Fertility of cows and heifers depending on various factors and methods of its correction

The main reason for the decrease in fertility in cattle is a violation of metabolic processes, which is primarily accompanied by a dysfunctional disorder of the gonads and the emergence of inflammatory diseases of the uterus. Therefore, further detailed study of the physiology of cattle breeding is an important task for obstetric science and practice. Studies have shown that during the year the lowest fertility in cows of black - and-white crossed with Holstein breed is observed in the summer months, and the highest in late spring and autumn. The higher the productivity of cows, the lower their fertility and more pronounced its seasonal changes. General patterns of changes in fertility in heifers depending on the productivity of the maternal herd and the season of insemination were not revealed. In the first 50 days of the postpartum period, only 8.5% of clinically healthy cows occur genital involution and resume sexual cyclicity. Depending on the time of insemination after calving, the highest fertility of cows is observed between 40 and 50 days, subsequently this figure is reduced to 80 days, and then again increases to 110 days...