2006 Annual Report 4d.Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Idaho, Hagerman - Ron Hardy. Additional details of research can be found in the report for the parent project, 5366-21310-003-00D, "Integration of nutritional, genetic and physiological approaches to improve production efficiency of rainbow trout." Collaborative studies were conducted to further the development of plant-based feeds by evaluating alternative ingredients and determining nutrient digestibility on additional feed ingredients. Six varieties of barley and a commercially available fermented soy product are being evaluated. A study was conducted to determine the value of soybean meal produced using newly patented method for the production of bio-diesel fuel. Seven diets were fed to triplicate lots of 30 fish for 12 weeks. Results indicated that weight gain of fish fed bio-diesel soybean meal diets was not significantly different from fish fed the control feed, regardless of inclusion level (17 or 15%). This new type of meal will have equal value to meals produced using conventional extraction systems and makes bio-diesel a more attractive option to fossil fuels. Additionally, an alternative crop, camelina was evaluated in a 12 week feeding study. The press-cake, or meal left after expeller pressing, was fed to satiation, to triplicate lots of 30 fish at 7 different inclusion levels. Weight gain and feed consumption was significantly decreased at any inclusion level relative to the fish fed the control diet. A second study indicated the substance that decreased feed consumption to be present in the non-lipid portion of the camelina meal. This study indicates that camelina oil has potential for use in trout diets, but the press-cake meal is not suitable for this specie.