A case of Y-autosome reciprocal translocation in a Holstein-Friesian bull.

Cytogenetic evaluation of young bulls of the Polish Holstein-Friesian breed, tested before approving for use in artificial insemination, revealed a carrier of a Y-autosome reciprocal translocation. The applied chromosome banding techniques and fluorescence in situ hybridization (FISH), with the use of locus-specific BAC probes, facilitated description of the translocation as t(Y;21)(p11;q11). The bull presented normal development, including body weight and the size of testicles, as well as libido. Testosterone concentration at the age of 8 months was similar in the carrier and a normal bull of the same age, but at the age of 12 months the testosterone concentration appeared to be lower in the carrier.