CHANGES IN THE IMPEDANCE OF VAGINAL VESTIBULE MUCOSA DURING OF ESTROUS-CYCLE IN CAUCASIAN MERINO EWES

The impedance of vaginal vestibule mucosa was measured in 10 Caucasian Merino ewes. The impedance was measured once a day from day 8 to day 15 after the end of heat, one day before the expected successive heat, twice a day during heat, and in the following period until day 6 after the end of heat the measurements took place once a day. A low-frequency two-terminal instrument with a probe was used; five electrodes are fixed in the sector of circle 130-degrees at its apical pole. The average values of the impedance of vaginal vestibule mucosa in ewes during of oestrous cycle ranged from 87 to 102 ohms. A slight decrease in impedance was recorded 12 hours before the beginning of heat and in the first hours of heat. The differences in the average values of impedance, recorded on individual days of oestrous cycle, were not statistically significant. The results have indicated that the measurements of the impedance of vaginal vestibule mucosa performed at the frequency of measuring current about 10 kHz cannot be used for the monitoring of individual phases of the oestrous cycle in sheep.