Non-fertility in cows with an abnormal indole metabolism and disturbed carbohydrate composition in the cervical mucus: a preliminary report.

Cervical mucus samples of the cow appear to provide information on the probability of becoming pregnant. In six 'repeat breeders' a strong indole metabolism was found in the cervix. When luteal tissue was decreasing and follicles increasing, compounds were found indicating possible exfoliation of the endometrium, which in dogs is a normal process in late metoestrus. Exfoliation of the endometrium was actually demonstrated in two cows after slaughter. It can delay the onset of oestrus for several days and can disturb implantation of an embryo. The carbohydrate composition of the cervical mucus was also different from that in normal cows. Treatment with PMSG and PGF resulted only twice in the formation of glucuronic acid and sorbitol, which are seemingly necessary for the receipt of spermatozoa. A disturbed carbohydrate composition and an abnormal indole metabolism, which is easily detectable in the cervical mucus, may prevent or disturb fertilization in cows.