When the outside temperature is higher than 32°C, the blood temperature and blood flow in the chicken will increase, which will further increase the body temperature of the chicken, causing dizziness, collapse, convulsive death, sudden death, etc.

　　一 Clinical symptoms

Suddenly died in the hot afternoon, and there were more obese chickens, body temperature increased, feed intake decreased, water consumption increased sharply, lying still, mouth breathing, two wings spread, laying hens mostly occurred at midnight, in cloaca There are unproduced eggs, thin and irregular feces, etc.

　　二 Pathological changes

Body burning and hot hands, cyanosis of the skin, a lot of water in the crop; poor blood coagulation, incomplete corpse; meningeal congestion, hemorrhage, congestion; liver swelling, fragility, gallbladder filling; pericardial effusion, myocardial hemorrhage; pulmonary congestion, edema ; Intestinal wall thinning, intestinal mucosa shedding; ovarian congestion, fallopian tube edema, etc.

　　Three preventive measures

　　1 Use materials with good thermal insulation properties to construct the poultry house. The roof and walls are painted white, and trees are planted around the poultry house to reduce solar radiation. In the case of good ventilation, use a wet curtain and strengthen longitudinal ventilation, which can reduce the temperature in the house by 3 to 6°C. Spraying cold water on the top of the house and the chicken body will help evaporate and dissipate heat. In hot times, cold water can be sprayed directly into the poultry house or poultry body, which can effectively reduce the heat stress reaction of the chicken.

　　2 Plant trees or shade nets around the poultry house to prevent long-term direct exposure to the hot sun; adopt longitudinal ventilation, increase ventilation, and reduce the temperature and humidity in the house.

　　3 Reduce the stocking density, increase the drinking utensils and the frequency of drinking water. Drinking water during heat stre