Residues in milk and production performance of goats following the intake of a pesticide (endosulfan)

A trial was conducted on 12 lactating Barberi milch goats (body weight 18.1 ± 0.9 kg, 2nd to 3rd parity, mid lactation), divided into three groups (G1, G2 and G3) of four animals each, in which endosulfan, an organochlorinated insecticide, was administered via the diet in two doses, i.e. 15 mg/goat/day in the G2 and 30 mg/goat/day in the G3 groups for 25 consecutive days. The G1 group served as a control. Endosulfan residues comprising of α, β isomers and endosulfan sulfate were present in milk samples, but the transfer coefficient, i.e. the percentage of daily intake of a pesticide excreted into the milk each day, was very low (0.23–0.33%). The residue concentration gradually increased during the administration period and reached a peak on day 25, the last day of treatment. Thereafter, the residues started to decline and reached approximately basis levels within 20 days after cessation of treatment. The kinetics of the decline phase followed the first-order kinetics and the statistical half-life was almost the same in both the treatment groups (8.67 and 8.88 days for G2 and G3, respectively). There were no perceptible changes in the utilization of nutrients, feed intake, milk yield and milk composition, and blood metabolites in the treated group of animals following ingestion of the pesticide. There was thus apparently no adverse effect on the performance of the animals following the intake of the pesticide, but research needs to be done on the long-term exposure to the pesticide in low doses.