Table 3 lists the effect of various levels of salinity in drinking water on livestock and poultry. Nitrate Nitrates are soluble and move with percolating or runoff water. Therefore, ponds with runoff from heavily fertilized or manured fields and water from poorly cased, shallow wells may contain nitrates. Water from deep wells is usually nitrate free. Nitrogen in the form of nitrate is not especially toxic, but when reduced in the rumen to nitrite and absorbed into the blood, nitrite reduces the oxygen-carrying capacity of the blood by reacting with hemoglobin.
Ruminants have an ability to convert some nitrate to usable products.
However, the rumen microbes in cattle and sheep can readily reduce nitrate to the toxic nitrite form. The total amount of nitrates in the diet is important and subject to change with growing conditions of harvested and pastured forage. For example, during a drought, corn silage may accumulate high concentrations of nitrate and when added to the nitrate present in water may result in a lethal combination. The ensiling process will reduce the nitrate level to acceptable levels after a period of aging for 60-90 days in the silo. Unlike other simple-stomached animals such as swine, horses do have a cecum containing microbes capable of converting nitrate to the more toxic nitrite form.