Changes in electrical resistance of the vaginal mucosa in prostaglandin-treated cows

Ten Hereford x Friesian cows each received 1 mg fenprostalene by a single subcutaneous injection between days 5 and 16 of their ovarian cycles and the treatment was repeated 17 days later. The cows' ovarian cycles were monitored by daily plasma progesterone measurements, and the electrical resistance of their vaginal mucosae was also measured daily, with a Wallsmeta. Luteolysis occurred after 13 of the 20 injections of fenprostalene, and vaginal resistance measurements corresponded to changes in progesterone concentrations in 14 of the 20 potential luteolytic periods. Vaginal resistance measurements decreased in three cases where progesterone concentrations did not decrease (false positive results) and failed to decrease in three cases where progesterone concentrations did decrease (false negative results).