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TheHorse.com THE HORSE December 2017
B
reeding stallions are sensitive guys. Anything from ambient
temperature to body weight can affect their semen quality. In
this article, we'll describe those factors and 12 more that can
impact fertility. Three veterinarians well-versed in stud health
will help: Edward Squires, PhD, Dipl. ACT (Hon), adjunct professor
in the University of Kentucky's Department of Veterinary Sciences;
Dickson Varner, DVM, MS, Dipl. ACT, professor and Pin Oak Stud
Chair of Stallion Reproductive Studies at Texas A&M; University's
College of Veterinary Medicine and Biomedical Sciences; and Peter
Sheerin, DVM, Dipl. ACT, owner of Nandi Veterinary Associates, in
New Freedom, Pennsylvania.
MERRI
MELDE
HEATHER SMITH THOMAS
Factors that can affect your stallion's fertility
Subpar
Semen?
14
1
Breed Differences
"There is a lot of anecdotal evi-
dence that certain breeds of horses have
more fertility problems, in both the mares
and stallions," says Squires. Draft horses
and Friesians, for instance, tend to have
poorer quality semen than most other
breeds. Friesian semen, in particular,
doesn't cool or freeze as well, he says.
"There's likely a genetic component to
that, which may include inbreeding in a
breed with low numbers," says Varner.
"The lesser-known breeds with less popu-
lation dynamics may have some subfertile
sires that transfer their reduced fertility to
their get. Some of these breed variations