Expected Progeny Difference (EPD) is the estimate of how future progeny of each sire are expected to perform in each trait listed. Each bull within the breed report can be compared to every other bull in the breed report. It is not practical to compare EPD’s across different breeds, and one must know what the breed average EPD’s are before making selections. Averages are not at point zero.
Example 1: An Angus bull with a birth EPD of 3.0, weaning EPD of 28, milk EPD of 10, yearling EPD of 45 may seem good if we make an assumption that average is zero. It would be a mistake to make this assumption. Angus breed averages are birth EPD 2.2, weaning EPD 42, milk EPD 20, yearling EPD 77. So, the bull above would sire calves a little heavier at birth than average for the Angus breed, weaning weight of offspring calves would be 14 pounds lighter at weaning, his daughters would give less milk than the average, and his offspring would be 32 pounds lighter as yearlings. He may look really good, but his offspring is where he is not up to average and he will not pay off as well at calf selling time.
A simplified example of how you can use EPD’s and how their use can be translated into practical information can be seen by comparing the weaning EPD of two bulls. Bull A has a weaning EPD of 35 and bull B has a weaning EPD of 47. We will need to make some assumptions in our example (you can use your cow herd numbers to make a comparison in your beef operation). Assumption 1: Each bull will sire 26 calves per year that will be marketed at weaning; 2: The bulls are used for four years and 3: Calves are selling for $1.30 per pound. The weaning EPD difference of 12 pounds per calf times 26 calves per year is 316 pounds additional weaning weight times four years is equal to 1,264 pounds more calf weight to sell at $1.64 (weekly average on Feb. 17, 2012) per pound. That is equal to $2,072.96, so there is a pretty good difference in these two bulls and you can’t see this difference by looking at the bulls. Also, reported on the Feb. 17 weekly average market report slaughter bulls sold for an average of $1,496.69 at $0.89 per pound.
There are other very important EPD’s to consider in bull selection, but for a brief explanation I selected only one. If you have questions about other EPD’s or bull selection, give me a call at 423-626-3742.