TURKISH JOURNAL OF FISHERIES AND AQUATIC SCIENCES, cilt.13, ss.827-834, 2013 (SCI-Expanded)
The effect of replacement of fish meal (FM) with graded level of poultry by-product meal (PBM) in diets on growth performance and fatty acid composition of carp fry (Cyprinus carpio) was examined in the experiment. Five isonitrogenous (34% crude protein), isolipidic (9% crude lipid) and isoenergetic (15.0 MJ/kg DE) experimental diets replacing 0 (control group), 25, 50, 75 and 100% of FM protein by PBM protein were formulated with lysine, methionine and threonine supplementation in order to balance the amino acid profiles of the experimental diets. Each diet was fed to twice daily to apparent satiation of groups of twenty fry (mean weight 0.39 g fish(-1)) stocked into 65L glass aquaria to maintain three replicates per treatment. At the end of the experiment, body weight gain, specific growth rate, protein efficiency ratio and feed conversion ratio decreased with increased dietary replacement of FM with graded levels of PBM, while condition factor, hepatosomatic indices, viscerosomatic indices and whole body composition did not exhibit significant differences among the experimental groups (P>0.05). There were significant differences in total fatty acid composition of each experimental group. Values of Sigma n-3 polyunsaturated fatty acids and Sigma n-3/Sigma n-6 ratio in the muscle of fish decreased. No significant differences in saturated fatty acids values were observed in fish, while monounsaturated fatty acids values increased as the PBM level increased in the diet.