A Multiregional Approach to Balancing Milk and Forage Quality in Organic Dairies Feeding High-legume Diets
Project Director
Andre Brito
Year Funded
2020
Award Number
2020-51300-32196
Funded Institution
University of New Hampshire
Grant Program
OREI (Organic Agriculture Research and Extension Initiative)
USDA NIFA Report
Project Overview
Dairy cow health, milk production, and quality depend on a favorable dietary ratio of energy to protein. Including legumes in pasture, hay, and silage improves milk production and quality; however, high phytoestrogen levels in some legumes such as red clover can compromise cow health and fertility. Field trials were conducted at multiple locations to identify the best legume and grass species, planting and harvesting/grazing practices, and forage processing methods to maintain perennial legume persistence in pastures, optimize milk production and quality, and manage dietary phytoestrogens to protect cow reproductive health.
Farmer Takeaways
(1) Adding perennial legumes such as alfalfa, clovers, and birdsfoot trefoil enhances dairy cow nutrition and can improve milk production, quality, and net return.
(2) Red clover (RC) shows greatest persistence, helps suppress weeds, and can be frost-seeded into standing forage, but its high phytoestrogen levels may reduce cow fertility.
(3) Replacing some of the RC with white clover (WC), kura clover, birdsfoot trefoil, or alfalfa reduces phytoestrogen intake without compromising milk production or quality.
(4) Legume-grass forages can be cut or grazed as close as 5 cm (2 inches), and haying at this height three times per year enhances legume persistence and reduces weed seed populations.
(5) Legumes, especially white clover, provide floral resources for beneficial insects. This ecosystem service is enhanced by limiting harvests to three times per year, while soil organic carbon sequestration by forage crops may be enhanced by rotational grazing five times per year.
Project Outputs
Mandal, P., D. A. Mortensen, A. F. Brito, A. K. Wallingford, M. R. M. Lima, N. D. Warren, and R. G. Smith. 2024. Water stress influences phytoestrogen levels in red clover (Trifolium pratense) but not kura clover (T. ambiguum). J. Agric. Food Chem. 72:10247-10256.
Warren, N. D., D. A. Cox, and R. G. Smith. 2023. Effects of soil amendments on hairy vetch no-till interseeded into a hayfield. Agronomy J. 115:887-895.
Teixeira, C. D., B. T. Castillo, L. Bernhardt, N. D. Warren, C. Petry, J. G. Ernakovich, R. G. Smith, and S. D. Frey. 2023. Frequent defoliation of perennial legume-grass bicultures alters soil carbon dynamics. Plant Soil 490:423-434.
Lange, M. J., L. H. P. Silva, M. Zambom, K. J. Soder, and A. F. Brito. 2024. Feeding alfalfa-grass or red clover-grass mixture baleage: Effect on milk yield and composition, relative abundance of ruminal microbiota taxa, and nitrogen and energy utilization in dairy cows. J. Dairy Sci. 107:2066-2086.
Mandal, P., Warren, N.D., Lima, M.R.M., Brito, A.F., and Smith, R.G. 2024. Influence of defoliation frequency and severity on phytoestrogen concentrations in red clover and white clover. Annual Graduate Conference April 15, University of New Hampshire, Durham, USA.