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Crossbreeding Made
Easier |
For anyone who wants to begin
exploiting heterosis, John Welch, CEO of Spade Ranches at
Lubbock, TX says, “I’d do it as simply as possible. If you have
straight-bred English cows, as an example, find a
moderate-framed, moderate-milking Continental bull of whatever
breed you choose. Then, never breed to have more than 50 percent
of that breed in your heifers. So, the replacements are never
more than 50 percent Continental, but you can get there quickly.
“Go back on those replacements with a hybrid bull comprised of
the same breed and you quickly stabilize and maintain the
percentages. It’s as easy to manage as straight-breeding, but
you retain 50 percent maternal heterosis.”
Welch understands the management and marketing constraints a
more complicated crossbreeding system imposes. When he first
arrived here there was an intensive 4-breed rotational system
that maximized maternal heterosis, but created separate sets of
cattle (see Time to Crossbreed, page 80).
Optimizing rather than maximizing the retention of heterosis is
one reason hybrid bulls have become more popular in recent
years. They can be plugged into an existing herd where heterosis
can be established quickly, maintained over the long haul and
managed with ease. Think here of popular registered hybrids such
as Balancer (Gelbvieh X Angus), Lim-Flex (Limousin X Angus) and
SimAngus (Simmental X Angus).
Obviously, you can include the venerable Black Baldy in the mix,
as well as other English X English hybrids. However, one reason
the aforementioned English X Continental blends have gained
acceptance is that they represent the genetic blend coveted by
most feedlots and packers in the mainstream.
Use and Repeat
If you want to glimpse a straight-forward users guide for
simplified crossbreeding, check out the SmartCross® program (www.smartcross.org)
developed by the American Gelbvieh Association (AGA). The same
principles apply, no matter the breeds involved.
The program is aimed at creating the 50-75% English and up to
50% Continental crossbred calves feedlots and packers typically
prefer for feeding and carcass performance, while creating
replacement females.
In basic terms, the SmartCross program and other systems focused
on this 50-50 mix goes something like this:
If you have straight-bred or high percentage English breed cows,
use a purebred Continental breed bull and then use a hybrid of
the same two breeds on the resulting females to maintain the
blend, heterosis and consistency.
If you have straight-bred or high percentage Continental breed
cows, use a purebred English breed bull and then use a hybrid
comprised of the same two breeds on the resulting females.
If you already have mostly English X Continental cows, use a
hybrid bull of the same breeds to maintain the mix, heterosis
and consistency.
If you have a high percentage of Brahman genetics, use a
purebred Continental breed bull to add muscle. Follow up with a
hybrid bull of the same Continental breed and an English breed.
Assuming the environment demands the production benefits of
Brahman genetics, ideally the hybrid used would also contain a
shot of Brahman so those advantages can be preserved. Typically,
most feedlots and packers prefer cattle with 25% or less Brahman
in them.
Keep in mind, the above is aimed at maximum crossbreeding
convenience, while exploiting as much direct and maternal
heterosis as possible. If the goal is to maximize heterosis, a
more complex and intensively managed system is required.
Moreover, even this simple system can be tailored to fit the
needs of specific production environments and market goals.
Trash Begets Trash
Of course, successes with such a system assumes making logical
breed choices that compliment one another, as well as
intelligent choices within the chosen breeds that lead toward
rather than further away from goals.
“I believe one of the most important things in doing this is to
select on both sides of the bull’s pedigree what you’re shooting
for.” Welch says. “Like someone told me once, with
crossbreeding, if you breed trash to trash, you still get trash,
they just live longer.”
“Be very selective in buying these bulls, as selective as when
you buy purebred bulls, maybe more so,” continues Welch. “Make
sure that the breeds you select for crossbreeding are
represented by breeders and associations serious about
collecting and providing accurate performance data. You can’t
throw away all of the performance and genetic evaluation
information just because it’s a crossbred bull.”
Likewise, optimizing heterosis revolves around consistency,
relative to the identified goal.
Welch sees too many swinging the genetic pendulum from one
extreme to the next by using a different breed on mostly
straight-bred cows until the herd is mostly straight-bred with
the genetics of the new breed. Then, they select a different
breed and start all over again.
“We need to keep cattle breeding simple,” says Dave Daley,
animal science professor at California State University-Chico.
“We have wonderful within-breed selection tools (EPD’s). We have
the ability to capitalize on breed differences and capture both
heterosis and breed complementarity through crossbreeding.
Designing simple, long-term breeding programs to capture direct
and maternal heterosis, while capitalizing on maternal and
terminal lines, is a significant step in attempting to maximize
sustained profit.”
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