Management
“Preg” Check and Cull Replacement Heifers Early
By Glenn Selk, Oklahoma State University
Many ranchers choose to breed
the replacement heifers about
a month ahead of the mature
cows in the herd. In addition,
they like to use a shortened 45
to 60-day breeding season for
the replacement heifers. The
next logical step is to determine
which of these heifers failed to
conceive in their first breeding
season. This is more important
today than ever before.
As the bulls are being removed
from the replacement heifers,
this would be an ideal time to
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call and make arrangements
with your local veterinarian to
have those heifers evaluated
for pregnancy in about
60 days. In two months,
experienced palpaters should
have no difficulty identifying
which heifers are pregnant
and which heifers are not
pregnant (open). Those heifers
that are determined to be
“open” after this breeding
season, should be strong
candidates for culling. Culling
these heifers immediately
after pregnancy checking
serves three very economically
valuable purposes.
1. Identifying and culling
open heifers early will remove
sub-fertile females from the
herd. Lifetime cow studies
from Montana indicated that
properly developed heifers
that were exposed to fertile
bulls, but did not become
pregnant were often sub-fertile
compared to the heifers that
did conceive. In fact, when the
heifers that failed to breed in
the first breeding season were
followed throughout their