Management
Cow Disposition Affects Pregnancy Rate
By Glenn Selk, Oklahoma State University
Now we have another good
excuse to cull cows due to bad
temperament. Producers that
routinely breed cows artificially
realize that cows that are
unruly and nervous are less
likely to conceive to artificial
insemination. Presumably
the lowered conception rates
were because they have been
stressed as they are passed
through the working facilities
and restrained while being
synchronized and inseminated.
Elevated core body temperature
could be one reason that
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conception rates of agitated
cows after artificial insemination
are lowered. Now it seems
that, even in the serenity of
a natural breeding pasture,
cows with bad dispositions
are less likely to conceive
when mated with bulls.
University of Florida animal
scientists recorded disposition
scores over two years on 160
Braford and 235 Brahman x
British crossbred cows. They
wanted to evaluate the effects
of cow temperament and
energy status on the probability
to become pregnant during a
90-day natural breeding season.
Cows were scored as 1= calm,
no movement to 5= violent
and continuous struggling
while in the working chute.
Also, a pen score assessment
was assigned as 1= unalarmed
and unexcited to 5 = very
excited and aggressive toward
technician. An exit velocity
speed score was measured as
the cows exited the working
chute as 1= slowest and 5 =
fastest. An overall temperament