Influence of the Dominant White/KIT Genotypes on the Reproductive Organs of Pigs

Abstract

Based on earlier studies with mice and pigs, the possible pleiotropic effects of the individual porcine Dominant White/KIT genotypes on the size, histological parameters, and surface features of the ovaries; on the size, histological characteristics, and volume of the testes; and on the occurrence of abnormal epididymal sperm cells were studied in two F2 generations of an intercross between Hampshire boars and Hungarian Large White sows. The KIT genotypes were determined by a PCR-RFLP method. The ovarian diameters of gilts of various KIT genotypes did not differ significantly (P=0.292), and the II pigs had the smallest diameters. The proportion of the investigated follicular types among the different KIT genotypes did not differ significantly (P=0.329-0.919), and the highest numbers of degenerated and atretic follicles were found in the ovaries of II genotype pigs, which also exhibited the highest proportion of primary follicles. The testis volume in the II homozygote white genotype boars (249.5 cm(3)) was significantly (P<0.01) larger than in the Ii (205.4 cm(3)) and ii (197.5 cm(3)) boars. Bodyweight and age significantly (P<0.01) affected testicular volume. KIT genotypes had no profound effect on the proportion of the various epididymal sperm abnormalities, and ii type boars showed the highest (nonsignificant) numbers of primary abnormalities. The changes in abnormal sperm cell frequency were linear to the changes in bodyweight and testis volume. We were unable to demonstrate disadvantageous effects of the KIT genotypes on the investigated ovarian, testicular, and epididymal sperm characteristics. Therefore the reproductive traits of white colored pigs examined in this study are no worse than those of pigmented breeds.