PH(1) VALUES OF MEAT OF HYBRID PIGS WITH HETEROZYGOUS GENOTYPES OF HAL LOCUS

Locus HAL genotypes were determined in the parental generation of boars and sows by DNA-test. The boars and sows came from the elite stock of the breeds Landrace (L) and Large White (LW). In their castrated offspring (barrows) tested at a pig progeny testing station meat quality was established on the basis of pH(1) value determined 45 minutes after slaughter, at the weight of 91 to 108 kg and at the age of 150 to 200 days. pH(1) values were measured on the right side of pork, behind the last rib in the musculus longissimus lumborum et thoracis with a stab electrode. Locus HAL genotype was also determined in all offspring. Among these individuals, 20 hybrid pigs of two types of reciprocal crossing of maternal and paternal breeds L x LW and LW x L with heterozygous genotypes were chosen. The first group (n = 10) comprised the offspring after seven sows of L breed and one boar of LW breed. The second group (It = 10) involved the offspring after five sows of LW breed and one boar of L breed. pH(1) values were assessed for the whole set on the basis of the limit value pH(1) > 6.00 for normal meat and pH(1) less than or equal to 6.00 for PSE meat. The acquired data were also processed using the limit value for PSE meat pH(1) less than or equal to 5.80 and pH(1) less than or equal to 5.60. A similar method was used to analyze the pH(1) values in both sets of reciprocal crossing (L x LW and LW x L). Meat quality was evaluated on the basis of various limits of pH(1) for the whole set of hybrid pigs with heterozygous genotypes of HAL locus (Tab. I). First, the limit values pH(1) less than or equal to 6.00 were used to discriminate PSE meat and normal meat. The set of 20 pigs of both types of hybrids of reciprocal crossing of the breeds L x LW and LW x L comprised 45% of animals with normal meat and 55% of pigs with PSE meat. Further evaluation worked with the limit value pH(1) less than or equal to 5.80. The percentage shifted to 60% pigs with normal meat and 40% pigs with PSE meat. For the last evaluation of the whole set, pH(1) less than or equal to 5.60 was used as the limit value. The share of individuals with normal meat increased to 75% while the remaining 25% had PSE meat. The crossbreds L x LW showed the percentages of 40% and 60% animals with normal and PSE meat, respectively, at pH(1) less than or equal to 6.00 (Tab. II). The percentages for the limit value pH(1) less than or equal to 5.80 were identical. At the value pH(1) less than or equal to 5.60, the shares of pigs shifted to 60% of animals with normal meat and 40% with PSE meat. The crossbreds of the breeds LW x L showed different percentages of animals with normal meat and PSE meat for the same limit values (Tab. III), i.e. 50% and 50%, 80% and 20%, 90% and 10%, respectively.