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Quantitative dietary threonine requirement of juvenile Pacific white shrimp, Litopenaeus vannamei (Boone) reared in low‐salinity water
Author(s) -
Huai MingYan,
Tian LiXia,
Liu YongJian,
Xu AnLong,
Liang GuiYing,
Yang HuiJun
Publication year - 2009
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2009.02181.x
Subject(s) - litopenaeus , biology , shrimp , threonine , zoology , fish meal , meal , food science , corn gluten meal , soybean meal , gluten , feed conversion ratio , biochemistry , fishery , ecology , body weight , serine , endocrinology , enzyme , fish <actinopterygii> , raw material
An 8‐week feeding trial was conducted to determine the threonine requirement of juvenile Pacific white shrimp Litopenaeus vannamei (Boone) in low‐salinity water (0.50–1.50 g L −1 ). Diets 1–6 were formulated to contain 360 g kg −1 crude protein with fish meal, wheat gluten and pre‐coated crystalline amino acids with six graded levels of l ‐threonine (9.9–19.0 g kg −1 dry diet). Diet 7, which was served as a reference, contained only intact proteins (fish meal and wheat gluten). Each diet was randomly assigned to triplicate groups of 30 shrimps (0.48±0.01 g), each four times daily. Shrimps fed the reference diet had similar growth performance and feed utilization efficiency compared with shrimps fed the diets containing 13.3 g kg −1 or higher threonine. Maximum specific growth rate (SGR) and protein efficiency ratio were obtained at 14.6 g kg −1 dietary threonine, and increasing threonine beyond this level did not result in a better performance. Body compositions, triacyglycerol and total protein concentrations in haemolymph were significantly affected by the threonine level; however, the threonine contents in muscle, aspartate aminotransferase and alanine aminotransferase activities in haemolymph were not influenced by the dietary threonine levels. Broken‐line regression analysis on SGR indicated that optimal dietary threonine requirement for L. vannamei was 13.6 g kg −1 dry diet (37.8 g kg −1 dietary protein).