Genetic variation of in vivo muscle glycerol, glycogen, and pigment in Danish purebred pigs

Heritability values of glycerol, glycogen and pigment concentrations measured on muscle biopsy samples from longissimus dorsi obtained from 85 kg boars of Danish purebred pigs (Landrace, Yorkshire, and Duroc) and their genetic correlations to performance and meat quality traits were calculated. The heritability values of glycogen, pigment, and glycerol were 0.38 +/- 0.02, 0.17 +/- 0.02, and 0.065 +/- 0.016, respectively. Glycogen was negatively related to the feed conversion ratio (FCR) (r(g) = -0.25 +/- 0.06) and ultimate meat pH (r(g) = -0.41 +/- 0.04), and positively to the carcass meat percentage (r(g) = 0.35 +/- 0.04), L* (lightness of meat, r(g) = 0.32 +/- 0.04) and a* (redness of meat, r(g) = 0.12 +/- 0.03). Pigment was positively related to the FCR (r(g) = 0.12 +/- 0.05), the meat percentage (r(g) = 0.28 +/- 0.05), and a* (r(g) = 0.59 +/- 0.04), and negatively to the L* (r(g) = -0.46 +/- 0.06). The concentrations of pigment and glycogen (r(g) = 0.27 +/- 0.05) were interrelated. Based on the heritability values and the signs of the genetic correlations the present data suggest that it is possible to select for higher ultimate pH and improved colour by selection for either lower muscle glycogen or higher pigment concentration, respectively. However, the positive genetic correlation between these two traits may restrict the efficiency of simultaneous selection for lower glycogen and higher pigment. All genetic parameter estimates presented are calculated across three purebreds. Values for each breed are warranted for use in pig production. However, this requires more animals per breed.