Open AccessEffects of lysine and methionine supplementation on growth, body composition and digestive function of grass carp ( C tenopharyngodon idella ) fed plant protein diets using high‐level canola meal
Author(s) -
Jiang J.,
Shi D.,
Zhou X.Q.,
Feng L.,
Liu Y.,
Jiang W.D.,
Wu P.,
Tang L.,
Wang Y.,
Zhao Y.
Publication year - 2016
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.12339
Subject(s) - biology , grass carp , amylase , zoology , hepatopancreas , methionine , feed conversion ratio , canola , meal , fish meal , soybean meal , composition (language) , lipase , food science , amino acid , biochemistry , endocrinology , body weight , fishery , fish <actinopterygii> , enzyme , ecology , raw material , linguistics , philosophy
A 76‐day feeding trial was carried out to evaluate the effects of L ysine and M ethionine supplementation on growth and digestive capacity of grass carp ( C tenopharyngodon idella ) fed plant protein diets using high‐level canola meal ( CM ). Fish with initial average weight 103.9 ± 0.6 g were fed three extruded diets. Fish meal ( FM ) diet was formulated as the normal control with 40 g kg −1 FM and 300 g kg −1 CM ; CM diet was prepared by replacing all FM with CM (total 340 g kg −1 ) without L ys or M et supplementation; CM supplement ( CMS ) diet was similar to CM diet but was supplemented with essential amino acids ( EAA ) to ensure the levels of L ys and M et similar to those in the FM diet. Feed intake, feed efficiency and specific growth rate of the grass carp fed CMS and FM diets were similar ( P > 0.05), but higher than those of the grass carp fed CM diet ( P < 0.05). The hepatosomatic index, relative gut length, intestosomatic index and intestinal folds height were significantly improved in fish fed FM and CMS diets as compared to CM diet ( P < 0.05). Lower activities of trypsin, lipase and amylase in hepatopancreas were observed in fish fed CM diet ( P < 0.05). Three hundred and forty gram per kilogram CM without L ys or M et supplementation significantly decreased trypsin, lipase and amylase m RNA levels in hepatopancreas ( P < 0.05). These results indicated that the high supply of CM (340 g kg −1 ) in plant protein (200 g kg −1 soybean meal and 100 g kg −1 cottonseed meal) diets decreased digestive ability through decreasing digestive enzyme activities and enzyme gene's expressions of grass carp, and these side effects can be reversed by supplementing L ys and M et. Therefore, CM could be high level used in a plant protein blend‐based extruded diet for grass carp as long as EAA were supplemented.