THE USE OF DIPEPTIDE SUPPLEMENTATION AS A MEANS OF MITIGATING THE NEGATIVE EFFECTS OF DIETARY SOYBEAN MEAL ON ZEBRAFISH Danio rerio

This study focused on the supplementation of health promoting dipeptides: carnosine (Car), anserine (Ans), and alanyl-glutamine (Ala-Glu). The dietary supplementation of these dipeptides has been shown to exhibit anti-inflammatory properties within the animal body.  While the anti-inflammatory properties are known, little is known about their use in fish diets to mitigate the intestinal inflammation caused by dietary plant protein (PP). Therefore, the following objectives were included in this study: 1) To determine the effect of supplementation of Car, Ans, or Ala-Glu into PP-based feeds on growth performance of fish; 2) To determine if the supplementation of Car, Ans, or Ala-Glu affects the expression of genes associated with intestinal inflammation; 3) To assess if dietary Car, Ans, or Ala-Glu supplementation affects the expression of intestinal peptide transporter Pept1.

The study used zebrafish Danio rerio as a model species.  At 33 dph zebrafish were randomly distributed into 15 (3L) tanks, with 50 fish in each tank. There were 5 treatment groups in this study. The first group ((+) Control) received a fish meal (FM)-based diet. The second group ((-) Control) received soybean meal (SBM) diet. The third group (Ala-Glu) was fed SBM-based diet, supplemented with Ala-Glu. The fourth group (Car) received SBM-based diet, supplemented with Car. The last group (Ans) was fed SBM-based diet, supplemented with Ans. All groups received their respective diets during 33-59 dph.

The results from this study show that the dietary supplementation of Car and Ala-Glu significantly improved the growth of zebrafish that were fed SBM diet. This study provides support for further research on how dipeptide supplementation can be utilized to improve fish performance on PP-based feeds. Intestinal gene expression and morphology results will be discussed in the oral presentation.