Surviving Newcastle Disease: Tips and Tricks Every Poultry Farmer Needs to Know

Newcastle disease is a highly contagious viral disease that affects poultry, including chickens, turkeys, and other fowl, as well as wild birds. This article aims to provide a comprehensive overview of Newcastle disease, including its etiology, transmission, clinical signs, diagnosis, treatment, and prevention.

Etiology

Newcastle disease is caused by the paramyxovirus, which has been classified into a single serotype. However, within this serotype, there are different strains that vary in their virulence. These strains can be categorized as velogenic (highly virulent), mesogenic (medium virulence), and lactogenic (mild virulence).

Notable examples of mesogenic strains include Roakin, Komarov, and Mukteswar, while lactogenic strains include Hitcher B-1, F, and Lasota. It is important to note that most strains used for vaccine production are lactogenic, and many exhibit neurotropism.

Transmission

Newcastle disease is highly contagious and can be transmitted through various means, including contact with infected birds, carrier wild birds, contaminated feed and water, movement of infected commercial and wild birds, human contact, and contaminated equipment. The virus is primarily spread through nasal discharges and droppings, and it can also be carried from one flock to another on shoes, hands, crates, and other objects.

Clinical Signs

Signs of Newcastle disease can manifest in affected birds and mammals. In poultry, the disease is characterized by lesions in the respiratory tract, visceral organs, and brain, leading to minor to severe mortality in susceptible flocks.

Clinical signs in poultry include sneezing, nasal discharge, coughing, greenish and watery diarrhea, depression, muscular tremors, drooping wings, and complete paralysis.

Infected birds may also exhibit a drop in egg production, thin shells, or shell-less eggs. Mortality rates associated with Newcastle disease can be high.

Diagnosis

Diagnosing Newcastle disease involves considering clinical signs, and postmortem lesions, and conducting serological tests. Laboratory analysis, such as virus isolation, can confirm the presence of the virus. Swabs taken from the trachea, cloaca, among other samples, should be sent to the laboratory for testing.

Differential Diagnosis

Respiratory signs with minimal impact on egg production and low mortality may indicate Infectious Bronchitis, a disease affecting only the respiratory system. It is essential to differentiate Newcastle disease from other similar conditions to ensure proper treatment and control measures.

Treatment and Prevention

Currently, there is no specific treatment for Newcastle disease. Antibiotics are commonly administered to prevent secondary infections. Prevention and control measures are crucial in combating the disease. Strict hygienic practices, sanitation, and vaccination are key components of effective control strategies.

Vaccination should be implemented, especially in areas where the disease is likely to occur, as it remains the most effective measure for Newcastle disease prevention.

Additionally, implementing biosecurity measures, administering vitamins and minerals for quick recovery, and adopting an all-in-all-out system policy during outbreaks are recommended practices.

Vaccination Program

A well-planned vaccination program is essential to protect poultry against Newcastle disease. The program typically includes vaccination at specific intervals, such as 7 days (depending on the source of day-old chicks), 10-12 weeks (using vaccines like Lasota, Hitchner B1, F), 21 weeks, and subsequent vaccinations every 6 months.

Breeders are often revaccinated every 2 months, while turkeys should be vaccinated at 3 weeks and again at 8 weeks.

Routes of Vaccination

Various methods can be employed to administer the Newcastle disease vaccine:

Vaccination in Drinking Water: To use this method, provide 2 liters of water per 1000 chicks for several days, adjusting the amount based on the age of the birds. For adult birds, 30 ml of water per bird is sufficient. Adding 2-4 grams of skimmed milk powder to each liter of water helps protect against the virus.

It is crucial to ensure that birds are thirsty, have enough drinking space, and administer the solution immediately after reconstitution.

The water should be free of disinfectants, and antibiotics should be discontinued during the treatment. If applying the vaccine through drinking water, increase the number of drinkers accordingly.

Eye Drop Application or Nostril Installation: This method yields a higher response. The vaccine can be applied directly to the eyes or nostrils of the birds. Careful administration is necessary to ensure accurate dosage.

Aerosol Application: This method provides the best response. The vaccine is dispersed as an aerosol, allowing birds to inhale it. Proper equipment and techniques are required to achieve optimal results.

Biosecurity Measures

Implementing biosecurity measures is crucial to prevent outbreaks of Newcastle disease on your farm. Here are some suggested practices:

1. Restrict access: Keep visitors off the farm, and instruct chicken and egg buyers to stop at the farm gate.
2. Separate sales: Carry birds and eggs for sale away from the farm premises.
3. Use new feed bags: Procure poultry feeds in new feed bags and avoid using old bags from the feed store.
4. Clean and disinfect: Thoroughly wash and disinfect crates and egg trays before returning them to the farm.
5. Quarantine new stock: Introduce new birds to the farm only after a quarantine period of at least two weeks, monitoring them for any signs of disease.
6. Avoid returning exhibited birds: After participating in fairs, agricultural shows, or laying contests, refrain from bringing birds back to the flock.
7. Choose reputable hatcheries: Purchase chicks from hatcheries that adhere to stringent sanitary control measures.
8. Prompt disposal: Dispose of birds that die from any cause promptly, either through deep burial or burning.

Conclusion

The Newcastle disease poses a significant threat to poultry, requiring comprehensive understanding, preventive measures, and proper management. By implementing vaccination programs, maintaining strict biosecurity measures, and following appropriate hygiene practices, poultry farmers can effectively control and prevent the spread of Newcastle disease, ensuring the health and well-being of their flock.