Cervical secretions of clover-affected and control ewes in the luteal phase of the ovarian cycle were obtained by flushing the anterior vagina. The flushings were analysed for proteins, carbohydrates and enzyme activities, and were found to be similar to the secretions of the normal ovine uterus. There was significantly more protein, carbohydrate and acid-soluble glycoprotein but less alkaline phosphatase, N-acetylglycosidases (EC 3.2.1.30 and 3.2.1.53) and ribonuclease I in the vaginal flushings of clover-affected ewes.The observed changes were not due to more inflammation in the cervix of clover-affected ewes as there were fewer bacteria, leukocytes and epithelial cells and no elevation of lysozomal enzyme activities in their flushings. It is suggested that the cervix of the clover-affected ewe behaves as though under a stronger than normal oestrogenic stimulation during dioestrus.
IntroductionEwes rendered permanently infertile by prolonged ingestion of oestrogenic clover produce abnormal cervical mucus which prevents normal sperm transport and fertilization (Lightfoot et al. 1967;Smith 1971). Histological changes of the cervices of these ewes have also been observed by Heydon and Adams (1977). A test on cervical secretions could be expected to be a useful diagnostic method for detecting permanent clover infertility.Adams (1967a) found that mucus from clover-affected ewes had a spinnbarkeit value significantly lower than that from control ewes. Although the mucus spinnbarkeit test was subsequently found to be useful for assessing lowered reproductive performance in ewes exposed to oestrogenic pasture (Adams 1977), it has limitations. Spinnbarkeit varies with the time of the breeding season so that adjustment is needed to compare results obtained at different times. Cervical mucus is abundant only when the ewe is in oestrus and even then some ewes produce so little that collection of an adequate sample is impossible. Because of these limitations it is worthwhile to seek other diagnostic methods and one possible area is the biochemical analysis of cervical secretions during the luteal phase of the reproductive cycle.In the present experiment proteins, carbohydrates and some enzymes, including lysozomal enzymes, in the. luteal-phase cervical secretions obtained by flushing the anterior vagina of clover-affected and control ewes were assayed and compared.