Your pond or dugout water might look fine, but it could just as easily be compromised by concentrated levels of salts, minerals and bacteria, which can compromise livestock health.
“We recommend that livestock producers test water quality prior to livestock turnout,” North Dakota State University Extension Service livestock environmental stewardship specialist Miranda Meehan says.
Poor water quality can impact livestock health negatively, according to Gerald Stokka, NDSU Extension veterinarian and livestock stewardship specialist.
“At a minimum, it can result in decreased water consumption, reducing feed intake and gains,” he adds. “However, elevated levels of some salts and bacteria can result in severe illness and even death.”
NDSU veterinary toxicologist Michelle Mostrom says water sources should be tested for total dissolved solids (TDS), sulphates and nitrates. TDS measure salts. These levels should be less than 5,000 parts per million (ppm) for most classes of grazing livestock. Elevated levels of TDS may not be harmful to livestock health, but in some cases it is an indicator for high sulphate levels. Sulphate recommendations are less than 500 ppm for calves and less than 1,000 ppm for adult cattle. High levels of sulphate can reduce copper availability in the diet.
Elevated levels of sulphates may cause loose stool, whereas very high levels of sulphate can induce central nervous system problems and polioencephelomalacia, a brain disorder found in cattle.
Nitrate is not toxic to animals, but at elevated levels, it causes nitrate poisoning. Water sources that receive run-off from fields and confined feeding locations that contain elevated levels of nitrogen are at risk of contamination. Water with elevated nutrient levels also are at a higher risk for blue-green algae blooms in periods of hot, dry weather. Some species of blue-green algae (cyanobacteria) contain toxins that can be deadly when livestock and wildlife consume them.
“Monitoring water quality throughout the grazing season is important because it changes in response to climate and environmental conditions,” Meehan says. “What is especially important is to keep a close eye on water quality during drought when using a shallow water source and sources with a history of water quality issues.”
If concerned about livestock diseases caused by contaminated drinking water, contact your local veterinarian or extension personnel.