A. Introduction
Water is the most important nutrient for poultry. In
addition to being a nutrient, water also softens food and carries it through
the body, aids in digestion and absorption, and cools the body as it evaporates
through the bird’s lungs and air sacs.
Water helps remove
waste, lubricates joints, is a major component of blood, and a necessary medium
for many chemical reactions that help form meat and eggs.
Although water is
regarded as the most essential nutrient, it is impossible to state its exact
requirement. Under normal conditions, chickens will consume, by weight,
approximately twice as much water as food.
During periods of
extreme heat stress, water requirements may easily quadruple.
Table 12.1 indicates the typical quantities
of water required for various poultry species and age.
Table 12.1 - Approximate water consumption
for poultry (gallons/100 birds/day)
Type of
poultry
|
Normal ambient temperature
(68°F/20°C)
|
Hot weather (89.6°F/32°C)
|
|
Average
(growing)
|
Mature
birds
|
Mature
birds
|
|
Layer
pullets
|
2.64
|
3.43
|
5.28
|
Breeder
pullets
|
3.17
|
4.23
|
6.60
|
Layer
hens
|
-----
|
5.55
|
10.57
|
Broiler
breeders
|
-----
|
7.93
|
15.85
|
Broiler
chickens
|
4.23
|
6.60
|
13.21
|
Roaster
chickens
|
5.28
|
7.93
|
15.85
|
Broiler
turkey
|
7.66
|
14.27
|
26.42
|
Heavy
female turkeys
|
10.04
|
16.91
|
31.70
|
Heavy
male turkeys
|
14.53
|
26.42
|
47.55
|
Adequacy of a
water supply is typically evaluated in terms of how many gallons per minute
(gpm) it can deliver on a sustained basis.
A typical 500-ft
broiler house requires about 2 gpm for drinking water, so a 5-house complex
would require a 20-gpm water supply, just for drinking water for the broilers.
For comparison, a
well for a single-family residence is usually judged to be adequate if it can
deliver around 4-5 gpm.
Evaporative
cooling systems, using either foggers or pads, typically require about 8 gpm
per house, which will up the total water requirement per house to 10 gpm.
Recirculating pad
systems are more efficient in water use than non-recirculating types, in that
water not evaporated is ‘recycled’ and not lost.
However, with
either type system, almost all the water will be evaporated into the air going
into the house during peak hot weather demand times, so the design gpm
requirement will be the same no matter which type evaporative cooling system is
used.
B. Evaluating
water quality
When water looks clear and tastes okay, water quality is
easy to take for granted. However, water quality is impossible to judge
adequately except with laboratory testing.
Field experience
has conclusively shown that unobservable differences in water quality, from
farm to farm and even from one well to another within a complex, can result in
significant differences in bird performance.
Drinking water
should be clear, tasteless, odorless, and colorless. As a general observation,
a reddish-brown color may indicate the presence of iron, while a blue color
indicates the presence of copper.
Hydrogen sulfide
is indicated by a rotten egg odor. Hydrogen sulfide may also combine with iron
to form black water (iron sulfide) that may also implicate the presence of
sulfate-reducing bacteria.
Taste can be
affected by the presence of salts, and a bitter taste is usually associated
with the presence of ferrous and manganese sulfates.
Water quality
attributes can have a direct or indirect effect on performance. Poor water
quality can retard growth, curtail egg production, or produce lower egg
quality.
Feed conversion,
for example, has been positively correlated to the presence of sulfate and
copper concentrates in the water, and livability with potassium, chloride, and
calcium.
Body weight is
positively influenced by water hardness and dissolved oxygen and negatively
influenced by total bacteria and a pH less than 6.0.
While several
elements can cause poor water quality, the interaction between elements is more
significant in water quality problems than the simple fact of their presence.
Table 12.2 lists the standards for water
quality for poultry use.
Table 12.2 -
Drinking water quality guidelines for poultry.
