Comparative Anticoccidial Activity and Compatibility of Lasalocid in Broiler Chickens

The anticoccidial activity of lasalocid (X-537A, sodium salt), at the concentration of 0.0075% in feed, was compared with other anticoccidials, namely monensin 0.012%, robenidine 0.0033%, clopidol 0.0125%, buquinolate 0.00825%, amprolium and ethopabate 0.0129%, zoalene 0.0125%, sulfadimethoxine and ormetoprim 0.02%, and nicarbazin 0.0125%, against a mixed Eimeria infection in chickens. Lasalocid medicated, infected birds were heavier, converted feed more efficiently, showed negligible pathology and no mortality (P ≤ .01) when compared to controls (IUC). Other anticoccidial agents, compared to the IUC, also performed well (P ≤ .01). When compared to other anticoccidial agents, lasalocid medicated birds had better weight gain (P ≤ .025) than buquinolate, amprolium and ethopabate, zoalene, and robenidine medicated birds. It was equal to clopidol, sulfadimethoxine and ormetoprim, nicarbazin, and monensin. Lasalocid birds had fewer lesions (P ≤ .05) than the zoalene medicated birds. Parameters of activity for the other anticoccidials were similar to those for lasalocid. Lasalocid at the concentration of 0.0075% fed alone or in combination with the growth promotants procaine penicillin 50 g./ton, zinc bacitracin 50 g./ton, lincomycin 4 g./ton, bambermycins 10 g./ton and roxarsone 50 g./ton, exhibited a high degree of anticoccidial activity against a mixed Eimeria infection in chicks. Lasalocid and lasalocid combinations performed significantly better than the growth promotants alone and the IUC (P ≤ .01). No interference with the anticoccidial activity of lasalocid was detected. Lasalocid fed to uninfected chicks at 0.0075% in combination with the above cited growth promotants, at their respective concentrations did not interfere with the increased growth and improved feed conversion performance elicited by the growth promotant additives. The performance of birds fed various drugs in combinations was significantly different from that of the controls (P ≤ .05).