Several periods in which chickens are not suitable for vaccination

1. during the incubation period or when the chickens are not completely healthy, the chickens have just recovered from the disease, and the functions of the body have not been fully restored. It is recommended to use antiviral traditional Chinese medicine for 3 to 5 days before epidemic prevention, stop for 1 day, and then carry out epidemic prevention.

Second, herding and vaccination should not be carried out at the same time, which means that a variety of huge stresses are added together to act on the body, resulting in a decrease in body weight instead of an increase in body weight. in serious cases, a considerable number of chickens will go on hunger strike, diarrhea, or even die as a result of stress. It is recommended that vaccination should be carried out 3-5 days after the conversion.

Third, Newcastle disease Ⅰ vaccine and other vaccines such as fowlpox should not be mixed because Newcastle disease Ⅰ vaccine can strongly induce the body to produce anti-interferon, which greatly reduces the immune effect of other vaccines inoculated at the same time, resulting in immune failure. It is recommended that Newcastle disease Ⅰ vaccine and fowlpox vaccine should be vaccinated at an interval of one week.

Fourth, it is not suitable to be vaccinated during the rising laying rate of laying hens because of the huge physiological reaction after laying, the defense function of the body becomes very fragile and is easy to be infected with diseases. Therefore, it is not suitable to vaccinate the laying hens in this period.