasis is placed on the capacity of the cow to breed
a good quality calf, it must be remembered that 50% of that quality comes
from the bull. Producers should carefully consider if the poor quality
of calf produced is a bull or cow factor. One of the ways to identify
this is to examine the quality of calves produced by that set of cows
bred to the bull. Where the overall quality is good, any poor-quality
calf is likely to be related to the genetics of the cow rather than the
bull. Where the vice versa though is true, the decision to cull will depend
primarily on economics, i.e. will a new bull increase the quality of calves
sufficiently to justify the cost of acquiring that new bull.
Once the breeding season ends, it's important to start getting breeding
bulls back in good shape. In most cases, access to good quality grazing
followed by good winter forage is all that is required. The end of the
breeding season is also a good time to think about the role the breeding
bull plays in the overall breeding program. Consideration should be given
to such factors as bull health, presence of daughters in the herd, bull
temperament, history of calving difficulty and calf quality when making
decisions around culling. Ideally, decisions around culling should be
made as early as possible once the breeding season is completed to allow
as much time as possible for research into and finding the ideal replacement.
Field, J. and Anderson, N. 1985. Beef
Breeding Season Management. OMAFRA Fact Sheet 85-054. Accessed July
Greiner, S. 2010. The Rules of Yearling Bull Management. BEEF Magazine. Accessed July 6th, 2020
Halfman, W., 2016. Bull Management 101 for Breeding Season Success. University of Wisconsin-Madison Beef Information Centre. Accessed July 3rd, 2020.
Rasby, R., 2012. Management of Young Bulls Before and After the Breeding Season, Cattle Production, University of Nebraska-Lincoln. Accessed, July 3rd 2020.
Selk, G. 2020. What to do with the Bull after the Breeding Season? Beef 2 Live. Accessed July 3rd, 2020.
For more information:
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|Author:||James Byrne, Beef Cattle Specialist, OMAFRA|
|Creation Date:||11 August, 2020|
|Last Reviewed:||11 August, 2020|