The differences of electrical resistance values of vaginal mucus (ERVM) in yearling and mature saanen goats

Abstract

It has been reported that during the oestrous cycle, an increase in the volume of cervical mucus occurs due to the influence of high oestrogen concentration on vaginal vasodilation, leading to a decrease in the electrical resistance of vaginal mucus (ERVM) as the goat approaches estrus. The present study aims to understand the differences between yearling (n:14) and mature (n:22) Saanen goats when continuous measurements of ERVM were taken by using the digital Draminski® device (Draminski Electronics, Poland). Oestrus was synchronized using intravaginal sponges and the ERVM measurement was taken every 6 hours right after the sponge removal until insemination. The results indicate that ERVM measurements for mature Saanen goats were significantly lower at 0, 6, 12, 30, 36, and 42 hours compared to those of yearling Saanen goats. Additionally, within the yearling Saanen group, there was a significant difference between the measurement taken at the 18th hour and the measurements taken at other time points. Furthermore, as goats approached estrus, the differences in ERVM measurements between mature and yearling Saanen goats disappeared. Based on these results, the ERVM values in yearling Saanen goats can be reliably used for predicting time of estrus, while a more cautious approach should be taken for mature Saanen goats.