Rate of decline of chlorfluazuron concentration in the fat of cattle
Related Experiment Video
Updated: Oct 29, 2026
Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri
Published on: April 24, 2018
S A Spence1, R Murison, S Harden
1NSW Agriculture, Wollongbar Agricultural Institute.
Objective:
To determine the rate of decline of chlorfluazuron (CFZ) concentration in the fat of cattle.
Design:
A field depletion study.
Animals:
Fifteen steers that had become contaminated with CFZ through eating cotton trash or cotton leaf pellets derived from CFZ-treated cotton crops.
Procedure:
Fat samples were collected from the cattle at about 3 week intervals according to a schedule where each animal was sampled on four occasions up to 340 days after removal from the contaminated feed source.
Results:
When the effects of dilution are removed CFZ concentrations were found to decline slowly for about 200 days. Depletion was minimal between 200 and 340 days.
Conclusion:
According to this trial, CFZ-contaminated, nonlactating cattle which have finished growing will remain contaminated. Field experience has not supported this conclusion.
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