ANALYSIS OF THE POSSIBILITY OF IMPROVING THE INDICATORS OF PORK QUALITY THROUGH SELECTION WITH PARTICULAR CONSIDERATION OF INTRAMUSCULAR FAT (IMF) CONTENT

The aim of the study was to estimate coefficients of heritability for intramuscular fat (IMF) content and other fattening, slaughter and meat quality traits of the pig breeds raised in Poland. In addition, genetic correlations were estimated between IMF content and a group of fattening, slaughter and meat quality traits, which enables this parameter to be included in the BLUP estimation of breeding value. The experiment used Polish Landrace (PL), Polish Large White (PLW), Pulawska, Hampshire, Duroc, Pietrain and line 990 animals. A total of 4430 gilts of these breeds, tested at Pig Performance Testing Stations (SKURTCh), were investigated. Heritability of IMF was at intermediate level for the two most common breeds raised in Poland (h(2) = .318 for PLW, h(2) = .291 for PL). In the group of meat quality traits, high heritability was noted for meat colour lightness (L*) measured by Minolta (from h(2) = .453 to h(2) = .572). No relationships were found between IMF level and indicators of fattening performance. The highest value observed in this group of traits concerned the genetic relationship with daily feed intake (r(G) = .227) for the entire group of animals. For the PLW and PL breeds, these relationships were with feed conversion (kg/kg gain) (r(G) = .151 and r(G) = .167, respectively). One of the higher relationships observed were genetic correlations with water holding capacity (above r(G) = -.3) and, for the PLW and PL breeds, with meat redness (a*), which amounted to r(G) = .155 and r(G) = .143, respectively.