Contaminant or characteristic
|
Level considered average
|
Maximum acceptable level
|
Remarks
|
Bacteria
Total
bacteria
Coliform
bacteria
|
0/ml
0/ml
|
100/ml
50/ml
|
0/ml
is desirable
0/ml
is desirable
|
Nitrogen
compounds
Nitrate
Nitrite
|
10
mg/l
0.4
mg/l
|
25
to 45 mg/l
4
mg/l
|
Levels
from 3 to 20 mg/l affect performance.
|
pH
|
6.8
to 7.5
|
----
|
A
pH of less than 6.0 is not desirable. Levels below 6.3 may degrade
performance.
|
Total
hardness
|
60
to 180
|
----
|
Hardness
levels < 60 are unusually soft; those > 180 are very hard.
|
Naturally
occurring chemicals
Calcium
Chloride
|
60
mg/l
14
mg/l
|
----
250
mg/l
|
Levels
as low as 14 mg/l may be detrimental if the sodium level is higher than 50
mg/l.
|
Copper
|
0.002
mg/l
|
0.6
mg/l
|
Higher
levels produce a bad odor and taste.
|
Iron
|
0.2
mg/l
|
0.3
mg/l
|
Higher
levels produce a bad odor and taste.
|
Lead
|
----
|
02
mg/l
|
Higher
levels are toxic.
|
Magnesium
|
14
mg/l
|
125
mg/l
|
Higher
levels have a laxative effect. Levels > 50 mg/ml may affect performance if
magnesium and chloride levels are high.
|
Sodium
|
32
mg/l
|
----
|
Levels
above 50 mg/l may affect performance if the sulfate or chloride level is
high.
|
Sulfate
|
125
mg/l
|
250
mg/l
|
Higher
levels have a laxative effect. Levels >50 mg/l may affect performance if
magnesium and chloride levels are high.
|
Zinc
|
----
|
1.50
mg/l
|
Higher
levels are toxic.
|
Source: Adapted from T.A. Carter and R.E. Sneed,
Drinking water guidelines for poultry. Poultry Science and Technology Guide No.
42, North Carolina State University
Bacteria
The presence of microorganisms is typically a result of
surface contamination by organic minerals and can result in poor performance.
The presence of
coliform bacteria is generally related to fecal contamination of drinking water
due to runoff to surface or ground waters.
Ideally, bacterial
contaminants should not be present in drinking water and measurable levels
should be zero. The first step towards eliminating contamination is to
determine if the source is the well or the distribution system.
Samples taken for
bacterial testing should be obtained in a sterile manner and may need to be
taken at the source and at strategic points to localize any problems.
Chlorination or
filtration of the water supply can eliminate bacterial contaminants. For a
properly sealed and located well, treatment of the well cavity with a chlorine
source such as sodium hypochlorite may remedy the problems.
If continuous
chlorination seems necessary, it should be applied gradually. Between two and
five ppm of residual chlorine is recommended.
Start at the lower
concentration and increase it until control is satisfactory. Since water intake
is the most sensitive criteria, it should be monitored during this process for
signs of intolerance.
Long term correction
may require well sealing or re-siting. Chlorine levels in the water can also be
monitored using a pool test kit.
A common water
quality problem in the Southeast U.S. is excess iron, along with bacteria that
feed on the iron and form a reddish brown slime that clogs filters, drinkers
and fogger nozzles.
Mild iron bacteria
problems can often be dealt with by ‘shock chlorination,’ which involves a
one-time treatment between flocks, injecting a strong chlorine solution into
the well and circulating and flushing it through all pipes in the system.
For more severe
iron bacteria problems, continuous chlorination is called for, installing a
‘chlorinator’ to continuously inject chlorine into the water system.
Chlorine not only
kills bacteria but is an oxidizing agent, meaning it causes minerals such as
iron and manganese to combine with oxygen, in the process coming out of
solution and forming a solid precipitant.
Because of this
reaction, a sand media filter must be installed downstream from the chlorinator
to remove the mineral solids from the water.
Chlorination also
prevents other kinds of bacterial contamination, and may be needed even if iron
and iron bacteria are not present in the water supply.
Use of an
iodine-base disinfectant to control bacteria in drinking water is effective and
provides more residual activity but is usually more expensive than
chlorination.
Be sure to use
only approved chemicals at the recommended rates and ensure that the chemicals
are compatible with watering equipment.
Also, be sure to
remove the disinfectant from the waterers and water lines before using a water
vaccine or medication that is incompatible with the disinfectant.
12.5 Nitrogen
compounds
Nitrates (NO3) are produced during the final stage of
decomposition of organic matter. Their presence in water usually indicates
contamination by runoff containing fertilizer or human and animal wastes.
Nitrates are
soluble and may move with surface runoff or leach into the groundwater by
percolation through the soil. Nitrates from sources such as animal and human
wastes, nitrogen fertilizer, crop residues, and industrial wastes may move
considerable distances in the ground.
