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Selection
What traits should I emphasize in my bull selection? This is a common
question and there is not a simple answer. A large number of predictions for traits are available for
most beef cattle breeds. Using this information and other types of information, cattle producers can select
the best animals to match their production and marketing environments. Trait categories can be grouped into
the following categories: growth and production, maternal traits, carcass traits, reproductive traits,
survivability and adaptability traits, and convenience traits. It is important to determine the traits of
economic importance. A producer should the question, “Do the trait(s) we have in our selection criteria
contribute to reducing costs of production or increasing revenue?” Are the traits we select for in our herd
important to the success and profitability of our customer(s)?
Ideally, the traits of economic importance include those that increase
profitability. For example, one producer may have a limited amount of labor during calving; therefore,
calving ease would most likely be on the list of economically important traits. Another cattle producer might
market his cattle through a retained ownership program, and premiums or discounts are awarded for carcass
quality. This producer would place a larger emphasis on carcass traits. These examples do not promote
selection emphasis on one trait or trait category. Important trait categories, such as reproduction, should
not be overlooked. Previous research has shown that in a cow calf operation, where calves are sold at
weaning, reproduction has greater economic impact over growth and carcass traits. According to Roy Berg, “a
dead calf has a very poor growth rate” and “a dead calf also has very poor carcass performance”.
Bull Buying
The late Robert Taylor at Colorado State University often stated that the best
approach to buying the right bull was to develop a Want Ad. In their Want Ad, the producer would identify the
desirable characteristics of both the cattle and supplier. Purchasing a bull can be similar to buying a
car. For cattle producers to get the best deal available, they need to research and study all available
information about the cattle before going to the sale. A buyer needs to ask what features are mandatory for
my bull and what options do I want in the bull? Some options might include high growth rate and easy
calving. Additionally, the producer should ask how much they are willing to pay for the different options
above the basic model price.
Selection tools available to cattle producers to assist with selection decisions
include, but are not limited to, pedigrees, EPDs, ratios, carcass data, financial records, indexes, and many
others. Having a large amount of information is a benefit; however, the volume of information can be
overwhelming. If a cattle producer devotes the needed time to analyze many of the previously mentioned items,
including their financial records, the economically important traits should start to surface.
Currently, Expected Progeny Differences (EPD) are the highest accuracy selection tool
available and a superior prediction of performance compared to an animal’s actual trait observation. Expected
progeny differences account for differences in herd management and feed environment, genetic differences between
herds, the genetic merit of parents, and culling for poor performance. Unfortunately, EPD cannot account for
incomplete reporting, inaccurate reporting of data, incomplete pedigrees, and inaccurate assignment of animals to
contemporary groups. Therefore, it is very important for producers to correctly and accurately report all
information on their cattle.
What is an EPD? According to Rick Bourdon, formerly with Colorado State
University, an EPD is a prediction of the difference between the average performance of future progeny of an
individual and the performance of theoretical reference animals with an EPD of zero. Using birth weight EPD
as an example, imagine there are two sires being mated to the exact same cow herd. Sire A has an EPD of 0 and
sire B has an EPD of +4. On average, sire B is expected to produce calves 4 pounds heavier at birth than
calves from sire A. Simply, an EPD is a prediction of progeny performance.
What is accuracy? Many sire summary catalogs will list accuracy values next to
the corresponding list of EPDs. Accuracy is a measure of the amount and type of information used to calculate
an EPD. It determines the reliability of the EPD and provides you with a way to determine the level of
information going into the each individual’s genetic prediction. For example, an individual with an accuracy
of 0.10 might just have pedigree information contributing to its EPD; however, an accuracy value of 0.99 has
thousands of observations contributing to its EPD.
How should a person categorize accuracy? One way to evaluate accuracy values is
to group accuracy levels into low, moderate, and high categories. The low range for accuracy might range from
0 to .40, the moderate range from .40 to .80, and the high range from .80 to 1.0. On the low end, the EPD are
much better than just guessing and probably include information on the animal, its parents, and maybe some brothers
or sisters. The moderate accuracy values are still considered risky but they are useful for making selection
decisions. The high accuracy genetic predictions are very reliable and useful in making
comparisons. Often yearling bulls are criticized for having low accuracy EPD, but this is only because
they haven’t had a large amount of data collected toward their EPD. If given the choice between the EPD and
the actual observation to make a selection decision for a trait, the most reliable decision will be with the
EPD.
As good beef cattle managers, take the time to admire your successes and critically
evaluate your mistakes. It is important to maintain quality financial and performance records. Always
be critical of the performance and profitability of your cattle in their production environment. Keep profit
in mind when making selection decisions and ask yourself if you can raise better cattle at a lower cost and higher
profit.
How To See and Select A Fertile Bull
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