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18. Sanitation:
Cleaning And Disinfectants
Diseases
and infections have always been a major concern to the poultry
industry--especially in the hatchery. Fortunately, microbial
contamination can be prevented and controlled using proper
management practices and modern health products.
Microorganisms are everywhere! Some are relatively harmless
while others are highly pathogenic. Some pose a lethal threat to
one species of animal while remaining harmless to another
species. Some organisms are easily destroyed while others are
very difficult to eliminate. The moral is: Treat all
microorganisms as if they are a severe threat to the chick's
livelihood.
Understanding the terms used to describe microbial control is
important when selecting the appropriate action for eliminating
disease causing organisms. Three terms commonly used but often
misunderstood are sterilization, disinfection, and sanitation.
-
Sterilization
- The destruction of all infective and reproductive forms of
all microorganisms (bacteria, fungi, virus, etc.).
-
Disinfection
- The destruction of all vegetative forms of microorganisms.
Spores are not destroyed.
-
Sanitation
- The reduction of pathogenic organism numbers to a level at
which they do not pose a disease threat to their host.
Most
hatchery personnel have the impression that they are approaching
a sterile condition because they use disinfectants when
"disinfecting" the facilities. In fact, they may only achieve a
sanitized condition at the very best. The most important
consideration to remember when striving for a sanitized hatchery
is that cleanliness is essential.
Proper
cleaning of facilities removes the vast majority of all
organisms and must be used before application of disinfectants.
This applies to all areas within the hatchery including floors,
walls, setters, hatchers, trays, chick processing equipment, air
and personnel. The success of a hatchery sanitation program is
limited only by its weakest link.
It is
extremely important to remove as much organic matter as
practicable from surfaces to be disinfected. All debris
including down, egg shells, droppings, tissue residues, etc.
must be removed from the hatchery. This is followed by thorough
cleaning using warm water and appropriate cleaning aides. Care
is focused on selecting the proper detergent and thus producing
the cleanest hatchery environment possible. Special attention is
placed on compensating for variations in hardness, salinity and
pH of the cleaning water. A thorough rinsing with abundant
quantities of clean sanitized water completes the cleaning
process and removes most lingering residues of detergents,
organic matter or microbial organisms that can interfere with
the effectiveness of a disinfectant.
Only
after the facilities have been thoroughly cleaned are the
surfaces treated with an appropriate disinfectant solution. Not
all disinfectants are suited for every situation. When selecting
the right disinfectant, carefully consider:
-
The type
of surface being treated.
-
The
cleanliness of the surface.
-
The type
of organisms being treated.
-
The
durability of the equipment/surface material.
-
Time
limitations on treatment duration.
-
Residual
activity requirements.
If the
surface is free of organic matter and residual activity is not
required, quaternary ammonium compounds and possibly halogen
compounds can be used effectively. However, if surfaces are
difficult to clean, residual activity is required or the
contaminating organisms are difficult to destroy, then multiple
phenolics or coal tar distillates may be needed.
Careful
attention must assure that the disinfectant, if used as
directed, meets requirements of the user. Be reasonable and
don't expect the product to produce unattainable performance.
Instead, select a different product or modify disease control
practices.
In
general, disinfectants can be divided into seven major
categories. A more detailed summary of the basic attributes of
each category of disinfectants is available later in this
discussion as "General Characteristics of Disinfectants". The
various classes of disinfectants are:
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Alcohols
-
Halogens
-
Quaternary Ammonium Compounds
-
Phenolics
-
Coal Tar
Distillates
-
Aldehydes
-
Oxidizing Agents
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Although many disinfectants are available, those most suited for
use in today's hatcheries include quaternary ammonium compounds,
phenolics and aldehydes. However, each disinfectant is used only
in appropriate locations for meeting the purposes for which it
is designed.
Several
considerations must be remembered when using any disinfectant to
maximize its effectiveness. Some of these general considerations
are:
Few
disinfectants are effective instantaneously. Each requires a
certain amount of time to bond with the microbe and exert a
destructive influence. Allow adequate contact time (usually 30
minutes is sufficient) or select a different disinfectant.
When
selecting disinfectants, consider their effectiveness on
organisms that are of greatest concern. If a hatchery is
experiencing problems with a certain viral disease, the
disinfectant selected must be effective for destroying the
specific organism causing the problem. Not all disinfectants are
effective on all types or species of organisms.
In most
situations it is advisable to clean and disinfect in two
different operations that are separated with thorough water
rinsing. Many cleaning/disinfecting producers promote their
product based on ease and economy of use because they clean and
disinfect in one operation. If these products are used, make
sure that they satisfy all efficacy requirements demanded of
other disinfectants.
The
efficacy of disinfectant solutions is usually enhanced when
applied in warm solutions rather that cold solutions. "Hot"
solutions, however, may reduce disinfectant efficacy or promote
a "cooked-on" condition for unremoved protein-rich residues.
When
possible, allow all surfaces to dry thoroughly prior to reuse.
Dryness helps prevent the reproduction, spread and transport of
disease organisms. Although a surface is clean, it is more
easily recontaminated with organisms if water remains on the
surface.
A
listing of important characteristics for the more commonly used
disinfectants used by the poultry industry is shown in General
Characteristics of Disinfectants.
It is
important when selecting the best disinfectant to consider its
effect upon the developing embryo and the hatchery environment.
Embryos are in a very sensitive stage of development when the
eggs enter the hatchery. They can be severely affected if
subjected to chemical vapors, even if a sterile environment is
provided.