Nitrite (NO2) is
produced during intermediate stages of the decomposition of organic compounds.
The toxicity of
nitrates to poultry varies with the age of the birds, older birds being more
tolerant.
Research with
commercial broilers have shown that nitrate levels greater than 20 mg/l have a
negative affect on weight, feed conversion, or performance.
Levels between 3
and 20 mg/l are suspected to affect performance.
Nitrites are toxic
at much lower levels than nitrates; concentrations as low as 1 mg/l can be
toxic.
Nitrate itself is
not toxic. After ingestion, however, it is converted to the toxic form of
nitrite by microorganisms found in the intestinal tract of the bird.
Once absorbed into
the bloodstream, nitrite binds strongly to hemoglobin and, thereby, reduces the
oxygen carrying capacity of the blood.
Chronic nitrate
toxicity causes poor growth, anorexia, and poor coordination. Students
demonstrate that nitrate nitrogen levels in the drinking water as low as 3 to 5
mg/l depress broiler growth rate.
Well-drilling
techniques have improved since many of the older, shallow wells were
constructed. If nitrate or nitrite levels in your well water are too high and
you cannot eliminate the source of contamination, drilling a new or deeper,
properly constructed well may solve the problem.
Nitrate is a very
soluble substance, easily dissolved in water and extremely hard to remove.
Treatment for nitrate is, therefore, very complicated and expensive.
The three methods of reducing or
removing nitrate are:
• Demineralization by distillation or reverse osmosis
• Ion exchange
• Blending
Demineralization
removes nitrate and all other minerals from the water.
Distillation is
one of the oldest, most effective types of demineralization.
The distilling process has only three
steps:
1. The water is boiled;
2. The resulting steam is caught; and
3. The steam is condensed on a cold surface, turning back
into water. The nitrate and other minerals remain concentrated in the boiling
tank.
Reverse osmosis is another way to
de-mineralize water. It reduces but does not remove all nitrates.
In a reverse osmosis system, the water is put under pressure
and forced through a membrane that filters out minerals and nitrate. One-half
to two-thirds of 12.6 the water remains behind the membrane as rejected water.
The yield of
treated water to reject water is related to the amount of pressure applied; the
lower the water pressure, the greater the volume of reject water.
Higher-yield
systems use water pressures in excess of 150 psi. The systems that operate
using standard household water pressure (35 to 45 psi) will yield some treated
water, but a large amount of untreated water goes down the drain, and could
reduce the efficiency of home septic systems.
Household units
are usually small enough to fit under the sink or on a kitchen counter. Both of
these demineralization systems require a lot of energy to operate efficiently
and are high-maintenance systems. They are also low-yield systems that may
provide enough water for a family, but cannot produce the large quantities
needed for livestock.
The second type of water treatment for
nitrate contamination is ion exchange.
Ion exchange introduces another substance that
trades places with the nitrate. Most often chloride is exchanged for nitrate.
The ion exchange
unit is a tank filled with special resin beads that are charged with chloride.
As water containing nitrate flows through the tank, the resin takes up nitrate
in exchange for chloride.
In time, all the
chloride will be exchanged for nitrate. The resin can then be recharged by back
washing with a brine solution (sodium chloride) and reused.
Because ion exchange
systems can treat large volumes of water, they are more appropriate than
demineralization for treatment of livestock water supplies.
There are,
however, some drawbacks to ion exchange systems.
- First, in addition to exchanging nitrate, the resin
beads will also take up sulfate in exchange for chloride. Therefore, if
sulfates are present in the water supply, the capacity of the resin to take up
nitrate is reduced.
- Second, the resin may also make the water corrosive.
For this reason, the water must go through a neutralizing system after going
through the ion exchange unit.
- Finally, backwash brines, which are high in nitrate,
must be disposed of properly so they do not re-contaminate the groundwater
supply.
The third and most
common way to reduce nitrates is to dilute the nitrate-polluted water by
blending it with water from another source that has low nitrate concentrations.
Blending the two waters produces water that is low in nitrate concentration.
Blended water is not safe for infants but is frequently used for livestock.
There is no simple
way to remove all nitrates from your water. Although it is common to think of
boiling, softening or filtration as a means of purifying water, none of these
methods reduce nitrate contamination.
Boiling water is,
in fact, the worst thing to do because it actually concentrates the nitrate.
