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We may not think of water as a livestock nutrient, but an animal will generally consume more pounds of water each day than any other feedstuff. For example, a 700-pound feedlot steer might be expected to consume about 20 pounds of dry matter per day. The same steer will consume about 60 to 75 pounds of water per day (7 to 9 gallons) and perhaps more in hot weather. (See Crop File 5.03.014, Daily Water Consumption by Livestock.).
Water quality affects animal performance. Animals drink less water when water quality is poor. This reduced water consumption also means lower feed consumption, which ultimately hurts animal performance.
Less water consumed can induce stress that can leave animals more susceptible to health problems. Poor water quality or dehydration may also aggravate existing animal health problems. This is especially true for young animals that consume comparatively large amounts of water relative to their body weight.
Following are the various analytical ranges, general ratings, and brief interpretations for the Servi-Tech Laboratories "Livestock Water Suitability" analysis results. The final impact of water quality may be different for different livestock classes or may be affected by weather and other external conditions.
Ratings for individual livestock types are found in Crop Files 5.03.012, Water Quality Ratings – Beef & Dairy Cattle and 5.03.013, Water Quality Ratings – Swine, Poultry, Horses, Sheep.
Water analysis results may be expressed in different units. It is important to identify the units being reported and make sure they are equivalent to the units used in this Crop File. Otherwise, the quality rating may be interpreted incorrectly.
¶ Table 1. Conversion Factors |
| 1 mg/L ≈ 1 ppm |
| 1 mg/L = 1,000 µg/L |
| 1% = 10,000 mg/L |
| TDS ≈ µmho/cm x 0.64 |
| NO3 = NO3-N x 4.43 |
| SO4 = SO4-S x 3 |
| mg/gallon = mg/L x 3.785 |
| oz/gallon = mg/gal x 0.0000353 |
¶ Table 2. Total Dissolved Solids (TDS) |
|
| TDS mg/L | Rating |
| less than 1,000 | Excellent |
| 1,000 – 2000 | Good |
| 2,000 – 4,000 | Fair |
| 4,000 - 6,000 | Poor |
| 6,000 – 10,000 | Very poor |
| over 10,000 | Extremely poor |
Total dissolved solids (TDS) analysis provides an estimate of the total salt load or total salinity of the drinking water. It is typically calculated from the electrical conductivity results.
Excellent ("fresh" water): Low salinity level. Suitable for all classes of livestock and poultry.
Good (slightly saline): Very satisfactory for all classes of livestock and poultry. Could cause temporary and mild diarrhea (watery droppings) in livestock not accustomed to it, but should have no long-term effect on health or performance.
Fair (moderately saline): Generally satisfactory for livestock consumption. May cause temporary diarrhea (watery droppings) or be refused at first, but should present no long-term effect on health or performance. May cause watery droppings and depressed performance in poultry.
Poor (saline water): Acceptable for use by most adult livestock, but can result in depressed performance. Avoid use (if possible) for swine, pregnant animals, lactating animals, or young livestock. Not acceptable for poultry, causes depressed performance or increased mortality.
Very poor (very saline water): Avoid use as source of livestock drinking water, if possible. Marginal quality (at best) for use by healthy adult livestock. Presents high risk for use by pregnant, lactating, stressed, or young animals. Not acceptable for use by poultry or swine.
Extremely poor ("briney" water): This water is considered unsatisfactory as a drinking water source for all classes of livestock.
¶ Table 3. Nitrate-Nitrogen & Nitrate |
||
| NO3-N mg/L | Rating | NO3 mg/L |
| less than 10 | Very low | less than 45 |
| 10 - 30 | Low | 45 - 135 |
| 30 - 70 | Medium | 135 – 310 |
| 70 - 100 | High | 310 – 445 |
| 100 - 300 | Very high | 445 – 1330 |
| over 300 | Extremely high | over 1330 |
Very low (less than 10 mg NO3-N /L): Should have no effect on animal health or performance.
Low (10 to 30 mg NO3-N /L): Considered safe as livestock water source if diet is low in nitrates and is nutritionally balanced.
Medium (30 to 70 mg NO3-N /L): This water by itself should not harm livestock or poultry. It could add to the total nitrate intake, especially during situations when animals would drink large amounts of water while consuming feedstuffs with elevated nitrate levels.
High to Very High (70 to 300 mg NO3-N /L): Could be harmful to cattle, sheep, or horses if consumed over a long period of time. This water by itself should not be harmful, but could add to the total nitrate intake. This could occur during situations when animals drink large amounts of water while consuming feedstuffs containing elevated nitrate levels. Depressed performance or death losses may occur during high stress conditions. This water by itself should have little direct effect on swine or poultry, but could aggravate existing health problems.
Extremely high (over 300 mg NO3-N /L): Considered unsafe for use as drinking water source for cattle, sheep, or horses. This water could cause typical nitrate poisoning. Avoid use of this water for swine or poultry.
