Water Quality for Dairy Cattle
A. Water is often overlooked as an important nutrient
B. Water intake may limit milk production and growth, and adversely affect health.
C. Animals need a plentiful supply of good, clean water for:
1. normal rumen fermentation and metabolism
2. proper flow of feed through the digestive tract
3. good nutrient digestion and absorption
4. normal blood volume
5. tissue needs
D. Lack of good data on effects of quality problems on performance; must depend largely on experiences, and further research encouraged.
Requirements for Water
Expected intakes for various dairy cattle may be found in Table 1. Note that drinking water for producing cows depends on milk level and ration water intake.
A. Requirement for milking cows includes water from both drinking and the ration consumed
B. Ration intake depends primarily on amount of silage, haylage, or fresh forage consumed as opposed to hay and grain
C. Intake may be considered a problem if it varies more than ±15 to 20 percent of expectedD. Intake may vary according to temperature
1. higher at air temperatures over 80 degrees F
2. lower at air temperatures under 50 degrees F
E. Possible causes of inadequate intake
1. lack of supply or drinking devices, corroded valves, pipes clogged from iron-bacteria slime or scale
2. inadequate pressure in the system; not enough animals can drink in a short period of time; use 20 lbs minimum pressure
3. low chemical quality
a. very acidic
b. very alkaline
c. hydrogen sulfide (rotten egg odor)
d. metallic taste from iron, manganese, sulfates
e. high total dissolved solids content
- high total bacteria counts (most common)
-coliform from fecal or non- fecal sources
-other types, especially Streptococci and Pseudamonas
-iron-loving bacteria (restrict flow, bad taste)
b. algae, especially blue-green type
d. sites of contamination
-pressure tank, reservoir
-drinking device (feed or manure)
5. stray voltage
a. around drinking devices
b. around surface upon which animal stands
F. Signs of inadequate intake
1. firm, constipated manure
2. low urine output
3. infrequent drinking
4. high packed-cell volume or hematocrit in blood
a. over 38 percent in a group of dairy cows
b. other causes
i. dehydration from toxins
5. considerable unexplained drop in milk production
6. drinking of urine, puddles-may also result when salt, potassium, and protein are lacking.
G. Possible causes of excessive intake
1. excessive salt or sodium bicarbonate intake
2. abnormally high urine production
a. mercury contamination of feed or water
b. excessive protein, NPN, or nitrate intake
H. Signs of excessive water intake
1. excessive urine production
2. abnormally loose manure (diarrhea); normal in color and smell
3. relatively bloated condition, especially in calves-may also result from sucking habit
I. Determining water intake
1. measure average daily consumption from drinking devices
a. use water meter on lines to drinking devices only, not milk house, etc. (available from most water companies or their suppliers)
b. keep cattle from other sources of drinking water and pasture.
c. obtain data over a period of at least 5 to 10 days to minimize weather differences
2. keep track of number and type of animals (dry cows, calves, heifers, etc.)
3. subtract expected intakes for animals other than milking cows from total drinking water
4. determine average daily ration for cows in milk
5. compute water intake from ration (forage and grain); test silages, haylages and high-moisture grains to improve accuracy
6. calculate total water intake from drinking and ration
7. determine average daily milk production for the period from amounts shipped, plus any used on the farm or discarded
8. compute average daily water intake per pound of 4 percent fat corrected milk produced
a. 1 gallon of water weighs 8.34 lbs
b. 1 cubic foot of water weighs 62.4 lbs
Introduction to Water Quality
A. Water quality problems occur more frequently in mining areas.
B. mine drainage and/or industrial wastes sometimes are involved.
C. cows are more sensitive to water problems due to:
a. large intakes which may run from 200 to 300 lb per cow or more daily in high-producing herds
b. relatively high incidence of ulcers or breaks in the lining of the rumen and rest of the digestive tract
c. rumen pH needs to be within a relatively narrow range for good metabolism (6.4 to 7.0) in cattle not on fattening rations
d. rumen microflora and metabolism may be altered by water with a high total bacteria count
A. Hard water generally does not adversely affect cows. Include calcium and magnesium intake from water in ration formulation if water contains over 500 ppm Ca or 125 ppm Mg. Also include sodium from water in formulation of anionic rations if levels are considerably above average.
B. Chemical treatment of water to reduce bacteria counts generally does not adversely affect cattle.
C. A combination of high sulfate and high magnesium content may result in loose manure or diarrhea.
D. Hydrogen sulfide (rotten egg odor) may increase problems with anemia and those related to copper, selenium, and vitamin E nutrition.
