About
Providing the American sheep industry with
access to state-of-the-art genetic evaluation
The National Sheep Improvement Program (NSIP) is a computerized, performance-based program for genetic selection. NSIP is designed to help purebred sheep producers identify the best genetic stock for their breeding programs. NSIP also gives breeders reliable information that they can use to advertise and sell their breeding stock. Breed groups that currently participate in NSIP include Boer goat, Columbia, Dorper, Dorset, Hampshire, Katahdin, Polypay, Rambouillet, Romney, Suffolk, and Targhee. Virginia Tech is home to the U.S. National Sheep Improvement Program Genetic Evaluation Center. NSIP, established in 1986, was developed to assist producers into compiling records into a usable form for selection decisions. NSIP accepts on-farm performance records from participating flocks, uses sophisticated mainframe computer programs to generate estimates of genetic value, and returns Expected Progeny Differences (EPDs) for reported traits.
The EPD for an animal estimates how well its offspring (progeny) compare to the breed average. Producers marketing breeding stock benefit the most from NSIP. NSIP works through breed associations to deliver across-flock EPD’s to participating producers. NSIP works through the breed associations, and in certain situations groups of producers, to deliver across-flock EPDs to purebred producers.
By using EPDs, a breeder can make genetic improvements efficiently and reliably.
Breeders use these EPDs to guide them in their selection and genetic improvement programs. Flock EPD’s (FEPD) are the same as EPD’s except that all the data is derived from a single flock. A producer who is a member of NSIP receives reports on the genetic values for every animal in a flock, based on the performances of those animals and all the animals that are genetically related to them, over many years and management systems. By using EPDs, a breeder can make genetic improvements efficiently and reliably. EPDs allow a breeder to rank all the animals by genetic value, identify high-producing replacements, and cull poor-producing animals.