New Insights into the Effectiveness of Fungi-Degraded Date Pits Supplemented Diet on the Physiological and Biological Indices of Oreochromis niloticus Fingerlings

This study examined the effects of fungi-degraded date pit (FDDP) as a dietary supplement in fish diets in vitro and in vivo. In the in vitro study, FDDP was prepared and characterized for its nutritional and biological impacts on animal health. A total of nine Nile tilapia (Oreochromis niloticus) experimental fish groups were used to assess the sub-chronic toxicity of FDDP crude and ethanolic extract on growth performance and biochemical markers. Four groups of fish (15±0.1g) received varying concentrations of crude FDDP (5, 10, 20, 30g/ kg diet), while another four received varying concentrations of FDDP ethanolic extract (2.5,5,7.5,10 g/kg diet) in addition to the control group. The chemical compositions of FDDP showed high protein, fiber, organic matter, and hemicellulose contents. For the analysis of FDDP, an increase was recorded in mineral contents and xylanase & cellulase enzyme activities, compared to the degraded date pits (DDP). The results of fish biochemical composition and physiological analyses showed that diets containing ethanolic FDDP extract (1%) and crude FDDP (2%) had the highest weight gain (WG), condition factor (K) and protein efficiency ratio (PER) values. Additionally, an increase was detected in the antioxidant capacity by upregulating reduced glutathione (GSH) levels and superoxide dismutase (SOD) activities.  In both liver and brain tissues, oxidative stress levels, such as thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) were declined. In conclusion, our findings indicate that supplementing fish diets with either FDDP ethanolic extract (1%) or crude FDDP (2%) could promote fish growth, increase physiological competence and stress resistance while reducing oxidative stress in the Nile tilapia.