Open AccessDietary threonine requirement to optimize protein retention and fillet production of fast‐growing N ile tilapia
Author(s) -
Michelato M.,
Vidal L.V.O.,
Xavier T.O.,
Graciano T.S.,
De Moura L.B.,
Furuya V.R.B.,
Furuya W.M.
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.12293
Subject(s) - nile tilapia , threonine , fillet (mechanics) , biology , tilapia , food science , weight gain , amino acid , zoology , feed conversion ratio , body weight , biochemistry , oreochromis , fishery , fish <actinopterygii> , endocrinology , serine , enzyme , materials science , composite material
Threonine is the third‐limiting essential amino acid in diets based on cereal ingredients. A 4‐week trial was conducted to determine the threonine requirement of large Nile tilapia based on fish growth, feed efficiency, body composition, protein and amino acid retention. Six hundred fish (563.3 ± 15.1 g) were distributed into twenty 1.2‐m 3 cages. Five diets containing 288 g kg −1 of crude protein, 12.7 MJ kg −1 of digestible energy and 8.9, 10.5, 12.2, 13.7 and 15.4 g kg −1 of threonine were elaborated. Fish were hand‐fed five times a day to extruded diets. Significantly, differences in growth performance and amino acids retention among the treatments were observed. Fish fed 10.5 g kg −1 of threonine showed higher daily weight gain, gutted weight and fillet weight ( P < 0.05) compared to fish fed with other experimental diets. Diets containing 8.9–15.4 g kg −1 of threonine did not affect whole body and muscle proximate composition. Based on second‐order regression analysis, the dietary threonine requirement estimated based on final gain, fillet weight and fillet yield was 12, 12.1 and 11.5 g kg −1 diet, respectively. The dietary threonine requirement for maximum fillet yield of Nile tilapia was estimated to be 11.5 g kg −1 .