The beginning of summer is very suitable for the survival and spread of viruses and bacteria. If the farming conditions of the farmers are poor and the management level is low, the chickens are often in a hostile environment, the disease resistance will be reduced, and the three syndromes are susceptible. Egg drop syndrome Frequently occurring in the peak period of egg production or the rising period of egg production are common in natural conditions such as sudden temperature rise and sudden drop. The egg production of chickens decreased by about 20%, and some even exceeded 40%. The symptoms are similar to those of respiratory syndrome. The causes are related to factors such as viral infection, inappropriate feed or feeding, stress factors, and drug toxicity. Prevention and control measures: In addition to immunization with egg-laying down syndrome vaccine, and strengthening comprehensive health care, other prevention and treatment of respiratory syndrome are similar. Broiler Ascites Syndrome More common in 4-5 weeks old chickens, the incidence rate is generally 3% -5%, is the most serious disease of broilers in late spring and early summer. The diseased chicken's abdomen enlarged, purple in the head and face, difficulty in breathing, and gradual failure. The necropsy of the dead chicken showed a pale yellow liquid on the abdomen, pericardial effusion, right heart dilation, pulmonary congestion, and edema. The disease is mostly due to diseases, including chronic hypoxia, ammonia concentration is too high, feed high-energy feed, excessive growth rate, nutritional factors (such as lack of selenium, vitamin C, phosphorus), poisoning (such as salt, drugs) Genetic factors and other factors are the major causes of the disease. Prevention: 1 Improve the feeding environment. Pay attention to the health of the house and maximize ventilation. 2 reasonable with feed. Feed energy should not be too high, salt can not be excessive, calcium and phosphorus to balance, appropriate vitamin supplements (especially vitamin E, vitamin C) and sodium bicarbonate (0.2%). 3 Early feeding restrictions. Broilers can be fed properly at 2-3 weeks of age and fed 90% of the normal diet. 4 Reduce stress response and prevent poisoning. In particular, it is necessary to prevent the administration of sulfa drugs that are more toxic to the kidneys and liver. Aminoglycosides, quinolones, and other antibiotics must not be used excessively; Fatty liver syndrome The disease is a nutritional disorder caused by impaired fat metabolism in chickens. He suffered from pale anemia and pale feicidemia in chickens, gray and white excrement, head and neck flexion or back flexion, falling to the ground, and eventually weight loss. Prevention: 1 Control the energy level in the diet and increase the protein content by 1%-2%. 2 Add 100 grams of choline chloride, 50 grams of methionine and 5 grams of multivitamin, 12 milligrams of vitamin B12, and 0.05 milligrams to 0.1 milligrams of selenium per 100 kilograms of feed. 3 chickens were fed individually, each feeding 0.1 g - 0.2 g choline chloride and 1 mg vitamin E.