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Research Project: Advancing the use of Alfalfa Leaf Protein Concentrate in Aquafeeds to Enhance Finfish Production.

Location: Office of The Director

Project Number: 5090-31320-005-008-I
Project Type: Interagency Reimbursable Agreement

Start Date: Sep 1, 2019
End Date: Aug 31, 2023

Objective:
Test digestibility and establish substitution rates of alfalfa leaf meal protein concentrate (APC) for rainbow trout and apply this knowledge to formulate cost-effective diets using sustainable sources of plant (APC) protein. This work is proof-of-concept for aquafeeds formulation, and utilize novel alfalfa cultivars, that will impact how we formulate diets for carnivorous fish species and increase economic opportunities to U.S. forage growers.

Approach:
Studies will be conducted in a stepwise fashion, each building on information obtained in the previous objective. In Objective 1, we will evaluate functional quality of feed pellets, digestibility efficiency of a commercially-available APC product as a protein component of diets for trout, and define the ideal substitution rate for trout as a proof of concept (Yr 1 & 2). Two feeding trials will be conducted addressing the Objective 1. The first experiment will characterize pellet quality, acceptance and digestibility in trout, over a 4 week trial. The second experiment will identify the most favorable range of APC inclusion for trout, based upon growth performance and health over an 8-12 week trial. For Objective 2 (year 2), we will then use the alfalfa APC material from alfalfa expressing the MtDef5 (plant defensin, which is an antimicrobial peptide) gene at the best inclusion levels identified for trout from Objective 1 and evaluate growth, survival and expression of immune genes. Objective 3 (years 1 & 2) will focus on increasing the nutritional quality and production efficiency of APC from Midwest U.S. alfalfa foliage, with two primary tasks: Task 1: Develop new technology to produce domestic APC for use in aquafeeds. Task 2: Evaluate the nutritional quality and production cost of domestic U.S. APC products.