The Fate of Antimicrobial Residues during Composting and Stockpiling of Manure Srinivas Sura 1,2, Tim A. McAllister 1, Francis J. Larney 1, Allan J. Cessna 2, Inoka D. Amarakoon 3, Lisa D. Tymensen 4, Jollin Charest 4, Andrew F. Olson 1, John V. Headley 2, and Francis Zvomuya 3 1 Agriculture & Agri-Food Canada, Research Centre, Lethbridge, AB 2 Environment Canada, Saskatoon, Saskatchewan 3 University of Manitoba, Winnipeg, Manitoba 4 Alberta Agriculture and Rural Development, Lethbridge, Alberta Compost Matters in Alberta March 4 & 5, 2015, Red Deer, Alberta
Use of Veterinary Antimicrobials Antimicrobials are administered to livestock via feed or water to prevent disease and enhance weight gain Up to 80% or more of administered antimicrobials can be excreted in feces and urine and be present in solid manure in pens or liquid manure in lagoons Manure may also contain antimicrobial metabolites (may be biologically active) and antimicrobial-resistant pathogens and genes 3
Antimicrobials used Veterinary and Human Medicine Some veterinary antimicrobials used to treat livestock are also used in human medicine Antimicrobial use in veterinary medicine is approximately 4 times that in human medicine Antimicrobial Animals Treated Uses in human medicine Chlortetracycline Oxytetracycline Cattle, swine, sheep, chicken (broilers), turkey Pneumonia, respiratory, urinary, intestinal and skin infections; Lyme disease, smallpox, anthrax, malaria, Rocky Mountain spotted fever, typhus, venereal disease, Chlamydia. Tylosin Cattle, swine, sheep, chicken (broilers and layers), turkey Pneumonia, bronchitis, diphtheria, Legionnaires disease, whooping cough, rheumatic fever, venereal disease; ulcers; ear, lung, intestinal, urinary and skin infections.
Concerns of the Canadian Public regarding Veterinary Antimicrobial Use Use of veterinary antimicrobials in confined animal feeding operations is of growing public concern regarding: Environmental issues: Possible negative impacts on surface and ground water quality, aquatic ecosystems, and soil health Human health issues: The use of veterinary antimicrobials may be contributing to widespread bacterial resistance (multidrug resistant super bugs ) to antimicrobials used in human medicine, rendering the antimicrobials ineffective Antimicrobial residues in meat products
Application of Manure (and Antimicrobials) 1 km >10 km High manure loadings Low manure loadings
Fate of Veterinary Antimicrobials Veterinary antimicrobials in manure can move into surface waters via snowmelt or rainfall runoff from feedlots, manure storage sites (stockpiles, windrows, lagoons) and manure-amended crop and pasture land, or to groundwater via leaching Manure management options such as windrow composting, stockpiling, or storage in lagoons (liquid) may affect antimicrobial concentrations in raw manure and, subsequently amounts transported to surface and ground waters Windrow composting Manure stockpiling Application of raw manure
Studies to Understand the Life Cycle of Veterinary Antimicrobials in Manure Effect of manure management on antimicrobial concentrations Stockpiling (Lethbridge Research Centre) Windrow composting Transport of antimicrobials in runoff Feedlot pens (Lethbridge Research Centre) Compost windrows Manure-amended cropland Concentrations of antimicrobials in water due to runoff Commercial feedlot catch basins (feedlots at Acme and Nanton, Alberta) Irrigation supply canals (Irrigation Districts in Alberta) Catch basin Irrigation canal
Manure used in Studies carried out at the Lethbridge Research Centre Feedlot based studies were carried out in research facility at the Agriculture and Agri-Food Canada Research Centre, Lethbridge Beef cattle were administered antimicrobials via feed CTC CTCSMZ TYL Control Chlortetracycline @ 44 mg per kg feed (dry-weight) Chlortetracycline + sulfamethazine @ 44 mg kg -1 feed each Tylosin @ 11 mg kg -1 feed Feed only Manure was removed from the feedlot pens to determine the effect of windrow composting and stockpiling on antimicrobials Manure in pens and in compost windrows was used to determine transport in simulated rainfall runoff Manure applied to cropland (soil-incorporated and surface applied) was used to determine transport in rainfall runoff
Antimicrobials in Manure from Feedlot Pens All three antimicrobials were detected in the manure (dryweight) used in the Lethbridge Research Centre studies 5000 Antimicrobial concentration ( g kg -1 ) 4000 3000 2000 1000 0 Chlortetracycline Chlortetracycline* Sulfamethazine Tylosin Antimicrobials in Manure * Chlortetracycline in CTCSMZ
