Management
Got Twin Calves? Make Sure you Write it Down
By Donald Stotts
Freemartin heifers, those
resulting from a twin birth
where the other calf is a bull,
have long been known to
be infertile. So, if you get
a set of twins this spring,
remember to write down twin
births of calves while they
are still nursing the cow.
Estimates of the percentage
of beef cattle births that
produce twins vary. One of
the more famous examples –
146 | JUNE/JULY 2018
reported in Hoard’s Dairyman
in 1993 – puts the percentage
at about 0.5% or one in every
227 births. Research indicates
approximately half of the
sets of twins should contain
both a bull and a heifer calf.
Cow-calf producers should
make certain they do not
retain the heifer born twin
to a bull as a replacement
female, warns Glenn Selk,
Oklahoma State University
Cooperative Extension
emeritus animal scientist.
“Freemartinism is recognized as
one of the most severe forms
of sexual abnormality among
cattle,” he says. “This condition
causes infertility in most of the
female cattle born twin to a
male. When a heifer twin shares
the uterus with a bull fetus,
they also share the placental