Kashmiri Begum and Gaichamdinliu Gonmei
Department of Poultry Science, College of Veterinary science, AAU, Guwahati- 781022
Infectious agents are a threat to poultry health and have significant impacts on socio-economic conditions of the farmers. These agents include bacteria, viruses, protozoa, fungi, parasites and any other agents capable of introducing diseases in a poultry flock. As control measures, medication and vaccination has been the first hand approach to contain diseases. However, these alone are not sufficient to control diseases in field conditions. Therefore, the most effective form of protection against disease under modern techniques, with the objectives of preventing the introduction and dissemination of infectious agents in poultry production is the implementation of biosecurity procedures along with vaccination and medication.
What is Biosecurity?
Biosecurity refers to principles engaged in reducing the chance of introduction and spread of pathogens within and between farms by preventing infectious agents from entering (bio-exclusion) or exiting (Bio-containment) the farm and the principle elements are segregation, traffic control, cleaning and disinfection. Biosecurity at the farm level provides the foundation for biosecurity of the entire production chain. It is also the best form of defence against emergency diseases.
An effective biosecurity has three levels-
- Conceptual Biosecurity: It is the primary level of biosecurity which revolves around the location of farm facilities and their various components. It is best to build the farm at least 3 km away from nearest poultry farm in case of breeder farm and 1.6 km in case of commercial layer and broiler farm. Farm should not be located next to public roads and limiting the use of common vehicles and facilities.
- Structural Biosecurity: This is the secondary level of biosecurity which deals with farm layout, fencing of farm perimeter, drainage, sanitation of vehicles, storage of bagged feeds, prevention of spreading of microbes by foot wear, housing design with suitable wild birds and rodent proofing and facilities for safe and scientific disposal of dead birds.
- Procedural Biosecurity: This is the tertiary level of biosecurity which deals with routine procedures to prevent introduction of infection within a facility. The routine procedures are like maintaining records of visitors, routine disease monitoring procedures, regular culling of unhealthy and unproductive flocks, proper decontamination and disinfection of equipment, houses etc., following depletion of flock.
Biosecurity threats to poultry farms:
Avian influenza (AI) listed by the World Organization for Animal Health (OIE) is the most important biosecurity threat to the animal and human health. AI emerged from the reservoir animal and therefore, is a great concern for public health. AI in poultry has increased sharply and number of birds involved in the disease has also increased, which causes a negative repercussions on people. Highly pathogenic Avian Influenza is a lethal infection in certain domestic birds (e.g., chicken and turkey) and has a variable clinical effect in domestic birds. Feral birds, particularly water fowl are the natural hosts for these viruses. Guidelines provided by the World Organization for Animal Health (OIE), the Food and Agriculture organization (FAO) and the World Health Organization to prevent and control the infection requires to be strictly followed.
Routes that causes threats to poultry farm:
- Personals- Disease or food borne pathogens may be carried in a person’s hair and hand, clothing, footwear, personal items such as mobile phones and jewellery. Visitors like neighbours, contractors, suppliers, drivers, maintenance and service personal are potential carriers.
- Vehicles and equipments- Contaminated vehicles and equipments entering the farm pose the highest risk of spreading pathogens and cause disease outbreak.
- Feral animal, wild birds, domestic, insects and vermin, other poultry species –These vectors are capable of harbouring infectious biological agents that when moved or carried around is capable of disseminating and spreading agents. Mixing of new birds to the flock without quarantine may most probably cause infection and disease outbreak and older birds are more likely to carry disease.
- Litter- Poor quality litter infested with rodents, birds or animals residues acts source of disease and wet litter are good breeding ground for pathogens.
- Feed and water- Poor quality and contaminated feed and water act as breeding ground for pathogens and become potential sources of transmission of disease.
- Air- Disease outbreak in neighbouring poultry farms and piggeries may quickly spread by aerosol transmission and infect the farm birds if proper distances are not maintained between the farms.
