Comparative Study on the Efficacy of Some Antimycoplasma Drugs on the Performance of Commercial Broiler Flocks from Infected Breeders

body weight gain, feed consumption, feed conversion rate and European efficacy factor were used to evaluate the efficacy of some antimycoplasma drugs on the performance of commercial broiler flocks derived from Mycoplasma infected breeders. Lincospectin, Pulmotil and Tylan were administered in drinking water at 1 day old and repeated at 19 days. Mycoplasma infection in the used chicks was confirmed by clinical signs, air sac lesions, positive results to serum agglutination test for Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). MG antigen was detected in tracheal sections by immuno-histochemistry. The obtained results proved that the used antimycoplasma drugs still effective in controlling of Mycoplasmosis in broilers and their efficiency varied by repeated successive use in flocks reared in the same house. Pulmotil showed stable results, followed by Lincospectin and tylan. It was concluded that antimycoplasma drug administration in broiler from infected breeders have a marked role in improvement of their performance