Diseases and infections have always been a big problem for the poultry industry - especially in the hatchery. Fortunately, microbial contamination can be prevented and controlled through good management practices and modern products for health care.
Microorganisms are everywhere! Some of them are relatively harmless, others are highly pathogenic. Some of them are deadly threat to the species, while remaining harmless to other species. Some organisms are easily destroyed, while others are very difficult to remove. The moral is: Treat all microorganisms as a serious threat to living young.
The understanding of the terms used to describe microbial control is important in selecting appropriate measures to eliminate pathogenic organisms. Three terms are often used, but often poor sterilization, disinfection and sanitation.
Microorganisms are everywhere! Some of them are relatively harmless, others are highly pathogenic. Some of them are deadly threat to the species, while remaining harmless to other species. Some organisms are easily destroyed, while others are very difficult to remove. The moral is: Treat all microorganisms as a serious threat to living young.
The understanding of the terms used to describe microbial control is important in selecting appropriate measures to eliminate pathogenic organisms. Three terms are often used, but often poor 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:
- Alcohols
- Halogens
- Quaternary Ammonium Compounds
- Phenolics
- Coal Tar Distillates
- Aldehydes
- Oxidizing Agents
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.
