Implications
The frequency of the RN- allele in the Hampshire population studied is much lower than reported in previous literature reviews and provides evidence of Hampshire sire lines in the U.S. population that are not carriers of the RN- allele. The presence of rn+/rn+ sire lines will allow seedstock producers the opportunity to selectively breed against the RN- allele and thus improve the muscle quality traits that are becoming more important to pork consumers and processors.
Although the differences between genotypes in this study were not of the magnitude of those found in other studies, the trends observed mimic results previously reported. Given the potential classification errors with regard to using GP as an indicator of RN status, work on the establishment of a more definitive molecular test for the RN gene must continue. A molecular test will provide the opportunity to identify and select animals with the desired RN alleles in concert with improvement in performance, efficiency and carcass traits.