Survey of Tiamulin+Oxytetracyclinein control of CRD complex due to La Sota vaccine in broiler chickens

Mycoplasma gallisepticum (MG) is one of the most important diseases of poultry industry in Iran and all over the world. Mortality, poor weight gain and increasing of feed conversion ratio (FCR) were seen in MG infected flocks. Several drugs are used for prevention and control of MG, the purpose of this study was to investigateoxytetracycline + Tiamulinefficacy on MG, and its role on broilers performance.In this study, 240 Ross 308 broilers divided in 2 groups. In one of the groups, oxytetracycline + Tiamulinwere used in days 21 to 30 following La Sota vaccination for controlling vaccination reaction and in the secondgroup, placebo was used and that group mentioned as a control group. Gross lesions, mortality, and growth parameters include body weight gain,feed intake and FCR were calculated in all groups weekly after 21 day.Results showed that in treatment groups mortality percent was significantly (p<0.05) lower than control group and pericarditis, perihepatitis and airsacculitis was sever in control groups in comparison to antibiotic treated groups. Also body weight and FCR was significantly were different between control group and oxytetracycline + Tiamulin group (p<0.05).It can be concluded that usage of these antibiotics simultaneously could prevent vaccination reaction due to La Sota vaccine and also following MG complications, economical losses in poultry and finally it can be improve broilers performance