Frequent intake of small amounts of a high nitrate feed increases the total amount of nitrate that can be consumed daily without toxic effects. More of a high nitrate forage can be fed without harmful effects by feeding it in limited amounts several times daily rather than feeding large amounts once or twice daily. Similar results can be obtained by using the high nitrate forage in a complete self-fed ration rather than feeding the roughage free choice separate from the other ration components. With frequent intake of limited amounts of high nitrate feed, the concentration of nitrate in the rumen does not become extremely high at any one time. Hay, straw, or fodder that is suspected of being high in nitrate should not be fed when damp.
Damp feed seems to be more toxic.
The probable explanation is that some of the nitrate is converted to the more toxic nitrite in the blood. Even if the forages are high in nitrates, they often can be diluted to a safe level with other forages that are low in nitrate or with grain. Some dietary guidelines for feeding forage with different levels of nitrates are shown in Table 3. Nitrate levels in forages for cattle and sheep. General rules of thumb for using forages in sheep and cattle diets.