THE SYNERGISTIC INFLUENCE OF THYMUS VULGARIS AND VITAMIN E ON GROWTH PERFORMANCE AND OXIDATIVE STRESS AT OREOCHROMIS NILOTICUS SPECIES

Alina Antache, V. Cristea, Iulia Grecu, Mirela Creţu

Abstract
    The aim of this research was to evaluate the influence of thyme and vitamin E on growth performance indicators, biochemical composition of meat and oxidative stress at Oreochromis niloticus species, reared in a recirculating aquaculture system. The experiment was conducted in duplicate, for one month. The experimental variants were: V1 - 1% thyme (Thymus vulgaris)/kg feed and V2 - 1% thyme/kg feed supplemented with 500 mg vitamin E/kg feed. Fish were fed with SOPROFISH pelleted feed, with 38% crude protein. At the end of the experiment, the results showed that in V2 variantwere recorded the best values of SGR (0.65 %/day) and FCR (1.42 g feed/g biomass gain). Regarding the biochemical composition of meat, significant differences were recorded only in case of fat content (p=0.03; p<0.05). In terms of oxidative stress, was observed a decrease in lipid peroxidation (MDA-malondialdehyde) in V2 variant, significant differences (p<0.05; p=0.01) were obtained only in case of bloodplasma. But, the increase of total antioxidant capacity (TAC) was registeredin V1 variant at the level of bloodplasma, muscle tissue, liver and gut. In conclusion, the research shows that the administration of thyme (1%/kg feed) in combination with vitamin E (500mg/kg feed) has a synergistic effect on growth performance indicators and lipid peroxidation, at Nile tilapia.

Key words: thyme, vitamin E, growth performance, Oreochromis niloticus, aquaculture system