Food safety has become and increasingly important issue for all sectors of the poultry industry. For eggs, the food safety focus has been on bacteria, especially Salmonella species, which cause human illness. To promote safety, a growing number of egg producing companies are adopting egg quality assurance programs, which stipulate actions for all aspects of egg production to reduce the risk of egg becoming contaminated with harmful bacteria.
These actions include making efforts to ensure that poultry feeds are pathogen free, that chicks and pullets do not harbor certain bacteria, that good vaccination programs are followed to protect flock health, that eggs are washed, sanitized and refrigerated properly, and so on.
To the average person working on an egg farm, the complexity of an egg quality assurance program may be bewildering. Nonetheless, what happens on the farm will determine the success of a quality assurance program, so farm workers must understand the program's importance. Trace-back of a food poisoning outbreak to a farm which has not made a serious effort to ensure that eggs are free from contamination could trigger sanctions on further production from that farm.
Fortunately, many aspects of an egg quality assurance program need not concern the people who work on layer farms. Quality assurance procedures for the farm are actually quite straight forward. The goal is to minimized the chance of eggs becoming contaminated with something that can threaten human safety. This can be done by keeping the hens healthy, keeping the layer house clean and free of rodents and other pests, handling eggs properly, and keeping pesticides and hazardous chemicals from getting on eggs; in other words, by good basic management. Quality assurance is then created by keeping a system of records which document that good management has been followed.
Keep hens healthy
A hen that is healthy and not badly stressed will be resistant to infection by Salmonella bacteria. In the event that it does carry these bacteria, there is less likelihood that they will be shed into eggs if the hen is in good condition.
Things to do:
- Maintain optimum temperature and air quality in the house.
- Do not allow the supply of feed and water to be interrupted for extended periods except when called for by scheduled management.
- Ensure that the water supply is clean and uncontaminated.
- Hens should not be overcrowded
- Monitor feed and water consumption closely to be able to identify and deal with a disease outbreak as soon as possible.
- Maintain good biosecurity, e.g., keep birds, animals and unauthorized people out of the layer house. Farm workers should avoid contact with poultry other than birds in the farm flock.
Keep the house clean
A house that is clean and free of vermin will harbor fewer Salmonella bacteria and present fewer opportunities for contamination of eggs. Rodent control is especially important because rodent feces may contain great numbers of Salmonella bacteria.
Things to do:
- Pick up mortality promptly. Carcasses left to go putrid can grow large populations of bacteria, creating risk of hens becoming infected or eggs becoming contaminated.
- Don't let manure build up on dropping boards. Dropping must fall freely away from cages to minimize the number of eggs soiled by fecal materials.
- Prevent buildup of dust, dirt, broken eggs, and cobwebs in the house. These can harbor bacteria in the vicinity of hens and eggs.
- Scrape or wash dried yolk from broken eggs of egg belts, egg elevators, cross conveyors, and egg packing machines. Clean the egg packer regularly.
- Consult your county extension office for information about rodent control, or obtain the services of competent rodent control professionals.
- Keep worker restrooms clean.
Handle eggs properly
Fresh, whole eggs contain natural resistance factors that inhibit bacterial growth if the eggs are kept cool.
Things to do:
- Collect all eggs promptly, especially in hot weather.
- Store unprocessed eggs under refrigeration as soon as possible on farms without in-line processing plants. The temperature in the egg cooler should not rise above its set point except briefly when eggs are moved into or out of the cooler. Repair broken refrigeration units without delay. Keep the cooler door closed.
- Handle eggs carefully to minimize cracks.
Keeps pesticides and hazardous chemicals away off eggs
Things to do:
- Use pesticides and other hazardous chemicals in the house only when necessary.
- Use these products only if approved for egg production.
Quality assurance involves creation of confidence that eggs have been produced under high standards for food safety. This cannot be done without keeping good records. Unfortunately, record-keeping may prove to be the most difficult task in the entire quality assurance program, because, for the most part, people are not used to doing it.
Things to do:
- Specific individuals should have the job of keeping specific records.
- Records should be kept on file in designated places until they are judged to be obsolete.
How to choose eggs
There are several ways of determining the freshness of an egg. A common test is to place it between the eye and a strong light. If fresh, the white will appear translucent, and the outline of the yolk can be distinctly traced. By keeping, eggs become cloudly and when decidedly stale, a dark, cloudlike appearance may be discerned opposite some portion of the shell.
Another test is to shake the egg gently at the ear; if a gurgle or thud is heard, the egg is bad. Again, eggs may be tested by putting them in a vessel containing a solution of salt and water, in the proportion of a tablespoonful of salt to a quart of water. Fresh eggs will sink; if more than six days old, they will float in the liquid; if bad, they will be so light as to ride on the surface of the brine. The shell of a freshly laid egg is almost full, but because the shell is so porous, with age and exposure to air a portion of the liquid substance evaporates and air accumulates in its place.
How to keep eggs
There is a difference of opinion as to which end should be placed down in packing; most authorities recommend the smaller end. However, an experienced poultry man offers the following reasons for packing with the larger end down: The air cell is in the larger end, and if that is placed down, the yolk will not break through and touch the shell and thereby spoil. Also, if the air cell is down, the egg is not so likely to shrink away.