Determination of optimal insemination time in sheep by assessing cervical mucus arborization

Abstract

Insemination and estrus synchronization are one of the most used biotechnological reproductive methods used in sheep breeding, but also in most other livestock species. Subsequent insemination values are influenced by several factors such as age, condition, health, hereditary establishment of the animals, quality of the insemination doses and the quality of the performance of the insemination itself. Another way to optimise the insemination values is to determine the optimal time for insemination, which varies between livestock species but may also vary slightly within the individuality of the individuals within the breed. One way of determining the optimal time for insemination is to assess the arborisation of cervical mucus, which forms different types of structures after crystallisation at different stages of estrus. Changes in the arborisation structures are influenced by endocrine changes, by the action of oestrogen on the cervical glands, where electrolytes are concentrated and which, after association with mucin and subsequent crystallisation, form typical structures. The experiment took place from September 2020 (synchronization of estrus and insemination) to March 2021 (end of lambing). In this experiment, it was found that the type of crystallization structures at the time of insemination has a conclusive effect on the subsequent pregnancy rate. Animals with "V" type crystallization achieved the best pregnancy rate (80%).