Dry weather has greatly reduced surface water availability to cattle in many pastures. As if the problem of water quantity is not enough to worry about, now the issue of water quality enters the picture. This reduction due to evaporation and cattle usage may cause certain contaminants in pond water to become concentrated. Two of the more common potential contaminants include nitrates and sulfates. Others may include microorganisms such as leptospiral and coliform bacteria. Although alternative water sources may be expensive and labor intensive, preventing serious sickness and death loss will still be cost savers. Sadly, some situations may require culling of the cow herd so that safe water is used for the remaining cattle.
In some instances, water testing can be helpful in determining if some ponds are safer than others. Livestock water samples can be brought to the Pottawatomie County OSU Extension Center. Routine water analysis performed by Oklahoma State University assesses:
pH: Values outside the range of 5.1 to 9.0 may have an adverse effect on the digestive tract.
Nitrates: <100 ppm should not harm livestock.
100 – 300 ppm should not harm livestock by itself but beware of additive effects when animals are exposed to foodstuffs containing increased nitrate levels. (If nitrite is measured, safe levels are much lower, 10 ppm).
Sulfates: Increased levels may cause a transient diarrhea that subsides when adaptation occurs in 3 to 5 days.
Water levels of 2000 to 2500 ppm sulfate and sulfate levels in foodstuffs allowing the animal to attain a total of 4000 ppm or greater dry matter intake; can be associated with a neurological disease in cattle call Polio encephalomalacia.
Chronic intake of elevated (> 250 ppm) levels of sulfates can result in copper deficiency.
Total soluble salts:
A Guide to the Use of Saline Waters for Livestock
Total Soluble Salts
Less than 1,000: These waters have a relatively low level of salinity and should present no serious burden to any class of livestock or poultry.
1,000 - 2,999: These waters should be satisfactory for all classes of livestock and poultry. They may cause temporary and mild diarrhea in livestock not accustomed to them or watery droppings in poultry (especially at the higher levels) but should not affect their health or performance.
3,000 - 4,999: These waters should be satisfactory for livestock, although they might very possibly cause temporary diarrhea or be refused at first by animals not accustomed to them. They are poor waters for poultry, often causing watery feces and (at the higher levels of salinity) increased mortality and decreased growth, especially in turkeys.
5,000 - 6,999: These waters can be used with reasonable safety for dairy and beef cattle, sheep, swine, and horses. It may be well to avoid the use of those approaching the higher levels for pregnant or lactating animals. They are not acceptable waters for poultry, almost always causing some type of problem, especially near the upper limit, where reduced growth and production or increased mortality will probably occur.
7,000 - 10,000: These waters are unfit for poultry and probably for swine. Considerable risk may exist in using them for pregnant or lactating cows, horses, sheep, the young of these species, or for any animals subjected to heavy heat stress or water loss. In general, their use should be avoided, although older ruminants, horses, and even poultry and swine may subsist on them for long periods of time under conditions of low stress.
More than 10,000: The risks with these highly saline waters so great that they cannot be recommended for use under any conditions.
If you have questions concerning this topic or related topics, please contact the OSU Extension Center in Shawnee at 273-7683, stop by the office at Acme Road and MacArthur, or visit our website: http://www.oces.okstate.edu/pottawatomie/
This article originally appeared on The Shawnee News-Star: Hay bales: Pond water quality and livestock