EPDs are key genetic selection tools
January 20, 2014
Last time I contributed to Tri-State Livestock News (5 weeks ago), I talked about the importance of cow-calf producers determining if their cattle are above average performers and working with cooperative feeders and packers to capture some of the added value that superior performance brings to those cattle.
One of the things I said in that column was that measuring performance was key; a person can't manage these traits if they don't measure them. So lets say that you go out and do what I suggested in that column: communicate with the feeder that finished the calves and the packer that harvested them and learn about their feedlot and carcass performance. If they had rapid and efficient ADG and feed efficiency, and a large percentage graded choice or higher with lean yield grades, you have evidence that your cattle deserve higher prices. In this case the next step would be to actively market that evidence so that you get a share of that additional value. But what if you learn that your cattle don't perform well in the feedlot or on the rail? Maybe they gain rapidly, but grade poorly. Or vice-versa, what if they grade well with a high percentage of USDA Choice or Prime grade carcasses, but they gained at a slower than average rate and had below average carcass weights?
Increasing their genetic potential to perform better in the feedlot or packing plant is a primary way to improve these deficiencies. And this is the bull-buying season, so now is the time to take advantage of the opportunity to improve those genetics through the next bulls that you purchase. Many bull sale catalogs list a wide variety of EPD and selection indices that can aid in selecting bulls that are superior in various traits. Unfortunately, many bull buyers find the abundance of numbers overwhelming and avoid using them. Spending some time studying the catalog before the sale can be a worthwhile investment of your time. You don't necessarily need to use all those numbers. Focus on the ones that apply to the deficiencies in your herd. For example, if postweaning rate of gain and final carcass weight turn out to be below average in your calves, every breed has one or more EPD that apply to post-weaning growth, such as yearling weight, mature weight, carcass weight, etc. Go through the sale catalog and find bulls that have above average EPD for those postweaning growth traits. Those are the bulls that you might want to focus your bidding on when you go to the sale. Some have EPDs that provide a prediction of feed efficiency. On the other hand, if the issues are quality grades that are too low, then there are EPDs for marbling. If yield grades are too high (remember, higher yield grade numbers mean more fat and less lean in the carcass), many breed associations provide EPDs for backfat thickness, ribeye area, etc. Some breed associations now provide selection indices that are combinations of EPD to achieve specific goals, such as the $WEAN, $BEEF, and other economic indices that the Angus breed now provides.
There is strong evidence from producers that have used these tools that performance records and disciplined bull selection can lead to rapid advances in deficient traits.
One important caveat is to avoid single trait selection. For example, lets say too few of your calves grade choice or higher. Therefore, you would want to choose bulls with above–average marbling EPD. However, you don't want to get so over-focused on marbling that you ignore other traits that could deteriorate in your herd if the bulls you purchased were deficient. In this example, once you have gone through the sale catalog and marked all the bulls with high marbling EPD, then go back through those marked bulls and make sure none of them have undesirable numbers for their other EPD. This means you may "unmark" some of them because they don't fit your other needs. For example, if a bull in the sale catalog with the highest marbling EPD also has the highest birth weight EPD, you may not want him if you are concerned about calving difficulty.
While they are not perfect, EPDs are one of the most powerful genetic selection tools we currently have available. Evidence is strong that they work when used properly. There are educational resources available for anyone that is uncomfortable using them and would like to overcome that discomfort. Many university Animal Science Departments and Extension Services have web-based resources explaining the use of EPD, including all of the Land-Grant Universities in the Tri-State Livestock News readership area. Extension educators and specialists can provide guidance. Semen service companies also provide resources and advice on bull/semen selection. Opportunity exists for all producers to improve the genetic capability of their cattle.