A case of impaired fertility in a Large White boar with sex chromosome chimerism

Chromosomal abnormalities are a well-established cause of fertility impairment in domestic animals. Chromosomal abnormalities in pigs may result in low prolificacy and subsequent reduction in reproductive parameters (e.g. litter sizes and nonreturn rates) having substantial impact on swine industry. Until now, the effect of sex chromosome abnormalities on fertility has not been thoroughly documented for male pigs. We report a case study involving a Large White boar with sex chromosome chimerism (2n = 38, XX/XY) identified by conventional karyotyping and fluorescence in-situ hybridization. Progeny of this boar was evaluated; there was reduction (p < 0.001) in litter size demonstrating the potential impact of sex chromosome chimerism on herd productivity in pigs.