Date Published: July 16, 2004

Introduction:

Bio-security means protecting the health of poultry by preventing the introduction of infectious agents. Preventing diseases from entering farms is crucial. The cost benefit of a bio-security system depends on the type of production, system and the disease. Many inexpensive systems can generate substantial benefit. As you review your current bio-security system .. think about all aspects of it. Sometimes the routine practices you take for granted are actually serious breeches of bio-security. Today we are especially aware of the very real consequences of disease as we follow developments of the Avian Influenza outbreak in British Columbia.

There are several different ways to think about bio-security. One approach is to rank the risk factors around the possible introduction of disease. These include disease in other poultry flocks or wild birds in your area, farms located in a high poultry density area, backyard flocks located within 1 km. and nearby spreading of litter from other farms. While many of these risk factors are beyond your direct control they all increase the pressure on any farm bio-security system.

Farm bio-security systems are mostly dependant on owners, employees, visitors, service personnel and neighbors who either use or control systems.

Farm gate:

Bio-security needs to begin at the farm gate with posted notices prohibiting any unauthorized entry to the premises. No one should enter the premise without owner or agent permission even when on official business. Remember that improperly cleaned or sanitized vehicles, such as feed and supply trucks, can physically carry diseases as can dirty clothing and equipment. Consider placing a standard pump sprayer at the entrance to your property. CFIA recommends using a solution of equal parts bleach and water. Infectious agents can't be seen but anything which appears dirty is an indication of a problem and should be considered contaminated. Clean-up is a two step process - washing to clean followed by disinfection. If you have concerns about incoming equipment or trucks spray them with disinfectant. A similar protocol should be followed by service people as they exit your premise.

Barns:

The second and even more important site to implement a bio-security system is at the barn. Think of the barn as being surrounded by an invisible barrier through which you do not want any infectious agents to pass.

The most obvious risk is at the people entrance to the barn which should be locked. Owners should provide clearly written instructions for people to follow and keep a log book of all traffic. There should be access to a well maintained foot bath and change room so outside street clothing and foot wear can removed. One then passes through an intermediate zone which divides dirty and clean. In an ideal situation this would be a shower but these are not always available. The importance of hand washing in this zone should be stressed. Next comes the clean zone where clean clothing, boots and head covers supplied by the owner, are put on. Once work in the barn is completed the same procedures, in reverse, should be followed to exit.

Another important potential source for infectious agents is the moving of equipment into barns. In the BC there have been suggestions that catching crews and their equipment have moved the AI virus to new farms. Also, recent information indicates that dirty egg crates may be responsible for moving the AI virus. However, people are still considered the primary way AI virus has been moved from farm to farm in BC.

Backyard flocks:

Backyard flocks continue to be a source of concern to commercial producers. These flocks do represent some risk as their disease status is often unknown. Flocks having access to the outdoors are at increased disease risk as there is no tight bio-security system or barrier against poultry diseases found in local reservoirs. Farm owners or employees should not own backyard flocks. Having these flocks within 1 km. of a commercial farm does increase the pressure on any farm bio-security system. In known situations prevention needs to be in place to stop direct traffic into commercial barns. Indirect movement of disease is also a concern. In the USA one case has been reported in which a backyard flock owner was a babysitter for the commercial owner. It was assumed that disease passed mechanically from the babysitter to the owner then into the commercial barn.

Reservoirs:

Other potential sources of the virus are local reservoirs. It is well documented that wild birds such as geese and especially ducks can carry HPAI and often not be ill. In Nova Scotia we have a population of migrating waterfowl of which the AI status is unknown. It would be wise to consider these birds at least potential sources for AI. Remember AI virus is stable in the environment and can survive at least 90 days in feces. A serious outbreak of AI in Holland last year was thought to have originated from the direct tracking of AI infected wild duck feces from an adjacent pond directly into a commercial barn.

Other possible vectors or mechanical carriers for infectious agents include rodents or wild birds which get into barns. A rodent control program is essential including cutting of a zone of grass around the outside of barns. Screening of ventilators to keep birds out is also important.

Water contaminated by surface run off is a possible virus source and in-barn water systems need to be on a regular program for cleaning and sanitation. In-barn chlorination systems are good to stop or reduce the spread of many diseases should they be accidentally introduced to the water system.

Other:

Proper dead bird disposal is important. Birds should be quickly removed from the barn area to ensure that they do not serve as a source of disease back to the poultry in barns.

Proper composting of manure essentially destroys common disease pathogens by the heating process but the nearby spreading of fresh manure is a risk. If it is manure from your own barns the risk is less that if it is from other barns of unknown disease status.

Conclusions:

I urge all poultry producers to review their farm bio-security system in accordance with the national on-farm food safety assurance programs being implemented by your commodity groups, identifying all possible ways that infectious agents can be introduced into barns. Introduce as many barriers to prevent the introduction of disease as possible. As mentioned earlier - changes can often be made for a relatively low cost which may have a big pay-back.

Acknowledgments:

The CFIA web site (www.inspection.gc.ca) contains a lot of information on AI and the BC situation. It is updated regularly plus you can subscribe to a notification service advising you directly by E-mail when changes are posted.

I have also used several ideas from .. The U.S. Poultry & Egg Association’s (1530 Cooledge Road, Tucker, GA, 30084-7303) excellent (free) CD-ROM called “Poultry Disease Risk Management: Practical Bio-security Resources “

Dr. Gord Finley, Program Veterinarian
Nova Scotia Department of Agriculture
Truro, Nova Scotia
Tel: (902) 893-3491