AS-438

How a Boar Test Station
Can Enhance Genetic Progress
Allan Schinckel, Swine Breeding and Genetics, Department of Animal Sciences
When discussing the role of the central test stations, it is important to keep in perspective the relative importance of on-farm and central testing. Without on-farm performance testing, central boar test stations can generate only limited genetic progess since the number of superior, centrally tested boars is 2 percent of that needed by Seedstock producers. Also, test stations cannot measure reproductive traits such as litter size and 21 -day litter weight which are easily obtained on Seedstock producer farms. On-farm performance testing and selection of superior replacement animals are essential for genetic improvement to occur at any appreciable rate.
Depending upon (1) the traits measured, (2) completeness of testing, and (3) method of genetic evaluation, on-farm performance testing and selection could generate 166-259 times more genetic improvement annually (dollar improvement in profit-potential/hog/year) than current boar test stations alone. Central test stations must complement on-farm testing and never be considered as substitutes for within-herd on-farm testing programs.
When used in conjunction with on-farm testing, the boar test station fulfills a valuable role by directly evaluating boars from different herds and many different sires. Participants of the central test stations involved in on-farm performance testing and selection programs can be confident that the higher-ranking boars will improve the genetic merit of the Seedstock herds for the traits measured.
Procedural Guidelines
Transporting boars to a central location and collecting performance test information will not improve the genetic merit of Seedstock herds. There are certain procedures essential for the boar test station to enhance genetic progress. These procedures are:
1.	Participants must collect on-farm performance data and select superior boars and
gilts as replacements. Two procedures must occur if any long-term genetic progress is to be made in the swine industry: (a) performance testing and selection must occur within the Seedstock herds and (b) the Seedstock herds must use a high percentage of superior performance tested boars either from their own herd or from other herds with sound performance testing and selection programs. These procedures will guarantee that the average genetic merit of the centrally-tested boars will improve over time.
2.	Central test stations must measure economically important traits such as average daily gain, backfat thickness, and feed efficiency in a consistent, uniform manner. The National Swine Improvement Federation has suggested guidelines for the collection of data.
3.	Purebred boars must be evaluated within each breed. The goal in performance testing is to improve the genetic merit of each breed, not to compare a boar of breed A with a boar of breed B. Boars of some breeds may be superior in traits not measured at test stations (litter size or 21 -day litter weight) but only have average postweaning performance.
Also, the indexes are based on within-breed parameters (genetic and phenotypic correlations and variances) and are not designed to rank boars of different breeds. The goal of the test station is to improve the postweaning performance of all breeds and not discriminate against any particular breed.
4.	To evaluate boars within a breed, each boar’s performance must be compared with the average performance of an adequate number of boars (contemporaries) of the same breed. Twenty boars representing at least four farms would constitute a minimum contemporary group size. Twenty boars per breed are
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animal sciences swine