Abstract
The main aims of this paper were to investigate the rate of spontaneous reactivation of butyrylcholinesterase from plasma and serum of farm animals inhibited by the organophosphorus, chlorfenvinphos and trichlorfon. Organophosphorus are among the most toxic of all substances that cause poisoning in farm animals and are the most frequently encountered insecticides, commonly detected in agricultural products, animal-derived foodstuffs, environmental samples and home use and represent a significant potential health risk.The first-order rate constants obtained for spontaneous reactivation (ks) for chlorfenvinphosand trichlorfon for plasma and serum was ranged between 0.012 to 0.811h-1, while aging of phosphorylated butyrylcholinesterase follows the kinetics of a first-order reaction with rate constants aging (ka) ranged between 0.004to 0.653 h-1. Half-time (t1/2) for spontaneous reactivation and aging are higher in trichlorfon compared to chlorfenvinphos and ranged from 1.1 to 28.9h (sheep), 2.1 to 63 h (cattle) and 2.8 to 53.3 h (goat), respectively