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Rate of decline of chlorfluazuron concentration in the fat of cattle |
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| Authors: | SA SPENCE R MURISON S HARDEN |
| Institution: | NSW Agriculture, Wollongbar Agricultural Institute, Wollongbar, New South Wales, 2477;Department of Maths, Statistics and Computing, University of New England, Armidale, New South Wales 2351;NSW Agriculture, Tamworth Centre for Crop Improvement, Tamworth, New South Wales, 2430 |
| Abstract: | Objective To determine the rate of decline of chlorflu-azuron (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, non-lactating cattle which have finished growing will remain contaminated. Field experience has not supported this conclusion. |
| Keywords: | Chlorfluazuron cattle rate of decline |