By Dr.Manish Kumar, TVO,Bihar
What is biosecurity?
Biosecurity is a practice designed to prevent the spread of disease onto your farm. It is accomplished by maintaining the facility in such a way that there is minimal traffic of biological organisms (viruses, bacteria, rodents, etc.) across its borders. Biosecurity is the cheapest, most effective means of disease control available. No disease prevention program will work without it.
Biosecurity has three major components:
1. Isolation
2. Traffic Control
3. Sanitation
Isolation refers to the confinement of animals within a controlled environment. A fence keeps your birds in, but it also keeps other animals out. Isolation also applies to the practice of separating birds by age group. In large poultry operations, all-in/all-out management styles allow simultaneous depopulation of facilities between flocks and allow time for periodic clean-up and disinfection to break the cycle of disease.
Traffic Control includes both the traffic onto your farm and the traffic patterns within the farm.
Sanitation addresses the disinfection of materials, people and equipment entering the farm and the cleanliness of the personnel on the farm.
How much biosecurity do I need?
In order to assess how much biosecurity is practical for your farm, look at these three factors.
1. Economics
2. Common Sense
3. Relative Risk
The greatest threat to the wellbeing of any creature comes from other creatures of the same species. The closer they crowd together, the greater the risk of disease – disease which can be passed directly from human to human, from animal to animal, or through indirect carriers such as contaminated surfaces, feed or water, vermin or insects.
Biosecurity, in other words excluding disease organisms from the creature’s environment, is the most effective form of protection, especially those farmed using modern production techniques. From viruses or bacteria, coccidia or fungi, disease may spread via recognised vectors of infection, from the animals themselves, the people who handle them, contaminated food and water, housing and equipment, and even the air itself. Viruses causing Chicken Anaemia or Gumboro are not only extremely persistent in the environment, but are also immunosuppressive, thus increasing susceptibility to additional pathogen attack. Modern biosecurity techniques are a key element in disease control, providing a healthier environment for your livestock.
Disease Transmission:
The mode of disease transmission between birds, or between sites, differs depending on the type of infection. For example, respiratory disease viruses replicate in the respiratory tract. Subsequent sneezing and coughing release virus particles which are then spread by aerosol transmission. On the other hand, enteric (gut) diseases cause diarrhoea, so infectious agents spread through droppings, whilst air sac and oviduct infections lead to egg contamination and transmission.
Other diseases persist on sites through the contamination of equipment and litter by stubborn virus particles. Many organisms will persist outside the host, and coccidia, salmonella, aspergillus and many viruses can survive in this way for a considerable time, especially in organic material. Pasteurella, mycoplasmas and some bacteria can also live for some time. Respiratory viruses tend to be fairly fragile once outside the host, although may be able to travel at least five miles in the air if conditions are favourable.
Factors Influencing Biosecurity:
• Introduction of diseased birds
• Introduction of healthy birds who have recovered from disease but are now carriers
• Shoes and clothing of visitors or caretakers who move from flock to flock
• Contact with inanimate objects (fomites) that are contaminated with disease organisms
• Carcasses of dead birds that have not been disposed of properly
• Impure water, such as surface drainage water
• Rodents, wild animals and free-flying birds
• Insects
• Contaminated feed and feed bags
• Contaminated delivery trucks, rendering trucks, live hauling trucks
• Contaminated premises through soil or old litter
• Air-borne fomites
• Egg transmission
Of all the possible breakdowns in biosecurity, the introduction of new birds and traffic pose the greatest risk to bird health. Properly managing these two factors should be a top priority on your farm.
Infection may be harboured and spread in a variety of ways. In relation to poultry, these may include by vermin (mainly wild birds, rats and mice), in feed, in droppings, by wind, by inadvertent human intervention and on equipment or litter. These factors all influence the planning of a biosecurity programme.
In an ideal world, sites should be located away from other poultry, and breeders should probably be sited at least five miles from any commercial farms in order to avoid airborne spread of disease. Obviously, this is frequently impracticable, so some air borne respiratory viral challenge will often be a feature of the disease load.
However, disease avoidance measures are still worthwhile and can be undertaken at various stages. For example, avoid building sites near waterways, ponds or lakes utilised by migratory water fowl, and choose well drained areas to avoid standing water. Birds on range will be susceptible to contamination from wild birds and will attract vermin. Wherever possible, poultry houses should also be located away from major roads that handle high volumes of poultry vehicles.
Avoid putting new birds, including baby chicks, in contact with droppings, feathers, dust and debris left over from previous flocks. Some disease-causing organisms die quickly, others may survive for long periods. For examples, see Table 1.
