At present, the enterprises of the agro-industrial complex report many cases of cows having liver dysfunctions caused by the failure of metabolic processes. As a rule, in the early stages of the disease, clinical signs are absent; it leads to a productivity decrease, the birth of weak young animals with low adaptive capabilities, and pathologies of the reproductive system. There is a need in drugs and biologically active feed supplements that can prevent and eliminate pathological processes in the liver at early stages, adjusting physiological metabolic processes. The article presents the research results on the use of the herbal feed supplement ZIGBIR having hepatoprotective properties in cows’ diets. Biochemical studies of blood serum have shown a positive effect of the feed supplement on most parameters in relation to physiological norms. Since the studied parameters are referred to as hepatic (they have a diagnostic value for the liver), it is possible to assume an improvement in the functional state of the liver.