A 61, XXV CHROMOSOME COMPLEMENT IN SUBFERTILE JERSEY CROSSBRED BULL

Abstract

Cytogenetic studies in animals as well as humans have identified chromosomal abnormalities as one of the reasons contributing to
reduced fertility and infertility. The commonly found X-chromosome anomalies in domestic species are aneuploidy, trisomy (XXX) and
monosomy (XO), mosaicism and chimerism. Nondisjunction of the X chromosome during meiosis can result in XO, XXX or XXY zygotes. However, in cattle, the incidence of trisomy - X is very rare (Pinheior et al. 1987), this paper describes the occurrence of XXY, which appears to be first case in a crossbred bull.