Performance Line
Value of Crossbreeding
By Tonya Amen, National Center for Beef Excellence
Among seedstock breeders, a lot of the focus on
genetic improvement gets placed on EPDs. We
should not lose focus of the other tools in the
Animal Breeding tool box; crossbreeding. NALF
does register hybrid animals, however, even
those of you breeding purebred and full-blood
animals can discuss the value of crossbreeding
with your customers, including potential
benefits of keeping replacements when your
bulls are used on English-based cows. Making
use of the two pillars of crossbreeding, breed
complementarity and heterosis (hybrid vigor), can
have a huge impact on profitability for commercial
users of Limousin and Lim-Flex genetics.
First, let’s consider that there are three
genetic factors that affect efficiency and
profitability of beef operations:
1.
2.
3.
Breed Complementarity: The strengths of one
breed being used to complement another
Hybrid Vigor (a.k.a. heterosis): The higher
performance of crossbred animals as
compared to the purebred average
I believe breed complementarity is straightforward,
but hybrid vigor is often misunderstood, and
its value underestimated. Here are some key
items of importance regarding hybrid vigor:
• It is most impactful for survival
and reproductive traits.
• Its benefit tends to be greater for breeds
that are more genetically different from
each other. For example, there is more
expected hybrid vigor in British-Continental
crosses than between crosses of only
British or only Continental breeds. The
largest impact of hybrid vigor is expected
in Bos indicus-Bos taurus crosses.
• It tends to be proportional to the degree
of heterozygosity. In other words,
maximum hybrid vigor is achieved
in the first generation of a cross.
The characteristics of the animals
produced - having marketing goals
and producing a calf crop that most
optimally meets those goals.
Hybrid vigor (both direct and maternal).
The characteristics of the sires and dams
- there are ways it makes sense to design
a breeding program. Choose females that
are well suited to the environment in which
they will be expected to produce and
select sire breeds to complement them.
Employing crossbreeding can be used to
influence all three of these factors. First, let’s
recall the two primary benefits of crossbreeding:
breed complementarity and hybrid vigor.
22 | MARCH 2019
The use of crossbred females is especially
important because some of the largest impacts
are on traits related to female productivity
(maternal ability and reproduction). Crossbred
females are expected to have a younger
age at puberty, a quicker return to estrus
postpartum, more longevity in the herd as well