Response of Coliform Populations in Poultry Waste Digesters to Three Insecticides1
- P. E. Ballington,
- H. D. Skipper and
- R. O. Hegg2
This investigation was initiated to determine if three insecticides could be responsible for die-offs of E. coli in poultry waste digesters. A pure culture and a digester effluent slurry system were used to test several concentrations of dimethoate, dichlorvos (organophosphates), and carbaryl (carbamate) against E. coli and other enteric coliforms. Dimethoate and dichlorvos were used individually at concentrations of 0, 100, 1,000, and 10,000 ppmv (ppm by vol), and combined at concentrations of 0+0, 50+50, 500+500, and 5,000+5,000 ppmv. Carbaryl (1-naphthyl N-methylcarbamate) was used at 0, 1, and 40 ppmv concentrations. Dimethoate [O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate] and dichlorvos (2,2-dichlorvinyl dimethyl phosphate) at 1,000 ppmv caused a significant decrease in E. coli, and the highest concentrations resulted in a complete die-off of E. coli in the pure culture system. Carbaryl had no effects on E. coli in the pure culture study and was not used in the effluent slurry study. In the effluent slurry, dimethoate and dichlorvos at 100 and 1,000 ppmv did not significantly reduce coliform populations. Dimethoate, dichlorvos, and the combined insecticides at 10,000 ppmv caused a >90% die-off of the coliforms.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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