We’ll soon be into haying season and cattle producers are reminded of the threat to cattle that is possible from nitrate poisoning.

Whether you’re a hay producer or one who purchases hay from others, be aware of the potential threat of lower production and loss of animals that can result from nitrate poisoning.

Results of nitrate poisoning can be devastating. One situation I know about resulted in the death of several pregnant cows and the abortion of calves in other cows of the herd. The financial impact of this was significant.

Nitrate poisoning is not something most livestock producers think about on a regular basis. It is important to be aware of the danger and keep in mind the situations, which lead to nitrate accumulation in plants to be fed to cattle.

All plants take nitrogen from the soil and convert it into amino acids, which are the components of protein. Nitrate is converted in the rumen to nitrite and then to ammonia. A build-up of nitrates in the rumen can cause the formation of a type of hemoglobin in the blood that is not able to carry oxygen and results in oxygen starvation, causing illness and death of the animal.

Certain plants are known to be more prone to nitrate accumulation and therefore have a greater tendency for nitrate poisoning. Many of the small grains are in this group. Barley, flax, oats, rye and wheat are more prone to high nitrogen content. Corn, soybeans, sorghum and sudangrass also have this tendency.

Certain non-crop plants tend to be higher in nitrate accumulation. This group includes Canada thistle, dock, Jimsonweed, kochia, lambsquarter, nightshade, pigweed, Russian thistle and wild sunflower. When any of these weeds show up in hay, they have the potential of creating a nitrate toxicity problem.

Situations that stress plants can result in higher nitrogen content. Plant stress can result from things that interfere with the normal plant growth process, such as drought, frost, hail and the application of herbicides. Heavy nitrogen fertilization can also result in more nitrogen than the plant can process. Combinations of several of theses factors, such as nitrogen fertilization of hay that is experiencing low moisture intake can setup a situation that can cause nitrate poisoning.

Cattle are more susceptible to nitrate poisoning than are sheep or horses. Sheep tend to break down nitrate in the rumen more quickly than cattle and are therefore less prone to nitrate poisoning. Horses are not ruminants, but have a rumen-like fermentation process in their cecum and can experience some nitrate toxicity.

If there is any reason or thought of the possibility of nitrate poisoning, it is best to have the hay tested. Nitrate content can be determined by laboratories that test forages for nutrient content. Potential buyers may want to have information on the protein content and energy levels, as well as, the nitrate content of the hay before making a purchase.

To avoid the ravages of nitrate poisoning, cattle producers should be aware of the plants prone to nitrate accumulation and the conditions that contribute to its occurrence. The threat of nitrate poisoning is always present and both livestock and hay producers need to be alert to its possibility with specific plants and under certain conditions.

Columnist Doug Warnock writes about issues related to grazing.

Recommended for you