It must
be remembered that an egg is not produced in a sterile
environment. Before it is laid, the egg is subjected to a series
of microbial attacks that can reduce the embryo's potential to
develop into a healthy, robust chick. The vent of the hen is
probably the most contaminated area that an egg passes through.
Poorly maintained nests can also distribute organisms to
noninfected eggs. Fortunately, nature has provided several
protective barriers for the embryo. Hatchery personnel must not
conduct any procedure that interferes with the egg's natural
defense. Producers must make every effort to collect and store
eggs so that natural protections are not compromised.
Keeping
egg shell surfaces dry is very important to prevent excessive
microbial contamination and shell penetration. Without benefit
of aqueous water the potentially dangerous microorganisms have
little opportunity to invade the egg shell and infect the
embryo. Sweating of eggs as they are moved from warm to cool
environments must be prevented if sanitation programs are to be
successful.
Embryos
have the same requirements prior to pipping that the chicks have
following hatching. They have the need for heat, moisture, and a
high-quality source of air. They can be severely affected by
harmful fumes originating from many chemicals often found in or
near the hatchery. Although hatchability may not be affected,
the quality of the chicks can be reduced. Whenever unusual odors
from detrimental chemicals are detected in the hatchery, the
product must be removed. This applies to all chemicals within
the hatchery, including disinfectants. As an example, vapors
produced by improper use of phenolic disinfectants can cause
changes in egg proteins and impair hatchability and chick
quality.
Improper selection or use of some disinfectants can damage or
hinder the function of hatchery equipment. Many disinfectants
are corrosive and damaging to equipment parts. Some
disinfectants can clog and gum-up spray nozzles if added to the
water used in humidifiers. It is possible that electronic
control devices can also be severely damaged or destroyed after
prolonged exposure to some disinfectants.
Select
disinfectants wisely and always follow label directions for
their safe use. Not only does management have the responsibility
to maximize hatchability and chick quality, but also to provide
a safe working environment for the hatchery personnel. Safety of
the people working in the hatchery must never be sacrificed for
cost or productive efficiency.
Assuming that a proper state of sanitation is achieved, it must
be remembered that the status of disease-free surfaces can be
compromised if facilities are not maintained properly. Hatchery
personnel must be made aware that they can be a major source of
reinfection by transporting of microorganisms on clothes, hands
and attire. Since people are direct carriers of microbes,
provisions must be made available at appropriate locations in
the hatchery for the washing of hands and footwear. Laboratory
coats and caps can significantly reduce the spread of microbial
organisms. Restricting movement of hatchery personnel by
assigning duties within specific areas can reduce the
distribution of organisms throughout the hatchery.
The
risk posed by disease causing organisms is a constant challenge
to hatchery personnel. Always use control measures that have
been proved effective rather than trusting visual cleanliness as
an indicator of sanitation. A clean surface does not always
indicate a disease-free state. Assuming so may be fatal to the
chicks and the management program.
General
Characteristics Of Disinfectants
ALCOHOLS
(Isopropyl or Ethyl Alcohol)
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Wide
germicidal activity, non corrosive, but poses a fire hazard.
-
Limited
residual activity due to evaporation.
-
Alcohols
provide limited activity in the presence of organic matter.
-
Not
considered effective against bacterial or fungal spores.
-
Excellent for disinfecting instruments or other small objects.
-
Too
expensive for general use in the hatchery.
-
Must use
as a 70-95% concentration for effectiveness.
HALOGENS (Iodines
or hypochlorites)
-
Provide
wide germicidal activity but are corrosive.
-
Limited
activity when in the presence of organic matter.
-
Poor
residual activity, low toxicity, but may stain surfaces.
-
Not
effective as sporocidal agents.
-
Effective at low concentrations for disinfecting clean, small
objects.
-
Low cost
but requires frequent applications.
QUATERNARY
AMMONIUM COMPOUNDS
-
Limited
germicidal range.
-
Not
sporocidal, effective against vegetative bacteria, fungi and
viruses.
-
Reduced
efficiency in the presence of organic matter.
-
Limited
effectiveness in soaps, detergents and hard water salts.
-
Non-irritating, non-corrosive and low toxicity.
-
Residual
activity is limited by the amount of recontamination.
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Good
disinfectant for use on cleaned surfaces.
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Low
cost.
PHENOLICS
(Single or Multiple)
-
Wide
germicidal range, not sporocidal.
-
Low
toxicity and low corrosiveness.
-
Very
effective in the presence of organic matter.
-
Good
residual activity and deodorizer.
-
Low to
moderate cost.
COAL TAR
DISTILLATES ( Cresol and Cresylic Acid)
-
Wide
germicidal activity, not sporocidal.
-
Corrosive and toxic at high concentrations.
-
Excellent residual activity with heavy odor.
-
Highly
efficient in presence of organic matter.
-
Not well
suited for use near eggs or chicks due to noxious gases.
-
Moderately expensive.
ALDEHYDES
(Glutaraldehyde)
-
Wide
germicidal activity, sporocidal and fungicidal.
-
Slight
to moderate efficiency in presence of organic matter.
-
Slight
residual activity.
-
Moderately toxic.
-
Moderate
cost.
OXIDIZING
AGENTS (Hydrogen peroxide, Potassium Permanganate)
-
Moderate
to wide germicidal activity, not sporocidal.
-
Rendered
ineffective in the presence of organic matter.
-
Moderately corrosive, limited toxicity.
-
Poor to
limited residual activity.
-
More
valuable as a cleansing and deodorizing agent.
-
Moderate
cost.
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