by Jill J. Dunkel

When it comes to water at your feedyard, you may think you're doing everything right. You clean the troughs regularly. Cattle have easy access to clean water. The troughs stay full, and there's plenty of space around the trough. But do you know what's in the water those cattle are drinking? Research shows that elevated levels of certain minerals in the water could dramatically decrease performance in cattle.

According to Dr. Gary Sides, Sr. Technical Services, Cattle Nutritionist with Pfizer Animal Health, high sulfate levels in livestock drinking water can dramatically decrease performance, and have an impact on health. Citing research from South Dakota State University (SDSU), Dr. Sides explains that water with 1,000 ppm of sulfates can have detrimental - and even deadly - affect on cattle.

Toxic levels of sulfur can occur when cattle consume water high in sulfates. High levels of sulfur consumption can impair digestion in the rumen, and can also cause polioencephalomalicia (PEM or Polio.) Symptoms of polio include lethargy, anorexia, blindness, muscle tremors, staggering, plus many others.

In addition to the initial health and digestive problems, elevated sulfur in the water can impair some trace mineral absorption, affecting reproductive and immune function in cattle.

Effect of water quality on health and performance: Performance vs. Sulfates in water
Sulfate Level (mg/l)	441	1725	2919	4654
In wt.	640	638	638	638
Out wt.	825	810	792	708
ADG	1.8	1.65	1.5	.8
% Pull	4.8	4.8	0.0	52.4
% Dead	0.0	0.0	0.0	33.3
% Polio	0.0	0.0	0.0	47.6

New research from SDSU evaluated steers on summer pasture and their performance on varying levels of sulfates in the water. Cattle that consumed what is considered "safe" levels of sulfates (less than 500 ppm) had an average daily gain of 1.8, with a 4.8 percent pull rate, zero deads and zero cattle with polio. As the sulfate levels increased, performance decreased considerably, with ADG down to just .6 pounds for the highest-consuming sulfate group. That group had a 53 percent pull rate, with 33 percent deads and 48 percent with Polio.

Similar research was conducted last year at SDSU, comparing not only sulfate levels, but including the source of the water for each group (rural water system, well water and dam stock water). Lab analysis showed that the well water and dam water contained high levels of sulfates, with the sulfates increasing in the dam water as the summer continued and the overall water level decreased. "With five percent dead, and a high rate of polio cattle, it would have paid to have all the cattle drinking quality water," explains Sides.

Six percent of 498 subsurface water samples taken across the U.S. in 2002 had sulfate levels of 1000 ppm or great. Of those, 50 percent came from water in heavy cattle feeding areas of Kansas and Nebraska, as well as South and North Dakota. A simple water test can determine if sulfate levels are acceptable. Odds are, your water is probably okay... but considering the potential impact on performance and health, are you willing to take the chance? ©