Effective waste disposal and removal of used litter from the site is essential. Areas around houses should be constructed of materials and surfaces that can be cleansed and disinfected, to reduce transmission of organic material on vehicles, tyres, boots etc. Use a multipurpose broad spectrum virucidal and bactericidal disinfectant which will be capable of dealing with gross organic challenge.
People are the most important animate factor – including employees, servicemen, lorry drivers, vaccination crews and vets. Staff movements should be as limited as possible, particularly where the disease situation on a site has deteriorated.
Control site traffic.
Keep it to a minimum and exclude all unauthorised persons.
Wherever possible, vehicles should be excluded from the site. Those vehicles which must enter should be subject at the site entrance to spray disinfection of wheels and wheel arches. All visitors should observe standard operating procedures on vehicle cleansing and disinfection, and protective, farm only clothing should be provided to and used by drivers.
All visitors should enter on foot. Use regularly refilled foot dips, charged with a suitable disinfectant.
All site visitors should be provided with adequate protective clothing, and should wash their hands prior to visiting birds. Use an effective hand hygiene system which is equally effective even when there is no available water supply (Antibacterial Hand Soap and Instant Hand Sanitizer). A shower in, shower out facility should also be put in place wherever possible.
The birds themselves can also be a cause of disease spread. Incoming poultry should therefore be from high health status sources, and there should be a well defined health monitoring and audit procedure for breeder supply flocks. This should extend to hatchery hygiene procedures with regular microbiological monitoring. Avoid the potential spread of infection from diseased carcasses by on-site incineration.
Effective cleaning and disinfection reduces pathogen numbers and the weight of disease challenge, and enhances any biosecurity programme. It can only be achieved with sufficient turnaround/down time to allow removal of all litter, and to satisfy required contact times for the disinfection products used prior to restocking.
Cleaning and disinfection should include houses, equipment and surroundings.
Use potable drinking water with a low total viable count. Maintain a closed water system with lids on all header tanks. At turnaround, clean and disinfect the water system with a suitable product to remove the greasy biofilm that will harbour and protect pathogens.
Treat feed bins and feed delivery systems. Feed delivered to the site must be of high health status and vermin protected. Finished feed and stored raw materials should be sampled regularly for salmonella. “High risk” raw materials or sources should not be used.
Check biosecurity procedures regularly. Use only biosecurity products with independently proven broad spectrum efficacy against viral and bacterial pathogens, and use them according to manufacturers’ instructions. Maintain an effective, audited rodent and wild bird control programme, and prevent entry of poultry houses by vermin through good house design and repair.
Biosecurity Checklist:
1. Properly implemented biosecurity measures will limit the spread of disease-causing organisms.
2. When these are combined with cleaning and disinfection, vaccination and strategic treatments, many pathogens can be reduced to non-infectious levels.
3. Remember – different infectious agents spread by different methods, so use appropriate measures against each type.
4. Site location and design, and density of poultry in a given geographical area, are vital. When planning a new site, there is the opportunity for very effective biosecurity to be implemented at the design stage. However, biosecurity practices must concern themselves with practicalities, rather than a theoretically ideal set-up.
5. All sites have traffic – personnel, feed, stock, and equipment – but this should be kept to an absolute minimum.
6. Only essential vehicles should have access to a site, and these should be disinfected on arrival.
7. Use protective, farm only, clothing to prevent pathogen spread.
8. Priority should be given to biosecurity measures on breeding sites since errors here are magnified greatly at the commercial level.
9. Similar priority should be given at the hatchery level.
10. Site decontamination, turnaround times and a well-audited and structured cleansing and disinfection procedure should be in place for all sites.
11. Effective vermin control must be maintained.
12. Only disinfectants with independently proven broad spectrum efficacy against viral and bacterial pathogens should be used and at manufacturers’ stated dilutions and directions.
In emergency disease control situations, it is appropriate to consider all restrictions which may be imposed by the country specific governmental agricultural department.
Terminal Biosecurity Programme:
Four Stage Terminal Biosecurity Programme:
The standard terminal biosecurity programme comprises of 4 specific stages, the objective of which is simple – to prevent the “carry-over” of pathogenic organisms, thus ensuring that each new crop gets a completely clean, fresh start.
