Management
pregnancy. Fertilized embryos of
superovulated donor cows will
be removed and transferred in
the first seven to eight days after
insemination and no chance of
freemartinism will occur in the
normal embryo transfer process. “freemartins” are often difficult
to identify if replacement heifers
are purchased. Therefore, this
is another good reason to
cull any open (non-pregnant)
replacement heifer soon after
her first breeding season.
In some cases, there are few, if
any, symptoms of freemartinism
because the male twin may
have been aborted at an earlier
stage of gestation. Hidden Another hidden cost of multiple
births will be manifest in the
mother of the calves. Cows
that are nursing twin calves
will require an estimated 13%
34 | APRIL 2019
more energy intake to maintain
body condition. The additional
suckling pressure on the cow
will extend the post-calving
anestrus period. Therefore,
cows nursing twins will take
longer to re-cycle to rebreed
for next year’s calf crop. In some
cases, producers may want to
consider early weaning of the
twin calves to allow the cow to
re-cycle in time to stay with the
other cows in the herd. I