Determining the reproductive potential of repair heifers

Abstract

Reproduction and culling of productive animals are the main factors that affect the number of cows in a herd. Timely determination of fertility in replacement heifers with subsequent culling of problem heifers will help reduce direct economic losses in breeding dairy cattle. When making a diagnosis, veterinarians should exclude all forms of temporary or permanent infertility, including Congenital anomalies (infantilism, freemartinism, deformities, etc.).In order to establish the hormonal status of heifers-freemartin in the blood serum, the concentration of sex hormones (progesterone, estradiol-17ᵦ, and testosterone) and anti-Müllerian hormone (AMH) was determined.Studies of the level of AMH using an enzyme-linked immunosorbent assay in blood serum have proven the possibility of early assessment of fertility in heifers. This method will allow early culling of Freemartin heifers from a productive herd. The study of AMH levels showed that its amount directly correlates with fertility in cattle, regardless of the period of the estrous cycle. When the concentration of AMH in the blood serum is below 100 pg / ml, heifers are not capable of fruitful insemination, while a high level of anti-Müllerian hormone (more than 380 ng / ml) makes it possible to successfully fertilize animals on the first attempt. All clinically healthy replacements obtained during a single pregnancy were successfully inseminated. At low concentrations of anti-Müllerian hormone, Freemartin heifers were sterile, even after hormonal stimulation (Co-Synx) and sperm doses were administered without clinical manifestation of sexual desire.The introduction of testing for the level of AMH by the ELISA method in the mandatory gynecological clinical examination of cattle in livestock enterprises is expedient and effective.