THE STAGE OF REPRODUCTIVE, FATTENING AND CARCASS PERFORMANCE TRAITS OF PIETRAIN PIGS OF DIFFERENT MHS-GENOTYPE PRODUCED IN 2 BREEDING HERDS

For the purpose of the comparison of the reproductive, fattening and c arcass performance traits of different MHS-genotypes of the Pietrain r ace there were available 343 sows and 470 animals of progeny testing b oth produced in two breeding farms. The most important results can be summarized as follows: Stress-resistant sows are inferior to stress-su sceptible sows with regard to reproductive performance; but the differ ences are not significant. Stress-resistant pigs, especially of pure s tress-resistant genotype, verified a lower fattening performance than stress-susceptible pigs; but the differences are not significant, too. Pure stress-resistant pigs produce significantly higher fat and lower lean meat portions than stress-susceptible pigs; mixed stress-resista nt animals occupy the middle of both. The meat quality of pure-resista nt pigs, followed by mixed stress-resistant animals, is much better th an that of stress-susceptible pigs. According to the results which hav e been discussed a general selection for pure stress-resistance of the Pietrain race is recommended.