Location: Plant Science Research
Project Number: 5062-12210-003-03-A
Project Type: Cooperative Agreement
Start Date: Jun 1, 2016
End Date: Oct 31, 2018
The objectives of the research are to: (1) develop methods for extracting alfalfa leaf protein; (2) evaluating relationship between canopy reflectance measurements and protein content; and (3) feed utilization of fish fed diets with alfalfa protein concentrate.
An ARS biomass type non-lodging alfalfa variety was established at the University of Minnesota Southern Research and Outreach Center in 2014. The alfalfa will be harvested three times per year: late spring for total forage, then mid-summer and early fall for total forage and for leaf-stem separation using a mechanical leaf stripper. Diverse alfalfa cultivars and low lignin varieties will be harvested at early bud using conventional harvesting equipment. Prior to harvest, reflectance measurements will be made from each entry. Yield of total forage and alfalfa leaves will be measured at each harvest. Alfalfa will be juiced and the protein extracted using a range of methods to identify the most effective methods. The alfalfa leaf protein concentrate will be used to formulate diets for tilapia and yellow perch in aquaponic systems using a range of protein concentrations. Growth of fish and feed efficiency will be measured monthly. The economics of the three production systems, immature alfalfa, stripped leaves from conventional production, and total mature forage, will be calculated using establishment costs, harvest costs, costs of extraction, and protein yield to evaluate the profit potential from each system.