This study aimed to assess the effect of dietary supplementation of a mixture of botanical compounds and essential oil (Phyto AquaMeric, PAM) on the growth, immune and antioxidant parameters and environmental benefits in Nile tilapia. Two diets including a control and a PAM-supplemented diet at 0.5 g kg⁻¹ were prepared for the trial. The diets were isonitrogenous (30% crude protein) and isoenergetic (17 MJ kg⁻¹) extruded diets. Nile tilapia weighing initially 74.22 ± 1.96 g fish⁻¹ were stocked in 2 m³ hapas at a density of 20 fish per m³ (40 fish per hapa). Each group was tested in triplicates over 80 days. The antioxidant potential of PAM was compared to vitamin C through KRL test, showing a higher value from 35 to 100 mg. The in vivo trial did not exhibit any significant growth performance improvement. However, the PAM group had a significantly improved feed conversion ratio (FCR) and protein efficiency ratio (PER). Moreover, the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), Malondialdehyde (MDA), immune parameters (ACH50, lysozyme, phagocytic and phenoloxidase activities), digestive enzymes and hepatic enzymes were significantly improved in the PAM-fed group. An evaluation of eutrophication potential of PAM supplementation revealed a low input in the system. In conclusion, this mixture of botanicals and essential oil exhibited in vitro and in vivo antioxidant potential, improved health and digestive parameters and contributed to a reduced eutrophication risk in the tilapia production system.

The goal of this study was to evaluate the effect of the supplemental plant-based blend Phyto AquaNity (PAN) on growth, profitability and health status of Nile tilapia (O. niloticus) cultured in hapas. Juvenile fish of average weight 73 g were stocked in 2-m³ hapas in triplicates at a density of 20 fish m⁻³ (40 fish hapa⁻¹). Four extruded diets were formulated following isonitrogenous (30% CP), isoenergetic (17 MJ kg⁻¹) standards, with incorporation levels of 0, 0.25, 0.50, or 1.00 g of PAN kg⁻¹ diet. Fish were fed the experimental diets at a daily rate of 2–3% of their body weight (BW) over 80 days. From this study, results showed that growth performance and tissue composition were not significantly impacted by these treatments. Feed intake exhibited a significant reduction while feed efficiency was improved in the groups fed 0.5 g kg⁻¹. Diets supplemented with PAN were also more profitable than the control diet, with 0.5 g kg⁻¹ indicating the highest return (9.24% increase). Digestive enzyme activity and hepatic enzyme activity were significantly improved with an increase in the level of PAN up to 0.50 g kg⁻¹. In addition, immune parameters (lysozyme activity, alternative complement and phagocytic cells) and antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) were significantly enhanced with increasing PAN level up to 0.5 g kg⁻¹ (p < 0.05). Gene expression of cytokines was also upregulated in fish fed with PAN at levels of up to 0.5 g kg⁻¹ (p < 0.05). Moreover, the results showed that higher levels of PAN promoted the growth of beneficial bacteria while reducing the load of pathogenic bacteria. Additionally, intestinal fold length and goblet cell count were significantly increased in the group fed PAN up to 0.5 g kg⁻¹. A quadratic regression analyses performed on feed efficiency, profitability, hepatic enzyme activity and gut microbial load revealed that 0.60–0.65 g kg⁻¹ of feed were the optimal dosages. Regarding immunological and antioxidant responses, the optimal dosages ranged between 0.75 and 0.85 g kg⁻¹. Overall, about 0.60–0.85 g PAN kg⁻¹ feed is suggested for optimum performance, profitability, gut health and overall health status of Nile tilapia, depending on the target objective for which this product is added.

The present study aimed to evaluate the fishery status of the Atlantic horse mackerel (Trachurus trachurus)stock in the western Egyptian Mediterranean waters. Random monthly samples of fish were collected during the period from April 2015 to March 2016, with a total of 1054 fish. Growth parameters were determined and the vectors of natural mortality (M) by age, total mortality (Z) and fishing mortality (F), length cohort analysis, and Beverton & Holt Yield per recruit analysis were performed by FiSAT and Virtual Population Analysis (VIT software) programs to estimate the limit and target reference points. The present results showed that the Von Bertalanffy growth parameters were L∞ = 29.58 cm, K = 0.27 years-1, and t0 = -1.49 year. The mean values of Z, F and M were 0.828, 0.575 and 0.253 year-1, respectively. The exploitation rate (E) was 0.694 year. The current yield per recruit (Y/R), biomass per recruit (B/R), and spawning stock biomass (SSB) at the current fishing mortality (0.575 year-1) were 14.27, 31.35 and 12.15g, respectively. The percentage of the current B/R to the virgin biomass was 25.11%. The reference point F0.1 = 0.27, and the limit reference point (FMAX) was 0.48 year-1. These two values are lower than the current value of fishing mortality (0.575 year-). The ratio between FC and F0.1 was 2.128; this value indicates that T. trachurus stock in the Egyptian Mediterranean waters is at a high over-exploitation state.