More than 200 cows in Missouri died last month from nitrate poisoning, according to the University of Missouri Veterinary Medical Diagnostic Laboratory. Unusual weather the last couple years likely set up this problem with nitrogen entering plants as nitrate during wet periods and remaining as raw nitrate because of dry weather. This may result in too much raw nitrate in plants causing hay to become toxic.
Source: Successful Farming, March 5, 2019. Link. “Know your hay,” Craig Roberts, MU Extension forage specialist says. Know where it came from and whether fertilizer or poultry manure was used. Risks rise in hay made in drought. Hay detective work doesn’t come easy.
INSIGHTS: County Extension centers may have quick-test kits available that indicate if further testing is needed. If you call on producers feeding hay that has been baled in the last couple of years, letting them know kits are available may save a few cows, as well as some unborn calves that may be on the way.