Updated June 20, 2024:
Goal and Objectives:
The overall goal of our proposed project is threefold: i) increase the usage of soybean meal (SBM) and decrease the soy protein concentrate in feeds for the commercial production of Rainbow trout; and ii) demonstrate how selected trout for soy-based diet can improve their resistance against pathogen; and iii) overall soybean-based feed can improve profits for fish farmers. For this project, we will work toward improving our understanding of fish-disease dynamics, with the long-term goal of reducing losses to the U.S. rainbow trout industry. For this one year period, we will address this goal with the following objectives:
Objective #1: Define the best feed formulation to incorporate maximum amount of soybean meal (SBM) and decrease the soy protein concentrate (SPC) in two lines (selected and commercial) of rainbow trout diet.
Objective #2: Optimize the SBM inclusion level in trout by measuring growth performance, feed utilization, intestinal barrier function, immune related parameters and gut microbiome
Objective #3: Determine the effects of pathogens (viral pathogen, Infectious hematopoietic necrosis virus, IHNV and bacterial pathogen, Flavobacterium psychrophilum, Fp) challenge on survival, immunomodulation, and gut health in rainbow trout.
Objective #4: To examine and genes expression, distal intestinal structure (enteritis), intestinal barrier function and gut microbiome in pre and post challenge study of trout strains with different genetic backgrounds.
Fish Growth and Disease Trials:
Feed ingredients and diet formulation: Based on our previous work, soybean meal-based diets (SBM diet) have been formulated to contain 43% crude protein and 22% crude lipid. All five diets are isonitrogenous and isolipidic. All five-diet formulations were designed to meet the essential amino acid (EAA) requirements of juvenile Rainbow trout.
Five experimental diets:
Diet 1: Control feed - 0% SBM/SPC + 30% fishmeal (FM)
Diet 2: 13% SBM + 20% SPC
Diet 3: 23% SBM + 13% SPC
Diet 4: 34% SBM + 7% SPC
Diet 5: 45% SBM + 0% SPC
Feed Extrusion: Feeds have been manufactured at USDA, Bozeman Fish Technology Center, Bozeman, MT and were shipped to ARI, University of Idaho, Moscow ID.
Experimental setup: Rainbow trout eggs were acquired from two commercial sources, ARS/UI and Trout Lodge, hatched and reared to ~5 grams. The growth trial will begin late June 2024 and will be followed by the disease challenge trials.