Question of the Week: What are some guidelines
that I can use to evaluate livestock water quality?
(This question comes from a
Veterinarian in Central Iowa)
WATER QUALITY AND GUIDELINES
by Dr. Dave Hutcheson, PhD
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 + (.1040xMT) + (.2923xDMI) - (2.5971xPP) -
(1.1739xDS). |
| |
-
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
|
|
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
Source of Information: http://www.cattleinfonet.com/emerge/site.home?p_site=CATTLEINFO
|

It is possible to program intake of corn based
diets to meet requirements for gestation, lactation, or a level of growth
desired for replacement heifers.

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