What are some guidelines that I can use to evaluate livestock water quality?
This question comes from a Veterinarian
in Central Iowa,
by Dr. Dave Hutcheson, PhD
Water Quality and Guidelines
Water is the most common molecule in the body, and makes up about 98 percent of all molecules in the body. Loss of 20 percent of body water is fatal. Water has the highest heat of vaporization, heat of fusion, heat capacity, dielectric constant, electrical conductivity and surface tension (Quinton, 1979). Water is needed for regulation of the body temperature, digestion, metabolism, excretion, hydrolysis of protein, fat, and carbohydrates, lubrication of joints, nervous system cushion, transporting sound and eye sight. Water distribution in the body is divided into two major compartments, extracellular (33 percent) and intracellular (67 percent). Most of the water is in the intracellular pool and the proportions vary with feeding practices and environmental conditions. The intracellular pool is made up of interstitial water, plasma and transcellular water. The interstitial water is the spaces surrounding cells in the body. The transcellular water is gastrointestinal water that can range from 15 percent of the body to 35 percent of the body. (Guyton, 1971).
The minimum requirement of cattle for water is a reflection of that needed for body growth; for fetal growth or lactation; and of that lost by excretion in the urine, feces, or sweat or by evaporation from the lungs or skin. Water requirements are affected by many factors, and it is impossible to list specific requirements with accuracy. Water intake equation for feedlot steers has been developed by (Hicks et al. 1988):
Water intake(gallons/day) = − 4.939 + (.1040×MT) + (.2923×DMI) − (2.5971×PP) − (1.1739×DS).
- MT is the weekly maximum temperature in degrees Fahrenheit
- DMI is dry matter intake in lbs fed daily
- PP is weekly mean precipitation inches
- DS is the percent of dietary salt in %.
The major influences on water intake in beef cattle fed typical rations are dry matter intake, environmental temperature, and stage and type of production. Water quality is important in maintaining water consumption of cattle. Physio-chemical ( pH, total dissolved solids, hardness, and total dissolved oxygen), organoleptic (odor and taste), compounds present in excess (nitrates, iron, sodium, sulfates, and fluorine), toxic compounds (arsenic, cyanide, lead, mercury, hydrocarbons, organochlorides and organophosphates) and bacteria are criteria for evaluating drink water for humans and livestock.
Salinity
Salinity refers to the amount of dissolved salts in water and is measured by total dissolved solids. These dissolved salts are primarily sodium chloride but may include carbonates, nitrates, sulfates, calcium, magnesium and potassium Table 1 was adapted from Nutrients and toxic substances in water for livestock and poultry, NAS, 1974.
Table 1 - Guide to the Use of Saline Water
| Total Dissolved Solids (TDS) mg/l or ppm | Effect on Livestock |
|---|---|
| Less than 1,000 ppm fresh water | Presents no serious burden to livestock |
| 1,000 − 2,999 ppm slightly saline | Should not affect health or performance but may cause temporary mild diarrhea |
| 3,000 − 4,999 ppm moderately saline | Generally satisfactory, but may cause diarrhea, especially on initial consumption |
| 5,000 − 6,999 ppm saline | Can be used for reasonable safety for adult ruminants but should be avoided for pregnant cattle and baby calves. |
| 7,000 − 10,000 ppm very saline | Should be avoided if possible. Pregnant, lactating, stressed or young animals can be affected. |
| Greater than 10,000 ppm brine | Unsafe, should not be used under any conditions |
Salinity is part of the total dissolved solids but is not hardness. For and example high saline waters may contain high degree of salt and yet not be hard due to the lack of magnesium and calcium. Concentration of calcium and magnesium contributes to hardness. Hardness, calcium plus magnesium classification is defined in table 2 (Nutrients and toxic substances in water for livestock and poultry, NAS, 1974).
