Potentiation of ionophorous anticoccidials with dihydroquinolines: battery trials against Eimeria tenella in chickens.

Seven battery tests, employing a total of 1344 Hybro cockerels, were conducted in order to study the interaction between ionophorous anticoccidials and a new dihydroquinoline-type antioxidant known as duokvin. A significant, non-selective, toxic interaction was established, resulting in growth depression and improved anticoccidal efficacy against Eimeria tenella and E. mitis in these chickens. The duokvin itself showed no appreciable activity against the coccidia. The adverse effects of the interaction were eliminated, and the anticoccidial efficacy of the approved levels of ionophores was maintained, when the dietary levels of monovalent cation ionophorous monensin, salinomycin and narasin were reduced to approximately 12% in the presence of 120 p.p.m. duokvin. No adverse effects on the growth of chickens appeared in the combination with maduramicin, yet the enhancement of anticoccidial activity allowed an approx. 50% reduction of this ionophore as well.