title: [Chromosome studies of 300 young Dutch-Friesian and Holstein-Friesian bulls intended for use in artificial insemination].
abstract: Three hundred young Dutch Friesian and Holstein-Friesian bulls, kept in the Central Opfokstation (Central Breeding Station) in Terwispel (Friesland), were studied cytogenetically, using conventional staining methods. Structural chromosome aberrations were not observed. Four animals showed XX/XY-chimerism in the lymphocytes, probably caused by the interchange of haemopoietic cells between the male and its female co-twin by placental vascular anastomosis. The number of (iso)chromatid gaps in 25 metaphase plates varied from 0 to 4. Chromosome breaks were not observed. The chimeric bulls and those with (iso)chromatid gaps were not found to show significantly reduced fertility rates.
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D002678:Chimera; D002869:Chromosome Aberrations; D002874:Chromosome Mapping / Q000662:veterinary; D002875:Chromosomes / Q000032:analysis*; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D012730:Sex Chromosomes
vernacular_title: Chromosoomonderzoek aan 300 jonge Fries-Hollandse en Holstein-Friesian stieren bestemd voor KI-gebruik.