- Poultry waste and dead birds- Improper management of disposal of poultry waste, dead birds, manure, spilled feed etc., can lead to disease outbreak in the farm as they are potent source of pathogens.
Management strategies in poultry production:
The concept of creating microbiological barriers to prevent pathogen is the basis of biosecurity. Monitoring of the effectiveness of the barrier can be done either qualitatively (for example, presence or absence of specific bacteria) or quantitatively (for example, bacterial counts or detection of antibodies).
The following are the management factors of disease prevention-
Isolation- All in all out system should be practice and the infected birds should be isolated. New birds should be quarantine for 1 month before mixing with other birds.
Managements of outsider- Outsiders should not be allowed to enter in the farm. On entrance, strict measures like showering before entry, changing into freshly laundered clothes and farm boots and then shower-out, should be followed to ensure the highest level of protection. It is also necessary to maintain records of visitors, workers, purpose of visits, previous farm visited and next farm to be visited.
Managements of vehicles and equipment– The farm premise should be designed with a one-way traffic route for personal and vehicles. Chick delivery vehicles should be fumigated and equipment should be cleaned and disinfected before and after use.
Feral animal, wild birds, vermin and other poultry species– Farm should have proper fencing to avoid feral and domestic animals from entering the farm premises. As a preventive measure against wild birds which are carriers of pathogens and can cause infection to farm birds, the farm area should be planted with non-flowering trees, making the shed bird proof Farm birds should be reared in a well designed and constructed house with a provision of indoor feeding and watering to prevent other poultry species from entering. Wall of the poultry house should be rodent proof, otherwise rodenticides should be used at night according to specifications. Use of insecticides sprays or dusting at required intervals is also recommended for preventing insect infestation of the poutry shed. Feed and bedding should be stored in a vermin proof area.
Litter Management- To reduce the risk of litter as source of disease, litter should be purchased from reputable supplier, free from rodents, birds or animals residues and reduce wetting litter by managing drinkers. After de-population of the birds from the poultry house, the litter should be cleaned and disposed off as soon as possible for manure or other purpose and the floor should be disinfected.
Quality Chicks- The chicks received should be healthy and of normal weight range. The chicks should be vaccinated against Marek’s Disease. The hatchery from where the chick is purchased should be taken care and guard of mycoplasmosis, salmonellosis and Infectious bursal disease.
Proper Nutrition- A balanced feed with proper nutrient requirements at different ages with addition of coccidiostats, vitamin and mineral supplementation in the diet will ensure proper health. Feed is a well known source of Salmonella, other bacterias and mycotoxins and thus, requires careful handling. Animal by-products such as fishmeal and meat meal, being higher risk ingredients, should be moved and stored in separate bins.
Water Quality- Microbial and chemical quality of the water need to be tested before establishing a poultry farm in an area. Mineral level in the water depends on soil conditions and show only minor fluctuation based on the season and water table. This leads to hardness in water and affect the taste and palatability.
Managements of farm– Aerosol transmission of diseases should be considered while designing the poultry houses. The air intake of one poultry house should be located away from the outflow vents of other houses. The house should be located at least 1-3km away from other private facilities.
Carcass disposal- Carcass should be disposed off scientifically and can be carried out through various methods viz., disposal pit, incineration or composting. A disposal pit saves labour, no noticeable odour or fire hazards and decomposition of carcass requires no chemicals. Incineration is possibly the best means of disposing because it saves time and causes no biohazards. Composting, however, should be monitored and managed well.
Biosecurity is a fundamental component in poultry production, if neglected, will ultimately results in heavy losses to poultry industry as it creates a firewall against infection, penetration and perpetuation. Standards for biosecurity should be developed and more upgraded. There is a need for research tie-up with different institutions in relation to production, processing and marketing of poultry products. Awareness programme should be conducted at farmers’ level to update about biosecurity needs. Vaccination is a powerful tool for supporting eradication programs and timely information of efficacy of vaccine in a variety of different avian species requires updation. Last, but not the least, an enormous effort is required from government and funding bodies to make resources available.