Effect of 6-amino-9-(substituted benzyl)purines on oocyst sporulation.

A series of experiments have been conducted utilizing 11 strains of Eimeria representing 4 of the major species to measure the effect of arprinocid [6-amino-9-(2-chloro-6-fluorobenzyl)purine] and the dichloro analog L-628,914 [6-amino-9-(2,6-dichlorobenzyl)purine] on oocyst sporulation. The results of these studies show that oocysts harvested from chickens fed graded levels of these compounds and infected with E. acervulina, E. maxima, E. necatrix, or E. tenella have a decreased capacity to sporulate. This effect was observed against each of the species of Eimeria tested at levels well below the proposed use level of 60 ppm to 70 ppm of arprinocid.