Prevalence of subclinical abortions in cows due to mycotoxicosis

The article presents data on the distribution and seasonal dynamics of subclinical abortions in cows with mycotoxin poisoning, particularly zearalenone. Subclinical abortion is a common phenomenon among cows in dairy farms and causes significant economic losses due to multiple unsuccessful inseminations, reduced animal productivity, and premature culling. The research aimed to study the seasonal fluctuations of hidden abortions in cows and the influence of the method of keeping in the conditions of feed contamination with microscopic fungi and their toxins. To diagnose hidden abortions, cows were diagnosed with the pregnancy on the 32nd day after insemination. When pregnancy was confirmed, the animals were examined for 92 days. At the same time, if the pregnancy was not confirmed, it was considered that an abortion had occurred. Seasonal fluctuations of subclinical abortions were established - the most significant number (up to 13.6 %) was diagnosed at the end of spring, associated with many animals entering the hunt after the transit period. It is also important that at that time, the number of mycotoxins in feed reached record values, which led to abortions due to toxic effects on the organs of the reproductive system in particular and the body in general. A large number of abortions (11.2 %) in the summer season was also confirmed. At the same time, animals kept free all year received a similar diet containing mycotoxins. At the same time, a concomitant negative factor was temperature shock at this time of year. This whole complex of reasons led to subclinical abortions followed by the resorption of the fetus. Sonographically, areas of reduced echogenicity of the uterus in cows after abortions were detected, which is evidence of the development of subclinical endometritis, confirmed by the uterus's heterogeneous echogenicity. In infertile animals, the presence of follicles with cavities and small yellow bodies that did not extend beyond the surface of the ovary was established sonographically. This indicates a hypofunctional state and impaired folliculogenesis and luteogenesis