Submitted to: Animal Genetics International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 7, 2004
Publication Date: September 11, 2004
Citation: Rohrer, G.A., Thallman, R.M., Shackelford, S.D., Wheeler, T.L., Koohmaraie, M. 2004. Genome scan for loci affecting pork quality in a Duroc-Landrace F2 population. Proc., 29th Int. Conf. Anim. Genet. (ISAG) Toyko, Japan, 9/11-16/2004. Abstract F076. Pg 143. Technical Abstract: A genome scan was conducted on 371 F2 Duroc-Landrace pigs with 182 microsatellite markers. Breed of origin of chromosomal segments inherited in the F2 progeny were predicted using GenoProb. Statistical tests for QTL were conducted on 43 phenotypes with SAS. The probability of inheriting a Duroc allele from the sire and the probability of inheriting a Duroc allele from then dam were used to develop covariates for additive and dominance effects or maternal and paternal imprinting effects. Fixed effects fitted were sex and slaughter age. Carcass weight, RYR1 genotype and/or PRKAG3 genotypes also were included in some analyses. Subjective and objective measures of composition and pork quality were recorded. The two regions with the greatest evidence of containing QTL were located on chromosomes 2 and 17. Chromosome 2 (60-66 cM) had two significant QTL detected for taste panel tenderness scores along with suggestive QTL for pH at 1 hr postmortem, intramuscular moisture content, slice shear force at 7 days postmortem and taste panel amount of connective tissue. Chromosome 17 harbored a significant QTL affecting loineye area along with suggestive QTL for intramuscular fat content determined by chemical analysis and subjective marbling score at position 32-39 cM. While the Duroc allele increased marbling and muscling at the chromosome 17 region, the Landrace allele was more desirable for chromosome 2. Follow-up studies are necessary to validate these QTL and determine their utility to the commercial industry.