There are many respiratory tracts in chickens in spring, which is mainly related to these factors

The weather in spring is cold and the temperature is changeable, and chickens mostly suffer from respiratory diseases. In many areas with intensive chicken breeding, high morbidity and mortality rates often occur, causing large economic losses to farmers. Therefore, it is urgent to find out the main causes of respiratory diseases in chickens.

Main causes of respiratory diseases in chickens

1. Unfavorable environmental factors

Adverse environmental factors have an important impact on the respiratory tract of chickens, especially in large-scale farms or intensive breeding areas, and sometimes even bring devastating blows.

The main unfavorable environmental factor is the cold temperature in early spring. In order to prevent colds, the chicken houses are closed, resulting in poor ventilation. The content of harmful gases such as ammonia and hydrogen sulfide in the air in the chicken houses greatly exceeds the standard, stimulating inflammation of the respiratory mucosa of the chickens and weakening their resistance. Significant decline, inducing respiratory diseases.

Secondly, the temperature suddenly turns cold, the humidity is too low, the body is stimulated by cold and dryness, the lack of VA, VC and other vitamins and trace elements, the stocking density is too high, the chicken body cannot breathe fresh air, the pollution of mycotoxins in the environment, etc.

These adverse environmental factors cause damage to the respiratory mucosal system of the body, and pathogens in the environment take the opportunity to invade, aggravating the symptoms of respiratory diseases in chickens, and then causing respiratory syndrome in chickens.

2. Respiratory pathogens exist in large numbers

The main reasons for the large number of respiratory pathogens in the environment are as follows: too intensive breeding and unreasonable planning; untimely removal of feces and random piles; improper handling of culled chickens and dead chickens; and untimely and lax disinfection.

These aspects result in the presence of a large number of known and unknown pathogens in the environment. Multiple respiratory pathogens act on the respiratory system of chickens at the same time or one after another. They can produce pathogenic synergy between them, which is more serious than a single pathogen.

Infections with viral pathogens (mainly mild avian influenza, Newcastle disease, and infectious bronchitis) cause damage to the respiratory epithelium. These minor damages create good opportunities for bacterial secondary and co-occurring infections. Viral infections, mycoplasma, mycotoxins, and E. coli interact synergistically to make respiratory illnesses more severe.

Due to the synergistic effect of multiple causes, the course of the disease is longer, the clinical symptoms are more complex, and the medication effect is unsatisfactory, resulting in long-term treatment failure or easy relapse after recovery.

3. Vaccine immunity

During the first 3 weeks of chicks' life, chicks receive frequent immunizations and stress factors increase; incorrect immunizations, especially the short immunization interval between infectious bursal disease vaccine and Newcastle disease vaccine, cause serious interference between the two. Cause severe respiratory illness.

Choose a highly virulent vaccine for the first vaccination. For example, choose a moderately strong infectious bursal vaccine for the first vaccination. This will cause damage to the immune system (bursa), reduce the chicken's immune response, and reduce the chicken's body's response to the virus. Resistance to Newcastle disease, infectious bronchitis, mycoplasma, etc.

When the live vaccine against Newcastle disease and infectious bronchitis is first immunized, a "reversible" respiratory reaction will occur. If combined with the mixed infection of mycoplasma and E. coli, severe respiratory symptoms will occur. This is what happens after the first vaccination of chickens. The real cause of respiratory symptoms.