As we all know, the immune function of the body is affected by many factors. Although there are many opportunities for immune failure in poultry farming practice, grassroots veterinarians often only consider the quality of the vaccine, the method of using the vaccine, the problem of the immunization program, and the stress factor when dealing with these situations. The effect of immune effect, but the changes in the body's own immune function and its influencing factors are not considered, resulting in difficult clinical improvement. The following is a brief introduction to the effects of drugs and additives on the immune function of the body and its influencing mechanism. It is hoped that it will help the clinical diagnosis of grassroots practitioners. First, the impact of drugs on immune function In order to prevent secondary bacterial infections in the body due to immune stress and injection immunity itself, the prophylactic use of some antibacterial drugs before and after immunization has become a commonly used measure by many aquaculture practitioners and veterinary clinicians. But what people often overlook is the effect of these antibacterial drugs on immune function. In fact, all kinds of antibacterial drugs have certain effects on immunity, and improper use may lead to failure of vaccine immunization. (1) Penicillin Antibiotics and Immunity Van den bruc et al reported that penicillin G can increase the intracellular bactericidal function of monocytes. In the veterinary field, early research suggests that the simultaneous application of penicillin and avian cholera vaccine can increase the immune efficiency coefficient by 30%, suggesting that penicillin drugs can promote immunity. (2) Cephalosporins and Immunization Some cephalosporin antibiotics have an inhibitory effect on lymphocyte transformation. 50 μg/ml of cefotaxime, cephalexin, cefotaxime, etc. can inhibit hemagglutinin-induced lymphocyte transformation and chemotaxis of polymorphonuclear leukocytes. Lymphocyte transformation and antibody production in animals receiving oral administration of 1.2 mg/day of ceftazidime were significantly inhibited. (3) Aminoglycoside antibiotics and immunization Streptomycin can interfere with the normal function of rat lung macrophages. In the veterinarian, the chick streptomycin aerosol was simultaneously vaccinated with Newcastle disease, and it was found that streptomycin inhibited the formation of antibodies in the chicks. If streptomycin aerosol is applied 2 days before inoculation or 3 days after inoculation, streptomycin has no adverse effect on chick antibody formation. It can be seen that the application time of streptomycin affects the immune status of chicks. Most aminoglycoside antibiotics have an inhibitory effect on chemotaxis. Gentamicin, amikacin and kanamycin have significant inhibitory effects on the transformation of T and B lymphocytes. Simultaneous aerosol immunization with neomycin vaccine and Newcastle disease vaccine, found that neomycin can inhibit the formation of antibodies in chicks; but when inhaled neomycin at j days and 3 days after immunization, the antibody titer of chicks did not decrease. . The neomycin aerosol has a significant inhibitory effect on the vaccination of infectious laryngotracheitis in poultry. One hour before immunization and three hours after immunization, the application of neomycin can reduce the immunity of the body. The therapeutic amount of apramycin does not affect the development of the thymus and bursa, while the high-dose application affects the organ index, the immune organ index, resulting in damage to the immune function of the chick. (4) Macrolide antibiotics and immunization The main targets of macrolide antibiotics against Sufeng defense are macrophages and leukocytes, which can promote the apoptosis of macrophages and neutrophils, while macrolides can inhibit mast cell degranulation and reduce The release of inflammatory molecules achieves anti-inflammatory goals. A certain concentration of erythromycin can reduce airway epithelial cells secrete mucin, block chloride channels, thereby reducing the secretion of sputum; block airway epithelial cells by inhibiting the mucosa of neutrophils and vascular endothelium and airway epithelium Alveolar macrophages and neutrophils secrete IL-10, IL-6, IL-8 and other inflammatory factors, inhibit the accumulation of neutrophils into the airway, and reduce airway epithelial damage factors such as peroxide and elastase. The production. (5) Tetracycline antibiotics and immunization Studies have shown that tetracycline and doxycycline can reduce the bactericidal action of polymorphonuclear cells and inhibit the release of granulocyte lysosomes at therapeutic concentrations. Chicks use oxytetracycline aerosol and immunize Newcastle disease vaccine. It was found that the formation of antibodies in chicks was inhibited; and the application of streptomycin 2 days before inoculation or 3 days after inoculation had no adverse effect on the formation of chick antibodies. Chlortetracycline can directly reduce the mitotic activity of T and B lymphocytes, thereby reducing cellular immunity and humoral immune function. (6) Chloramphenicol antibiotics and immunization Jin Jiushan research found that the addition of chloramphenicol to the feed can cause atrophy of the follicular lymphoid tissue in the bursa of the broiler broiler, and with the increase of the antibiotic dose and the prolonged taking time, the atrophy is more advanced, and the thymic cortex structure is loose. The lymphocytes in the spleen are reduced, the lymphoid tissue of the cecal tonsil is reduced, and the growth inhibition state is observed, and with the increase of the amount of chloramphenicol, the lesions are becoming more and more serious. (7) Corticosteroids mainly inhibit immunity 25Mm Utility Knife,Mini Knife Cutter 25Mm,Utility Knife Retractable,Razor Blades Knifes Yucheng Weisite Measuring Tools Co., Ltd , https://www.wsttool.com