For many years the computation of Expected Progeny Differences has been done independently by each breed association. This provided a very useful tool to assist beef producers in comparing and selecting bulls within a breed, but it did not provide a means to compare bulls of different breeds. Adjustment factors were developed to assist producers in comparing breeds, but this process adds another layer of inaccuracy and has never seen widespread adoption among commercial cattlemen. The best way to compare bulls of different breeds is to combine all of their data, including crossbred data from known breed percentages, into one genetic evaluation and this is exactly what several breeds have done.
Starting with the spring 2015 genetic evaluation the American Simmental Association is running a joint analysis that also includes Red Angus, Limousin, Gelbvieh, Maine Anjou, Shorthorn and Chianina/ChiAngus. In addition to the purebred data, this analysis allows the inclusion of crossbred data and data from the Canadian associations of many of these breeds. There are some distinct benefits to this type of analysis: as mentioned crossbred data can be used; EPDs can be generated for crossbred or composite bulls such as SimAngus, Limflex and Balancers; the EPDs on the bulls from all of these breeds can be directly compared to each other (with the exception of calving ease in Red Angus and some carcass trait EPDs).
As a heads-up for next year, the Simmental Association is in the process of overhauling and updating their genetic evaluation system to incorporate all of the latest technologies. This will likely result in re-tweaking the values for these breeds next year, but hopefully this will then stabilize. It is also anticipated that some other breeds may be joining this group or forming other joint analysis in the future. Even though change can be complicated and we have to do a little homework to re-familiarize ourselves with the new values the good news is that with each genetic evaluation change EPDs are getting a little better and in the end we have a better selection tool to assist us in buying our bulls.
We strongly recommend that you use EPDs to assist you in your bull purchases. The great thing about EPDs is they can help you increase, decrease or stay the same for all of the traits they are computed for; it's your job to determine the level of genetics you need to match your management, environment and market. For additional information on bull selection, crossbreeding or other beef genetics information please visit: http://afs.ca.uky.edu/beef/publications.