Enhanced growth effects on shrimp (Litopenaeus vannamei) from inclusion of whole shrimp floc or floc fractions to a formulated diet

A growth trial was conducted to determine the effects of inclusion of whole shrimp floc or floc fractions to a control diet on growth and survival of shrimp (Litopenaeus vannamei). The floc sample was collected from marine shrimp culture tanks and partially fractionated by extraction with water, acetone and hexane. A series of diets was manufactured by inclusion of whole floc (intact or ground), each of the fractions or their combination to a control diet. These diets were fed to shrimp (approximately 1.0 g) in an indoor laboratory under flow-through conditions for 8 weeks. It was found that addition of whole floc (200 g kg(-1)) or floc fractions (24-200 g kg(-1)) to the control diet improved (P < 0.05) shrimp growth rate without affecting (P > 0.05) shrimp survival (> 81.3%). Although inclusion of whole floc reduced the crude protein and crude fat contents and gross energy of the control diet, shrimp fed the whole floc-supplemented diets obtained the highest (P < 0.05) growth rates (1.01 and 1.03 g week(-1)) among the shrimp fed the 11 tested diets including two control (0.81 and 0.85 g week(-1)), two commercial (0.45 and 0.71 g week(-1)) and five floc-fraction-added (0.91-1.00 g week(-1)) diets. Many bioactive compounds in the floc that possibly affected shrimp growth were also analysed and quantified.