A good disease control program emphasizes three primary goals or areas:
- Reduce exposure to disease organisms by proper sanitation and stress management.
- Increase bird resistance to disease by using recommended immunization procedures.
- Treat disease outbreaks with specific medications that are effective against the disease being treated.
Diseases have consistently been a major limiting factor to profitable production. Some diseases result from egg transmission or organisms through the use of infected breeder flocks. Other diseases are brought into the poultry house by vectors like wild birds, rodents, parasites, and even the poultryman.
Disease results when exposure combined with the virulence of an organism is greater than the resistance of the host. Disinfectants reduce the exposure time and number of organisms. Vaccines help build the natural resistance or immunity of the birds. Medications and drugs help battle the disease organisms after they have overwhelmed the birds’ natural defenses.
Most diseases can be eradicated from the poultry flock by applying the basic principles of hygiene and excellent sanitation. Other diseases are not easily eliminated, but can be controlled by proper use of disinfectants and sanitizers. If not controlled, the potential for microbial contamination and spread of infectious diseases in the flock is always a threat to the success of any operation.
Sanitation is a rather simple word, commonly used in our daily conversations to refer to the establishment of environmental conditions that are favorable to health. It is those management practices that actually prevent disease or contamination by disease causing organisms. For the most part, they are simple mechanical applications. They are not sophisticated and usually require little in capital expenditures. These management practices do require a positive attitude, a workable program, and proper application.
There is a practical way to clean a poultry house or hatchery. Each time, the process involves time, labor, energy, and money, so the job must be done correctly to achieve the best results. Disinfecting alone will not control disease, but combined with other disease control practices, will do much to reduce the incidence of many diseases.
Vaccination is one of the more effective ways to prevent specific diseases. This is why we vaccinate poultry; so they are protected from explosive disease outbreaks. Viruses stimulate the development of better immunity than other types of microorganisms; so most poultry vaccinations are against viral diseases like Newcastle disease, infectious bronchitis, laryngotracheitis, fowl pox, and infectious bursal disease.
Disease producing microorganisms can be classified smallest to largest as viruses, bacteria, fungi, protozoa, and parasites. All except the viruses are sensitive to drugs or antibiotics, so treatment against them is available when outbreaks occur. Because viruses are resistant to drugs and antibiotics, their control is fully dependent upon prevention through sanitation, isolation, and vaccination.
Vaccination is basically the introduction of a specific biological substance (antigen) into the bird to stimulate the formation of a resistance or immunity to a particular disease. Usually the biological substance is some of the live disease organisms that you want to protect the bird against. The presence of these organisms in the blood stimulates the body’s defense mechanism to produce antibodies that attack the disease causing organisms when the bird is exposed to them. Scientists have developed weakened (attenuated) forms of most disease causing viruses with little danger of causing the severe form of the disease. Even the killed form of some disease causing viruses stimulate the production of antibodies. In these cases, the 100 percent safely killed virus is used. Short-term protection against a particular disease can also be given by vaccination with an antiserum that contains antibodies previously formed by animals that have been exposed to that particular disease.