Justification

The Meishan pig was imported from China because they excelled in female prolificacy (Young, 1994). The Chinese pigs were also quite useful for genomic analyses as they were phenotypically different from occidental pigs in virtually every trait of importance. Furthermore, due to limited exchange of germplasm between Chinese breeds and other breeds for nearly one thousand years, considerable genetic diversity exists. The dramatic phenotypic and genetic diversity made crosses between Meishan and occidental pigs the ideal quantitative trait locus (QTL) mapping populations for numerous production traits. Due to the poor growth rate and lean percentage of Meishan pigs, they currently have had little impact on commercial swine production in the US. However, QTL mapping with these pigs has greatly increased our knowledge about the inheritance of quantitative traits and has provided the markers necessary to improve the body composition of composite populations containing Meishan pigs