In the present work, the effects of Halofuginone hydrobromide and Maduramidn ammonium mixed with ration for 120 days in Bovans cockerels were studied on serum levels of testosterone , semen quality and histopathological changes of testes. It could be concluded from the present study that Halofuginone _hydrobromide at a dose of 1.5 p.p.m can be used successfully for Bovans cockerels. However, Halofuginone hydrobromide at a dose of 3 p.p.m cannot be used in Bovans cockerels as it caused significant decrease in serum testosterone levels, semen volume, sperm count, and increased sperm abnormalities as well as marked histopathological changes in testes. On the other hand, the recommended dose (5 p.p.m.) of Maduramidn ammonium can be used successfully in Bovans cocks.