Ovulation and the descent of the ovum in the Fallopian tube of the mare after treatment with gonadotrophic hormones

Abstract

1. In mares which had a follicle of a sufficient size in the ovaries, in most cases the intravenous injection of 1000 mouse units or over of pregnancy urine extract caused ovulation at any time in the oestrous cycle.2. In those mares which were in oestrus at the time of injection, ovulation occurred 22–30 hr. after injection, and the length of oestrus was reduced from 7 and 9 days to 3 days.3. In those mares which were not in oestrus when injected ovulation occurred 30–60 hr. after injection without the appearance of any symptoms of oestrus.4. Normal ovulation occurred after these injections, and in one case the ovum was recovered from the uterine end of the Fallopian tube about 95 hr. after ovulation, and 138 hr. after injection.