The effects of exogenous progestagen and oestrogen on cervical mucus in the ewe

Abstract

The production of mucus during the pro-oestrous and oestrous phases of the oestrous cycle, and the moisture content of the samples, were measured in normal cyclic ewes and in ewes in which the time of oestrus and ovulation were controlled by the application of Cronolone-impregnated intravaginal sponges, either alone or with the concurrent injection of 1 µg, 5 µg, or 25 µg oestradiol-17G (E₂) per day from the day of sponge insertion until the day before sponge withdrawal.

The average duration of oestrus was not affected by the treatments. Production of mucus and the percentage of moisture in the samples in the Cronolone-treated ewes were depressed following the injection of the higher doses of oestrogen. The content of dry matter in the mucus sample declined throughout the observation period in all groups apart from that which received 25 µg E₂/day.

The possible role of the changes in mucus characteristics recorded in this experiment is discussed in relation to the transport of spermatozoa into and through the cervix.