Softening and
filtration do nothing at all to remove nitrate.
pH - The acidity or alkalinity of water is
measured by pH.
A pH of 7 indicates that the water is neutral, a pH less
than 7 indicates acidity, and a pH greater than 7 indicates alkalinity.
Low pH water can
be unpalatable, corrosive to equipment, and may have a negative impact on
performance.
High pH water is
also unacceptable since it reflects high levels of calcium and magnesium, which
can clog watering systems.
Poultry accept
water on the acid side better than they accept water on the alkaline side.
12.7 Hardness
Hardness refers to the presence of dissolved minerals
such as calcium and magnesium in either bicarbonate or sulfate form and is
expressed as an equivalent of calcium carbonate. It measures the tendency of
water to precipitate soap and form scale.
Hard water is
commonly associated with the buildup of deposits and the formation of scale in
the components of the watering system. Hardness is not commonly harmful to
poultry unless certain ions are present in toxic amounts.
High levels of
magnesium sulfate (MgSO4) may cause an increase in water consumption, wet
droppings, and a drop in production.
Iron, aluminum,
and zinc can also contribute to hardness and should be considered if present in
unusual amounts.
Extreme hardness
may diminish the effectiveness of water-administered medications,
disinfectants, and cleaning agents. Hardness should not be confused with
salinity.
Water can be very
soft with low levels of calcium and magnesium, yet have a high salinity value
from dissolved sodium salts. Most ground waters have hardness values of less
than 2000 mg/l (may be higher in arid areas).
Occasionally,
hardness is reported as grains per gallon (1 grain per gallon is equivalent to
17.1 mg/l).
Water hardness has
been classified as follows:
Hardness
range (mg/l)
Description: 0 – 60 Soft
61 – 120 Moderately hard
121 – 180 Hard
> 180 - Very hard
When hard water is
a problem in proper equipment operation, it can easily be ‘softened’ with
commercial water treatment equipment.
Most of the
processes exchange the sodium ion from sodium chloride for other minerals
present.
It is recommended
that the sodium of softened water be monitored because it may influence the
amounts of fish meal, defluorinated phosphate, bakery products or salt used by
your nutritionist.
Salinity
Salinity refers to salts dissolved in water.
The anions
(negatively charged ions) commonly present include: carbonate, bicarbonate,
sulfate, nitrate, chloride, phosphate, and fluoride.
The cations
(positively charged ions) include calcium, magnesium, sodium and potassium.
Salinity may be
measured as Total Dissolved Solids (TDS) or Total Soluble Salts (TSS) and is
expressed as parts per million (ppm) which is equivalent to milligrams per
liter (mg/l) or micrograms per milliliters (μg/ml).
Salinity may also
be measured by electrical conductivity and is then expressed as reciprocal
micro ohms per centimeter (omhos/cm) or decisiemens per meter (dS/m).
Salinity by itself
tells nothing about which elements are present, but this may be of critical
importance. So when the salinity is elevated, the water should be analyzed for
the specific anions.
Total Dissolved Solids
Measurement of total dissolved solids (TDS), or salinity,
indicates levels of inorganic ions dissolved in water. Calcium, magnesium, and
sodium salts are the primary components that contribute to TDS.
High levels of TDS
are the most commonly found contaminants responsible for causing harmful
effects in poultry production.
Table 12.3
provides guidelines suggested by the National Research Council for the
suitability for poultry water with different concentrations of total dissolved
solids, which are the total concentration of all dissolved elements in the
water.
Table 12.3 - Suitability of water with
different concentrations of Total Dissolved Solids (TDS)
TDS (ppm)
|
Comments
|
Less than 1,000
|
These waters should present no
serious burden to any class of poultry.
|
1,000 to 2,999
|
These waters should be
satisfactory for all classes of poultry. They may cause watery droppings
(especially at higher levels) but should not affect health or performance.
|
3,000 to 4,999
|
These are poor waters for poultry,
often causing watery droppings, increased mortality, and decreased growth.
|
5,000 to 6,999
|
These are not acceptable waters
for poultry and almost always cause some type of problem, especially at the
upper limits, where decreased growth and production or increased mortality
probably will occur.
|
7,000 to 10,000
|
These waters are unfit for poultry
but may be suitable for other livestock.
|
More than 10,000
|
These waters should NOT be used
for any livestock or poultry.
|
Source: National Research Council. 1974.
