When the ambient temperature drops, the chicken house can not keep up with cold measures, which can cause exogenous chicken cold and induce respiratory system diseases. The temperature of the chicken house is too low, the humidity is too high, the ventilation is poor, the harmful gas is excessive, and coughing occurs. And dyspnea is a respiratory system disease characterized by clinical symptoms.
In order to keep warm, the breeding density is increased, and the ventilation of the chicken house is neglected, causing turbidity in the chicken house, lack of oxygen, harmful gas exceeding the standard, overcrowding of flocks, malnutrition, and respiratory mucosal resistance. Reduced ability causes respiratory disease.
Stress factors; generally include management stress, nutritional stress, environmental stress, physiological stress, and drug stress.