Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: November 6, 2007
Publication Date: February 9, 2008
Citation: Riche, M.A. 2008. Evaluation of digestible protein and energy in juvenile Florida pompano Trachinotus carolinus [abstract]. Book of Abstracts Aquaculture America. p. 325.
Digestible protein to digestible energy ratio, and minimal digestible protein for maximum growth, efficiency, and nitrogen gain of juvenile Florida pompano Trachinotus carolinus were determined. During a 10-week trial Florida pompano (6.3±0.50 g) were fed one of twelve diets formulated with an array of five crude protein (340, 380, 420, 480, and 500 g/kg diet) and five crude lipid (60, 100, 120, 160 and 180 g/kg diet) levels and estimated digestible protein/digestible energy (DP/DE) of 18.9 to 26.8 mg/kJ.
In a second trial, apparent protein and energy digestibilities were empirically determined. Apparent crude protein digestibilities (68.2 to 77.7 %) were not different whereas differences (P<0.05) were detected in apparent energy digestibility (40.8 to 77.1 %). Digestible energy intake was 4.2 to 13.0 kJ/fish/d and digestible protein intake 0.13 to 0.32 g/fish/d. Mean daily intake was 0.60 to 0.94 g/fish/d and increased (P<0.001) as digestible energy increased; however, when standardized to body weight (mg/g fish/d) consumption was higher (P<0.001) in fish fed low energy diets.
Average daily gain increased as a function of both digestible protein and digestible energy and maximum growth was attained at 15 MJ/kg dry matter approximating a DP/DE of 24.0 mg/kJ. Growth increased stepwise with increasing digestible protein in all diets containing a ratio of 24.0 mg/kJ DP/DE or greater, until a plateau at 366 g digestible protein/kg dry matter. Nitrogen gain (g/fish) was a function of both digestible protein and digestible energy. Increasing energy at constant dietary protein improved protein utilization. Minimum digestible protein to maximize growth and nitrogen gain was between 356 and 366 g/kg dry matter. Digestible energy to attain maximum growth in juvenile Florida pompano is at least 15.4 MJ/kg dry matter representing a DP/DE ratio between 23.8 and 25.1 mg/kJ.