Pairing Residues, Resistance Genes and Microbial Community Structure to Understand Off-Farm Impact of Antibiotic Use on Dairy Farms

Project Overview

Project Type: Partnership
Funds awarded in 2022: $29,057.00
Projected End Date: 08/31/2024
Grant Recipient: University of Connecticut
Region: Northeast
State: Connecticut
Project Leader:
Dr. Christine Georgakakos
SUNY College of Environmental Science and Forestry


  • Animals: bovine
  • Animal Products: dairy


  • Animal Production: manure management, therapeutics
  • Pest Management: genetic resistance
  • Soil Management: soil microbiology

    Proposal abstract:

    This proposal incorporates three aspects of the environmental side of the one-health approach to addressing antimicrobial resistance in animal agriculture: We propose to measure (1) antibiotic residues in surface waters, (2) antimicrobial resistance gene abundance in soil, and (3) soil microbial community composition to understand the full environmental impact of antibiotics on agricultural operations. Our year-long study will allow for monitoring of temporal shifts in antimicrobial impacts across the landscape. Sampling for resistance genes and resistant bacteria will allow us to understand the extent of environmental impact of semi-continuous and seasonal manure application. These samples will be paired with a funded study that examines how human decision making and livestock management influences stable water isotope data within the same watersheds over the same period. Together, this sampling will build a holistic picture of the sources and impacts of antibiotics on the human and soil microbial populations and trace hydrologic flow paths and associated residence times of these contaminants in the landscape.

    Project objectives from proposal:

    Our broad objective is to understand the transport and impact of antimicrobials in the environment from animal agriculture. We will achieve this by adding additional analyses (antibiotic residues, resistance genes, and soil microbial communities) to an existing project (USDA NIFA AFRI Workforce & Development Postdoctoral Fellowship), allowing us to draw broader impact assessments of antimicrobial usage on dairy farms in Connecticut.  Specifically, our objectives are to:

    (1)  Understand linkages between surface water antibiotic residues, soil microbial communities, and antibiotic resistant genes in soil on dairy farms.

    (2)  Partner with appropriately compensated farmers to ground this study in on-farm applicability across farm sizes.

    (3)  Communicate the results of this work to scientific, agricultural, and public audiences to increase cross-sector understanding and support.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.