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S
Purebred Simmental
SA
SimAngus™
HT
Heat Tolerant SimAngus™
A
Purebred Angus
C
Purebred Charolais
H
Purebred Hereford
B
Brangus
BREED IDENTIFICATION KEY
SO, YOU BULL BUYERS STILL LOOK AT ACTUAL WEIGHTS?
By Dr. Jerry Lipsey, former EVP, American Simmental Assn.
Every year, in every herd, environmental factors (almost always weather and climate) affect the actual weights of cattle. I don’t care when you record
the weight; birth, weaning, as yearlings or later in life the impacts of temperature and related feed availability have huge effects on weights. Knowing
that, can you believe there are still cattle producers who use weight records vs. EPDs and indexes to make selection decisions?
Each year there are regions of this nation that experience drought often accompanied by excessive heat. I can guarantee the raw weights of cattle in
every age class are greatly reduced in these areas. Birth weights in those regions will be greatly reduced compared to areas that had cooler weather and
more rainfall. Weaning weights too in areas of drought are greatly depressed unless owners “pony up” big bucks for supplemental feed. Even with the
reduction in reported weights, the DNA for potential birth and weaning weight remains unchanged.
Neither prudent, nor exceptional care effects that potential either. Anyone can creep feed or provide either practical or generous nutrition to their
cowherd, but it does not impact EPDs. I have heard plenty of bull buyers say, “I won’t buy a bull unless he has a big weaning weight.” Those folks have
made a resolution to require some magic weaning weight of the young sires they purchase. Go ahead and enjoy spending dollars on a measurement
that potentially has no impact on your genetic progress or enterprise profit. That big weaning weight achieved by your herd bull may be no reflection
at all of his genetic makeup. Since we are nearing the end of summer the following comments relate to genetic improvement and dealing with hot dry
weather.
Thermal heat stress of cattle caused by hot, humid weather, endophyte toxicity (such as fescue) or both, have very large impacts on calf and body
weights. Reduced forage availability and even reduced forage quality have much the same effect. From a seedstock production standpoint however,
neither of these impact the genetic worth and breeding potential from the reduced weight calf crop at all.
There still remain cattle producers who diligently search for “high performers” even in environmental situations that make them very difficult to find.
That said, we absolutely salute everyone who finds and selects seedstock that have advanced genetic merit. We just regret the wasted effort, time and
money spent on the ineffective tunnel vision focus on raw cattle weights as an obsolete tool to find those cattle. EPDs have long since replaced actual
weights, adjusted weights and even weight ratios as “best predictors” of genetic worth.
The members of the American Simmental Association know the facts of measuring and comparing genetic values. Not until the weight data are entered
into our genetic evaluations resulting in up-to-date EPDs, do we make good decisions about true breeding values. Without doubt there will be calves,
particularly in challenging environments with unimpressive actual weights and yet their Weaning Weight EPDs will be superior to some calves with
maximum available nutrition and more much more impressive actual weaning weight data. The truth is that most cattle producers already know these
details. They don’t become distracted looking at birth, weaning and yearling weights. They know that EPDs are their “protection insurance” from pur-
chasing cattle with misleading weights. For example, an animal with a 75 pound birth weight, born in the fall after a long hot summer in the southern
US might have considerably less calving ease and reduced birth weight potential than a 95 pound calf born in the north after a long cold winter to a
cow that received substantial supplemental nutrition. Along the same line, it is impossible to compare actual yearling weights from cattle developed on
grass to those fed in a feedlot. The weights alone do not tell the real genetic story. Only EPDs provide a clear, environment-free measurement of genetic
worth.
For nearly three decades we have explained the advantages of using EPDs vs. weights, adjusted weights and/or weight ratios to select valuable seed-
stock. There is little doubt the proof of their impact on the beef business has been large and positive. Now, science is now marching even farther along,
farther past the antiquated use of raw weight data as we enter the era of selection using designed indexes. Simply by summing the market worth of
every EPD trait and knowing how those traits affect both costs and income, we can estimate how an animal’s genetics will impact the economic bottom
line of the cow herd enterprise.
ASA’s All Purpose Index (API) reflects the summation of every EPD on potential costs and production value. Considering everything from calving ease
to growth to cowherd lifetime feed costs, maternal longevity and even carcass value, API works as a cutting edge tool to really simplify seedstock selec-
tion. Terminal Index (TI) too can be a great profit selection tool for those that plan to sell all of the calves and not keep daughters. Average SimAngus
and Simmental API values are currently +$122 and it takes around +$135 to get in the top 20% of the bulls available in the breeds, so remember to use
all of the tools and buy carefully.
