Nutritional Programming of Yellow Perch Perca flavescens Increases second generation's Ability to Utilize Soybean Meal-Based Diets

Dietary fish meal protein replacements with plant proteins have been studied for decades, yet there are still limitations surrounding these formulations at higher inclusions levels.  In more recent studies, nutritional programming has been used to alter the animal response to their diet.  Nutritional programming refers to the changes that occur very early on in life, following initial exposures that can have permanent, long-term effects. We examine nutritional programming across two generations of yellow perch to determine if this approach can enhance dietary soybean utilization.  Each generation of fish went through 4 phases. F1 generation; phase 1 consisted of four diets where plant proteins replaced 75% fish meal protein: 1) fish meal control (FM), 2) wheat gluten meal (WG) and 3) and 4) two soybean meal (SBM) varieties all fed to juvenile yellow perch for 2 months. In Phase 2, fish were fin-clipped and combined in triplicate tanks and all fed a FM diet for 9 months. In Phase 3, the "challenge" phase, all fish were transitioned to a SBM diet for 7 months. In Phase 4, fish were fed FM diets for 6 months during winter months when gametogenesis occurs and there is minimal somatic growth.

Eggs from 4-programmed females from each initial dietary group (4) were fertilized with the same males (n=3) from an outside source to minimize variability.  Females solely fed a commercial control (CONT) diet were also fertilized with the same males. The F2 juveniles were reared for ~30 days on live feed prior to beginning phase 1. F2 generation; Phase 1 consisted of two programming diets, fish meal (FM), and 75% soybean meal (SBM).  Each group of juveniles (61±12mg) was equally divided, and fed either FM or SBM for 2 months. In phase 2, juveniles were fin-clipped, combined with siblings and fed a FM diet for 9 months.  In Phase 3, which is currently ongoing, fish are being fed SBM diet for 6 months.  All fish will then be transitioned back to FM diet in Phase 4, for 6 months over the winter.  

Results from the F2 generation in Phase 1 showed no significant differences in weight gain (%) within groups fed FM or SBM (Fig. 1A). Figure 1B depicts the differences in the F1 and F2 generation from Phase 1. Weight gain between fish fed FM showed no significant difference between generations.  However, the SBM fed fish in the second generation had a significantly higher weight gain than those in the F1 generation.