Management
Preg Check
and Cull Open
Replacement
Heifers
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
30 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.
The bulls were removed from the
replacement heifers about 60 days ago,
therefore, this would be an ideal time
to call and make arrangements with
your local large animal veterinarian
to have those heifers evaluated for
pregnancy. After two months of
gestation, 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
14 | OCTOBER 2018