Abstract: Methods for screening pigs to determine which are more likely to produce larger litters and/or are less likely to produce larger litters are provided, based on identification of OPN alleles present in a sample of pig genomic DNA. Kits for use in such methods are also provided.

Abstract: Coat color is important to the pig breeding industry for a number of reasons. It is therefore desirable to develop populations of pigs which will breed true for coat color. However, establishing such populations would be time-consuming and costly using traditional test mating programs. It is therefore desirable to determine the coat color genotype of individual pigs. The inventors have shown that the KIT gene in pigs is involved with coat color determination. Specifically, the inventors have discovered that the difference between the I, IP, and i alleles of the coat color determining gene is duplication of at least part of the KIT gene in the I and IP alleles. Further, the inventors have discovered that the difference between the I and IP alleles is that, although both I and IP have a duplication in the KIT gene, only I and not IP exhibits a deletion in one of the duplicated regions.