依照免疫程序,肉鸡在常规疫苗接种后引发呼吸道症状是养殖实践中经常遇到的问题,通常以咳嗽、甩鼻、气管啰音和头部震颤为特征,对鸡的存活率和生产性能均有不利的影响。特别是在冬季,当鸡舍密闭保温时,空气交换减少,灰尘和氨气的积累,空气质量下降,疫苗反应更加严 In accordance with the immunization schedule, broiler respiratory symptoms caused by routine vaccination are common problems encountered in farming practice and are usually characterized by cough, nasal rejection, tracheal rales and head tremor, both in terms of viability and performance of the chickens negative effect. Especially in winter, when houses are closed and insulated, the exchange of air is reduced, the accumulation of dust and ammonia gas, air quality is reduced, and the vaccine response is more severe