Open AccessEffects of dietary protein and lipid levels with different protein‐to‐energy ratios on growth performance, feed utilization and body composition of juvenile red‐spotted grouper, E pinephelus akaara
Author(s) -
Wang J.T.,
Han T.,
Li X.Y.,
Yang Y.X.,
Yang M.,
Hu S.X.,
Jiang Y.D.,
Harpaz S.
Publication year - 2017
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.12467
Subject(s) - grouper , biology , juvenile , dry matter , feed conversion ratio , zoology , epinephelus , lipid metabolism , composition (language) , food science , weight gain , biochemistry , endocrinology , body weight , fish <actinopterygii> , fishery , ecology , linguistics , philosophy
An 8‐week feeding trial was conducted to assess dietary protein and lipid levels on growth performance, feed utilization and body composition of juvenile red‐spotted grouper (7.85 ± 0.03 g fish −1 ). Nine semi‐purified diets were formulated containing varying protein levels (440–520 g kg −1 , dry matter) and lipid levels (60–120 g kg −1 , dry matter). The weight gain of juvenile Epinephelus akaara was affected by dietary protein ( p = .005) and its interaction with dietary lipid ( p = .020). Viscerosomatic index, intraperitoneal fat ratio and whole‐body lipid level increased with increasing dietary lipid level ( p < .001). Nitrogen retention was not affected by dietary protein and lipid, while lipid retention decreased with increasing dietary lipid level ( p < .001). The plasma blood urea nitrogen increased with increasing dietary protein level ( p = .003). This study showed that diet with 520 g kg −1 protein and 60 g kg −1 lipid with 30.58 mg kJ −1 P:E provided a maximal growth for this species. Moreover, an increase in dietary lipid levels (from 60 to 90 g kg −1 ) could reduce the protein requirement (from 520 to 480 g kg −1 ) without affecting the growth performance, while higher fat deposition was observed in fish fed high‐lipid diets.