Drought conditions can compromise water quality in ponds and dugouts, causing elevated levels of salts, minerals and bacteria.
“Because the majority of the state is experiencing some level of drought, 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.
“The risk of problems is greater in areas of the state that had poor water quality in 2016.”
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 says. “However, elevated levels of some salts and bacteria can result in severe illness and even death.”
NDSU veterinary toxicologist Michelle Mostrom recommends water sources be tested for total dissolved solids (TDS), sulfates 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.
“However, due to our geology in North Dakota, water with high TDS often have high sulfate levels,” Mostrom says.
High levels of sulfate can reduce copper availability in the diet. Elevated levels of sulfates may cause loose stool, whereas very high levels of sulfate can induce central nervous system problems and polioencephelomalacia, a brain disorder in cattle.
Sulfate recommendations are less than 500 ppm for calves and less than 1,000 ppm for adult cattle.
Nitrate in itself is not toxic to animals, but at elevated levels, it causes nitrate poisoning. Water sources are at risk of contamination if they receive runoff from fields and confined feeding operations that contain elevated levels of nitrogen.
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 the quality 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.”
Many commercial laboratories and the NDSU Veterinary Diagnostic Laboratory provide testing for livestock water quality and specialized testing. The cost of a basic water quality test is approximately $25. Contact a county office of the NDSU Extension Service for a list of commercial laboratories in the state.
If concerned about livestock diseases caused by contaminated drinking water, contact your local veterinarian, the NDSU Extension veterinarian, or the NDSU
Veterinary Diagnostic Laboratory at 701-231-8307 or www.vdl.ndsu.edu/.
More information on livestock water quality is available in the following Extension publications: