We’re all aware of the current drought in the Midwest and its potential effects on crop yields, particularly corn. I wouldn’t have known about this hazard though if I hadn’t been reading the farm press:
KANSAS CITY, Mo. (AP) — Missouri agriculture officials are warning that cattle grazing on some drought-stressed plants are at risk of falling ill or even dying.
One issue is nitrate poisoning. The University of Missouri Extension says nitrate poisoning poses the biggest risk in pastures that contain sorghum sudan, millet and Johnsongrass.
Animals that eat nitrate-laden plants appear to be suffocating because nitrate poisoning inhibits the ability of blood to transport oxygen.
Nitrate is a naturally occurring form of nitrogen found in the soil. Normally, little nitrate accumulates in plants because they rapidly convert nitrate to amino acids and proteins. But when conditions are dry, the roots will take up nitrate faster than the plant can convert it.
Dry conditions also can lead to potentially toxic accumulations of prussic acid in plants such as sorghum.