A case report on X‐trisomy in cattle

摘要

A case of XXX-gonosome aberration in a heifer of the Norwegian Red Cattle (NRF) is reported. Cytogenetic examination of leucocytes from the animal showed the karyotype of 61. XXX. Except for the failure to express oestrus more than one time during 18 months, the NRF-heifer showed clinically nothing peculiar. Post mortem the ovaries were found to be underdeveloped, one of them having a small corpus luteum. The cells of the corpus luteum had the morphological characteristics of active lutein cells, but in contrast to this observation. the concentration of blood plasma progesterone remained at low levels (0.3 ng/ml) in the period of observation. The rest of the reproductive organs did not show pathological changes. Chromosome analysis of the peripheral blood cells of the mother and the maternal half sisters of the heifer did not demonstrate any genetical disposition in the family to the formation of non-disjunctive gametes.