Effects of Graded Taurine Levels on Juvenile Cobia

Abstract

Taurine, which has multiple important physiological roles in teleost fish and mammals, is an amino acid not found in alternative protein sources not derived from animals. Although taurine is found in fish‐meal‐based feeds, its high water solubility leads to lower taurine levels in reduction‐process‐based feeds, which marine carnivores such as Cobia Rachycentron canadum are adapted to in their natural diets. Graded taurine supplementation (0, 0.5, 1.5, and 5.0%) added to a traditional fish‐meal‐based formulation was examined in two growth trials with Cobia: one initiated with 10‐g individuals and the second initiated with 120‐g individuals. During the first trial, in which growth as weight gain ranged from 123 to 139 g per fish, there was an increase in dietary taurine and a decrease in the feed conversion ratio from 1.04 to 0.99. During the second trial, in which growth ranged from 227 to 313 g gained per fish, there was no significant difference in performance characteristics between dietary treatments. Messenger RNA transcript expression levels for two of the genes involved in taurine synthesis, cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO), as well as the membrane‐bound taurine transporter, TauT, were also measured at the conclusion of the second trial. Increasing dietary taurine in a diet containing 34.5% fish meal did not result in significantly different growth or production characteristics in Cobia, but did result in significantly increased taurine levels in fillet, liver, and plasma.

Effect of dietary taurine and methionine supplementation on growth performance, body composition, taurine retention and lipid status of Persian sturgeon,Acipenser persicus(Borodin, 1897), fed with plant-based diet

“…The diet without taurine supplementation (M) significantly declined Persian sturgeons' growth performance, which is in accordance with previous studies on different fish species (Chatzifotis et al., ; Han et al., ; Jirsa et al., ; Johnson et al., ; Lim et al., ; Matsunari et al., ; Park, Takeuchi, Yokoyama, & Seikai, ; Watson et al., ; Wu et al., ). Taurine may be synthesized endogenously from methionine, but this capacity depends on fish species (El‐Sayed, ; Salze & Davis, ); nevertheless, it has been suggested that taurine supplementation augments trout growth only when dietary methionine level is suboptimal (Gaylord et al., ), meaning that this species is efficiently able to convert methionine to taurine.…”

“…These results are hard to interpret. Dietary taurine supplementation increased muscle and/or liver taurine content in R. canadum , P. olivaceus and P. major (Han et al., ; Kim et al., ; Matsunari et al., ; Watson et al., ). In S. salar , methionine intake increased muscle and liver taurine, but had no effects on methionine levels (Espe et al., ).…”

“…This effect has been extensively observed in mammals (Nakaya et al., ; Nandhini, Thirunavukkarasu, & Anuradha, ). In fish, although scarcely studied, some authors have found that taurine had also a glycolytic effect and the subsequent reduction in blood glucose (Han et al., ; López et al., ; Salze, Spangler, Cobine, Rhodes, & Davis, ; Watson, Barrows, & Place, ).…”

Feed Utilisation Efficiency of Lupin Inclusion in Cobia: Role of Dietary Organic Selenium Supplementation

“…A deficiency of taurine in plant-based diets has been linked to the reduced lipid deposition in the tissues of cobia (Lunger, McLean, Gaylord, Kuhn, & Craig, 2007). However, in the current study, taurine was added at 5 g/kg to satisfy the nutritional needs of cobia as quantified by Watson et al (2014). Thus, the reduced muscle lipid contents of cobia fed 315 g/kg LKM diet in the current study might be due to the low energy intake and energy digestibility, similar in cobia fed other plant-derived ingredients (Luo et al, 2012;Luo et al, 2013;Zhou et al, 2005).…”

“…Chromic oxide (Cr 2 O 3 ) was added to all test diets as the inner marker. Taurine (Sigma-Aldrich, St. Louis, MO, USA) was added to all diets at a level of 5 g/kg to meet the nutritional requirement of cobia as the recommendation by Watson, Barrows, and Place (2014). Fish oil and distilled water were added and then thoroughly mixed.…”