September 2006
Use EPDs to Match Bull to Herd

by Jimmy Hughes Recent numbers reported by the USDA confirms what has been assumed for several years: • Cattle placements for August 2006 are over 10 percent higher than August 1st replacements were in 2004. • August 1st inventory of feedlot cattle is at the second highest level since 1996. • July placements were 17% higher than 2005 and 14% higher than 2004. These numbers indicate that the number of heifers retained on the farm are starting to produce calves for the feedlot. While consumption of beef remains high and import markets continue to open, there is still concern about the increased cost of energy leading to a decrease in beef consumption. An increased cost in feedlot production due to transportation and higher grain prices are also leading to speculation that cattle prices will continue to decrease. While brood cow producers are still profitable, the record profits over the last few years may well be over. With this in mind, we now need to consider management practices that will help us produce the type of cattle that the market place demands. These types of cattle will also top the market and will assure you the most return on your investment. I have talked with several producers over the past couple of weeks that are in the market for a bull. With production sales starting soon, I though it would be a good idea to look at several considerations when making a decision on what bull to purchase. The first consideration is breed selection. What bull will best match my herd to produce a desirable offspring? Another consideration will be the overall appearance of the bull including muscle, structural correctness, disposition and overall appearance. When you have evaluated potential herd bulls on these attributes, it remains imperative that you also evaluate the bull on genetic potential to improve the overall quality of your herd. With this in mind, let’s look at characteristics that are available for you to evaluate through Expected Progeny Differences (EPD). EPD is the difference of a bull’s progeny when compared to the average progeny performance of all bulls evaluated. EPDs are reported in pounds and other units of measurement and are directly comparable across all herds within a breed, but not across breeds. The following are common measurements that you can utilize when selecting the very best bull for your herd: Birth Weight EPD (BW): Calf weight at birth adjusted to a mature dam equivalent. Birth Weight EPD predicts the difference in average birth weight of bulls calves compared to calves of all other bulls evaluated. Example: Bull A has a Birth Weight EPD of 3 while Bull B has a Birth Weight EPD of -1. This means that Bull A should produce calves on average that are 4 pounds heavier at birth than Bull B. Weaning Weight EPD (WW): Predicts the difference in average adjusted 205-day weight of a bull’s calves compared to calves of all other bulls evaluated. Example: Bull A has a WW of 20 while Bull B has a WW of 30. This means that Bull B should wean calves that on average will be 10 pounds heavier that those calves produced from Bull A. Milk or Maternal EPD (MK): Predicts the difference in average 205-day weight of a bull’s daughter’s calves (due to milking ability) compared to calves of all bulls evaluated. Note: This is pounds of calf weaning weight and not pounds of milk. Scrotal Circumference EPD (SC): Predict the difference in yearling scrotal circumference (measured in centimeters) of a bull’s male calves compared to male calves of other bulls evaluated. There is a direct correlation between scrotal circumference and heifer maturity. Ribeye Area EPD (REA): Expressed in inches, is a predictor of the differences in ribeye area of the sires progeny compared to progeny of other sires. Example: Bull A has a ribeye area of 12.5 while Bull B has a ribeye area of 14. This means that Bull B should produce calves on average that has a ribeye area that is 1.5 inches greater than Bull A. The larger the ribeye area the greater amount of muscle that should be in the bull. Fat Thickness EPD (BFAT): Expressed in inches, is a predictor of the differences in external fat 12th rib (as measured between the 12th & 13th ribs) of a sire’s progeny compared to progeny of other sires. Marbling Score EPD (Marb): Can be used to select sires that will produce progeny with more marbling at a constant fat or age endpoint. The higher the marbling score EPD, the higher the amount of intramuscular fat in the ribeye. The genetic correlation between marbling score and external backfat at the 12th rib is zero. This means breeders can select for increased marbling and not have to worry about selecting for increased external fat. Intramuscular fat plays a small role in tenderness of beef. It is a significant component of juiciness and flavor of the beef product. Ultrasound Body Composition EPDs are measured through the use of ultrasound equipment. Intramuscular Fat (% IMF): A predictor of the difference in a sire’s progeny for percent intramuscular fat in the ribeye muscle compared to an average sire. Ribeye Area (UREA): A predictor of the difference in square inches of ribeye area of a sire’s progeny compared to the progeny of an average sire. Fat Thickness EPD (UFAT): Expressed in inches, is a predictor of the difference in ultrasound fat thickness at the 12th rib of a sire’s progeny compared to the progeny of other sires. It includes the weighted average of 60% of the rib fat measurement and 40% of the rump fat measurement Percent Retail Product (%RP): A predictor of the difference in pounds of saleable retail product of a sire’s progeny compared to the progeny of an average sire. I hope that an explanation of information that will be available to you on sale day will assist in helping you to select the very best bull for your operation I have several beef producer meetings scheduled through local Co-op stores over the next couple of months. I look forward to seeing you at one of these meetings as we discuss winter feeding options. If I can assist you in any manner, please contact me at This e-mail address is being protected from spambots, you need JavaScript enabled to view it . Jimmy Hughes is AFC’s animal nutritionist.