Managing respiratory diseases in poultry

Some of the chicken reared by Naftal Mocha, a rabbit and poultry farmer in Mwiki, Nairobi, on Friday, July 24 2020. [David Njaaga,Standard]

The environment in which our farmers operate is constantly changing and evolving, meaning they continue to face several challenges, including low genetic potential, low productivity, poor nutrition, diseases, poor stockmanship, and lack of markets. Among these, respiratory infections or distress top the list. These infections also tend to limit the participation of our small poultry players. The main causes of persistent respiratory infections or diseases can be divided into two categories: a) management lapses and b) respiratory disease pathogens (disease-causing organisms).

Management issues

Although most farmers try to effectively manage all farm activities with the best intentions, things can go wrong at some stage, potentially triggering respiratory distress in the birds. Let’s look at some of these factors in detail.

Poor air quality

A dusty chicken house or barn can cause persistent irritation of the respiratory airways, leading to coughing, sneezing, rales, and breathing difficulty. Dust can be introduced through wood shavings, sawdust, or rice husks. Make sure to select the best chicken bedding for your farm. If the primary cause is not addressed, the use of antimicrobials to relieve the symptoms will be counterproductive. It is critically important to maintain proper ventilation in the units. Keep side curtains open to allow good air movement, which will remove toxic gases, excess heat, and bring in plenty of highly needed oxygen.

Dusty feed

Much of the feed available on the market for long-living birds is made of small-sized particles that, if inhaled during feeding, can cause irritation of the mucosal surfaces of the upper sinuses, resulting in coughing and difficulty in breathing. Additionally, there will be reduced feed intake and low nutrient absorption, leading to poor performance in the long run. Ensure that you buy feed with a coarser structure and consistent quality.

Chilling effect

Although birds have fully developed feather cover by week 7 and can withstand low temperatures, any drop below 17 degrees Celsius can impact their health due to chilling stress. Ensure that night temperatures are bearable; if not, additional brooders in the house at night will help keep the birds comfortable.

Contaminated drinking water

Provide fresh, clean, potable water free from disease-causing organisms. Contaminated water with E. coli or coliforms can be a leading cause of respiratory infection in poultry. Make sure that your water is treated with chlorine tablets at least once a week. To avoid the buildup of biofilms in the water lines, it is important to periodically flush the water pipes with hydrogen peroxide.

Respiratory diseases

There are many viral and bacterial diseases that cause respiratory distress in poultry. These diseases tend to manifest similar clinical signs, making them difficult for a lay farmer to identify. Some of these diseases include Mycoplasmas, Newcastle disease, Infectious Bronchitis, Coryza, E. coli, Aspergillosis, and more. It is important to contact a veterinarian near you to make the correct diagnosis and provide treatment based on a full flock examination and laboratory tests.

Vaccination

Proper vaccination is an integral part of poultry rearing, with direct benefits in controlling both viral and bacterial diseases. The primary objective of immunizing any poultry flock is to reduce the level of clinical disease and promote optimal performance. In countries where vaccinations have been enforced through legislation or awareness campaigns, most respiratory diseases have been completely eradicated. These include Coryza, fowl cholera, Mycoplasma, Newcastle disease, fowl pox, and chronic respiratory disease.

Hatchery vaccination

Recently, hatcheries have become a place where many chicks can be vaccinated conveniently and effectively. For this reason, an increasing number of vaccinations are being administered at this stage. Major diseases like Marek’s disease, Newcastle disease, Infectious Bronchitis, Reovirus infections, and Gumboro can now be vaccinated at the point of hatch. It is important to ask your chick supplier what type of vaccines are given at chick take-off and the recommended vaccination program for your type of flock.