Effects of trypsin inhibitors on growth, enzyme activity, intestinal histology and body composition in purified and practical soybean meal based diets for young Atlantic salmon (2004)
In compliance with the 2003-2004 USB Managed Aquaculture Program, researchers at Michigan State University (MSU) developed a 2-phase experimental design with the goal of examining the effect of trypsin inhibitors in SBM based diets on Atlantic salmon. Phase I focused on the effect of growth, feed consumption, digestibility, and pancreatic proteolytic enzyme activity of juvenile and smolting Atlantic salmon (Salmo salar) fed purified diets with graded levels of trypsin inhibitors. Two feed trials were completed in 2003 under phase I of this project.
The second phase of MSU’s research was initially designed to examine effects of trypsin inhibitors in SBM based diets containing practical feed ingredients under different processing conditions. Based on results obtained from other researchers in the Managed Aquaculture Program in 2003, and an extensive literature review, MSU expanded the focus of this research towards the development of an open formula practical diet, containing 5-30% SBM, that is nutritionally acceptable for young Atlantic salmon. Our objective is to develop a practical diet containing the highest level of SBM possible, based on best available knowledge, which would be available for incorporation by commercial feed suppliers for use with not only Atlantic salmon, but other picivorous fish as well (e.g. salmonids).
Phase II research was initiated in spring of 2004. Diets were formulated to contain 0- 30% SBM, which according to literature, is the range in which SBM diets appear to have anti-nutritional characteristics affecting Atlantic salmon. An open formula practical diet developed by the Ontario Ministry of Natural Resources (OMNR) for Atlantic salmon was used as a baseline diet formulation. In late May of 2004, a setback was encountered. The well pumps which supply water to the MSU Aquaculture Lab had a variable frequency drive malfunction. The repair was rather extensive and wasn’t completed in September.
The Atlantic salmon available for the study were donated from the Michigan Department of Natural Resources. Prior to pick up, we learned that these fish had Bacterial Kidney Disease (BKD). The fish were transported to MSU in late October, 2004, and were treated with erythromycin for BKD under the direction of Dr. Mohammod Faisal, MSU faculty member and State Fish Health Specialist. An INAD was not required since these fish are to be used solely for research and not human consumption.
The phase II feed trial began after the erythromycin treatments were completed on 1/11/05. The trial is designed to evaluate the potential effects of long term feeding (3-4months) of SBM diets on young Atlantic salmon.