Bull Buying 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. Take time to consider the points presented above. What you learn may help you overcome your hesitation to take action. If you've picked some pointers about Bull that you can put into action, then by all means, do so. You won't really be able to gain any benefits from your new knowledge if you don't use it.
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