IMPORTANT TO TEST WATER QUALITY ON A REGULAR BASIS

by: Stephen B. Blezinger
Ph.D., PAS

Part 2

In Part 1, we began an in-depth look at why water is so important and what contributes to water quality or the lack thereof. As mentioned there, many producers take water for granted. That is until the supply becomes short or until there are production or health issues that are created or perhaps contributed to by a compromised water supply. To begin, let's examine some parameters that are indicators of water quality.

When considering water quality, if a cattle operation is dependent on stock ponds, especially those that vary significantly in water level, it is important to test water quality on a regular basis. Optimum animal performance depends on water quality so the following chemical properties should be considered when evaluating water for livestock (adapted from http://beef.osu. edu/library/water.html, downloaded Jan 23, 2012):

Salinity or Mineral content

Salinity refers to salts or mineral compounds dissolved in water. The term salinity and salt does not only refer to sodium chloride (i.e. table salt). Examples of common salts include: carbonates, bicarbonates, sulfates, nitrates, chlorides, phosphates, fluorides. Highly mineralized water (high solids) do not have a significant effect on health unless high levels are consumed (such as during high temperature periods or no other sources are available.) In these cases problematic laxative effects may be observed. As a frame of reference, one gram of sulfate per liter may result in scouring. Salts such as sodium chloride or potassium chloride can change the electrolyte balance and intracellular pressure in the body, producing a form of dehydration. Salts also place a strain on the kidneys. Excess fluoride causes degeneration of the teeth.

High salt concentrations that are less than toxic, may actually cause an increase in water consumption. Animals may refuse to drink high saline water initially, followed by a period of high consumption. This can lead to sickness or death. The tolerance of animals to salts in water depends on factors such as water requirements, species, age, physiological condition, season of the year (temperature and humidity) as well as the salt content of the total diet and the water. Animals do have the ability to adapt to saline water quite well, but abrupt changes from a water source with low salts to high salts may create problems while a gradual change generally does not.

Salinity is typically reported as parts per million (ppm) or as milligrams per liter (mg/l). The expression "Total Dissolved Solids" (TDS) is often used to indicate the level of water salinity.

The values listed below are for a mineral (salt) content that makes the water either unpalatable if used as a drinking source can be expected to have a negative effect on health. It appears to make little difference whether the total quantity of dissolved salts or dissolved solids is made up of a single salt or a combination.

The term “hardness” is often used to describe water. Hardness is actually caused by calcium and magnesium. Softening the water through exchange (reducing the level) of calcium and magnesium with sodium may cause problems if water is already high in salinity.

Degree of hardness does not seem to effect livestock production. An exception to this may be, as indicated above, if the level of these minerals interferes with the absorption of others. For instance, high levels of calcium in the diet are known to reduce the absorption of selenium.

When there is a significant amount of calcium in water from a limestone source, it should be considered as a part of the total mineral intake. However many mineral salts are relatively insoluble and pass through the body without being absorbed. Even in hard water, the amount of mineral ingested from the water is not likely to be substantial.

Animals can become acclimated to the sulfates in water. Consider diluting high sulfate water with low sulfate water for newly arrived animals. The sulfate recommendation for calves is for less than 500 ppm (167 ppm sulfur as sulfate) and for adult cattle it is less than 1000 ppm (333 ppm sulfur as sulfate). Caution is required in evaluating sulfate levels in water because interactions with copper and molybdenum and the inhibiting effect of compounds such as sodium fluoride have on sulfate absorption for the digestive tract. These interactions and inhibitions make determining guidelines about sulfate removal from water difficult. Aquifers at different depths may be lower in sulfates. Conversely, water high in sulfur or sulfates can also create problems with the absorption of copper and other minerals such as selenium.

Nitrates

Nitrate toxicity is seldom caused by the water content alone. It is usually a forage problem. The majority of nitrate poisoning cases involve drought stressed forages such as Johnson grass or sorghums. It can also be caused by oats, corn and barley. High nitrate content interferes with the oxygen absorbing power of the blood. Ruminants are the most susceptible since non-ruminants may convert small amounts of ingested nitrate to nitrite in their intestines, but the amount converted is not harmful.

Symptoms of high nitrate intake include shortage of breath, blood that is brown in color instead of red, frothing at the mouth, convulsions, blue muzzle and bluish tint around eyes. Sub-acute levels of nitrate toxicity are believed to cause poor growth, infertility, abortions and vitamin A deficiencies.

Sources of nitrates in ground water include nitrogen fertilizers, animal manure, crop residues, human wastes and industrial wastes. Nitrates may be found in a shallow ground water table. The nitrate concentration will be the greatest in the upper part of a shallow ground water table and wells which just penetrate into the table. Shallow wells may have higher levels than deeper wells since the shallow ground water tables are more easily polluted with leached nitrates. As such well water should be evaluated from time to time.

Protect water sheds against erosion, manure or chemicals. Shallow wells with poor casing are susceptible to contamination. In older wells, problems such as a cracked well casing may allow contaminated ground water into a deep aquifer. Chlorination of water does not destroy nitrates but chlorination can convert nitrites back to nitrates. It is questionable however, if this procedure will solve a nitrite problem. Chlorine in the drinking water cannot prevent the change of nitrates to nitrites in the rumen of the cow or sheep or in the large intestine of the horse.



pH

High saline water is not the same as alkine (high pH) water. Water pH denotes either alkalinity or acidity. A pH of 7 would be neutral, over 7 considered alkaline, below 7 designates acidity. An acceptable pH range for water consumed by cattle is from 6.5 to 8.0. Water pH influences palatability, corrosiveness, and chlorination efficiency. Water with a pH less than 5.5 may potentially cause acidosis in cattle and lead to lowered feed intake and performance. Excessively alkaline water can cause digestive upset in cattle and increase the laxative effect of high sulfate consumption.

There are numerous non-chemical components and contaminants in water that we will cover in the next part of this series. Contaminants such as manure, various bacteria, algae and so on can create a variety of issues for the animal.

Conclusion

The quantity and quality of drinking water provided to beef cattle has a significant impact on animal life, health and performance. As mentioned, in the next part of this series we'll continue to take a more in depth look at the many factors that affect water quality. Water is the number one nutrient and cannot be taken for granted.

Dr. Steve Blezinger is a nutritional and management consultant with an office in Sulphur Springs, TX. He can be reached by phone at (903) 352-3475 or by e-mail at sblez@verizon.net. You can also follow us on Facebook at www.facebook/Reveille Livestock Concepts.







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