Effect of Dursban in the Drinking Water of Chicks1

Dursban®, (O, O-diethyl O-(3,5,6-trichloro-2-pyridyl)phosphorothioate), was added to the drinking water of young Leghorn cockerels at 8 levels ranging from 0.08 to 1280 ppm active ingredient. Experiments were begun with chicks 3 or 5 days old and were concluded after 3 and 4 weeks. Mortality at 80 ppm was 20%, and mortality at 320 and 1280 ppm was 100%. No adverse effects increased were apparent at lower levels. Solvent and inert ingredients of Dursban emulsifiable concentrate had no adverse effect on the chicks up to 717.7 ppm. Cholinesterase activity in whole blood was monitored at all treatment levels, and the activity decreased at 80 ppm Dursban and above. At lower levels there was no significant difference from the controls. Weight gain per day diminished with increased levels of Dursban. Starvation of treated chicks did not affect blood-cholinesterase activity.