Be sure water is safe. Above 2100 Potentially lethal. Poor appetite, vcitamin A deficiency, abortions, general production lowered. Hazardous intake level for all animals. In most situations feed would refer to forages.
Most forages contain some nitrate.
Nitrate is not particularly toxic to cattle. When feeds containing nitrate are eaten by ruminants, the nitrate is normally broken down to ammonia and converted by bacteria into microbial protein. Some of the nitrite is absorbed into the animal's bloodstream where the nitrite is capable of changing the normal oxygen-transporting substance, hemoglobin, into methemoglobin, a substance that cannot carry oxygen from the lungs to the tissues. Nitrates also cause dilation of blood vessels, and further lack of oxygen is caused by peripheral circulatory failure. Lack of oxygen to the tissues may be the cause of abortions, which sometimes occur following nitrate poisoning.