¶ Table 4. Sulfate & Sulfate-Sulfur |
||
| SO4 mg/L | Rating | SO4-S mg/L |
| less than 200 | Very low | less than 65 |
| 200 - 500 | Low | 65 - 165 |
| 500 – 1,000 | Medium | 165 - 335 |
| 1,000 – 2,500 | High | 335 - 835 |
| 2,500 – 4,000 | Very high | 835 – 1,330 |
| over 4,000 | Extremely high | over 1,330 |
Very low (less than 200 mg SO4/L): Considered safe for all classes of livestock. No problems are expected. Could possibly affect poultry performance at upper end of range when sodium, magnesium, or chloride levels are high..
Low (200 to 500 mg SO4/L): Considered safe for all classes of livestock. No problems are expected, but availability of certain trace minerals could be affected. Likely to affect poultry performance, especially when sodium, magnesium, or chloride levels are high. Consider diluting 1:2 to 1:4 with low sulfate water for use with poultry.
Medium (500 to 1,000 mg SO4/L): Generally safe for most livestock. May cause mild laxative effect (watery droppings) in newly arrived animals or at weaning time. Animals can become acclimated over time to drinking water sulfates. Copper or other trace mineral availability may be affected and could affect performance of confined cattle, especially if under stress. Marginal to poor for use as poultry drinking water source. Suggest diluting 1:7 to 1:10 with low sulfate water for use with poultry.
High (1,000 to 2,500 mg SO4/L): Generally safe for mature livestock. Not recommended for use with poultry. Use with caution for young pigs. May cause laxative effect (watery droppings) in newly arrived animals or at weaning time. It may be beneficial to dilute this water with low sulfate water until animals become acclimated, then reduce dilution rate over time. Availability of copper and other trace minerals could be reduced and may significantly affect performance of confined cattle on dry feed, especially if under stress.
Very high (2,500 to 4,000 mg SO4/L): Marginal quality for mature animals and likely to result in diarrhea (watery droppings). Dilution with low sulfate water may be necessary. Do not use this water for poultry, young animals, newly arrived animals, or at weaning time. High sulfates are likely to affect trace nutrient availability, potentially affecting performance of confined and grazing livestock. Sporadic cases of sulfur-associated polioencephalomalacia (PEM or "brainers") may occur.
Extremely high (over 4,000 mg SO4/L): Unsuitable quality and Not recommended for use as a livestock drinking water supply. Likely to result in substantially reduced performance and severe health problems. Possibly toxic.
¶ Table 5. Chloride |
|
| Cl mg/L | Rating |
| less than 35 | Very low |
| 35 - 125 | Low |
| 125 - 250 | Medium |
| 250 - 500 | High |
| 500 – 1,000 | Very high |
| over 1,000 | Extremely high |
Very low (less than 35 mg Cl/L): Chloride is considered a dissolved solid. See TDS comments. Levels greater than 15 to 25 mg/L might affect poultry production when sodium exceeds 50 mg/L.
Low (35 to 125 mg Cl/L): Chloride is considered a dissolved solid. See TDS comments. Levels greater than 15 to 25 mg/L might affect poultry production when sodium exceeds 50 mg/L.
Medium to Extremely high (over 125 mg Cl/L):
Chloride is considered a dissolved solid. See TDS comments
¶ Table 6. Magnesium |
|
| Mg mg/L | Rating |
| less than 25 | Very low |
| 25 - 50 | Low |
| 50 - 120 | Medium |
| 120 - 250 | High |
| 250 – 500 | Very high |
| over 500 | Extremely high |
Very low (less than 25 mg Mg/L): Presents little or no risk to livestock or poultry.
Low (25 to 50 mg Mg/L): Presents little risk to livestock. Levels over 50 mg/L Mg may affect poultry if the sulfate plus chloride is 75 mg/L or greater.
Medium (50 to 120 mg Mg/L): Presents little risk to livestock, but considered part of dissolved solids (see TDS comments). Levels over 50 mg/L Mg may affect poultry if the sulfate plus chloride is 75 mg/L or greater.
High (120 to 250 mg Mg/L): Magnesium plus sodium exceeding 50 percent of the total dissolved solids may encourage a laxative effect in livestock. Use with caution for poultry.
Very high (250 to 500 mg Mg/L): Magnesium plus sodium exceeding 50 percent of the total dissolved solids may encourage a laxative effect in livestock. Not recommended for poultry.
Extremely high (over 500 mg Mg/L): Not suggested for livestock use if another water supply is available.
¶ Table 7. Calcium |
|
| Ca mg/L | Rating |
| less than 40 | Very low |
| 40 - 80 | Low |
| 80 - 120 | Medium |
| 120 - 160 | High |
| 160 – 200 | Very high |
| over 200 | Extremely high |
Very low (less than 40 mg Ca/L): No effect expected for livestock or poultry use. Calcium mineral supplementation may be needed in certain cases.
Low to Medium (40 to 120 mg Ca/L): No effect expected for livestock or poultry use.
High to Extremely High (120 to over 200 mg Ca/L): No effect expected for livestock or poultry use. Consider including drinking water calcium in ration formulation.
