Associations of DNA markers with meat quality traits in pigs with emphasis on drip loss G. Otto a , R. Roehe a,b, * , H. Looft c , L. Thoelking c , P.W. Knap c , M.F. Rothschild d , G.S. Plastow e , E. Kalm a a Institute of Animal Breeding and Husbandry, Christian-Albrechts-University of Kiel, Hermann-Rodewald-Straße 6, D-24118 Kiel, Germany b Animal Breeding and Development, Sustainable Livestock Systems Group, Scottish Agricultural College, Bush Estate, Edinburgh EH26 0PH, UK c PIC Deutschland GmbH, Ratsteich 31, D-24837 Schleswig, Germany d Department of Animal Science, Center for Integrated Animal Genomics, Iowa State University, Ames, IA 50014, USA e Sygen International, 2 Kingston Business Park, Kingston Bagpuize, Oxfordshire OX13 5FE, UK Received 26 October 2005; received in revised form 23 March 2006; accepted 23 March 2006 Abstract Phenotypic information on 1155 market pigs for several pig meat quality traits, was collected. Genotypes on 12 DNA markers, includ- ing RYR1 and PRKAG3 I199V, were also obtained on all pigs to investigate the relationship between genetic markers and meat quality. The RYR1 gene had the highest impact on meat quality, however, several other markers showed significant effects on one or more traits. Animals heterozygous at the RYR1 locus were significantly inferior in almost all meat quality traits, except ultimate pH value, initial conductivity and redness of the meat. Drip loss from case-ready meat (measured from 1 to 7 days post-mortem) was 43% higher for heterozygotes than animals of the stress resistant genotype. The homozygous genotype II at position I199V of the PRKAG3 locus also resulted in less drip loss than genotypes IV and VV, regardless of the method and time of measurement. Furthermore, the favourable genotype related to higher ultimate pH and darker meat. Both loci significantly affected the intercept, linear and quadratic terms of fitted drip loss development curves. The favourable genotypes showed a lower drip loss after one day of measurement and a slower increase and a more linear development over time. Whilst the RYR1 and PRKAG3 markers influenced numerous meat quality traits, some of the other markers were also found to have significant effects on one or two meat quality traits. Markers at MC4R and HMGA1 loci signif- icantly affected drip loss, whereas LDHA, CAST (Hpy188I) and ATP2A1 influenced pH value. In addition, the marker ATP2A1 was associated with variation in intramuscular fat content in M. longissimus dorsi. GLUT4 affected temperature 45 min post-mortem and several markers (MC4R, LDHA, GLUT4, HMGA1, CAST (Hpy188I and PvuII)) influenced one or two of the different colour measure- ments. The markers at MC4R, CKM, AGRP, PRKAG3, and HMGA1 loci were tested for their interactions with RYR1 regarding drip loss. Only AGRP showed a significant interaction, but this was based on only a few animals with the homozygous genotype for one allele. Our results suggest that genetic markers provide a useful tool to improve meat quality in pigs independently from RYR1, especially the mutation I199V in the PRKAG3 gene. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Drip loss; Meat quality; Genomic markers; Marker-assisted selection; Pigs 1. Introduction Meat quality is influenced by several factors as described by Le Roy, Naveau, Elsen, and Sellier (1990), Leach, Ellis, Sutton, McKeith, and Wilson (1996), Wood and Enser (1997), Støier, Dall Aaslyng, Olsen, and Henckel (2001) Kremer, Stahly, and Sebranek (1998), for example. In this literature, there is a dependence on genotype, feeding, fast- ing, pre-slaughter handling, stunning method and slaughter procedure (for review see Rosenvold & Andersen, 2003). With respect to genotype, the effects of the ryanodine 0309-1740/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2006.03.022 * Corresponding author. Tel.: +44 131 535 3059; fax: +44 131 535 3121. E-mail address: Rainer.Roehe@sac.ac.uk (R. Roehe). www.elsevier.com/locate/meatsci Meat Science 75 (2007) 185–195 MEAT SCIENCE