Temperatures during Stockpiling Temperature, o C 80 70 60 50 40 30 20 10 0-10 CTC CTCSMZ TYL CON Ambient Air Sampling Day Manure temperature: 0.4 o C to 65.4 o C -20-30 0 10 20 30 40 50 60 70 80 Age of Stockpile, days Air temperature: 6.3 o C to -24 o C
Degradation of Antimicrobials: Stockpiling vs Windrow Composting Antimicrobial Stockpiles Half-lives * (days) Windrows Chlortetracycline 2 to 6 15 to 21 Sulfamethazine 21 27 Tylosin 5 32 * Half-life is the time period for an antimicrobials to decrease to 50 % of initial concentration measure of persistence. Shorter half-life means antimicrobial disappears rapidly. Conclusions: Both stockpiling and windrow composting were effective in decreasing concentrations of all three antimicrobials Decreased amounts of antimicrobials in composted or stockpiled manure means lower inputs of these chemicals onto crop and pasture land and, subsequently, into the broader environment (surface and ground waters)
Loss of Antimicrobials in Rainfall Runoff: Feedlot Pens To measure the concentrations of chlortetracycline, sulfamethazine, tylosin in the simulated rainfall runoff from the bedding and non-bedding areas of feedlot pens To determine the amount of each antimicrobial that would potentially be transported in runoff from a feedlot pen to the adjacent catch basin
Rainfall Simulation Setup Photograph showing one of the beef cattle pens in the Lethbridge Research Centre Research Feedlot used in this study. Guelph rainfall simulator is seen in the in-set.
Antimicrobials in the Pen Floor Material Concentrations of all three antimicrobials were higher in the bedding than non-bedding material. Concentration in pen floor material ( g kg -1 ) 3500 3000 2500 2000 1500 1000 500 Bedding area material Non-bedding area material 0 Chlortetracycline Chlortetracycline Sulfamethazine Tylosin (in CTC) (in CTCSMZ) (in CTCSMZ) (in TYL) Veterinary Antimicrobials (Treatment) Concentrations of antimicrobials in bedding and nonbedding area material.
Antimicrobial Loss in Rainfall Runoff Mass of antimicrobials transported in rainfall runoff: Antimicrobial Loss from pens Loss per head Chlortetracycline 13 to 36 g (2.4 to 6.7%) 1.3 to 3.6 g head -1 Sulfamethazine 19 g (3.6%) 1.9 g head -1 Tylosin 2 g (1.5%) 0.2 g head -1 Conclusion: Runoff from feedlot pens can be a source of veterinary antimicrobials and ratifies the importance of well-maintained catch basins for retaining runoff from feedlot operations.
Loss of Antimicrobials in Rainfall Runoff: Manure-Amended Soil 19
Antimicrobials are transported in rainfall runoff from manureamended soil Antimicrobial Concentration in Runoff (% of applied) Antimicrobial Surface Soilapplication incorporated Chlortetracycline 8.7-9.5 1.8-3.4 Sulfamethazine 6.5 4.6 Tylosin 0.6 0.5 Antimicrobial losses were greater when the manure was surface applied compared to when it was soil-incorporated 20
Antimicrobial Concentrations in Surface Waters: Commercial Feedlot Catch Basins Antimicrobial concentrations at Acme and Nanton sites Antimicrobial Acme (µg/l) Chlortetracycline 20 31 Sulfamethazine 1 5 Tylosin 5 56 Nanton (µg/l) Monensin 6 310 Lincomycin 69 7 Tetracycline 38 107
Antimicrobial Concentrations in Surface Waters: Irrigation Canal Water (Alberta) Sampled water from irrigation canals (24 sites) Antimicrobials Sampled four times concentrations during summer * in irrigation (Once a water month in from Alberta June to September, 2014) June July August September Antimicrobial (ng L -1 ) (ng L -1 ) (ng L -1 ) (ng L -1 ) Chlortetracycline 41 30 28 38 Sulfamethazine 1 1-2 Tylosin 1 2 1 18 Monensin - 1 4 2 Lincomycin 2 2 1 2 Tetracycline 57 77 70 85 Erythromycin 5 3 1 5 * Concentrations are average value of 24 sites
Conclusions: the Concentration Story Via feed @ 44 mg kg -1 Detected in pen floor manure @ 2000 to 3,000 µg kg -1 ) Degradation of CTC occurs during stockpiling Degradation of CTC occurs during composting 65 to 75% of CTC is excreted in feces and urine CTC in pen runoff (2000 to 7000 µg L -1 ) Half-life of CTC: 2 to 6 days Half-life of CTC: 15 to 21 days) CTC in runoff from windrows (1100 µg L -1 ) CTC in runoff from cropland (17 to 43 µg L -1 ) CTC in catch basins (20 to 30 µg L -1 ) CTC in irrigation water (30 to 40 ng L -1 )
Acknowledgements
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