Effects of progesterone and Pregnant Mare Serum (PMS) adminsitration in the anoestrous ewe. II. Histological examination of the genital tract

Abstract

Reproductive tracts from 105 anoestrous Romney ewes were examined histologically. Twenty animals served as controls, 10 received pregnant mare serum (PMS), and 10 mere given progesterone injections followed by PMS. Different amounts of progesterone alone mere administered during 4 days to the remainder. Sections were cut from tissues of the vagina, cervix, uterus, and three regions of the fallopian tubes. The findings in the control ewes in the present investigation agreed in general with those reported by earlier workers, with the exception of the fallopian tubes in the anoestrous ewe, for which no data were available in the literature. Apparently the upper part of the genital tract recedes in anoestrus to a condition not observed at any point in the breeding season. The influence of progesterone injections was most pronounced on the uterus, but was seen to a lesser degree in the cervix. Neither the vagina nor the fallopian tubes exhibited marked changes as a result of progesterone administration but both organs reflected slightly the ovulations which had been induced.