Open AccessDietary magnesium requirement and effects on growth and tissue magnesium content of juvenile grass carp ( Ctenopharyngodon idella )
Author(s) -
LIANG J.J.,
TIAN L.X.,
LIU Y.J.,
YANG H.J.,
LIANG G.Y.
Publication year - 2012
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/j.1365-2095.2011.00876.x
Subject(s) - grass carp , magnesium , zoology , biology , juvenile , dietary protein , carp , endocrinology , chemistry , fish <actinopterygii> , fishery , ecology , organic chemistry
A growth trial was conducted to estimate the optimum concentration of dietary magnesium (Mg) for grass carp ( Ctenopharyngodon idella ). Triplicate groups of grass carp (5.56 ± 0.02 g) were fed diets containing graded levels (187, 331, 473, 637, 779 and 937 mg kg −1 ) of Mg for 8 weeks. Weight gain, specific growth rate and feed efficiency were linearly increased up to 637 mg kg −1 dietary Mg and then levelled off beyond this level. For body composition, dietary Mg levels higher than 473 mg kg −1 significantly decreased the moisture content but increased the lipid content of whole body, muscle and liver. Dietary Mg levels higher than 473 mg kg −1 significantly decreased the ash contents of vertebrae, scales and muscle. Mg contents in whole body, vertebrae, scales and plasma were increased up to 637 mg kg −1 dietary Mg and then levelled off beyond this level. However, Ca and P contents seem to be inversely related to dietary Mg. Dietary Mg levels higher than 473 mg kg −1 significantly decreased Zn and Fe contents in whole body and vertebrae. Broken‐line analysis indicated that 687 mg kg −1 dietary Mg was required for maximal tissue Mg storage, as well as satisfied for the optimal growth.