Stacking Time and Aluminum Sulfate Effects on Polyether Ionophores in Broiler Litter

Abstract

The use of ionophores as antiparasitic drugs plays an important role in US poultry production, especially in the broiler () industry. However, administered ionophores can pass through the bird's digestive system and appear in broiler litter, which, when applied to agricultural fields, can present an environmental hazard. Stacking (storing or stockpiling) broiler litter for some time might decrease the litter ionophore concentrations before land application. Because ionophores undergo abiotic hydrolysis at low pH, decreasing litter pH with acidic aluminum sulfate (alum) might also decrease ionophore concentrations. We assessed the change in ionophore concentrations in broiler litter in response to the length of time broiler litter was stored (stacking time) and alum addition. We spiked broiler litter with monensin and salinomycin, placed alum-amended litter (∼pH 4-5) and unamended litter (∼pH 8-9) into 1.8-m bins, and repeatedly sampled each bin for 112 d. Our findings showed that stacking broiler litter alone did not have an impact on monensin concentration, but it did slowly reduce salinomycin concentration by 55%. Adding alum to broiler litter reduced monensin concentration by approximately 20% relative to unamended litter, but it did not change salinomycin concentration. These results call for continued search for alternative strategies that could potentially reduce the concentration of ionophores in broiler litter before their application to agricultural soils.

Monensin biodegradation pathway and role of epoxide hydrolase in Stenotrophomonas maltophilia DM‐2

“…The standard biodegradation assay was performed in 100 mL MM containing 10 mg L −1 monensin (0.1% Tween 20) at 30 °C, pH 7.0 and the initial inoculum was added at 3% concentration (v/v). Different temperatures (10, 20, 30, 40 and 50 °C), pH values (4, 5, 6, 7, 8 and 9), and initial monensin concentrations (5, 10, 25, 50 and 100 mg L −1 ) were tested for their effect on monensin degradation. Only one condition was altered at a time for each assay.…”

“…Owing to its long‐term use and high mobility in organic manure, soil, surface water and groundwater, its residual amount in some environments has greatly exceeded the maximum allowed concentrations . Monensin is toxic to zooplankton, protozoa, fungi and Gram‐positive bacteria, and even to higher organisms such as earthworm and fish . In addition, greater attention needs be paid to other potential effects caused by released monensin as veterinary antibiotics have been demonstrated to significantly affect the local function and structure of soil bacteria in the field .…”