Studies on the maintenance of the corpus luteum in the ewe

M.F. McDonald

Massey University, Palmerston North

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Proceedings of the New Zealand Society of Animal Production. 1964, 24: 69-76

In 18 ewes the life-span of the corpus luteum was examined following excision of parts of the reproductive tract on day 4 of the oestrous cycle. At slaughter on days 23 to 25 of the cycle, total hysterectomy always resulted in the maintenance of luteal tissue but partial hysterectomy was less effective; following sham operation or removal of the Fallopian tube, the corpus luteum was not maintained.

In a second experiment with 16 ewes, bilateral ligation of all main uterine blood vessels or of uterine veins alone usually caused the maintenance of luteal tissue. Unilateral ligation of blood vessels (except in one ewe) or the bilateral ligation of uterine arteries did not prolong the life-span of the corpus luteum.

Injection of extracts of endometrial tissue obtained from ewes in the late luteal phase of the oestrous cycle failed to cause regression of luteal tissue in hysterectomized elves.

Keywords: NZSAPAB;