Re-evaluation of Dietary Methionine Requirement by Plasma Methionine and Ammonia Concentrations in Surgically Modified Rainbow Trout, Oncorhynchus mykiss

Abstract

This study was designed to re-evaluate the dietary methionine requirement by means of the plasma methionine and ammonia concentrations in surgically modified rainbow trout, Oncorhynchus mykiss. A total of 35 rainbow trout averaging 505±6.5 g (initial body weight, mean±SD) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group of fish was fed one of seven L-amino acid based diets containing 0.5% cystine and graded levels of methionine (0.25, 0.40, 0.50, 0.60, 0.70, 0.80 or 0.95% of diet, dry matter bases) by intubation at 1% body weight on dry matter basis. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free methionine concentrations (PPmet, 5 h after intubation) and postabsorptive plasma free methionine concentrations (PAmet, 24 h after intubation) of fish fed diets containing 0.60% or higher methionine were significantly (p<0.05) higher than those of fish fed diets containing 0.50% or lower methionine. PPmet and PAmet in fish fed diets containing 0.60% or higher methionine were not significantly different except PPmet of fish fed diet containing 0.95% methionine. Postprandial plasma ammonia concentrations (PPA, 5 h after intubation) of fish fed diets containing 0.70% or higher methionine were significantly higher than those of fish fed diets containing 0.60% or lower methionine, and PPA of fish fed diets containing 0.25 and up to 0.60% methionine were not significantly different from each other. Broken-line model analyses on PPmet, PAmet, and PPA indicated that the dietary methionine requirement of rainbow trout was between 0.59 (1.69) and 0.67 (1.91) % of diets (% dietary protein bases) when the diets contained 0.5% cystine.

The effect of dietary methionine on growth, antioxidant capacity, innate immune response and disease resistance of juvenile yellow catfish (Pelteobagrus fulvidraco)

“…This sulphur‐containing IAA, in the form of S‐adenosyl‐methionine, serves as a principal donor of the methyl group, a major contributor to the entire body pool of carbon units that are required for trans‐methylation and the biosynthesis of choline, thymidine, polyamines and creatine (Bae et al . ). Deficiency of methionine may cause reduced growth performance and poor feed conversion, and in certain species of fish, it may lead to pathologies (Ahmed et al .…”

Modelling the effects of dietary methionine level and form on postprandial plasma essential amino acid profiles in rainbow trout (Oncorhynchus mykiss)

“…; Bae et al . , ). In this study, statistical models were used in an attempt to explain biological responses by allowing for the description of multifactorial relationships.…”

Evaluation of Optimum Dietary Threonine Requirement by Plasma Free Threonine and Ammonia Concentrations in Surgically Modified Rainbow Trout, <i>Oncorhynchus mykiss</i>

“…On the other hand, determination of amino acid requirements by measuring plasma free amino acid (PFAA) and ammonia concentrations can provide useful information on the amino acid requirements within weeks. This method has been employed in several species and results are similar to those obtained by feeding trials ( Bae et al, 2011 ). Furthermore, PFAA concentrations had been used to investigate amino acids metabolism and to evaluate the quality of dietary protein in rainbow trout ( Schuhmacher et al, 1997 ); common carp ( Dabrowski, 1982 ) and Atlantic salmon, Salmosalar ( Sunde et al, 2003 ).…”

“…A 3 mL syringe with a 23-gauge needle was used to remove air and blood clot and the cannula was flushed with the heparinized saline solution. The cannula was sutured behind the bubble on the roof of the mouth, led out from the right nostrum, plugged with a head pin, and sutured at the dorsal fin ( Bai et al, 2003 ; Bae et al, 2011 ). Thirty five dorsal aorta cannulated rainbow trout were randomly distributed into seven groups including five fish per group and intubated with one of the seven experimental diets per group.…”

“…Although the effects of dietary protein or amino acid mixtures on PFAAs concentrations in rainbow trout ( Schuhmacher et al, 1997 ) and sea bass, Dicentrarchus labrax ( Thebault, 1985 ) had been reported, the complete dose response relationships for amino acids have not been investigated. In our previous studies, requirements for dietary essential amino acids such as arginine, methionine, lysine and valine were obtained in rainbow trout using PFAA in surgically modified rainbow trout ( Bae et al, 2011 ). As a part of our consecutive studies on the essential amino acid requirements of rainbow trout, the purpose of the present investigation was to estimate the dietary threonine requirement based on the plasma free threonine and ammonia concentrations in dorsal aorta cannulated rainbow trout.…”