Stage 1: Removal of Equipment and Dry Cleaning
1. Remove any residual food from the feeder system and silo.
2. Remove all movable equipment.
3. Blow or wash down all surfaces to remove dust from ceilings, water pipes, fan boxes and inlets.
4. Remove all litter from the house using scrapers and blow or brush loose debris from the ceilings and floor.
5. Load litter onto lorry ensuring that all areas such as concrete pads by doors and silos are cleared of old litter, dust etc. Make sure that the load is covered before transporting from site.
6. Blow or wash down bulk feed bins before disinfecting.
Stage 2: Water System Clean and Disinfect
1. Isolate header tank at mains inlet point, check that it is free from debris and then drain entire system from the drinker points furthest away. Clean as required.
2. Fill the tank with the necessary volume of water to fill the entire drinking water system adding the appropriate amount of disinfectant concentrate to achieve the required dilution.
3. Allow disinfectant solution to fill the system to the drinker points farthest away from the header tank. Leave for one hour.
4. Thoroughly flush lines through with clean water. Repeat process if scale and biofilms remain.
5. Refill the header tank with clean fresh water.
Stage 3: Cleaning:
Buildings and Equipment
Thorough washing of all surfaces and equipment is essential to achieve the best results from the subsequent disinfection stage.
WASH:
Using a pressure washer apply an appropriate detergent solution to all surfaces. Ensure coverage of air inlets, fan boxes, partitions, feeders, drinkers and other equipment, including any removed from the house. Include any service/utility rooms in this cleaning procedure before rinsing all surfaces and equipment with clean water at high pressure.
PRE-SOAK:
1. Externally, spray air inlets and built-up deposits from around fan boxes and loading areas with detergent solution. Ensure that all dirty areas such as concrete aprons around the houses and bulk bin pads are washed clean.
2. Internally, soak all surfaces thoroughly with detergent solution applied at low pressure. Leave for 20-30 minutes, and then rinse at high pressure using clean water.
Ensure all surfaces and equipment are visibly clean before moving on to the disinfection stage.
Stage 4: Disinfection
The level of disease-causing organisms present after the cleaning stage is high enough to present a serious disease challenge to a new crop of birds.
Using a broad spectrum DuPont disinfectant proven effective against viruses, bacteria, fungi and moulds is essential.
1. Use either a knapsack sprayer or pressure washer on a low pressure setting (300psi) to disinfect all equipment removed from the building. Place the equipment back in the cleaned building prior to disinfecting the house itself.
2. Using a pressure washer on a low pressure setting (300psi) or an orchard sprayer for larger premises apply the disinfectant solution evenly to all washed internal surfaces to achieve thorough wetting.
3. Pay particular attention to corners, cracks and seams ensuring that all sides of supporting posts are covered.
4. Spray into the apex of the roof and work down the walls to the floors.
5. Working from one end of the building to the other, apply disinfectant solution to the floor of the building.
6. Upon completion of the disinfectant process, close all doors and place disinfectant footdips at all entrances.
7. To control organisms introduced to the house during the setting up procedure and to disinfect the air and other inaccessible areas of the building use either a fine mist sprayer or thermal fogging machine to apply a suitable disinfectant solution evenly.
Standard Continuous Biosecurity Programme Procedures:
The aim of the standard continuous biosecurity programme is firstly to prevent pathogens from establishing themselves on site and, secondly, to prevent the spread of infection within the farm site.
With this in mind the following continuous biosecurity procedures must be implemented at all times.
Disinfectant Footdips:
All personnel must use disinfectant footdips on entering the site or a house. Replenish every 4-5 days or when visibly contaminated.
Wheel Wash, Vehicle Sprays & Mobile Equipment
Any vehicle entering the site must pass through a disinfectant wheel wash or vehicle spray. The wheel wash should be topped-up regularly to avoid dilution or contamination. Mobile equipment brought onto the site from other units must be washed and disinfected before being allowed to enter.
Hand Washing:
Dirty / unwashed hands transfer infection. All visitors to the site must be required to wash their hands before entering. All staff must wash their hands before starting work, after breaks and when changing activities.
Visitors:
Care must be taken to ensure that visitors appreciate the biosecurity measures you have taken to protect your site, and protective equipment should be issued to visitors where appropriate.
Water Lines & Drinkers:
Continuous disinfection is important to maintain water quality during the production cycle. Drinking water can be a potent source and spread of infection. Header tanks and pipelines need to be regularly cleaned and disinfected with a non-tainting disinfectant.
Aerial Disinfection:
Spraying a fine disinfectant mist or fog over birds can help reduce cross infection and secondary infection during outbreaks of respiratory and other diseases. It is particularly of value in preventing secondary bacterial infection (e.g. E.coli septicaemia) following a virus challenge such as Infectious Bronchitis or Turkey Rhinotracheitis.
