Arprinocoid evaluation in broiler chicken pen trials in Europe.

The effect of arpinocid (9-[2-chloro-6-fluorophenyl)methyl]-9H-purin-6-amine) on artificial and natural coccidial infections in broiler chickens was evaluated in a series of pen trials conducted in England, France, and Germany. In trials with induced infections, mortality attributable to coccidiosis did not occur at 50, 60, and 70 ppm although it ranged from 3.2 to 9% in unmedicated groups. At 7 to 8 weeks of age, birds receiving arprinocoid in feed at levels of 40, 50, 60, and 70 ppm had improved body weights and feed conversion compared with unmedicated birds, the differences being significant (P is less than .05) in 4 out of 5 trials. Productivity of birds on arprinocid was equivalent or significantly superior (P is less than 0.5) to those on halofuginone (3 ppm), monensin (100 ppm), nicarbazin (125 ppm), and PANCOXIN (165 ppm). Based on the results of these pen trials, arprinocid at levels of 50 to 70 ppm in feed is a highly efficacious compound for the prophylaxis of coccidiosis, preventing mortality, and permitting good growth and feed conversion under conditions of both mild and severe infection pressure.