COLUMN: Nitrates could pose problems for area cattle


Dana Zook, Enid News & Eagle (OK) 

Jun 19, 2022


This article is coming to you after some much-needed rainfall across most of the Northwest Oklahoma.


Reports of green pastures abound, and the warmer temperatures have put forage growth into high gear. We now have ample forage for our livestock in the near term, but Mother Nature also has has blessed us with a flush of weeds and grasses that could be poisonous. One of the most common toxicants found in Oklahoma forages is nitrates.


What are nitrates?


Nitrates are found in most plants, but the issue begins when nitrates accumulate. Excessive nitrate accumulation occurs when the uptake of nitrate in the plant exceeds what can be utilized in the plant to produce protein.


Any conditions that stress the plant, such as drought, shade, frost or temperature extremes, increase the possibility to accumulate these toxins.


Regardless of the age of the plant, the highest nitrate accumulation will occur in the lower 6-12 inches of the stem. Producers who graze these crops should avoid forcing livestock to consume this part of the plant.


Why are nitrates toxic to livestock?


When high-nitrate feeds or forages are consumed by ruminant animals in excess, poisoning can occur. According to “Nitrate Toxicity in Livestock” PSS-2903 Factsheet, nitrate poisoning actually is “nitrite poisoning” due to the chemical conversion that occurs within the digestive system of the ruminant animal. This toxin is absorbed from the digestive system into the blood stream where there is a conversion of oxygen transporting hemoglobin to methemoglobin. Methemoglobin cannot transport oxygen to body tissues, which can cause potential asphyxiation of the animal. Ruminant livestock, such as cattle and goats, are most susceptible followed by sheep to a lesser degree. Simple stomached animals, such as swine and poultry, are not as impacted by nitrates as ruminant animals.


What plants accumulate nitrates? ...


How to manage a common problem ...