The influence of radiation on reproduction of sheep

Qualitative and quantitative histological changes in the sexual apparatus of slovak merino ewes were studies in the anoestrous period after irradiation (2.5 Gy) and hormonal stimulation. Estrus synchronization of the sheep has been carried out by application of 20 mg chlorosuperlutine in impregnated vaginal Ageline sponges. The sheep were hormone stimulated by application of 1500 IU of Serum gonadotrophin. The animals were killed approximately 120 h after the application of the hormone. Samples from the sexual apparatus were processed by the common histological methods for examination under a light microscope and for examination under a scanning electron microscope (SEM). Despite higher number of ovulations in irradiated and hormonally stimulated sheep, the examination of viability of irradiated oocytes showed absence of pregnancy in all 20 sheep after mating. This indicated that the dose of 2.5 Gy was not harmless to the reproductive system of sheep. (authors)