Innovative approaches in examining plant-based aquafeed ingredients

We propose a research project that will take a three-tiered approach in examining and addressing current perplexities in aquaculture nutrition. Many studies have been conducted to determine the effect of plant-based feed ingredients on salmonid fish. Bec ause these studies vary in methodology, it is difficult to compare results. We will perform a meta-analysis of six plant-based feed ingredients commonly fed to salmonid fish, standardizing growth results so trials may be compared with one another. Using t his approach, we will determine the effect of increasing the inclusion levels of each of the ingredients on the growth of salmonids. Saponins are known to be culprit antinutrients when present in salmonid feeds. They have been shown to negatively affect growth and nutrient digestibility. It has been deduced that the feeding of saponins must be reduced, either through ingredient processing to remove them or through low dietary inclusion levels of saponin-containing ingredients. We will conduct a digestibi lity trial and a growth study in rainbow trout to determine if the negative effect of dietary saponins can be impacted by an anti-foaming agent used in the human food industry to counteract saponins during food preparation or tannin extract, as tannins ha ve been shown to complex with saponins. Structural equation modeling between ingredient and diet chemical compositions and experimental results will be performed. The Canadian Light Source (CLS) is a third generation synchrotron facility capable of infra red spectromicroscopy that has been used for biochemical analysis of feedstuffs such as wheat, oat and barley. It may prove a useful screening tool in the study of antinutrients in plant-based feed ingredients. We will conduct synchrotron research at the CLS to examine aquafeed ingredients exposed to various methods of processing and the impact such methods have on their antinutrient composition, focusing specifically on their saponin content.