Experimental Induction Of Drug-resistant Strains Of Postcocious Line Eimeria Tenella To Salinomycin

The resistance of postcocious line Eimeria tenella to the anticoccidial drug salinomycin was induced experimentally.The initial concentration of the drug was60mg/kg salinomycin.Chickens were infected with60,000crude sporulated of postcocious line Eimeria tenella oocysts at15days of age and prophylactic medication commenced a day prior to infection. It took11passages for the drug-resistant strain of postcocious line Eimeria tenella to240mg/kg salinomycin.The effects of drug was assessed by calculating the anticoccidial index (ACI), reduction of lesion scores (RLS),relative oocyst production (ROP) and percentage optimum anticoccidial activity (POAA) based on relative weight gain, rate of oocyst production and lesion values.The specific process induced by passage of the11generation is:salinomycin60mg/kg (3generation),120mg/kg (3generation),180mg/kg (2generation) and240mg/kg (3generation), In order to evaluated and determination of subcultured strains and characteristics of different primary, antibody detection resistance, non induced passage of Eimeria tenella postcocious line strain ACI index was163.89(part of resistant), ROP (13.98), PLS (53.85), POAA (79.31) three indicators assessment the results were all negative; salt was induced by the passage of Eimeria tenella late to240mg/kg of hormone resistant completely, the resistance detection and data statistics and calculation, the ACI index was119.78(fully resistant), ROP (41.26), PLS (30.77), POAA (48.65results three) assessment were positive. The resistance can be obtained by laboratory conditions gradually increase the drug concentration, directional pressure selection of resistant strains.