The improvement of agriculture is inextricably linked with the increase in feed production. The intensive feed production system involves using high doses of nitrogen fertilizers. This significantly increases the yield, but at the same time nitrates accumulate in soil, water and feed. Excessive amount of nitrates causes the wrong course of functioning in natural ecosystems and animal organisms, there is a decrease in the biological value of products. Meanwhile, the importance of nitrates and their impact on human health has increased recently. However, this problem has not yet lost its significance and is increasingly attracting attention of many researchers of various specialties. Currently, there is no clear agreement on the permissible amounts of nitrates in feed for farm animals and on the effect of these toxicants on metabolism.