Summary
Pork producers currently utilize expected progeny differences (EPD), production indexes, phenotypic selection, and information on "major gene" (RN & Halothane) status, in order to improve traits of economic importance in pigs. The practical implementation of marker assisted selection (MAS) in commercial swine production will depend on future advances of both molecular and quantitative genetics.
This study contributes to the information available on genetic markers that have potential to be utilized in genetic improvement programs of commercial herds. The results also highlight the need for continued investigation of the effects of candidate genes within specific genetic lines. Larger populations will be needed in order to fully characterize the effects of these markers on traits of interest. It is important to note that the markers used for these association studies represent a single change in each gene of interest. There are potentially more markers within each gene, some of which may have greater effects where they have a direct effect on the trait, or they are in linkage disequilibrium with a causative mutation.
Acknowledgments
Access to primer sequences was provided by Dr. Graham Plastow of the PIC International Group, UK, Dr. Max Rothschild and Kwan-Suk Kim of Iowa State University, and Ms. Eli Grindflek of the Agricultural University of Norway.
The technical assistance of Ms. Eli Grindflek, Ms. Jeannine Helm, and Dr. Stephan Marklund at Iowa State University was greatly appreciated. Thanks to Dr. Michael Davis of The Ohio State University for statistical advice.
Partial funding and access to animals were provided by: The Ohio State University Department of Animal Sciences, The National Pork Producers Council, the National Swine Registry, the Hampshire Swine Registry, the Iowa Agriculture and Home Economics Experiment Station, as well as by Hatch Act and State of Iowa funds.