There are many reasons for the sudden drop in egg production rate of laying hens caused by the sudden drop in laying rate of laying hens, which can be summed up in the following aspects. First, feed layer chickens have higher requirements for feed nutrition. Feed problems often lead to a sudden drop in egg production. 1 Feed is mildewed or contaminated, resulting in reduced palatability of the feed, resulting in reduced feed intake for chickens and easily leading to gastro-intestinal diseases and a sudden drop in egg production. 2 improper mix of ingredients in the feed. If the ratio of calcium and phosphorus is not proper. If the ratio of calcium and phosphorus is not adjusted or the quality of feed ingredients is poor, the effective nutrient content is insufficient or lacking. 3 The poor quality or insufficient content of vitamin or trace element additives is also an important factor. 4 Suddenly changing feed formulas, resulting in the chicken's body digestive function can not adapt at one time. Second, environmental laying hens are very strong on environmental stress, with light, temperature, and ventilation being the most obvious. 1 Light, such as the sudden stop of lighting the chicken house, shortening the light time, reducing the light intensity, etc. can make a sudden drop in egg production, especially in rural areas often blackouts, and no backup lighting equipment, the impact is more serious. 2 Temperatures and temperatures suddenly rise or fall, such as the continued sultry weather in summer, the formation of high-temperature environment in the house, or sudden cold attacks, will generally reduce the intake of chickens, egg production will also decline. 3 ventilation, poor ventilation, indoor air turbidity, too rich ammonia, can also lead to decreased egg production. Third, poor management and management is also an important factor leading to a sudden drop in egg production in chickens, mainly in: 1 feeding management procedures are not standardized, such as feed more than one meal or one meal, drinking water can not meet the supply, change the operating procedures, etc. Both can cause a sudden drop in egg production. 2 The equipment is damaged, such as the pipeline is blocked, the water supply is not timely due to overhaul, and the ventilating equipment such as the electric fan is not smooth or fails to be repaired. 3 Abnormal noise, the presence of strangers, livestock, vaccination or anthelmintic treatment will not only cause a sudden drop in egg production, but will also increase malformed eggs, soft shell eggs and broken eggs. Fourth, the diseases caused by decreased egg production are numerous, of which the invasion of infectious diseases is particularly evident. There are two types of infectious diseases that can cause a sudden drop in egg production in chickens: 1 Viral infectious diseases. There are infectious bronchitis, Newcastle disease, infectious laryngotracheitis, egg drop syndrome, infectious encephalomyelitis, lymphatic leukemia and chicken pox. If the virulent newcastle disease attacks, the chicken egg production rate can suddenly drop from 70% to 90% to 20% to 40%; there have also been chickens suffering from mild Newcastle disease so that the egg production rate suddenly dropped 20% to 40 % of cases occur. 2 bacterial infectious diseases. There are mainly E. coli disease, septicomycosis, infectious rhinitis, and fowl cholera, etc. 5. Other major egg-laying chickens are on convalescence or overdose of drugs. In the relatively stable state of chicken production in the flock, if a sudden increase in the number of chickens laid off on a certain day suddenly occurs, there will be a sudden drop in egg production, but this phenomenon will generally return to the original in a very short period of time. Egg production level. As for the case of overdose of chicken poisoning or significant effect of laying eggs are also common.