Taurine Supplementation of All‐plant Protein Diets for Rainbow Trout (Oncorhynchus mykiss)

Abstract

Abstract.— Taurine has been demonstrated to be conditionally indispensable for several carnivorous fish species. Current trends in trout production include decreasing levels of fish‐meal content in feeds, along with faster growing strains of fish. Taurine may be a limiting nutrient in support of elevated planes of growth for rainbow trout. A 9‐wk feeding trial was conducted using a factorial treatment design with protein source (fish meal or plant) and taurine supplementation (four levels) as the main effects. The fish‐meal diet series included 23% herring meal and contained 1.76% total sulfur amino acids (TSAA). The plant diet series did not contain any animal proteins and substituted protein from soy protein concentrate in place of the herring‐meal protein and contained 1.5% TSAA. Taurine was supplemented at 0, 5, 10, and 15 g/kg dry diet to each of the diets in the plant series and the fish‐meal series of diets. All diets were formulated to contain 43.8% crude protein and 20% lipid with an estimated physiological fuel value of 4.2 kcal/g. Fifteen fish were stocked in each of 24 tanks with a mean initial weight of approximately 26.8 g per fish. The unsupplemented fish‐meal diet contained 2 g/kg taurine, and the unsupplemented plant diet had taurine levels below the detection limit of 0.1 g/kg diet. Taurine supplementation improved growth, feed conversion ratios, protein retention efficiencies, and energy retention efficiencies of fish fed the plant protein diets. No effects of taurine supplementation were observed for these response factors in fish fed the fish‐meal series diets. This study demonstrates that taurine supplementation may be necessary for rainbow trout fed plant‐protein‐based feeds.

An initial investigation replacing fish meal with a commercial fermented soybean meal product in the diets of juvenile rainbow trout

“…However, these values are much lower than those from other studies which fed soybean meal or other soybean products [48,50,52,53]. The only significant decrease in HSI observed in the current study was in the fish which received all of their protein from PSG.…”

“…In many of these other studies, fish meal-based control diets were not used, or the concentrations of other non-soy protein sources were altered in the experimental diets [14][15][16]24,[48][49][50][51][52][53]. However, Barrows et al [54] suggested that soybean meal replacement for fish meal should be limited to less than 25% (or 10% to 15% dietary inclusion rates).…”

Replacement of Fishmeal with Plant Protein Ingredients in Diets to Atlantic Salmon (Salmo salar) – Effects on Weight Gain and Accretion

“…The reduced methionine intake, and the lower liver taurine, resulted in higher accumulation of lipid in the liver while lysine limitations increased the lipid concentration in the whole fish (Espe et al, 2007). Also in the rainbow trout the methionine and taurine was found to affect the lipid deposition, but methionine rather than taurine was responsible (Gaylord et al, 2007). In juvenile Atlantic salmon we reported that taurine supplementation to plant protein based diets reduced the whole body lipid deposition without affecting protein deposition .…”

The Use of Cyanobacteria <i>Arthrospira platensis</i> and Cladoceran <i>Daphnia magna</i> as Complementary Protein and Lipid Sources in Transitional Diet for Common Carp (<i>Cyprinus carpio</i> L.) Nursery

“…Methionine is one of the most essential amino acid that becomes a limiting factor in diet [28]. Methionine deficiency in diet can inhibit transcription process, which inhibits some enzyme formation [29]. The high content of methionine in ED2 is thought to be the reason for the high survival during culture period, considering that methionine has many roles related with regulation and metabolic pathway mediating [29].…”

“…Methionine deficiency in diet can inhibit transcription process, which inhibits some enzyme formation [29]. The high content of methionine in ED2 is thought to be the reason for the high survival during culture period, considering that methionine has many roles related with regulation and metabolic pathway mediating [29]. Beside methionine, lysine often becomes one of the most limiting amino acid in commercial fish diet [28].…”