Effect of Dietary Synbiotic on Phenotypic Traits and Metabolic Activities in Monosex Tilapia (Oreochromis niloticus)

Abstract

The present study evaluated the effects of dietary synbiotic on growth performance, some selected phenotypic traits and digestive enzymes activities of Nile tilapia (Oreochromis niloticus). There had four types of treatment groups in the 45 days long study. Only commercial feed was used as a control (C) and other three different concentrations of synbiotics with commercial feed were used as treatments (T₁, T₂ and T₃). The synbiotic composition contained the mixture of probiotic bacteria Lactococcus lactis strain D1813 and prebiotic CaCO₃, starch QS2. The probiotics doses of 1gm/kg, 2gm/kg and 3gm/kg was given to these three treatments T₁, T₂, and T₃, respectively. The present results revealed that the diets containing different doses of synbiotic significantly (p<0.05) increased growth performance of Nile tilapia. The experiment documented significant changes (p<0.05) in phenotypic traits of total length, standard length, trunk length, eye diameter, body area and dressing percentage except in tail length and color patterns. The mixture of feed with synbiotic showed a significantly higher amylase and protease activity in intestine of fish than the fish fed with controlled diet; however the enzyme activity in muscle were also increased but it was not significant (P>0.05). This result suggested that the incorporation of dietary synbiotic (mixture of Lactococcus lactis D18113, CaCO3 and starch QS2) had beneficial effect on growth performance, phenotypic traits and digestive enzyme activity of Nile tilapia.