Achieving Peak Performance/Profitability on Individual Traits
When it comes to trait selection, EPDs (Expected Progeny Differences) are the most powerful tools there are in genetic selection. There are some people that will argue this. Two of the most common arguments are that EPDs are just another tool in the toolbox. I do use them but I use them in conjunction with all the other information. Secondly, numbers are fine and dandy but we’re breeding cattle for the real world and we need to know how they perform in the real world.
Argument 1: EPDs are just another tool in the toolbox. I do use them but I use them in conjunction with all the other information.
This argument is a derived from a basic misunderstanding of EPDs. The reason EPDs are not just another tool in the toolbox is because, in regards to individual traits, EPDs are the toolbox. The idea of using all the tools (that are valuable predictors, that is) that one can get their hands on (parental data, sibling data, actual performance data, progeny data, DNA data, ultrasound data, etc.) is the right idea. These are the tools in the toolbox. However, these tools must be evaluated and emphasized correctly. For example, a DNA test for marbling may have the same value is eight carcasses from progeny of that same animal. Would you therefore weight those two data points (carcass data on one animal and a DNA test) equally? How would you weight it? Can you evaluate that sitting in the stand at a bull sale or walking around the pens at a bull sale? The obvious answer is no. The good news is that EPDs do that for you. All data points are evaluated accurately and applied for you to maximize the effectiveness of you selection decision.
So we must then ask the question, “What happens if I use the EPDs along with other data presented in the bull sale catalog?” The answer, as you can probably now guess, is that you will make a less accurate or poorer selection decision. For example, if you look at the calving ease EPD and the actual birth weight of that same animal and use the birth weight information, in addition to the calving ease EPD to effect your selection decision, you will have placed far too much emphasis on the actual birthweight and not near enough emphasis on the other tools in the tool box. Remember, the actual birthweight is already in the EPD so you’ve basically analyzed it twice. In addition, you have effectively minimized the usefulness of such information as DNA data, parental data, progeny data, sibling data, ratios or contemporary data, etc because less overall weighting will be placed on that data. In order to be a peak performing animal breeder and achieve maximum genetic improvement, you must train your mind to exclusively look at the EPDs when it comes to trait selection.
Argument 2: Numbers are fine and dandy but we’re breeding cattle for the real world and we need to know how they perform in the real world.
This argument has to do with the trust you place in your breeders commitment, ability, and honesty when it comes to collecting data. A good breeder should be collecting accurate data in real-world scenarios. If your argument is “numbers are fine and dandy but we need to know how cattle perform in the real world” that would mean that you don’t trust that your bull provider is collecting accurate, real-world data to put into the EPDs. If you don’t trust that your bull provider is collecting accurate, real-world data and putting that data into a good genetic evaluation like the evaluation provided by International Genetic Solutions, the problem is not the EPDs, the problem is your bull provider. Therefore, the issue is not having to decide whether or not you trust the EPDs provided but having to decide whether or not you trust the bull producer collecting the data and providing the EPDs. Once you have a bull producer committed to data collection, the EPDs are as accurate, as powerful, and as “real-world” as anything out there.