Acrossbreed EPD adjustments as a comparison of breeds
Since 1993 for growth and late 2000 for carcass, each year, the U.S. Meat Animal Research Center (MARC) develops acrossbreed expected progeny differences (EPD) adjustments (Table 1). These factors are added to animals EPDs of a specific breed to put on an Angus base. If you add it to a breed base (Table 2), you get some idea how breeds relate (Table 3). You will see that Gelbvieh, Brangus and Beefmaster have no carcass EPDs. That is because MARC only uses breeds that adjust to age and carcass bases. Gelbvieh, on the other hand, adjusts to a fat constant basis and Brangus and Beefmaster adjust to an ultrasound basis.
There are many take home messages, which the remainder of this article will cover. First, there is wide variation between breeds (see Table 3), but it is often said “there is as much variation within breeds as there is between breeds.” Also, in recent commercial bull buyer surveys, hybrid bulls ranked higher than purebred Continental bulls like Simmental, Gelbvieh and Limousin, so it might be more representative to put the averages of their hybrid coun terparts,
SimAngus, Balancer and LimFlex, instead of the purebreds.
One size EPDs does not fit all! Management, environment and marketing play a big part in what is a good or bad EPD. In lush environments, very high milk is desired, while in desert conditions, lower milk is more desirable. Calves that are going to go to the feed yard right off the cow should have very high growth potential, while to the other extreme, calves that are going to be roughed through the first winter and grazed the second summer before going to the feed yard at a high weight, need only very moderate growth potential. Then you have all the scenarios in between.
Don’t forget about what is not on these Tables! The most economically important traits are reproductive, and no acrossbreed EPD adjustments are available for traits like calving ease direct, heifer pregnancy, calving ease maternal, stayabilty and scrotal circumference. There are also many other very economically important traits that are not available acrossbreed. These include maintenance energy or mature size, disposition and feed efficiency. Without these, a person is only seeing part of the picture. — Dr. Bob Hough [Dr. Bob Hough has served as the executive vice president of the Red Angus Association of America and more recently as executive vice president of the North American Limousin Foundation from 2009 to early 2011. He is now a consultant, freelance writer and semi-retired.]