North Carolina State University

The impact of NSIF has been through education and implementation of science. It has not had a role in development of new knowledge. The influence of NSIF started with a meeting in Des Moines in March 1974 when a group of test station managers, extension specialists and geneticists met to discuss standardization of testing procedures. Prior to 1974 there was little if any similarity among central test stations or on-farm testing programs in either testing procedures or methods of reporting results of tests. Most testing programs were not using selection indexes and those that were used "Ad Hoc" indexes that were not developed using selection index theory.

At the 1974 meeting Dr. P. J. Cunningham and I were designated to develop selection indexes. This resulted in indexes for pigs fed individually and in groups as well as for when only gain and backfat were measured. Correct selection index theory was used and incorporated genetic and phenotypic variances and covariances and economic values. These indexes were published in 1976.

At the 1974 meeting I was asked to serve as editor for a publication to be entitled "Guidelines for Uniform Swine Improvement Programs." The first edition was printed in 1976. It contained recommendations for management, nutrition and testing procedures as well as for adjusting and reporting data.

In 1977, Dr. Cunningham and I presented on-farm indexes for a general-purpose population, a maternal line and a paternal line. At the same meeting my recommendations for procedures to adjust backfat to 230 lbs. and days to 230 were accepted and published in the proceedings. In 1978 a tract on selection indexes and trait ratios was published and distributed by NSIF. A similar tract was produced in 1981 for sow productivity indexing. All of these were included in later editions of "Guidelines."

These publications were very useful in introducing the concepts of utilizing uniform procedures, h², genetic correlations and economic values in selection programs. Although some "fine tuning" has been applied to these procedures, they remain basically the same. The "Guidelines" have been updated periodically, and in 1997 included a section on EPD's. It should be remembered that while EPD's are the best estimate of genetic worth of an individual for a particular trait, selection indexes are still needed to evaluate the whole animal.

More recently NSIF has sponsored a certification program to validate users of ultrasound technology. As with the other procedures this has led to more uniform testing and reporting of data.

The latest technology concern has been use of marker assisted selection (MAS). This procedure utilizes some "easily" identified marker associated with genes that affect a quantitative trait in which we are interested. These genes (loci) are referred to as quantitative trait loci (QTL). We must remember that these relationships are specific for the population in which they are identified. They may not be applied to another population unless validated in that population. Further the relationships in the original population will change over time, especially if selection is practiced. Thus re-evaluation at intervals will be necessary even in the original population. Moreover, one must be careful that these "markers" are not associated with undesirable phenotypes for other traits.

Another recent development is identifying a specific gene that affects a trait of interest. As with MAS these effects may be specific to a population and will need to be validated in each population. This is due to the many other genes that may influence its effects and the frequency of these genes may differ among populations. Hence the effects of even a specific gene may differ among populations.

In summary NSIF has served a very useful role as an educational forum. The "Guidelines" and other publications have enhanced the awareness and utilization of sound science in swine improvement. Implementation of uniform procedures for testing programs and reporting results have made a major contribution. The annual program affords an opportunity for dialog between scientists and producers, which probably doesn't exist elsewhere.