[Meiotic chromosomes of the spermatocytes ejaculated by bulls]

The Sperling and Kaden (1971) approach was used in studies of the bull meiotic chromosomes. The number of meiocytes in the ejaculates of normal bulls ranged from 0.0001 to 0.0114% of the whole set of cellular elements in the ejaculate. Two of the studied bulls had a chromosomal abnormality in somatic cells (60, XX/60, XY mosaic). These bulls displayed no deviation as concerns the quantity of meiocytes in their ejaculates. In two other bulls examined, with cryptorchism and azoospermia, about 0.0017 and 4.75% meiocytes were counted in the ejaculate, respectively. A comparative analysis of ejaculated chromosomes and meiotic chromosomes obtained from the normal testes by biopsy did not reveal any differences in the chromosomal morphology. Various premeiotic and meiotic stages, from spermatogonium A and B to metaphase 1, were identified in the bull ejaculates. This technique may be valuable in cytogenetic diagnosis of meiotic abnormalities in sires.