You must be able to answer three important questions before a set of EPDs can be used . Some breed associations publish a single North American EPD for the entire breed. As a result, some breeds publish separate Canadian and American EPDs. Whether an EPD value is above average depends on what the breed average EPD value is. The breed average EPD value is not always zero.
Most breeds use a fixed base.
This means that the breed average EPD changes from year to year. Put simply, a positive EPD doesn't always mean above average. Be aware of what the current breed average EPD is for each trait. Current EPD values for a number of breeds are shown in the table. Most breeds update their EPDs twice per year.