Nutritional programming effects on growth and reproduction of broodstock and embryonic development of progeny in yellow perch (Perca flavescens) fed soybean meal-based diets

Abstract

The objective of this research was to determine if growth performance of yellow perch (Perca flavescens) could be enhanced through nutritional programming when fed soybean meal-based (SBM) diets as their first feed. It was hypothesized that juvenile yellow perch could be nutritionally programmed by being fed SBM-based diets as their first formulated feed, and that this would result in improved growth performance when reintroduced to this diet later in life. It is assumed that nutritionally programmed fish transitioned back to fish meal (FM)-based diets during gametogenesis would eliminate reproductive effects from the SBM-based diets, such as reduced fecundity, egg quality or fertilization rate.The experimental design was carried out over four phases. In Phase 1, juvenile yellow perch were divided into four dietary treatments: 1) FM control, 2) wheat gluten meal (WG) and 3) and 4) two soybean meal (SBM-A/SBM-B) varieties, all fed to fish in triplicate. Plant proteins replaced 75% of the fish meal protein in the diet formulations, and diets were fed to juveniles for 2 months. In Phase 2, fish were combined in a “common garden” design, and all fed the FM diet for 9 months. In Phase 3, all fish were transitioned to the SBM-A diet for 7 months. Mean individual weights of fish and survival were measured at the beginning and end of each phase. Growth performance was calculated as weight gain (%) and specific growth rate (SGR, %/day. In Phase 4, fish were fed the FM diet over winter (6 months) when gametogenesis occurs and somatic growth was minimal. When females were ready to ovulate, they were manually stripped of eggs and fertilized with pond-raised males. Mean egg weight, total number of eggs, fecundity, gonadosomatic index (GSI), and fertilization rate were all calculated to determine reproductive quality.Results from phase 3 show that fish nutritionally programmed with SBM-A, had a higher weight gain percent when returned to SBM than fish from the other three diets, though not significant. Specifically, weight gain of SBM-A fed fish was 150 ± 31%, whereas other groups were 114 ± 24% (FM), 110 ± 26% (WG) and 118 ± 15% (SBM-B). Female reproductive quality was not affected by diet and results showed no significant differences between any of the parameters examined. However, growth during phase 4 was correlated with time to ovulation, increased GSI and mean egg weight.