Beef Improvement Federation
Strategic Use of Heterosis
By Troy Smith
Plenty has been written about heterosis.
Volumes of information exist related
to heterosis — the hybrid vigor, or
enhanced performance, exhibited by
crossbred animals when compared to
the average of their purebred parents.
Todd Thrift wonders why relatively few
commercial cow-calf producers take
advantage of the available knowledge.
Why aren’t more producers reaping
the advantages of heterosis?
An animal scientist at the University of
Florida, Thrift posed that question to
cattle enthusiasts attending the 2017
Beef Improvement Federation (BIF)
Research Symposium and Convention
hosted May 31-June 3 in Athens, Ga.
He challenged the decades-old disdain
for crossbreeding, a tool proven useful
for increasing cow-calf profitability.
Well, not everyone has ignored
the advantages of heterosis. While
many cattlemen across much of
the United States have indulged
a preference for straightbred cow
herds, many Gulf Coast producers
have benefited from crossbred herds
utilizing Brahman influence.
“Many consider the F-1 Brahman-
cross to be the ‘Cadillac Cow’ for that
environment,” said Thrift, noting how the
infusion of Brahman genetics increases
adaptability to subtropical conditions.
“As the production environment
worsens, the more heterosis can matter.
The Gulf Coast is a good example.”
Just as valid, said Thrift, are
crossbreeding systems involving
complementary breeds that are suited
to other production environments.
While some people have suggested
that individual breed improvement has
18 | AUGUST 2017
advanced to the point crossbreeding is
no longer advantageous, Thrift insisted
that targeted heterosis remains a highly
effective means of increasing pounds
of calf weaned per cow exposed.
“Hybrid vigor is highest for maternal
traits, so the biggest bang for the
crossbreeding buck comes from using
a crossbred cow,” added Thrift, noting
how profitability can be improved
through increases in cow fertility,
calf survival and cow longevity.
Thrift said successful crossbreeding
requires a planned, targeted approach.
He admitted, however, that such
breeding systems are not necessarily
easy to apply. Heterosis can be
achieved, at various levels, utilizing
crossbreeding systems of three types:
terminal, rotational and composite.
Generally, terminal-sire systems deliver
maximum heterosis and enable a
producer to focus on the end product.
Terminal crossbreeding systems are
not meant to produce replacement
heifers. Instead, replacement females
are purchased. However, the plan
may fall apart when a producer
succumbs to temptation and keeps
some “big, good-looking replacement
heifers” from a terminal mating.
Rotational systems provide a lower
level of hybrid vigor, but produce
replacement females. Thrift said
an increased number of breeding
pastures may be required to maintain
the breeding rotation, which may be
challenging to smaller operations.
Large operations also may be better
suited to rotational systems because
University of Florida animal scientist, Todd Thrift,
speaking at the 2017 BIF Conference.
they may have the ability to market
different types and colors of offspring.
Composite systems also offer
heterosis, the most coming from
composites developed from four
breeds (25% each). According to Thrift,
utilization of cattle representing an
already established composite may
be well-suited to small operations,
because breeding can be managed
similarly to a straightbred system.
Thrift said it is unfortunate, but
many producers do not stick with a
crossbreeding system long enough to
realize the benefits. Too often the lure
of some new breed or cross will divert
attention from the original plan.
“Producers have to realize that
successful crossbreeding requires a
long-term commitment,” advised Thrift.
“If they want to know how to make
strategic use of heterosis, my answer
would be to use a crossbred cow.” I
Note: This article is reprinted with
permission from www.BIFConference.
com, the online coverage site of the 2017
Beef Improvement Federation Research
Symposium and Annual Meeting.