Making Sense of Genetic Trend

摘要

If you've attended a presentation about Breed Improvement, EPDs, or genetic selection, it's likely you have seen a table or chart representing genetic trend. Indeed, each breed association publishes a new genetic trend table at least once per year, and often-times more frequently. NALF releases a new genetic trend table bi-annually, each time that new EPDs are released.Typically, genetic trend tables are depicted as the average EPD for animals born in each year for the trait of interest. These charts or tables can be used to illustrate the traits that a breed has placed selection pressure on and the direction of that selection. They can also be used to illustrate those traits that are genetic correlated with traits that have been under selection and have thus experienced inadvertent directional change. Or, other times, it illustrates for which little change has been made.