Page 22 - MWC 8-25-2022s

PREPARING BULLS the breeding season. A variety The Midwest Cattleman · August 25, 2022 · P22
continued from page 7 of factors including nutrition, Examination of the
Research indicates bulls that injury, exposure to extreme reproductive system
exercise daily have higher li- heat or cold and infections includes palpation of
bido and improved seminal can reduce bull fertility. In internal organs, in-
characteristics including a addition, many states require spection of the penis,
17% increase in semen vol- bulls to be tested for trichomo- measuring scrotal
ume. Exercise will also pre- niasis annually. States usual- circumference and
pare bulls to cover ground to ly have a deadline for annual semen evaluation.
find cows in estrus without trich testing. Be sure to know Semen is evaluated
tiring. Forcing bulls to walk your state’s rules. Combining for concentration, mo-
daily may reveal individuals a breeding soundness exam tility, and presence
that have previously unno- with disease testing is a good of abnormal sperm.
ticed soundness issues. use of time and a veterinary To pass, semen must
call.
Breeding soundness exams Breeding soundness exams have greater than
Bull breeding soundness for bulls involve a physical 30% progressive mo-
exams eliminate bulls that evaluation, examination of re- tility and at least 70%
have a high probability of fail- productive organs and semen normal sperm.
ing to successfully impregnate evaluation. The physical exam Heat stress and
cows. Bulls need a breeding includes analyzing vision, feet cold stress
soundness exam every year and leg structure and mobili- Bull fertility can
approximately 30 days before ty. Bulls initially use sight to be greatly dimin-
locate cows ished by heat stress.
in heat by ob- Some damage due
serving cow to heat stress, such
to cow mount- as abnormal sperm
ing behavior. morphology, can be
Then they determined during a
travel to cows breeding soundness
and confirm exam. However, other
readiness to impairments (DNA
breed by smell damage, impaired acrosome scrotal frostbite, resulting in
and attempt- membrane) may not be detect- damage to testes and reduced
ed mounting. ed by standard exams. Heat fertility.
stress is one of the reasons Vaccinations
Annual Production Sale - 1st Saturday in March fewer bulls tested in July and Generally, bulls should be
August pass breeding sound-
ness exams (Figure 2). Bull on the same vaccination pro-
fertility is diminished for sev- gram as the cow herd. Con-
sult your veterinarian on a
Registered Simmental & eral weeks after heat stress; vaccination program for bulls.
therefore, it may take up to
two months for bulls to recov- Usually, bulls will be vaccinat-
er from heat stress. ed at the time of the breeding
SimAngus Bulls & Females when the temperature-humid- soundness exam. It is best to
Heat stress in cattle occurs
wait until bulls pass the exam
ity index (THI) exceeds 75 (see before vaccinating. Remem-
ber, vaccines may have a drug
Bred Heifers Figure 3). withdrawal time that must be
The extent of damage from
For Sale Private heat stress may be affect- followed before infertile bulls
can be marketed.
ed by wind speed and night
Recently, considerable re-
Treaty cooling. Providing shade or search and discussion has fo-
water misting can reduce
THIS FALL heat stress. While bulls used cused on the impact of vacci-
to breed fall-calving cows nating cows with modified-live
may not be experiencing heat vaccine (MLV) close to the
stress during the breeding breeding season. Unfortu-
season, ranchers should be nately, similar information for
aware of the carry-over effects bulls is limited. This would be
of heat stress on bull fertility. another good point to discuss
For this reason, it is important with your veterinarian.
to wait until close to the breed- Spending time and effort
ing season to conduct breeding preparing bulls for the breed-
soundness exams. ing season will pay off with
In Northern operations, more calves born early in the
calving season. Hopefully, fall
Keytesville, MO bulls servicing fall-calving will be temperate with plenty
cows may be breeding during
George Schupback - Keytesville, MO extremely cold weather. Ideal- of forage.
660.621.0121 ly, all animals should have ac-
George Schupback - 660.621.0121
Lane & Morgan Springer - cess to a windbreak and some
660.621.2651
Lane & Morgan Springer - 660.621.2651 bedding. January and Febru-
ary temperatures can result in