The Biochemical Evaluation of Aquaculture Nile Tilapia Muscle Tissue, in Condition of Some Phytobiotics Administered in Feed

The purpose of this research was to determine the effect of some phytobiotics on biochemical composition of Nile tilapia muscle tissue reared in a recirculating aquaculture system. The experiment was conducted for fourteen weeks, from August 17 to November 27, 2012. The experimental variants were: V1–control, V2–1 % Rosmarinus officinalis/kg feed; V3–1 % Hippophae rhamnoides/kg feed and V4–1 % Zingiber officinale/kg feed. During the experiment, the sampling for biochemical analysis of muscle tissue was performed at the beginning of the experiment (17.08.2012), on intermediary moment (28.09.2012) and at the end of the experiment (27.11.2012), from fresh meat. The results showed significant differences (p<0.05) both between initial (Vi) and intermediary (Vint – 28.09.2012) moment and between experimental variants (Vint) in terms of protein, fat, moisture and dry matter percentage. At the end of the experiment were registered significant differences (p<0.05) with respect to protein and moisture percentage. Also, in this paper is presented the dinamics of nutrient retention efficiency (PER-g/g, PUE-%, RP-g/fish and RL-g/fish) at Nile tilapia, in the muscle tissue. At the intermediary moment, in V3 was registered the lowest value of fat content (1.22%), and in V4 the highest value of protein content (13.11%). In conclusion, rosemary, sea buckthorn and ginger, in concentration of 1%/kg feed, influenced significantly the biochemical composition of muscle tissue at Oreochromis niloticus species