1)Under normal weather conditions, the concentration of ammonia in chicken houses is generally less than 25 mg/kg, while in cold winter, the concentration of ammonia in poor ventilation can exceed 100 mg/kg. High concentration of ammonia is harmful to chickens. It can destroy the tracheal cilia, damage the inner wall of the trachea, cause virus to enter the respiratory tract to induce respiratory diseases, and cause a large number of chickens to die. Therefore, the ventilation of chicken houses should be paid enough attention in broiler breeding.
2)Facing the contradiction between heat preservation and ventilation in broiler breeding in winter, the producers are afraid that the chickens will be frozen, do not ventilate or only do short-term ventilation, which results in the broiler living in an environment where the gases such as ammonia, hydrogen sulfide, methane and carbon dioxide exceed the standard seriously. The external pathogenic microorganisms are not only easily introduced into the chickens. Respiratory tract disease, and long-term poor ventilation, chicken tissue hypoxia, cardiopulmonary function decline, blood oxygen deficiency, immune function decline and cause disease. To solve this contradiction, we can choose automatic ventilator for chicken to solve the problem.