CL 259,971: a potent new polyether anticoccidial. 1. Battery efficacy and safety.

The anticoccidial activity of CL 259,971, a new polyether ionophore produced by Actinomadura yumaense sp. nov, has been demonstrated against six species of poultry Eimeria, tested individually or in mixed species infections. Statistically significant activity was obtained against some species with as little as 2.5 ppm of drug. The optimal treatment level, however, was determined to be 5 ppm. At this level, performance was comparable to 100 or 120 ppm of monensin. CL 259,971 is coccidiocidal and affects the early asexual stages of the life cycle of E. tenella. Fed to uninoculated cockerels in batteries at 10 ppm for 7 weeks, CL 259,971 permitted numerically superior weight gains when compared with 200 ppm of monensin.