LIPIDOMICS DERIVED TISSUE PROFILES OF JUVENILE RED DRUM Sciaenops ocellatus FED SOY PROTEIN AND SOY OIL BASED FEEDS

A nine-week feeding trial was conducted with juvenile red drum (200 g avg. starting weight) fed diets containing 36 g 100g^-1 soybean meal or soy protein concentrate and 0, 25, or 50% soy oil replacement of fish oil. Performance on these diets was compared to two fishmeal-based diets, one with all lipid provided by fish oil and one with 50% soy oil replacement of fish oil. Fish were maintained in a recirculating aquaculture system and fed to satiation daily.

At the initiation and conclusion of the trial, multiple tissues were collected including liver, adipose, plasma, kidney, heart, muscle, and brain. Tissue samples were snap frozen in liquid nitrogen and stored at −80 °C until processing. Tissues were homogenized using a cryomill to prevent thawing and extracted via standard methods for utilization in a liquid chromatograph/mass spectrometer. Tissue samples along with control and reference materials were analyzed via high resolution tandem mass spectrometry to provide both quantitative values for specific lipid species and semi-quantitative comparisons of lipid classes across the entire lipidome. Fatty acid profiles were also determined on fillet tissue samples via industry-standard gas chromatography protocols.

This presentation will highlight the differences in critical lipid species observed in various tissues (ex: Figure 1, liver and brain combined control materials) due to dietary protein and lipid source/concentration and the differences observed in fillet muscle profiles from the two profiling techniques employed.