What Is Biosecurity? - By The University of Maryland - Emergency and common diseases are produced by microbes or germs that are invisible except when viewed under a modern microscope.

In less than a day a single microbe can reproduce and multiply to a number greater than the number of people on earth. Microbes are our enemy. They are killers. Keeping these prolific killers off your premises and out of your poultry is the key to your flock's health and to the success of your business. It is possible to keep germ-free poultry by using a defense health plan called "biosecurity."

In simple terms biosecurity is informed common sense. Do not bring germs to poultry, and do not bring poultry to germs. In other words: Block the bug before it bugs your flock. Realize that you are dealing with persistent, invisible killers that readily survive in dust particles, droppings and debris, waiting to hitch a free ride to a lush living on your poultry farm.

Effective disease prevention reduces emergency diseases such as avian flu, Newcastle disease and duck plague. These diseases cause epidemics on poultry farms, public alarm, cancellation of shows and sales, and long expensive quarantines, resulting in severe personal and financial losses. Common diseases such as fowl cholera, laryngotracheitis, mycoplasmosis, paratyphoid infection and others can also cause problems and exact their price on poultry, such as: slower growth, lower egg production rates, reduced product quality, and lower customer satisfaction.

Fowl cholera and laryngotracheitis germs can cause 10 to 20 percent or more of the death rate in birds. Mycoplasmosis has been known to shave 30 to 50 percent off net layer flock profits. Paratyphoid infections (salmonellosis) erode public confidence in poultry and other animal food products.

How Microbes Travel

Microbes travel from place to place by chicken crates, egg-filler flats, trucks, and other equipment and people (Figure 1). They can be found on people's hands, in their hair, on clothing and on shoes. They are found on the skin and in the digestive and respiratory organs of dogs, cats, rats, mice, and wild, free-flying birds. Flies, beetles and other insects are also notorious spreaders of disease-causing organisms.

Many germs die in 2 or 3 days. But under certain conditions--such as cold, damp surroundings--they survive much longer. Even with a short, 1-day survival, germs can travel several hundred miles when clinging to drivers, trucks, chicken crates or egg-filler flats. Table 1 gives approximations of how long germs can survive in empty chicken houses, on loading docks and in other places where there are no chickens.


Putting new birds, including baby chicks, in contact with droppings, feathers, dust and debris left over from previous flocks can be a potentially dangerous practice. Microbes can significantly increase to dangerous levels from one flock to another.

Raising different types of fowl on the same farm is risky from the standpoint of disease. Microbes that cause little or no harm to one type of fowl can be devastating to another. For instance, chickens carrying blackhead infection ordinarily do not show obvious signs of sickness. But when the same agent gets into a turkey's intestinal tract, the result is severe and frequently fatal. Influenza viruses, though common and usually not bothersome in waterfowl, can produce serious disease problems in chickens and turkeys.

Pet birds may carry Newcastle disease viruses that can raise havoc in commercial flocks and game birds. Adult or semi-mature poultry often carry levels of disease-producing microbes that cannot be tolerated by newly hatched poultry.

How to Enforce Biosecurity

To avoid bringing disease to poultry, change into fresh, clean coveralls, hats and boots when visiting a farm or moving from one farm to another. Equipment used on farms should be cleaned, washed and disinfected before it is used on another farm. Equipment needing careful attention includes chicken hauling crates, egg-filler crates, delivery trucks, feeders and waterers. Also included are loaders and dumpsters, tractors, toolboxes, pickup trucks, vaccine sprayers and debeakers. Be alert to all of the ways that disease can spread to your farm.

To get rid of germs, thorough housecleaning, followed by vigorous washing, often is more important than the disinfectant you use because several kinds of microbes resist the direct killing action of many disinfectants. Microbes such as bursal disease viruses, coccidial oocysts and avian tuberculosis bacteria are resistant to disinfectants. Microbes often escape the germ-killing effects of a disinfectant when dirt or other filth take the punch out of a disinfectant's chemical activity.

Broken or unused equipment and furnishings, dust on fans, inlets and ceiling beams, tiny pieces of debris, cracks and joints in boards, and dried films of body fluids all provide places for microbes to hide from the effects of a disinfectant. Fight your invisible enemies with neatness, dust removal and a through cleansing with soap or detergents and hot water, if possible.

Scrub brushes, pressure sprayers, orderliness, and a lack of clutter are your power punches in your bout with germs. Use disinfectants for the final knock-out punch to kill stragglers. Remember that your invisible enemy is small, numerous, tough and hard to reach!

Follow all label instructions when using disinfectants. Effective disinfectants range from simple solutions of household bleach to complex manufactured formulas.

Other Preventive Measures

What other measures can you take to keep your birds germ-free?
Plan and engineer your operations to block situations which may expose your flock to disease. Equipment and house repairs can be scheduled after your flock has been marketed. A simple room for changing clothes can be provided for visitors.

A ready supply of smooth-soled rubber or strong-soled plastic boots for visitors' use is a good investment. Foot pans with disinfectant, and disinfectant-treated pads are hard to maintain and are often useless.

Good ventilation pays! Large amounts of fresh air dilute microbe populations and reduce disease buildup. Locate new poultry buildings and facilities as far as possible from other poultry operations and poultry traffic. Do business only with firms and organizations whose service representatives consistently practice high biosecurity standards.

Try now to design your own Biosecurity Insurance Program. Keep in mind that biosecurity expenditures should be viewed not as unnecessary costs, but rather as short- and long-range investments in a safer, more profitable future. Key ingredients are provided on the following pages, and remember that the list is far from complete.

Source: University of Maryland College of Agriculture and Natural Resources - August 2004