Nutrients and toxic substances in water for livestock and poultry. National
Academy of Sciences, Washington, DC
Mineral contaminants
A wide variety of minerals are commonly found in drinking
water. Normally, they are found in relatively low concentrations and cause no
harm (see Table 12.2).
High concentrates
of sulfates can combine with magnesium to form Epsom salt or with sodium salts
that cause a laxative effect and can result in wet litter.
High
concentrations of sodium or chloride may also increase water consumption and
increase litter moisture.
High levels of
sulfate may also interfere with the intestinal absorption of other minerals
such as copper.
High levels of
magnesium are only a problem in the presence of high sulfate levels since they
combine to form Epsom salt.
The formation of
scale in the watering system can be attributed to high levels of or
combinations of sulfate, magnesium, or calcium. 12.9
High levels of
iron may encourage the growth of bacteria, which can lead to diarrhea. When the
ferrous form of iron present in well water is exposed to the air, it is
converted to the ferric hydroxide form commonly referred to as rusty water.
Other contaminants
in the water may include pesticides, herbicides, industrial residues, petroleum
products, and heavy metals such as lead or cadmium. Such contaminants are more
difficult to detect and require more costly testing procedures.
Turbidity
Turbidity results from the suspension of materials such
as silt, clay, algae or organic materials in water.
Levels of
turbidity above 5 ppm result in unpalatable water and indicate surface
contamination.
Turbid water can
be filtered to remove particular contaminants and prevent clogged water lines.
C. Water
management
• Conduct water tests. Each farm should have its well
water tested. Water quality can change during periods of heavy rain or drought,
and additional water tests during these periods will ensure that water lines
continue to deliver adequate water volume for both the birds and the cooling
systems.
• Change filters regularly. Sediment and other
particulates can cause leaky water nipples that can have negative effects on
litter quality. Clogged filters restrict water flow to the drinker and cooling
systems.
In some cases,
simple cartridge filters may not be adequate, such as for water with high iron.
In those cases, consider other water treatments.
• Flush water lines regularly. Perform a high pressure
flush on water lines between each flock and after adding supplements through
the medicator (i.e., vaccine, medications, vitamins, electrolytes, etc.).
• Plan ahead before treating water. Before implementing
water treatment or sanitation programs, consult your county agent to be sure
contaminants in your water will not react negatively and cause the water system
to become clogged.
D. Water
treatments
Various methods are available that can reduce or
eliminate the impurities that adversely affect water quality.
Chlorination
Chlorination is
the most common method used to treat water for bacterial contamination and
effectively eliminate bacteria from the water supply.
Chlorine can be
administered through an in-line proportioner. General recommendations are to
have a level of 2 or 3 12.10 ppm at the drinker farthest from the proportioner.
Chlorine levels
can be easily monitored using a pool test kit.
Softeners
Use water softening equipment to reduce hardness. Most
softening equipment uses ion exchange to effectively remove the calcium and
magnesium ions and replace them with sodium ions.
Levels of TDS,
however, are simply substituted and increases in sodium concentration of the
water occur, possibly to unacceptable levels.
Poultry are
generally sensitive to increases in sodium levels, so producers should be
judicial in their selection and use of water softening equipment.
Polyphosphates
Polyphosphates are chemical compounds used primarily to
prevent the buildup of scale in the watering systems. They act to cause mineral
contaminants to go into solution more readily.
Electrical/Magnetic devices
Electrical or magnetic devices keep minerals associated
with scale buildup in solution by altering their electrical charges.
E. Water
temperature
Drinking water temperatures should be between 50°F to
60°F (10°C to 15°C) for the most comfortable consumption by mature birds, but
some studies have indicated that water temperatures of about 77°F (25°C) reduce
mortality in chicks and poults.
Temperatures over
86°F (30°C) will reduce consumption and birds will refuse to drink if water
temperatures are over 111°F (44°C).
Guidelines for chlorination
• Do not chlorinate market age birds under extreme heat
stress.
• Measure residual chlorine at the waterer to maintain at
least a 1.0 ppm level at the drinker mid-house.
• Discontinue chlorination and administer powdered milk
solution before vaccination to neutralize chlorine since chlorine kills
vaccines.
• Use caution since chlorine solutions are acidic
PURICARE
INDUSTRIAL
ENTERPRISES
Water
Treatment
Systems
http://www2.ca.uky.edu/poultryprofitability/Production_manual/Chapter12_Water_quality/Chapter12.pdf
No comments:
Post a Comment