Summer has arrived but there are many areas that don’t get enough runoff water to adequately fill the stock ponds, forcing producers to move cattle looking for forage and water. When drought causes a great reduction in surface water available in farm ponds, the issue of water quality becomes nearly as important as quantity of water available.

Water is the one most important nutrient required by livestock. Decreased intake can adversely affect health, reproduction and growth. Excessive salinity (salt) in livestock drinking water can upset the animals’ water balance and cause death. Unsafe levels of salt and toxins depend on the age of the animal, its stage of production and the amount of water consumed each day.

Water consumption is dependent on many factors. Water intake for dry beef cows is around 1-1½ gals./100 lbs. of body weight and this estimate can double for cows nursing calves.

Oklahoma has many potential sources for run-off pond water contamination.

  • Soil minerals and salt leaching from the ground.
  • Oilfield drilling sites and saltwater disposal wells.
  • Agriculture application of nitrate and sulfate fertilizer.
  • Animal manure and human waste control systems.

Suggested uses of livestock water containing different levels of contaminants are listed below: (remember 1ppm = 1mg/liter of water)

Nitrates: 100 ppm or less should not harm livestock.100-300 ppm should not harm livestock by itself, but beware of additive effects when animals are exposed to or grazing foodstuffs containing increased levels of nitrates (sudan, haygrazer and johnsongrass).
Sulfates: Water levels of 2,000-2,500 ppm and sulfate levels in foodstuffs allowing the animal to attain a level of 4,000 ppm or greater; can be associated with a neurological disease in cattle causing blindness.
Total Salts:

  • Less than 1,000 ppm: These waters have a relatively low level of salinity and should present no serious burden to livestock.
  • 1,000-2,999 ppm: These waters should be satisfactory for all classes of livestock. They may cause temporary and mild diarrhea in livestock not accustomed to them, but should not affect their health or performance.
  • 3,000-4,999 ppm: These waters should be satisfactory for livestock, although they might very possibly cause mild diarrhea or be refused at first by animals not accustomed to them.
  • 5,000-6,999 ppm: These waters can be used with reasonable safety for dairy and beef cattle, sheep, pigs, and horses. It may be well to avoid the use of waters approaching the higher levels for pregnant and lactating animals.
  • 7,000-10,000 ppm: These waters are unfit for pigs. Considerable risk may exist in using them for pregnant and lactating livestock. In general, their use should be avoided, although older animals may subsist on them for long periods of time under conditions of maintenance and low stress.\
  • Greater than 10,000 ppm: The risk of these high salinity waters are so great that they cannot be recommended for use under any conditions.

A routine water analysis performed at a lab with the help of your county Extension educator or local practicing veterinarian can be very helpful and cost very little. This would take all the guesswork out of trying to decide which animals would be safe to drink the water and which pastures might be able to be grazed.

As ponds start drying up, the concentration of salt and toxic ions begins to increase in them. Do the young calves in the group have a mild diarrhea due to salty water or coccidiosis? Do the distillers by-product feeds (which can be high in sulfur) have the potential to cause blindness in creep fed to my calves? Are pregnant cows at risk while grazing sudan forage and drinking water possibly containing nitrates? All these questions might be answered by a simple, routine livestock water analysis.