Water is the most important nutrient for livestock. A quality and safe water supply is essential to the production of healthy livestock. If water is not suitable for consumption, it can adversely affect the growth, reproduction, and productivity of livestock.

What makes water unsatisfactory for livestock in eastern Montana? It is often due to excessive salinity-too high concentration of dissolved salts, more specifically sulfates.

Salinity, or total dissolved solids (TDS), is a good general indicator of water quality. Total dissolved solids are the sum of all minerals, metals, and salts dissolved in the water. In our area, high TDS are typically a result of high sulfate and sodium ions. Sulfur can accumulate to toxic levels quickly in livestock and causes a brain disorders referred to as polioencephalomalacia (PEM) also known as polio, or "star grazing". When cattle and sheep consume high levels of sulfate, in water, feed, or both, the sulfate is turned into hydrogen sulfide in the rumen. This toxic gas is than eructated or "belched" and can be inhaled, damaging the lungs, and is then absorbed into the bloodstream causing death of brain tissues. Symptoms include blindness, lethargy, staggers and disorientation, head pressing, loss of appetite, decrease performance, legs may be rigidly extended, convulsions, and death. Additionally, high sulfate levels, can cause a cooper deficiency, because cooper is tied up by the sulfate ion. Sulfur in water is more readily available than sulfur in feed. However it is important to note the certain range plants, such as kochia, slender wheatgrass, yellow sweet clover and sunflowers can accumulate higher levels of sulfur.

Despite that there was run-of this spring, we still highly encourage livestock producers to test their dams and reservoirs before moving cattle to new pastures. More water in the reservoirs doesn't always mean that TDS and sulfate concentration decreased. There is evidence that suggests because of soil texture and profiles, concentration can increase during run-off events

The Fallon-Carter County Extension Office (as well as surrounding county Extension Offices) have water testing meters and will test for Total Dissolved Solids (TDS) and sulfates free of charge. If TDS and sulfate levels are high enough to cause health concerns in livestock, we may recommend sending a sample to the lab for further analysis. Please collect a pint size sample in a clean water bottle.

Testing water annual, if not more frequently, will help establish a baseline for the quality of water on your operation, as well as a baseline for the area and your county. If you have any questions or would like further sampling instructions or assistant, feel free to contact your Extension Office: (406) 778-7110 or [email protected].