Chlortetracycline and tylosin runoff from soils treated with antimicrobial containing manure

Abstract

This study assessed the runoff potential of tylosin and chlortetracycline (CTC) from soils treated with manure from swine fed rations containing the highest labeled rate of each chemical. Slurry manures from the swine contained either CTC at 108 μ g/g or tylosin at 0.3 μ g/g. These manures were surface applied to clay loam, silty clay loam, and silt loam soils at a rate of 0.22 Mg/ha. In one trial, tylosin was applied directly to the soil surface to examine runoff potential of water and chemical when manure was not present. Water was applied using a sprinkler infiltrometer 24-hr after manure application with runoff collected incrementally every 5 min for about 45 min. A biofilm crust formed on all manure-treated surfaces and infiltration was impeded with > 70% of the applied water collected as runoff. The total amount of CTC collected ranged from 0.9 to 3.5% of the amount applied whereas tylosin ranged from 8.4 to 12%. These data indicate that if surface-applied manure contains antimicrobials, runoff could lead to offsite contamination.

Keywords:

• Antimicrobial chemicals
• tylosin
• chlortetracycline

Acknowledgment

This research was partially funded by USGS Grant 104 program No. 06HQGR0120, US Environmental Protection Agency (EPA) grant number CP-97835401-0, EPA-319 fund, and the South Dakota Agricultural Experiment Station. The LC/MS was purchased with support from the National Science Foundation under grant no. 00091948. Thanks to Drs. V. Brözel and S. Gibson. Mitch Olson and Steve Biersbach provided field support for this project.

Notes

¹Permeability ratings are from Natural Resources Conservation Service (NRCS) bulletins.^{[ 18 , 19 ]} The average rapid permeability is 42 μ m/sec and average moderately slow permeability is 2.8 μ m/sec.

²Runoff classifications are reported from NRCS.^{[ 18 , 19 ]}

^†Data presented were pooled over landscape position.