Table 2 - Calcium and Magnesium Concentrations and Hardness
| Hardness | Calcium plus Magnesium ppm |
|---|---|
| Soft | 0 − 60 ppm |
| Moderate | 61 − 120 ppm |
| Hard | 121 − 180 ppm |
| Very Hard | 181 ppm and greater |
Apparently, degree of hardness does not effect livestock production (Blosser and Soni, 1957). Laboratory analysis sometimes reports hardness as grains of hardness. One grain per gallon is equal to .0058 ppm.
Nitrates
Cattle performance and reproduction is effected by nitrates in the water. Nitrate (NO3) is reduced to nitrite (NO2) which creates the toxicity. Nitrate levels in water in excess of .3 mg of nitrate nitrogen per liter contributes to excessive algae growth. Table 3 is a guide to levels of nitrate and nitrate nitrogen and precautions (Nutrients and toxic substances in water for livestock and poultry, NAS, 1974).
Table 3 - Nitrates in Water.
| Nitrate (NO3) ppm | Nitrate Nitrogen (NO3 − N) ppm | Comments |
|---|---|---|
| 0 − 44 ppm | 0 − 10 ppm | No harmful effects |
| 45 − 132 ppm | 10 − 20 ppm | Safe if diet is low in nitrates and nutritionally balanced |
| 133 − 220 ppm | 20 − 40 ppm | Could be harmful if consumed over long periods of time |
| 221 − 660 ppm | 40 − 100 ppm | Cattle at risk; possible death losses |
| 661 − 800 ppm | 100 − 200 ppm | Unsafe; high probability of death losses |
| Over 800 ppm | Over 200 ppm | Unsafe; do not use |
Water Quality Guidelines
Table 4 has been adapted from Mineral Tolerance Domestic Animals, NAS, 1980 and Nutrients and toxic substances in water for livestock and poultry, NAS, 1974 as a guide line for water quality for cattle.
Table 4 - Water Quality Guidelines
| Substance | Desired Upper Limits ppm | Maximum Upper Limits ppm |
|---|---|---|
| Aluminum | 5 | 10 |
| Arsenic | 0.2 | 0.2 |
| Bicarbonate | Unknown | <1000 |
| Boron | 5 | 30 |
| Cadmium | 0.01 | 0.05 |
| Calcium | 100 | 150 |
| Chloride | 100 | 300 |
| Chromium | 1 | 1 |
| Cobalt | 1 | 1 |
| Copper | 0.2 | 0.5 |
| Fluoride | 2 | 2 |
| Lead | 0.05 | 0.1 |
| Magnesium | 50 | 100 |
| Manganese | 0.05 | 0.5 |
| Mercury | 0.01 | 0.01 |
| Nickel | 0.25 | 1 |
| Selenium | 0.05 | 0.10 |
| Sodium | 50 | 300 |
| Sulfate (S from SO4) | 20 | 100 |
| Sulfate (SO4) | 50 | 300 |
| Vanadium | 0 | 0.1 |
| Zinc | 25 | 50 |
| Nitrate (NO3-N)N from NO3 | 10 | 20 |
| Total Dissolved Solids (TDS) | 960 | 5000 |
References
Blosser, T.H. and B. K. Soni. 1957. Comparative influence of hard and soft water on milk production of dairy cows. J. Dairy Sci. 40:1519.
Guyton, A. C. 1971. Textbook of medical physiology. 4th ed. W. B Saunders Co., Philadelphia, PA.
Hicks, R. B., F. N. Owens, D. R. Gill, J. J. Martin and C. A. Strasia. 1988. Water intake by feedlot steers. Animal Sci. Res. Rept. Oklahoma State University.
National Research Council. 1980. Mineral tolerance of domestic animals. National Academy of Sciences.
National Research Council. 1974. Nutrients and Toxic Substances in Water for Livestock and Poultry. Washington, D. C. National Academy of Sciences.
Quinton, P. M. 1979. Comparative water metabolism in animals: protozoa to man. Comp. Anim. Nutr. 3:100