Monitoring Range Water Quality Essential for Healthy Livestock

 BROOKINGS, S.D. -- The drought makes it imperative for producers to monitor the quality of water their livestock are drinking, South Dakota State University specialists say.

"Water from wells, stock dams, and streams in South Dakota is often high in total dissolved solids (TDS), and especially sulfates," SDSU range science professor and researcher Pat Johnson said. "Drought conditions compromise water quality in natural water sources, as salt concentrations increase from enhanced evaporation and diminished moisture recharge. In addition, producers may be forced to use marginal or poor water pumped from wells if water from streams and stock dams isn't available."

SDSU Extension Veterinarian Bill Epperson added that livestock may experience increasingly serious health and production problems as water quality declines. It is important to observe animals and to know how to confirm a water quality problem.

Animals will voluntarily consume less poor quality water, and as a result they eat less feed/forage.  Decreased feed intake leads to decreased weight gain or increased weight loss, decreased milk production, and decreased fertility. Reductions in performance may be more pronounced in cattle that are subject to heat stress, such as cattle in confinement. Poor quality water can lead to illness and death, especially if the water is high in sulfates.

In South Dakota, it appears that sulfates are the salt that causes most problems, Epperson said. High sulfate intake may cause health problems in ruminants. The physical signs seen in these animals are those of polioencephalomalacia ("polio") and include lethargy, anorexia, blindness, muscle tremor, exaggerated response to sound or touch, incoordination, staggering, weakness, and eventually convulsions and inability to get up.

 The symptoms occur because normal brain cell energy utilization is altered, and brain cells die from lack of energy. If severe, the animal will die. Young cows may be predominately affected. If animals exhibit signs of polio or die, producers should contact their veterinarian for assistance.

"Polio can be successfully treated if the brain damage is not too severe," Epperson said. "Affected animals need access to good water. Thiamine injections and anti-inflammatories also help affected animals. Animals dying from polio have characteristic lesions in the brain, with other organs unaffected."

Factors that increase water intake and so increase the likelihood that animals may show ill effects from poor quality water include large physical size, lactation, dark coat color, increased physical exertion, decreased forage moisture, confinement, and increased environmental temperature.

Most county Extension offices in South Dakota have conductivity meters and Extension staff will do a simple screening test to assess water quality free of charge. As the amount of salt in the water (expressed as Total Dissolved Solids or TDS) goes up, electrical conductivity goes up.

SDSU Extension Beef Specialist Trey Patterson added that it is the total sulfates ingested that negatively impacts animal health, not only from water but also from some plants (kochia, thistle, turnips, and rape), grain by-products (corn by-products), and supplements. Grasses are generally low in sulfate. Sulfate intakes below 0.4 percent of diet dry matter (including contribution of water) are safe, 0.5-0.6 percent may be associated with sporadic cases of polio, while intakes of greater than 0.7 percent may be associated with a significant number of cases.

The tests give some indication of whether water quality is a problem and can point to the need for more comprehensive lab tests.

If producers continue using water with high sulfates, SDSU specialists said there are steps they can take to help lessen the risk to livestock.

* Check livestock frequently, minimize other sources of sulfur/sulfates in the diet.

* Monitor water quality at regular intervals.

* Do what is possible to minimize heat stress.

* Work with a veterinarian to develop a protocol for treating acute cases of polio, as animals often die from the disease if not treated promptly.

* Consider alternative water or blending "good" and "bad" water, especially in very hot weather.

* Producers who have multiple water sources should test all sources and formulate a water use strategy. Use marginal water first, saving good quality water for later in the summer, since water quality will likely decline over the summer.

* Consider other measures to minimize water consumption and stress, such as weaning calves.

* Cattle consuming water with elevated sulfate levels should be provided a trace-mineral fortified supplement.  Producers should work with their nutritionist to achieve adequate consumption of mineral supplements, which can be difficult when salts in water are elevated.
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Contacts: Trey Patterson, (605) 394-2236; Pat Johnson, (605) 394-2236; Bill Epperson, (605) 688-6589
** For links to other sites showcasing SDSU's work in teaching, research, and Extension, visit http://sdces.sdstate.edu.

Lance Nixon, Editor
AgBio Communications Unit
South Dakota State University
ACC, Box 2231, Rm 200
Brookings, SD 57007
Telephone: (605) 688-4653
Lance_Nixon@sdstate.edu