Residues of chlordimeform in bovine tissues and milk following application by a handspray

Abstract

Three experiments were conducted to determine the concentrations of residues of chlordimeform in tissues and milk of cattle after spray application to control cattle tick. Subcutaneous fat, sampled by biopsy from animals sprayed with 0.45 per cent (w/v), 0.15 per cent and 0.05 per cent chlordimeform (buffered) contained maximum residues of chlordimeform (2.88 mg kg-1, 0.46 mg kg-1 and 0.1 5 mg kg-1 respectively) one day after treatment. The half life for the rate of disappearance of these residues was independent of the initial residue level and was calculated as 2.46 days. Sampling of six tissues, 24 hours after spraying with chlordimeform (buffered) showed that chlordimeform was found mainly in fat. Smaller concentrations were found in kidney, muscle and liver tissue. Concentrations of 0.45 per cent, 0.15 per cent and 0.05 per cent chlordimeform (buffered) produced residues of 1.42 mg kg-1, 0.28 mg kg-1 and 0.03 mg kg-1 respectively in the whole milk of lactating cows. A half life of 0.45 day was calculated for the rate of disappearance of chlordimeform from the milk.