title: Taurine supplementation of plant derived protein and n-3 fatty acids are critical for optimal growth and development of cobia, Rachycentron canadum.
abstract: We examined growth performance and the lipid content in juvenile cobia, Rachycentron canadum, fed a taurine supplemented (1.5 %), plant protein based diet with two fish oil replacements. The first fish oil replacement was a thraustochytrid meal (TM + SOY) plus soybean oil (~9 % CL) and the second was a canola oil supplemented with the essential fatty acids (EFA) docosahexaenoic acid (DHA) and arachidonic acid (ARA) (~8 % CL). The diet using the thraustochytrid meal plus soybean oil performed equivalently to the fish oil diet; both resulting in significantly higher growth rates, lower feed conversion ratios, and higher survival than the supplemented canola oil diet, even though all three diets were similar in overall energy and met known protein and lipid requirements for cobia. The poor performance of the canola oil diet was attributed to insufficient addition of EFA in the supplemented canola oil source. Increasing levels of EFA in the supplemented canola oil above 0.5 g EFA kg(-1) would likely improve results with cobia. When fish fed either of the fish oil replacement diets were switched to the fish oil control diet, fatty acid profiles of the fillets were observed to transition toward that of the fish oil diet and could be predicted based on a standard dilution model. Based on these findings, a formulated diet for cobia can be produced without fish products providing 100 % survivorship, specific growth rates greater than 2.45 and feed conversion ratios less than 1.5, as long as taurine is added and EFA levels are above 0.5 g EFA kg(-1).
authors.affiliation: Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USA. watsona@umces.edu
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Watson
authors.forename: Frederic T
authors.initials: FT
authors.lastname: Barrows
authors.forename: Allen R
authors.initials: AR
authors.lastname: Place
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000494:pharmacology; D001835:Body Weight / Q000187:drug effects*; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D029941:Fish Proteins / Q000032:analysis; D008055:Lipids / Q000032:analysis; D010473:Perciformes / Q000254:growth & development* / Q000378:metabolism; D010940:Plant Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D000074262:Rapeseed Oil; D013024:Soybean Oil / Q000008:administration & dosage / Q000494:pharmacology; D058009:Stramenopiles / Q000737:chemistry; D013654:Taurine / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3; D029941:Fish Proteins; D008055:Lipids; D010940:Plant Proteins; D000074262:Rapeseed Oil; D013654:Taurine; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D013024:Soybean Oil