E. High sulfate levels may increase needs for selenium, vitamin E, and copper.
F. High iron, manganese, or molybdenum content may increase needs for copper, or result in more iron-bacteria problems.
G. Acidic water with a pH of under 5.1 may increase problems related to chronic or mild acidosis in some cases.
1. reduced milk production
2. depressed milkfat test
3. poor gains and growth
4. lower feed intake
5. more infectious and metabolic problems
H. Alkaline water with a pH of over 9.0 may result in problems related to chronic or mild alkalosis in some cases.
1. symptoms similar to mild acidosis
2. amino acid and B-complex vitamin deficiencies may occur due to lack of rumen synthesis
3. more likely to interfere when rations contain excessive amounts of protein, minerals and buffers, especially rations high in alfalfa
I. High copper content may lead to liver damage. It may result from severe corrosion of copper lines, mine drainage, treatment of ponds for algae, etc.
J. Nitrate levels over 100 ppm as NO3 may adversely affect cattle and those over 44 ppm may harm young human infants. Levels of 500-1,000 ppm NO3 may cause moderate symptoms of toxicity in cattle while those over 1,000 ppm may result in acute symptoms and death. The guidelines for cattle assume normal levels of NO3 in ration.
1. more reproductive problems in adult cattle
2. reduced gains in young stock
3. no appreciable effects on milk production
4. nitrite levels in water over 4.0 as NO2 may be toxic to cattle
a. symptoms similar to high nitrate intake from feed and/or water, infertility, including abortions at very high intakes
b. reduce gains and growth
c. respiratory distress due to lack of oxygen
d. gray-brown mucous membranes and chocolate-brown colored blood
5. see Fact Sheet DAS 92-107 for details on the prevention and control of nitrate toxicity in cattle
K. Lead contents over 0.10 ppm may be toxic.
1. may result from discarded batteries contaminating water supplies
2. may result from severe corrosion of lead pipes
L. Water with over 125 ppm magnesium or 250 ppm sulfate may be too laxative. Less magnesium may be laxative if sulfate is relatively high.
A. For sanitation (washing equipment, udder, teats)
1. total coliform count should be zero
2. total bacterial count should be relatively low
B. For animal consumption
1. calves fecal coliform count should be zero
2. adult fecal coliform count should be 10 or under
C. Polluted water may adversely affect cattle
1. more calf problems and losses
2. more off-feed, ketosis, or acetonemia problems with cows
3. chronic or intermittent diarrhea
4. more liver damage
5. increased infections
D. Keep drinking cups, bowls, and tanks relatively clean
1. clean out and sanitize them weekly
2. use a raised base around bowls or tanks to reduce manure contamination
Blue Green Algae
At least six species may be toxic, especially if exposed to the sun in tanks or ponds in shallow areas.
See section below for recommended testing options for water. Water testing is available through numerous public and private laboratories.
Expected levels for various items in farm water supplies and values associated with problems may be found in Table 2.
A. Drinking cups for dairy cows in stall barns; use types and valves that are relatively trouble-free.
B. In free-stall or loose housing, use sufficient tanks, troughs, or fountains to enable most cows to drink relatively soon after milking or eating.
1. generally need one sizable tank per 40 cowsIntroduction to Testing Options
2. use valves that permit 15 gal/min of flow at 20 lb pressure
This information is provided to indicate types of tests that may be run on water samples for routine checking and in problem-solving situations when water may be suspect. When tests are performed to provide a history of water quality in areas subject to pollution from mining or other industries, a combination of options 1 and 3 should be used. Sometimes options 4 and 5 should also be included, depending upon the type of industries in the area.
It's preferable to have background or historical samples taken periodically by a professional third party, and have them tested at a laboratory certified for the tests involved by EPA and DER.
Further help with testing choices and the interpretation or test results and the alleviation and elimination of water problems is available from county cooerative extension offices and specialists in agricultural engineering, forest resources (land and water institute), and the Departments of Dairy and Animal Science and Veterinary Science at Penn State. Publications are available on most aspects of water use, problems, and treatment.
Option 1. Initial or Standard Test
This option is designed for a starter in problem-solving and for routine testing one to three times yearly, preferably during different seasons or rainfall situations. Suggested tests include
Request definitive counts via dilution techniques to obtain quantitative results.
