| AgBIO COMMUNICATIONS UNIT SOUTH DAKOTA STATE UNIVERSITY Monitor water quality for healthy livestock For release: 6-13-2006 Contact: Cody Wright, (605) 688-5448 Drought makes it imperative for producers to monitor the quality of water their livestock are drinking, South Dakota State University specialists say. Water from stock dams, streams, and wells in South Dakota is often high in total dissolved solids (TDS), and especially sulfates, SDSU Beef Specialist Cody Wright said. Drought makes the situation worse because salt concentrations increase from enhanced evaporation and diminished moisture recharge. In addition, drought conditions sometimes force producers to use marginal quality water if no other water is available. SDSU Extension Veterinarian Russ Daly 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, Daly said. High sulfate intake may cause health problems in ruminants. The most notable of these problems is sulfur-induced polioencephalomalacia ("PEM”). Symptoms of sulfur-induced PEM include lethargy, anorexia, blindness, muscle tremor, exaggerated response to sound or touch, and incoordination, progressing to staggering, weakness, and eventually convulsions and inability to get up. Recent research suggests that sulfur-induced PEM may be different than another type of PEM caused by a thiamin (Vitamin B1) deficiency. In the case of sulfur-induced PEM, supplemental thiamin has produced mixed results. 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. Sulfur-induced PEM may potentially affect cattle of many age groups. Sulfur-induced PEM can be successfully treated if the brain damage is not too severe, Daly said. Early recognition and intervention is crucial if these animals are to be successfully treated. Producers should seek assistance from their veterinarian if PEM is suspected in their animals. Treatment consists of thiamine injections and anti-inflammatories. Affected animals also need to be removed from possible sources of high-sulfate water. 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. The tests give some indication of whether water quality is a problem and can point to the need for more comprehensive lab tests. Wright noted that it is the total sulfur ingested that negatively impacts animal health, not only from water but also from some plants (kochia, thistle, turnips, and rape), grain byproducts (corn byproducts), and supplements. Grasses are generally low in sulfur. The level of sulfur intake that is problematic varies by the type of diet the cattle are consuming. Sulfur intakes below 0.3 percent of diet dry matter (including contribution of water) are safe for all classes of cattle. Levels above 0.3 percent can be associated with sporadic cases of polio in cattle on high grain diets. Cattle consuming forage-based diets can consume as much as 0.5 percent safely. Intakes of greater than 0.7 percent may be associated with a significant number of cases, regardless of diet. For reference, lactating cows during summer months will likely be consuming over 0.5 percent sulfur when their water contains between 2,500 and 3,000 ppm sulfate. 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 sulfur-induced PEM, 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 supplement fortified with copper and possibly thiamin. However, it is important to remember that the research on thiamin supplementation has been very inconsistent and thus positive responses are not a given. Producers should work with their nutritionist to achieve adequate consumption of mineral supplements, which can be difficult when salts in water are elevated. -30- |