NUTRITIONAL PROGRAMMING WITH PLANT PROTEIN USING LIVE FOOD AS A VECTOR IMPROVES DIETARY PLANT PROTEIN UTILIZATION IN LARGEMOUTH BASS Micropterus salmoides

Nutritional Programming (NP) has been studied as a means of improving dietary plant protein (PP) utilization in different fish species. While NP has been traditionally done with dry feed during the juvenile stage, this study looked into using live feed for NP during the larval stage. The objective of this experiment was to determine the effect of NP with dietary PP induced during the first feeding of larval largemouth bass (LMB) Micropterus salmoides using live food as a vector on: 1) LMB growth performance; 2) expression of genes associated with inflammation and any morphological changes in the intestine; and 3) muscle free amino acid composition in LMB during its later life stages.

At 4 dph (days post-hatch), larval LMB were randomly distributed into 12 (50L) tanks, with approximately18 fish per liter. There were 3 treatment groups in this study. The first group (LF-PP) received soybean meal (SBM)-enriched Artemia nauplii from 5-25 dph, fish meal-based diet from 26-77 dph, and was challenged with SBM-diet during 78-121 dph. The second group (FM-PP) was not programmed during the live feed stage, received FM diet from 26-77 dph, and was exposed to SBM-diet during 78-121 dph. The last group (+) Control was not programmed during the live feed stage and received FM-diet throughout the whole trial (26-121 dph).

The results from this study showed that the programming of larval LMB with SBM-enriched live feed significantly improved weight gain in juvenile fish during the period of SBM-diet feeding compared to the non-programmed group (Figure 1). This study provides support for the use of live-feed enrichment with SBM for programming of larval stages as a means of improving the growth performance of aquaculture species fed with PP-based diets. The results on intestinal health status and muscle free amino acid composition will be included in the oral presentation.