Biosecurity is a set of practices put in place to limit the spread of disease or contamination from one location to another. Because poultry is housed in close confinement, disease spreads rapidly from one bird to another and outbreaks can be economically devastating. Biosecurity is teamed with disinfectation and sanitation to reduce or preferably eradicate disease-causing pathogens. Location Commercial poultry farms should be located at least 3 km from the nearest neighbour, as far as possible from main roads, with a good source of potable water and as isolated as possible. Where this is not possible, measures have to be put into place to limit the amount of traffic, vehicular, human and vector that has access to the birds. Disease is transmitted in one or more of four ways
1. Humans – employees, visitors, veterinarians etc
2. New poultry – eg chicks, male breeders etc
3. Contaminated or improperly cleaned houses
4. Vectors – including rats, wild birds, insects, pets, wind, even contaminated feed or water.
By practicing traffic control, isolation and sanitation, the farmer can limit the possibility of the introduction of pathogens into his flock.
1. Controlling traffic – human and vehicles
• All staff must be well trained and understand the necessity of biosecurity. If employees have reason to visit another farm or a place where birds are, they should shower and change their clothes before entering the houses.
• The farm should be fenced to prevent unauthorised entry and all visitors should be approved and logged in a visitors book.
• The gate should be as far as possible from the houses and all vehicles entering the gate should be disinfected by spraying or – at minimum – driving through a disinfectant bath. Parking for vehicles should be as far from the poultry houses as feasible.
• Poultry houses should be locked to prevent unauthorized entry.
• Staff should be provided with protective clothing, boots, etc and must shower and change into protective clothing before entering the houses. Staff should be specific to one house if possible, but if it necessary to visit several houses, they should disinfect hands and boots between houses. Hand sanitisers and footbaths must be provided and cleaned daily to prevent build up of organic matter. Always spend the minimum time required in each house and always go from the youngest birds to the oldest. (Or from ‘clean’ areas first to ‘dirty’ areas last.)
• Sick employees, especially with stomach upsets must not be allowed to work as they can transmit pathogens such as salmonella.
2. Maintain Sanitation
• All-in all-out flock management is ideal but not always feasible. If this is not possible, young birds should be kept at a distance of at least 600 metres from older birds and always visited first.
• New birds eg day old chicks must always be bought from a reputable supplier.
• Floors should be concrete to allow effective cleaning and disinfection.
• Dead and sick birds must be disposed of promptly; preferably by burning.
• Manure must be regularly removed and disposed of suitably, by composting or slurrying. It may be necessary to spray manure heaps with a suitable insecticide.
• Never borrow or lend equipment from a neighbouring poultry farmer.
• Litter must be of good quality and disposed of between flocks.
• Never keep left over feed in bins between flocks. This must be destroyed and feed bins washed out and disinfected.
3. Vector Control
• The area should be kept free of rubbish and debris.
• Pets should never be allowed in a commercial poultry set up. Dogs and cats carry salmonella and pasturella spp which can infect poultry.
• Rats and other vermin should be controlled and killed with approved rodenticides and traps. The bodies should be burnt.
• Houses should be proofed against wild birds which will be attracted by the feed as they may carry pathogens.
• No other livestock should be within 1 km of the poultry houses.
• Feed and water must be clean and fresh and changed regularly.
4. Maintain Bird Health Surveillance
• Vaccination schedules should be strictly followed and maintained.
• Routine bird health surveillance should be observed.
• Dead birds should be post-mortemed to ascertain cause of death.
• In a disease outbreak, sick birds and samples should be sent to the laboratory for analysis and early disease control.
• Blood sampling may become necessary if birds are not thriving but no obvious cause is found.
BASIC CLEANING TECHNIQUES
Once a house is empty, all equipment must be removed, washed and sanitised. All facilities must be cleaned using the same procedure, including food stores, the egg room, changing rooms etc. An initial cleaning with a heavy duty detergent and high pressure hoses will rid the house of organic matter, which interferes with the process of disinfection. It is important to remember areas such as air inlets, fan shafts, gutters and roof.This should be followed with high pressure cleaning containing a suitable disinfectant. The final clean cycle is with an approved sanitiser. Once the building is dry, disinfectant should be sprayed around the building to include the area 6 metres from the house. Once the house is dry, clean litter and clean, sterilised equipment can be replaced. The house can now be fumigated with formaldehyde if required. This is a specialised procedure and requires trained staff and protective clothing.
(For different classes of disinfectants and how to use them, see http://animalscience.ucdavis.edu/Avian/pfs27.htm and http://www.cobb-vantress.com/contactus/brochures/Breeder_guide_2008.pdf)
Biosecurity is only as effective as the people putting the procedures in place. It is vital that everyone connected to the enterprise understands the necessity, the principles and practices it diligently.