BIMODAL DISTRIBUTION OF THE MUSCLE GLYCOLYTIC POTENTIAL IN FRENCH AND SWEDISH POPULATIONS OF HAMPSHIRE CROSSBRED PIGS

The distribution of m longissimus dorsi glycolytic potential (an estimator of resting glycogen content) was studied in two pig populations containing Hampshire blood, one in France and one in Sweden. The glycolytic potential was determined on biopsy samples taken using a shot biopsy technique. Napole yield measurements (NY, an indicator of the technological yield of cured cooked ham processing) were available for a part of the French population. The mean values of glycolytic potential were high in both populations (268 +/- 61 and 226 +/- 60 mumol g-1 for the Swedish population and the French population, respectively). In both populations, glycolytic potential distribution was markedly bimodal, suggesting that this trait is affected by a major gene. Pigs considered as RN- carriers on the basis of the NY value (NY < 91 %) had higher glycolytic potential values than those considered as rn+ homozygotes (NY greater-than-or-equal-to 91 %). The results suggest that the gene affecting the muscle glycolytic potential and the major gene rn+/RN known to influence meat quality are identical, the dominant allele RN- increasing muscle glycogen content.