Rangeland Ecology & Management

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Understanding EPDs
Sprinkle, Jim
The University of Arizona, College of Agriculture and Life Sciences, Arizona Cooperative Extension
Publication Year

Currently, most registered bulls have information available from their own performance records, progeny, or relatives which enable us to predict the performance of future offspring for various traits. An expected progeny difference or EPD is the difference in some trait (usually expressed as pounds, but sometimes as inches for carcass type traits) which one can expect when compared to other animals of the same breed. For example, if a bull’s birth weight EPD is +5.0, then on an average his offspring should weigh 5 pounds more at birth than does a bull with a birth weight EPD of 0. The actual difference you will realize within your herd for a particular trait will depend upon how your herd compares to the breed as a whole. For example, if weaning weights on a particular ranch are greater than the observed breed average, then it is conceivable that a bull’s weaning weight EPD in this herd may be less than that listed for the breed.

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Technical Report
breed differences
animal production
animal genetic resources
Animal breeding
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