Rodent Control:
Rats and mice can be responsible for the spread of a number of serious diseases on poultry farms including salmonella infections. Ensure that feed spillages are removed as quickly as possible and that houses are secure from vermin. Implement an effective rodent control program.
Poultry Transport:
Biosecurity Programme
Introduction
The importance of biosecurity for all vehicles associated with poultry production cannot be stressed enough. This applies especially to livestock and feed vehicles, but also to any others visiting poultry premises.
Livestock haulage and other vehicles, such as feed lorries, engineers and other visitors unfortunately provide an excellent vector through which disease can spread.
Our unique Transport Biosecurity programme provides poultry farmers and hauliers with step-by-step procedures to follow. If adhered to, these procedures can help reduce disease transmission via transportation of livestock.
Vehicle Disinfection Summary:
In addition to livestock haulage vehicles, all vehicles e.g. feed lorries and contractors must follow this summary to reduce the potential for transmission of disease.
• Only essential vehicles should enter the site.
• All vehicles visiting the unit should be kept outside the biosecurity perimeter if at all possible.
• Vehicles should be thoroughly cleaned and disinfected using the Vehicle Biosecurity Programme prior to arrival at the unit.
• Wheels, tyres and wheel arches should be cleaned and disinfected upon arrival at the unit using disinfectant wheel dips or sprays where provided.
• Personnel should wear appropriate personal protective equipment (PPE), use disinfectant footdips, and disinfect their hands prior to entering premises.
Step-by-Step Practical Guide to Vehicle Cleaning and Disinfection:
To help prevent the spread of disease via transportation, adopt the following procedures for vehicle cleansing and disinfection.
1. Before commencing, ensure you are wearing clean and disinfected personal protective equipment (PPE) consisting of waterproof coveralls, Wellington boots, gloves and goggles.
2. Once all modules are removed scrape and brush soiling/litter from the transporter deck.
3. Enclosed trailer only, scrape and brush the sidewalls, floor and tail lift of the vehicle
4. Remove any deposits of mud, straw etc from the wheels, wheel arches, mudguards and exposed chassis.
Cleansing and Rinsing:
Using an appropriate heavy-duty detergent solution, soak all surfaces of the vehicle allowing at least 10 minutes contact time for it to penetrate and loosen dirt.
1. Clean the outside of the vehicle, start at the top and work down each side, wash the transporter deck thoroughly and pay particular attention to the wheels, wheel arches & mudguards.
2. Inside (if applicable), soak the ceiling, sidewalls and floor of the vehicle.
3. Wash the tail lift thoroughly (where applicable).
4. Wash all vehicle equipment, tools and the belly box
5. After washing is complete high pressure rinse all surfaces with clean water and check that they are clean of any muck or debris.
Disinfection:
Wearing a protective face mask and gauntlets apply a suitable broad spectrum virucidal disinfectant solution to all vehicle surfaces, inside and out.
1. Outside, start at the top and work down each side and over the transporter decking, paying particular attention to the wheels, wheel arches mudguards and underside of vehicle.
2. Inside (if applicable), ensure that the ceiling, sidewalls and floor of the vehicle are disinfected thoroughly finishing the procedure on the tailgate (if applicable).
3. Disinfect all vehicle equipment and belly box.
Cab Disinfection:
1. Remove all removable items e.g. mats and boots from the vehicle cab and brush any debris or mud into a bucket or dustpan. Dispose of the cab waste into a refuse sack.
2. Wash the cab floor, mats and vehicle pedals with heavy-duty detergent and leave for 10 minutes allowing for the solution to penetrate and loosen dirt, then rinse with clean water.
3. Using a clean cloth soaked in virucidal broad spectrum disinfectant solution, disinfect the cab floor, mats and foot pedals.
Finally:
1. Park the vehicle on a slope to drain and dry.
2. Once the vehicle is removed from the wash area, wash down the concrete surface with heavy–duty detergent solution making sure no muck or debris remains.
3. Disinfect overalls and boots with virucidal broad spectrum disinfectant solution.
Table 1. Longevity of Disease Causing Organisms
Disease Lifespan away from birds
Infectious Bursal Disease Months
Coccidiosis Months
Duck Plague Days
Fowl Cholera Weeks
Coryza Hours to days
Marek’s Disease Months to years
Newcastle Disease Days to weeks
Mycoplasmosis (MG, MS) Hours to days
Salmonellosis (Pullorum) Weeks
Avian Tuberculosis Years
Reference:On request