¶ Table 8. Potassium |
|
| K mg/L | Rating |
| less than 40 | Very low |
| 40 - 80 | Low |
| 80 - 120 | Medium |
| 120 - 160 | High |
| 160 – 200 | Very high |
| over 200 | Extremely high |
Very low to High (less than 40 to 160 mg K/L): No effect expected for livestock or poultry use.
Very high to Extremely high (over 160 mg K/L): Potassium by itself poses limited risk to most livestock, but is considered a dissolved solid. Consider including drinking water potassium in ration formulation.
¶ Table 9. Iron |
|
| Fe mg/L | Rating |
| less than 0.1 | Very low |
| 0.1 – 0.2 | Low |
| 0.2 – 0.4 | Medium |
| 0.4 – 0.8 | High |
| 0.8 – 1.0 | Very high |
| over 1.0 | Extremely high |
Very low to Medium (less than 0.1 to 0.4 mg Fe/L): No production problems expected from using this water.
High (0.4 to 0.8 mg Fe/L): No production problems expected from using this water. May impart off-taste to meat of young animals (e.g., veal calves).
Very high (0.8 to 1.6 mg Fe/L): No production problems expected from using this water. Performance likely to be affected by improper equipment function rather than health problems due to high iron concentration resulting in increased microbial growth and biofilm buildup.
Extremely high (over 1.0 mg Fe/L): No production problems expected from using this water. Dietary copper need may increase. Performance likely to be affected by improper equipment function rather than health problems due to high iron concentration resulting in increased microbial growth and biofilm buildup.
¶ Table 10. Manganese |
|
| Mn mg/L | Rating |
| less than 0.010 | Very low |
| 0.010 – 0.025 | Low |
| 0.025 – 0.050 | Medium |
| 0.050 – 0.075 | High |
| 0.075 – 0.15 | Very high |
| over 0.15 | Extremely high |
Very low to Medium (less than 0.010 to 0.050 mg Mn/L): No specific production problems expected from using this water.
High (0.050 to 0.075 mg Mn/L): No specific production problems expected from using this water. Manganese may impart off-taste to meat of young animals (e.g., veal calves).
Very high to Extremely high (over 0.075 mg Mn/L): Performance likely to be affected by improper equipment functions due to high manganese concentration (resulting in increased microbial growth and biofilm buildup) rather than specific health problems.
¶ Table 11. Hardness, as CaCO3 |
||
| mg/L | grains/gallon | Rating |
| less than 60 | less than 3.5 | Soft |
| 60 - 120 | 3.5 – 7.0 | Moderately hard |
| 120 - 180 | 7.0 – 10.5 | Hard |
| 180 - 270 | 10.5 – 16.0 | Very hard |
| 270 - 400 | 16.0 – 23.5 | Extremely hard |
| over 400 | over 23.5 | Brackish |
Soft (less than 60 mg CaCO3/L): "Soft" water has no direct effect on drinking water safety or animal health, but may influence equipment, plumbing, and fixture performance.
Moderately hard (60 to 120 mg CaCO3/L): Hardness has no direct effect on drinking water safety or animal health.
Hard to Brackish (over 120 mg CaCO3/L) : Hardness has no direct effect on drinking water safety or animal health. It can cause scale buildup and clogging of pipes and drinkers, leading to reduced water consumption and associated problems.
¶ Table 12. Turbidity |
|
| NTU | Rating |
| less than 1 | Extremely low |
| 1 - 5 | Very low |
| 5 - 20 | Low |
| 20 - 50 | Moderate |
| over 50 | High |
Turbidity refers to the relative clarity of a liquid. Water loses its transparency due to the presence of suspended particulates (like sediment or algae growth), thus becoming cloudy or hazy. The “nephelometric turbidity unit” or “NTU” is used to express turbidity by measuring light that is scattered at 90° from a beam of light directed through the sample.
Extremely low (less than 1 NTU): Considered "very clear" water.
Very low (1 to 5 NTU): Considered "clear" water, not expected to affect animal performance.
Low (5 to 20 NTU): Not expected to affect animal performance, but may affect chlorination or ozonation.
Moderate to High (over 20 NTU): Turbidity source (sediment, organic matter, algae, microbes, etc.) may affect drinking suitability, disinfection effectiveness, or watering equipment performance.
¶ Table 13. pH |
|
| pH | Rating |
| less than 5.5 | Acidic |
| 5.5 – 6.5 | Moderately acidic |
| 6.5 – 7.5 | Neutral |
| 7.5 – 8.5 | Moderately alkaline |
| over 8.5 | Alkaline |
Acidic (less than 5.5): Acidic drinking water can affect digestion, degrade performance, corrode watering equipment, and be incompatible with certain medicines and vaccines.
Moderately acidic (5.5 to 6.5): Poultry performance may be degraded. Not expected to affect other livestock performance.
Neutral (6.5 to 7.5): Not expected to affect livestock or poultry performance.
Moderately alkaline (7.5 to 8.5): Not expected to significantly affect livestock or poultry performance.
Alkaline (greater than 8.5): Alkaline drinking water can affect intake and digestion, degrade performance, and may be incompatible with certain medicines and vaccines