Poultry Farm Advisor
University of California Cooperative Extension
U.S.A.
The egg processing plant can play a significant role in the distribution of disease agents to commercial egg-laying chicken flocks unless well thought out biosecurity plans are developed. Processing plants can be a melting pot, receiving eggs and equipment (pallets, racks and flats) from multiple sources, all of which could potentially bring infectious disease agents into one central location.
Individualized biosecurity plans will reduce the likelihood of disease spread to production from the processing plant through the incorporation of simple, straightforward policies that address both security and biosecurity. The plans should also aim to prevent the malicious or inadvertent adulteration of food products through these same policies and procedures.
What are we trying to accomplish? Basically, we are trying to accomplish two things: first, we have to protect the production flocks (both on-site and off-site) from any biological contaminants within the plant; and second, we have to prevent any cross contamination of the sanitized and finished product prior to shipment from the plant.
How can we accomplish this? These goals can only be accomplished through a set of policies and procedures that address traffic flow, sanitation, rodent and fly control, visitor policy, employee training and verification.
Traffic flow
A plan must be developed to separate clean and dirty activities within the plant. Examples of clean activities from the perspective of resident flock protection are bringing eggs into the incoming cooler and the cleaning and disinfection process of materials (racks, pallets, flats etc.) returning to the flock. From the perspective of protecting finished product, clean activities are dry storage management, packing and out-going cooler management. Basically, the processing plant can be divided into two general areas at the washer. Washed and sanitized eggs must be kept separate from all pre-wash activities.
There are many ways to accomplish separation within the plant. The best are physical barriers like walls and doors. These are usually only used when the plant was originally designed with biosecurity in mind. In lieu of walls, painting lines on the floor and signage that directs employees and visitors can be very effective. Obviously, lines and signs will only be effective if all employees and visitors have been trained and understand what the traffic flow policies are.
Personnel that work in the pre-wash areas (receiving cooler and the loader) should be separated from personnel working in the post-wash areas (dry storage, packing and out-going cooler). Ideally, each set of personnel should have their own designated parking area, work area entrance and restroom and break areas. When this is not possible, there needs to be some biosecurity measure in place to clean and decontaminate an employee that becomes dirty as a result of moving from their work area. The use of shoe dip pans, hand disinfectant gels and protective clothing (coveralls, smocks, etc.) can be effective. For instance, at lunch break, the loader needs to walk across the clean side of the washer to the break room. There should be a red line separating the two areas with a boot dip pan, a bottle of hand gel to disinfect with and a clean smock and hair net at the clean area entry point.
Traffic flow also has a temporal component which can be effective when trying to prevent the introduction of disease into resident flocks. One approach that has been used effectively is to process all eggs from the resident flocks first in the day. This allows the entire plant to be cleaned and disinfected over night before the next day's eggs are processed.
Equipment and plant sanitation
Processing plants receive and ship a variety of materials and equipment. Ideally, all equipment and materials should be either dedicated to one source or used in only one direction and then disposed of.
One-way disposable egg flats are the safest way to bring eggs into the plant and also to send eggs to the breaker. This practice has some obvious disadvantages however, in terms of cost and disposal issues. But during times of high risk, this may be a practice that must be used.
If plastic flats are used, at a minimum, they must be cleaned and sanitized before returning to the farm. Individual flat washers are best because all surfaces of each flat are directly exposed to the cleaning and sanitizing agents. Unfortunately these machines are expensive for most egg processing plants and are mainly used at hatcheries. Care should be taken when cleaning flats that hot water and adequate levels of sanitizing agent is present in every batch.
Following washing and sanitizing of the flats, care must be taken that they remain clean and not re-contaminated before returning to the farm. Colored flats should be considered in order to assure that the flats are returned to their original source and not to any other locations. Flats from different sources should be stored separately.
The same considerations should be given to pallets, racks and trolleys that are returned to the farm. These should all be returned clean and sanitized. Pallets, racks and trolleys can be easily color coded with paint and returned to the original source. Pallets that are used for dry material can be returned to general distribution. It is essential that incoming un-sanitized equipment be kept separate from sanitized equipment.
Trucks and their drivers bringing eggs from farms can carry disease agents and thus contaminate the processing plant. Trucks bringing eggs from farms should have their undercarriages and tires cleaned and disinfected with a high-pressure wash and disinfection system before entering the processing plant area. These trucks should also be disinfected again when they leave. Ideally, before the truck leaves the dock, the inside of the trailer should be disinfected before returning to the farm.
Truck drivers should not enter the processing plant. Eggs should be off-loaded by plant receiving personnel.
