FREQUENCY OF THE RYR1 N ALLELE AND ITS INFLUENCE ON FATTENING TRAITS

The RYR1 genotype was determined in 2403 animals, belonging to five di fferent pig breeds in Slovenia. The frequency of the RYR1 n allele was estimated to be 0.109 - 0.165 in Swedish Landrace, 0.001 - 0.160 in L arge White, 0.199 - 0.502 in German Landrace, 0.00 - 0.078 in Duroc an d 0.432 in Krskopolje pig. Under performance test conditions the follo wing fattening traits have been analyzed: age at 30, 60 and 100 kg, da ily weight gain in the period from 30 to 60, 60 to 100 and 30 to 100 k g body weight, daily feed intake and feed conversion during the same t hree periods, and backfat thickness at 100 kg body weight measured by ultrasound. Statistical evaluation revealed significant effect of the RYR1 genotype on some fattening traits. Animals with the RYR1 genotype nn were, compared to NN and Nn animals, older at 30, 60 and 100 kg bo dy weight, had lower daily weight gain between 30 and 60 kg and had lo wer back fat thickness at 100 kg. Results indicated differences betwee n testing stations but little difference between breeds.