Within-Herd Genetic Trends Provide Important Information for Breeders

Purdue University 1998 Swine Research Report. Across-herd genetic evaluations for purebred swine breeds have been available for several years. The resulting EPDs can be directly compared to each other, allowing breeders to identify the best animals in the breed. Breeders have used these EPDs when making decisions about which sows to keep in the herd, which herd boars to use for breeding, and which outside boars to purchase or use with AI. As a result, selection has produced genetic progress in individual herds and in the breed as a whole. Genetic trend graphs and reports have been made available to breeders. The trend for the breed gives information on the breed as a whole. Within-herd genetic trend reports are also available. These give the average EPDs for all animals used in a given herd, for each year of birth. Two pieces of information in these reports are extremely useful to the breeder. The average EPD in the last year or two can be compared to the breed average, to see whether the herd is superior to the breed as a whole. The trend over time tells the breeder how much progress has been made. This information is also useful for commercial producers. In order to find the best sources of animals, producers should look for a seedstock herd whose current average is above the average of the breed. They should also look at that herds genetic trend; herds with good trends in the past will probably continue those trends in the future. Seedstock herds which are above average now and which are improving at an above average rate are the best sources for good quality seedstock.