Clinical and laboratory prognostic indicators for fertility in sheep

Abstract

With the use of technology of artificial insemination in sheep farms are not yet defined criteria for assessing the full value of the preparation of females for insemination, and hence – the possibility of prediction and correction of their fertilization, which prevents the rational use of cryopreserved semen and ensuring the maximum reception of the offspring. We have proved the prognostic importance of fertilization of the morphofunctional state of the vulva and the vagina and the quality of mucus in sheep breeds during estrus. The material of the study was 327 sheep of ascanian breeding, which during the sexual intercourse before insemination examined the vulva, vagina and evaluated the estrus slime (number, color, consistency, presence of impurities, elasticity, electrical resistance, type of crystallization, protein content). The results of ultrasound diagnosis of pregnancy were determined by the fertility of sheep with different integral compositions of clinical and laboratory parameters. It has been established that in sheep, in which fertility in the first sexual cycle reached 65.1%, most often found a pink, moderately edematous vulva with clear mucus. In females with pale mucous membrane and insignificant amount of mucus, the effectiveness of inseminates declined to 53.3-58.0%. In a significant amount of estral mucus, the proportion of infertile animals increased twofold. At the same time, the selection of liquid, but cloudy, or thick mucus is a sign of an unfavorable prognosis, in which fertility decreases by 1.8-2.1 times (p <0.001). Dense, white, paste-like isolates were observed in a small number of sheep, mostly bright at the beginning of the anestral season. Low fertility in the first sexual hunting (35.5%) and a high multiplicity of repeated inseminations (29.0%) indicate that sheep with thick estral slime are only beginning to enter the sexual season, and this quality of secrecy indicates an inadequate estrogenization of the body. It was also found that in the infertile sheep during sexual hunting, the protein content of cervical mucus was 4.8 times higher, and the elasticity of mucus was reduced by 2.9 times. The most prevalent was the prognosis of average fertilization (53.3-58.0%), which was recorded in 62.9% of experimental sheep. The prognosis of high fertilization, which resulted in 62.5-65.1% of oseminins, was found in 27.8% of females. At the same time, the number of females with a fertility forecast at 40% was only 3.1%, and the prevalence of an unfavorable prognosis, in which fertility was the smallest (30.0-35.5%), reached 6.2%. Key words: sheep, askanian breeding, estrus, fertility prognosis, estral mucus, vulva, vagina, artificial insemination.