Pharmacodynamic Studies of Danofloxacin in Chicks Infected with Mycoplasma gallisepticum and E.coil

Minimal inhibitory concentrations(MICs) of Danofloxacin,Enofloxacin and Tylosin against Mycoplasma gallisepticum were determined in vitro and proved to be 0.062 mg/L, 0.125mg/L and 0.5mg/L respectively.Chickens were infected with both Mycoplasma gallisepticum S6 and E.Coil,and treated via drinking water with Danofloxacin (25mg/L, 50mg/L, 100mg/L), Enofloxacin (50mg/L) and Tylosin(500mg/L) respectively for five consecutive days.Mean weight gains of the medicated were significantly higher than those of the unmedicated groups.23.3%,3.5%,0%,0%,3.3% and 6.6% of chickens in the medicated groups died respectively,while 23.3% the unmedicated controls died.It demonstrated that Danofloxacin was highly effective in reducing mortality and frequency of MG reisolation as well as in preventing seroconversion and air\|sac lesions in surviving birds.