University of Vermont

Cultivating Healthy Communities

Research Project

Timing of Supplementation for Dairy Cows

Jersey Cow in Pasture

Photo courtesy of Bart Laridon, Wikimedia Commons.

Project Scope

A team of University of Vermont researchers has begun to research to identify supplementation strategies on organic dairies to determine how the timing of supplementation can potentially increase milk production.

Previous studies revealed that timing of supplementation can potentially increase milk production. For example, by just changing the time of day that corn silage was offered to cows relative to their pasture allowance, researchers in NZ were able to increase milk yield by over 6 lbs. per cow per day. Participating farms are year-round organic operations with more than 25 Jersey and/or Holstein milking cows.

During 2016 and 2017, the team will study 20 farms to assess a wide range of feeding strategies. The team will collect on-farm data, including pasture, supplement, milk, soil and economic information. In this early phase, participating farms may be "grass-only," those that include only small amounts of supplement in their cows' diets, or farms that feed higher amounts of supplement per cow per day.

In the second phase of the project, the team will focus on 6 farms. This second phase of on-farm research will be implemented with the goal of evaluating supplement timing and supplement type (high quality forage and other concentrates) timing used during the pasture season can impact farm productivity (milk yield, quality, and economics).

Dairy producers participating on this project will receive an End of the Grazing Season Report that includes:

  • Monthly milk production and composition
  • Fatty Acid Analysis of milk samples
  • Cow parameters (including BCS, calculated nutrient balance, herd statistics)
  • Estimates of dry matter intake (pasture and supplement intakes)
  • Feed nutrient profile (pasture and supplement)
  • Pasture quality (botanical composition, and nutrient profile)
  • Soil profile
  • Financial analysis
  • Stipend for participation ($500 per producer)

Research Team

  • Sabrina Greenwood , Dept. of Animal and Veterinary Sciences, University of Vermont (802) 656-0145
  • Sid Bosworth , Dept. of Plant and Soil Sciences, University of Vermont Extension (802) 656-0478
  • Jennifer Colby , Center for Sustainable Agriculture, University of Vermont Extension (802)656-0858
  • Heather Darby , Dept. of Plant and Soil Sciences, University of Vermont Extension(802) 524-6501
  • Juan Alvez , Center for Sustainable Agriculture, University of Vermont Extension (802)656-6116
  • Jana Kraft , Dept. of Animal and Veterinary Sciences, University of Vermont (802)656-5489
  • Kimberly Hagen Kimberly Hagen, Center for Sustainable Agriculture, University of Vermont Extension (802)656-3834
  • Robert Parsons , Dept. of Community Development & Applied Economics, University of Vermont Extension (802)656-2109

Support Team

  • Sara Ziegler, On-farm supervisor
  • Dave Ebenstein, Laboratory research technician and sample support

Research Students