Rodent and insect control
Rodents and insects can be an important source of pathogens. They can transmit diseases mechanically (on their bodies) or biologically (within their bodies), therefore their control is important to general plant sanitation and disease prevention. Exclusion of these pests is a first line of defense and the most cost efficient method of control. Exclusion requires the use of several common sense methods including closing doors tightly, air curtains and traps.
The first point of exclusion of rodents is the outside perimeter of the egg processing building. One excellent aid is to lay down a 5- to 10-yard perimeter of 2-inch aggregate gravel or other suitable material so that there is a relatively large open space that rodents travel across to reach the building. Rodents prefer not to cross open spaces because they are vulnerable to animals of prey. In addition to the open perimeter, live traps can be placed approximately 15 ft. apart and at doorways into the plant. All doors to the plant should fit tightly because mice and rats can squeeze through one-fourth and one-half inch openings, respectively.
Rodent control within the plant usually involves the use of traps and rodenticide baits. Only CDFA or USDA approved rodenticides are allowed for use in processing plants. Traps and baits should be placed along walls in all rooms of the plant, especially in the dry storage area.
Effective control programs for flies and other insects require the elimination of breeding habitat and the elimination of food sources. Organic matter such as manure and decomposing vegetation are excellent breeding habitats and should be removed from the building perimeter. Keeping doors closed and the use of air curtains can be effective mechanical barriers to prevent insect access to the interior of the plant. Good general sanitation in the plant will significantly reduce the risk of attracting insects. Pesticides approved by CDFA or USDA can also be applied within the plant.
Visitor policy
For the purpose of this discussion, visitors are defined as anyone who is not an employee of the egg processing division. Visitors would include government egg plant inspectors, university researchers, public utility workers, sales persons or anyone associated with the production side of the company.
In general, like poultry farms, visitors should be extremely limited and only allowed if the risk of contamination is small and the benefit of the visit great. Gas and electric meters should be located outside of the plant so that entry is not necessary. Sales personnel should be met off site if possible. If there is a retail store associated with the plant, public entry must be restricted to the store only and plant personnel should not have access to the store. During times of very high risk, the retail store should be closed.
There should be a designated parking area for visitors, that is separate from employee parking. The parking area should be well drained, so as not to accumulate standing water.
All visitors should sign in on a log form indicating the reason for the visit, the person they are meeting and they should be positively identified by a plant employee. All visitors should be queried as to when and where their last contact with poultry or a processing plant occurred. Processing plants should restrict visitation to those who have not been in contact with a farm or a plant within the previous 24 hours and have showered and changed clothes in the meantime.
Other than regular plant inspectors, no visitor should be allowed into the processing area un-chaperoned. An employee who is thoroughly familiar with the plant biosecurity traffic flow patterns should assure that they are strictly followed.
The visitor should be supplied protecting footwear and clothing including hair net. Ideally, the clothing should be of a color not used by plant personnel so that plant personnel will readily identify him/her as a visitor. Foot bath and hand disinfection stations should be used before entering the processing area.
Employee training
Employee training is essential to a functional biosecurity program. If employees understand what biosecurity is, why it is important and how they are an important part of it, they will be more likely to be motivated to follow the procedures. Frequent short training sessions will help keep their minds on biosecurity. Holding interactive training sessions where employees have an opportunity to ask questions and provide input will help to maintain their interest.
Verification
Verifying that policies and procedures are being adhered to, it is an important part of any operation. Verification gives credibility to the plan of operation, and can also bring to the attention of management, problems or weaknesses in day-to-day operations within the egg processing plant.
The Quality Control Supervisor is a logical person to oversee the verification process.
There are several ways that procedures can be verified. Checklists, logs and other records are commonly used to verify visitor screening, wash water temperature, chlorine levels in the wash water and rodent control programs. Quality assurance sampling is used to monitor egg interior and exterior quality and microbial contamination. But what about traffic flow and separating clean from dirty activities? We have found that a third party walk-thru of the plant during operation can yield useful information about what is really happening. By simply observing traffic patterns and employee activities through a fresh set of eyes, strengths and weaknesses in a plant's operation can be readily apparent. Some plants use camera monitors to observe certain critical control points such as cleaning and disinfection at the security gate and at the plant entrance.
Summary
In all, biosecurity and food quality assurance programs require the coordination of several components in a way that allows the un-finished product to flow through the processing system efficiently. The steps that are taken to prevent the contamination of the product and the flocks that produce it should be as simple and convenient as possible to assure employee compliance. Retrofitting an old processing plant to one that has reasonable biosecurity stop-gaps can present certain challenges. In most cases, these plants have to employ several steps that would not be necessary in a plant that was originally designed with biosecurity and food protection in mind in the first place.
From Proceedings of the "Midwest Poultry Federation Convention", St. Paul, Minnesota, U.S.A.
