The primary purpose of swine improvement programs is to measure the performance of pigs and to use these performance records in selection to increase the rate of genetic improvement. This publication outlines uniform procedures for measuring, recording and utilizing swine performance records. It also strives to achieve greater uniformity of terminology and methods of measuring performance traits.

Economic traits of swine include those that contribute to productive efficiency and desirability of product. Growth rate, feed efficiency, reproductive efficiency, and carcass merit are the economic traits of greatest importance. Performance testing offers those engaged in swine production a way of measuring heritable differences among animals to select parents that have the highest probability of transmitting their superior performance traits to their offspring.

Differences in performance among individuals or groups of animals are due to genetic and environmental effects. The observed or measured performance of each animal for each trait is the result of genes received from its parents and the total environment in which it is produced. Because differences among animals for economically important traits are due in varying degree to genetic reasons, systematic measurements and use of records in selection can increase the rate of genetic improvement. Furthermore, genetically superior individuals can be more readily identified when animals are maintained under the same management systems and their performance records are adjusted for known environmental effects.

Genetic improvement of pigs includes more than the improvement of efficiency of pork production. It is mandatory that we improve both product quality and production efficiency to ensure the survival of the swine industry. To meet these goals, an organized, systematic program is needed, involving swine producers, swine organizations, and meat processors. The primary features of a successful genetic improvement program include:

1. Accurate, consistent data measurement of economically important traits.
2. Use of appropriate data analysis and genetic evaluation procedures.
3. Use of these results when selecting breeding stock.

The success of a genetic improvement program is dependent on its use by both seedstock and commercial swine producers. No genetic progress can be initiated if seedstock producers do not utilize accurately identified, genetically superior animals in their breeding program. No genetic progress can be realized if commercial producers do not utilize offspring of these same animals in their breeding program. The technical direction of genetic programs can be supplied by trained personnel in both university and industry organizations. The education, coordination, and promotion of these programs can come from the Cooperative Extension Service and industry organizations. All pertinent groups must contribute for a genetic improvement program to produce maximum genetic progress.