Acceptance of a protein concentrate from alfalfa (Medicago sativa) by yellow perch (Perca flavescens) fed a formulated diet

Authors: COBURN, JESSICA - University Of Minnesota; WELLS, M. SCOTT - University Of Minnesota; PHELPS, NICHOLAS - University Of Minnesota; GAYLORD, T. GIBSON - Department Of Fish And Wildlife; Samac, Deborah - Debby

Submitted to: Fishes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2021
Publication Date: 3/25/2021
Citation: Coburn, J., Wells, M., Phelps, N., Gaylord, T., Samac, D.A. 2021. Acceptance of a protein concentrate from alfalfa (Medicago sativa) by yellow perch (Perca flavescens) fed a formulated diet. Fishes. 6(2). Article 9. https://doi.org/10.3390/fishes6020009.
DOI: https://doi.org/10.3390/fishes6020009

Interpretive Summary: Aquaculture, the raising of farmed fish and shellfish, is the fastest growing food sector around the world and the most efficient means of providing animal protein to human populations. A major bottleneck to sustainable aquaculture include identifying acceptable plant proteins for fish feeds to replace fishmeal, an expensive and limiting resource. Alfalfa protein concentrate (APC) is a high-protein product from refining alfalfa foliage. This research investigated growth and feed use efficiency of yellow perch fed a diet with APC replacing 100% of the fishmeal and evaluated the use of APC as an additive to support efficient growth of rainbow trout with APC replacing 3% and 6% of the fishmeal. Yellow perch accepted the APC diet but gained weight at a slightly lower rate than fish on the control diet containing fishmeal. The trout diets supplemented with APC were also accepted well and no growth or efficiency differences were detected. This research indicates that APC is a potential alternative to fishmeal providing a new cost-effective sustainable protein source for aquaculture diets.

Technical Abstract: A key factor for continued growth of the aquaculture industry is responding to the rising demand and limited supply of fishmeal for aquatic feeds by identifying alternative plant-derived proteins for aquaculture species. Alfalfa protein concentrate (APC) is a high-protein product from refining alfalfa (Medicago sativa) foliage into multiple products. This research investigated growth and feed efficiency response of yellow perch (Perca flavescens) fed a diet with APC replacing 100% of the fishmeal and evaluated the use of APC as an additive to support efficient growth of rainbow trout (Oncorhynchus mykiss) with APC replacing 3% and 6% of the fishmeal. Results showed that yellow perch accepted the APC diet but gained weight at a lower specific growth rate (-0.07% day-1) and had an elevated feed conversion ratio (+ 0.32 g feed g-1 growth) than fish on the control diet containing fishmeal. The trout diets supplemented with APC were also accepted well and no growth or efficiency differences were detected. This research indicates that although APC at 18% inclusion resulted in slower growth rates, the APC was accepted and did not impact survivorship or condition in either yellow perch or rainbow trout.