MacAdam - Research

Dr. Jennifer W. MacAdam's Research


Utah Natural Resources Conservation Service Conservation Innovation Grant. Improved beef liveweight gain using irrigated birdsfoot trefoil pasture. $74,906. 9/30/09 to 9/29/12. MacAdam (P.I.) and Feuz (USU Department of Applied Economics).

The goal of this project is to demonstrate the utilization of monoculture birdsfoot trefoil pastures for beef production. Four ranchers will establish approximately six acres of birdsfoot trefoil pastures in 2010. We will work with the NRCS to design grazing cells for these six acres, and assist producers with the installation of fencing and livestock water supply. Baseline economic information will also be collected in 2010. In 2011, we will train producers to collect information on pasture productivity and to rotationally stock pastures. We will weigh cattle at the beginning and the end of the season, and estimate potential costs and benefits of this alternative feeding system. In 2012, we will again work with producers to collect data on costs and benefits, cattle average daily gain and pasture productivity. We will prepare outreach materials and hold field days for other producers and interested community members.

Because birdsfoot trefoil contains a small amount of tannin, bloat will not occur, even when cattle graze pure stands. Gains of 3 to 3.5 lbs. per day have been demonstrated with cattle grazing birdsfoot trefoil.

Fred Thurston of Morgan is a cooperating rancher on MacAdam’s Utah NRCS Conservation Innovation Grant, demonstrating rotational stocking of cattle grazing pure stands of birdsfoot trefoil.


USDA Organic Agriculture Research and Extension Initiative. Improved organic milk production through the use of the condensed tannin-containing forage legume birdsfoot trefoil. $1,019,972. 9/1/10 to 8/31/14. MacAdam (P.I.), Brummer, Eun, Gray, Heleba, Islam, McMahon, Reeve, Shewmaker, Ward and Young. Collaboration of the Departments of Plants, Soils & Climate, Animal, Dairy & Veterinary Sciences and Nutrition, Dietetics and Food Sciences at Utah State University with Colorado State Univ., Univ. of Wyoming, Univ. of Idaho, and the Univ. of Vermont.

We will partner with established organic dairy producers in the Mountain West to determine the impact of replacing grass pasture with birdsfoot trefoil (BFT) on milk production and milk quality. This will be done through advanced on-farm research on working organic farms. Long-term environmental impacts on organic dairy systems will be estimated from short-term changes in nutrient utilization by organic cows, nutrient release and organic matter retention in soil, which will increase conservation and environmental outcomes relating to organically produced agricultural products. We will determine desirable traits for organically produced milk by comparing the quality of cheese made from BFT-, grass- and total mixed ration-fed cows. Milk production of BFT-fed cows is significantly higher than grass-fed cows, but per-acre herbage dry matter production of BFT is lower than for grass. Therefore, we will conduct an economic analysis to determine potential costs and benefits of the use of BFT. eOrganic Dairy will be a key tool for communication as well as data collection and dissemination during this project. Outreach strategies will be developed jointly by the project staff and cooperating producers with input from advisory panel members. We will use eOrganic, fact sheets, newsletters, pasture walks and field days to reach producers, and feature articles in local newspapers to communicate results to the public. This project has the potential to increase milk production and milk and cheese omega-3 fatty acid concentrations, and decrease nutrient release into groundwater and the atmosphere compared with current organic farming systems.

Like alfalfa, birdsfoot trefoil synthesizes its own nitrogen and has a deep taproot. Ruminant liveweight gain and milk production on birdsfoot trefoil are higher than for either grass or alfalfa because a high proportion of plant protein bypasses rumen digestion.

Mike Wangsgard is one of the Organic Valley Co-op dairy producers cooperating to carry out on-farm research on MacAdam’s USDA OREI grant.