Beef Improvement Federation
Tips for Using
Sexed Semen
By Troy Smith
It’s a fairly common occurrence in the beef
industry: Application of a technology usually lags
well behind its research and development. So it
is with artificial insemination (AI). According to
South Dakota State University (SDSU) Reproductive
Physiologist George Perry, as AI technologies
continued to advance, adoption by the dairy
industry far outpaced that of beef producers.
That has been true for use of sexed semen, too.
However, things could change. Perry said as much
during the June 19 National Association of Animal
Breeders (NAAB) Symposium hosted in conjunction
with the 2019 Beef Improvement Federation
(BIF) Convention in Brookings, S.D. Perry said
economics favor serious consideration of AI, citing
a 60% increase in the average price of breeding
bulls, between 2009 and 2016, compared to a
23% increase in the price of frozen semen for AI.
Noting how bull prices have continued to
creep upward, Perry pondered, “How can
producers afford the bull power they need
for natural service, especially when they want
different bulls for heifers than for cows, and
different bulls to produce replacement females
than those used for a terminal cross?”
Perry said he expects more commercial cow-
calf producers to embrace AI, and many of
those may consider the use of sexed semen.
Sometimes called gender-sorted semen, this
technology allows the breeder to choose the
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gender of calves resulting from mating cows to
AI sires for which sexed semen is available.
Perry admitted that a challenge exists. Several
studies have reported 38% lower pregnancy
rates when using sexed semen, as compared to
AI with conventional semen. Best results have
occurred when insemination occurs after heat
detection. Accordingly, use of sexed semen for
timed AI often is discouraged since, at the time of
mass-insemination, not all synchronized females
will be fully expressing estrus. For these females,
sexed semen may not survive the wait between
insemination and ovulation. The reason is that
sorting sperm cells by gender involves extra
physical stress that can lessen sperm survivability.
Perry described a research study involving nearly
900 heifers and cows. The study was designed
to compare results of insemination with sexed
semen vs. conventional semen following estrous
synchronization using a popular timed AI
protocol (CoSynch plus CIDR®). Of the females
inseminated with sexed semen, 52.4% became
pregnant, compared to 67.2% of the females
inseminated with conventional semen.
Also observed were differences among females
inseminated with sexed semen related to the
females’ expression of estrus. Though synchronized
for timed AI, all females had worn heat-detection
patches that provide evidence of mounting
activity associated with females coming into heat.
According to Perry, 69% of females with fully