Option 2. Bacterial Sources and Differentiation
This option determines if animal or human wastes may be primarily responsible for pollution of water with bacteria as may be found in iption 1. These tests must be run an fresh, iced samples taken in sterile containers provided by the laboratory Suggested tests are as follows:
Option 3. Intermediate Chemical Tests
This option is designed to determine if any of the usual chemical entities beyond those in option 1 may be responsible for a water quality problem. Tests include the following:
-specific conductance or total dissolved solids (TDS)
Option 4. Toxic Metals
This package is designed to determine if some of the unusual and toxic elements may be present in a suspected water supply when tests in option 1 or 3 do not indicate possible problems, or if certain types of industrial pollution may be present. These elements include the following:
Option 5. Organic Scan
This test is designed to determine if organic compounds such as pesticides, herbicides, solvents are present in appreciable amounts in a suspected water sample.
Option 6. Detailed Organic Tests
This option determines what organic compounds (as uncovered by option 5) may be present. Any or all of the following tests may be included, based on professional advice:
-pesticides and PCBs
Testing services are available from many laboratories in most areas. The federal EPA periodically publishes updated lists of laboratories certified for various tests. Some laboratories may be found in the yellow pages section of the phone book. Contact your county cooperative extension office or appropriate departments in the College of Agricultural Sciences at Penn State if help is needed in locating laboratories. Laboratories provide directions and special containers for use in sampling for various tests.
Table 1. Dairy cattle water intake
Note: Generally, beef cattle consume water at the rate of 1 percent of body weight in gallons daily. One gallon of water weighs 8.34 pounds. A cubic foot of water weighs 62.4 pounds. Water intake will be higher for all cattle during hot weather.
(a) At air temperatures between 50 and 80 degrees Fahrenheit, intake depends on the forage ration water content. Higher levels apply to an all-hay ration.
(b) Drinking water for lactating cows largely depends on production level, dry matter intake and ration water intake. It can be estimated using the modified Kertz Equation (A.F. Kertz, Ralston Purina Company). Total water and drinking water intakes for lactating cows may be calculated using the following equation and procedures:
-Total water intake (lbs/day) = (4 x dry matter intake) + pounds of 4% FCM + 25.6
-Drinking water intake (lbs/day) = Total water intake - ration water intake
-4% FCM (fat corrected milk) = (0.4 x lb milk) + 15 x (lb milk x % fat as decimal)
Example: Determine the drinking water intake for a 1,350-pound Holstein cow producing 60 pounds of milk with a 3.7% milk fat test. The moisture content of the ration is 55 percent (45% dry matter). The 4% FCM is (0.4 x 60) + 15 x (60 x .037) or 57.3 pounds. The estimated dry matter intake is 43 pounds.
Total expected water intake = (4 x 43) + 57.3 + 25.6
= 254.9 lbs of total water daily or
= 30.6 gallons (254.9 / 8.34) or
= 4.4 lbs per lb of 4% FCM produced daily
Expected drinking water intake = 254.9 - 52.5*
= 202.4 lbs of drinking water daily or
= 24.3 gallons or
= 3.6 lbs per lb of 4% FCM produced daily
*Ration water is derived as follows:
43 / 0.45 = 95.5 total as fed pounds of feed
95.5 x 0.55 = 52.5 lbs ration water
(c) when water is being metered for milk cows, make sure other livestock (i.e., heifers, dry cows, beef cattle or a bull) that have access to the same watering source are properly discounted so a more accurate estimate of water intake can be achieved.
(d) water from ration usually runs 25 to 50 pounds daily on low- and high-silage rations respectively. Lower levels of water intake given apply to wintertime intake, higher levels to hot, humid weather.
Table 2. Analysis of water supplies.
(a) For most parameters, averages are from approximately 350 samples. Most
samples were taken from water supplies on farms with suspected animal health or
(b) Based primarily on criteria for water fit for human consumption.
(c) Based primarily an research literature and field experiences.
(d) Should not be consumed by young human infants if over 44 ppm NO3 or IO ppm NO3-N.
(e) If pollution is from human wastes, fecal coliform should exceed fecal strep by several times. If pollution is from an animal source, strep should exceed coliform in refrigerated samples run soon attar taking.
*Free or residual chlorine levels up to 0.5 to 1 ppm have not adversely affected ruminants. Municipal supplies with 0.2 to 0.5 ppm have been successfully used. Swimming pool water with 1 ppm has no demonstrable effects on cattle. Levels of 3 to 5 ppm in farm systems with short contact time have caused no apparent problems.