Manufacture and Use of Alfalfa (Medicago sativa L.) Leaf Protein Concentrate as a Protein Supplement in Fish Culture Diets

Abstract

Alfalfa protein concentrate (APC) is a high-protein, low-fiber, refined product from the legume <i>Medicago sativa</i> L. intended for feeding monogastric animals. The research herein extends understanding of the potential for APC use in aquaculture by conducting feeding trials with yellow perch (<i>Perca flavescens</i>) and rainbow trout (<i>Oncorhynchus mykiss</i>) and evaluating APC yield and content by producing APC with alternative methods, from reduced-lignin varieties, and from stripped alfalfa leaves. Both fish species accepted APC feeds. Growth was slowed in the perch trial where APC was included at 18% of diet, while the trout did not show significant differences among feeds when APC was included at low levels to enhance growth. APC produced with acid contained less fiber while heating produced the highest protein concentration. APC produced from stripped leaves contained less protein than APC from whole forage. APC produced from reduced-lignin varieties did not differ from APC produced from conventional varieties.