Cutting Management Approaches to Understand Phytoestrogens Accumulation in Forage Legume Species Used in Dairy Production Systems

Project Overview

Project Type: Graduate Student
Funds awarded in 2022: $14,997.00
Projected End Date: 08/30/2024
Grant Recipient: University of New Hampshire
Region: Northeast
State: New Hampshire
Graduate Student:
Faculty Advisor:
Dr. Richard Smith
University of New Hampshire


  • Agronomic: clovers, medics/alfalfa
  • Animal Products: dairy


  • Animal Production: feed/forage, rangeland/pasture management
  • Education and Training: demonstration, extension
  • Farm Business Management: risk management
  • Natural Resources/Environment: other
  • Production Systems: integrated crop and livestock systems
  • Sustainable Communities: food hubs

    Proposal abstract:

    Organic dairies rely on perennial forage legumes for their high nutritional value and ability to supply biological nitrogen to the soil. However, some forage legumes have been reported to concentrate phytoestrogens in their tissues. Phytoestrogens are secondary metabolites that mimic the sex hormone estrogen, and if consumed in high quantities, may impair the reproductive performance of dairy cows. Previous research conducted outside of the US revealed that phytoestrogen concentrations differ among legume species and are influenced by environmental stresses, including the frequency and extent of defoliation, suggesting that forage harvest practices may alter phytoestrogens. Unfortunately, little is known about how phytoestrogen concentrations vary across forage legumes grown in the Northeastern US. We will fill this knowledge gap using 4 perennial legumes included in a field experiment established in 2018 to examine how cutting frequency (3 vs. 5 times per season) and cutting height (5 vs. 10 cm residual forage height) affect legume productivity, persistence, and phytoestrogen concentrations. Tissue samples of red clover, white clover, alfalfa, and birdsfoot trefoil will be collected at each cutting time. Phytoestrogen concentrations will be quantified using high-performance liquid chromatography. This study will provide farmers with new information about phytoestrogen concentrations of perennial forage species commonly used in dairy operations in the Northeast and the degree to which cutting practices can be used to manage phytoestrogens levels. Results will be disseminated to stakeholders through presentations at field days, a “Managing Phytoestrogens in Forage Legumes” fact sheet, and peer-reviewed publications.

    Project objectives from proposal:

    The overall goal of this research is to investigate variation in phytoestrogen concentrations among forage legumes.

    The specific objectives are to:

    1. Collect and process forage legume tissue samples from an existing field experiment.
    2. Quantify effects of cutting frequency and cutting height on variation in phytoestrogen concentration in red clover, white clover, alfalfa, and birdsfoot trefoil.
    3. Disseminate phytoestrogen data to stakeholders.
    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.