A 10-week feeding experiment was performed to determine the impacts of partial substitution of soybean meal (SB) with pumpkin seed cake (PSC) in Oreochromis niloticus diets on water quality, growth rate, antioxidant capacity, immunity, and carcass composition. One hundred and fifty tilapia fish (average weight, 11.93 ± 0.17 g) were randomly allocated to five diets. The first diet (the basal diet) contained 420 g of SB per kg of feed. The remaining four diets, namely, D1, D2, D3, and D4, had SB partially replaced by PSC at 10%, 20%, 30%, and 40%, respectively. The results revealed that D4 and D1 significantly improved dissolved oxygen levels, while water temperature, pH, total ammonia, and nitrate levels were not significantly affected. Replacing SB with PSC significantly improved specific growth performance indicators and feed conversion compared to the control, with the D4 group showing the best values. Increasing PSC levels decreased serum glucose, aspartate aminotransferase, alanine aminotransferase, cholesterol, and triglyceride levels. In contrast, the D4 group had higher globulin, albumin, total protein, and lysozyme serum levels. Moreover, fish-fed PSC had significantly increased superoxide dismutase, glutathione peroxidase, and catalase activities and significantly decreased malondialdehyde levels. Increasing PSC substitution levels in fish diets increased the ash and crude lipid contents in the bodies of the fish, while crude protein and moisture decreased. In conclusion, replacing SB with PSC in fish diets significantly enhances growth performance, feed conversion, and fish health. Moreover, the findings suggest that PSC can be a promising alternative protein source for sustainable aquaculture practices.

Adding natural product such as Humic acid (Humabol) and Yucca schidigera extract to enhance water quality under scarce water exchange regiment; has numerus effects on both fish environment and health. Yucca showed significant reduction on NH3 and NO2 levels, while humic acid showed significant reduction on orthophosphate and total phosphorus compared to negative control; in addition to maintaining acceptable growth rate under designed experimental conditions. Furthermore, the hematological study showed that, Yucca and humic had positive effect on Red cell indices values such as, HCT, MCV, MCH, MCHC as well as WBCs total count and the proportion of the NEU, MONO, ESO and LYM of the treated treatments. Also, the histological study of gills, liver, stomach and intestine highlighted the tissue protective effect manifested by Yucca and humic.

This experiment aimed to appraise growth performance, hematological and immuno-physiological indices of Nile tilapia when fed on diets in which soybeans were partially replaced by Azolla pinnata or Nannochloropsis oculata. A control diet (basic diet) was tested against 6 practical diets (3 diets partially replaced soybean with Azolla pinnata and 3 diets partially replaced soybean with Nannochloropsis oculata at three different percentages (2.5, 5 and 7.5 %) The highest values of growth parameters were recorded in T3 (Azolla 5 %), followed by T4 (Azolla 7.5 %), T5 (Nano 2.5 %), T7 (Nano 7.5 %), T6 (Nano 5 %), T2 (Azolla 2.5 %), and then T1 (negative control). At the end of the experiment, T4 recoded the highest values of Total protein and Globulin while the lowest readings were in T3, Albumin lowest value was in T5 and the highest one accomplished in T2 with a significant differences between all treatments. For the antioxidant parameters, the negative control (T1) recoded the highest MDA value, while had the lowest values of SOD, GPX and Lysozyme. The highest values of (SOD and GPX) accomplished in T6 while the highest value of Lysozyme was recorded in T4. The challenge with A. hydrophila showed that, the highest mortality rate (80 %) was recorded in control, while the lowest one (10 %) was recorded in T3 and T4.

The study investigated the efficiency of adding extracted chitosan from shrimp wastes to enhance water quality, reduce stress and enhance tilapia flesh quality. Water quality parameters showed no significant differences among all treatments in (Dissolved oxygen, Temperature, pH, NO2 and Orthophosphate values). Treatment fish water with chitosan affected some nitrogenous parameters such as NH3 and NO3, where the values were (0.7, 0.6, 0.1 and 0.5 mg / l) for NH3, and (0.62, 0.61, 0.36 and 0.59 mg / l) for NO3, respectively. The lowest value of NH3 and NO3 was recorded in T3 (15 mg / l chitosan) followed by T4 (20 mg / l chitosan), T2 (10 mg / l chitosan) and finally T1 (negative control). Chemical composition of the samples revieled that the adding chitosan to the water improved moisture, protein, fat and increased ash content for fish flesh respectively, followed by control. Physiochemical quality parameters such as pH, acid value, Free amino nitrogen (FAN), Free fatty acids (FFA), total volatile bases nitrogen (TVB-N) and trimethylamine (TMA-N) showed that the addition chitosan reduce the increase in this parameters of the three treatments compared to the control The blood chemistry indices revealed that; T3 had the lowest AST; T4 had the lowest ALT values compared to control and T2, respectively. Despite the variation in Alb, Glob and ALP values among treatments they showed no significance differences. T3 showed the lowest values among all treatments for GLU, CHO, HDL, LDL and TG followed by T4, T2 and control, respectively.

This study aimed to evaluate the effect of both different initial weights and stocking densities on growth performance, productivity and the total economic revenue of Nile tilapia reared in earthen ponds under Egyptian conditions. Twelve earthen ponds with an area of 2 feddans were divided into two groups according to the initial fish weight, fingerlings (10 g) and fry (0.3 g.), Each group had three carrying capacities of 30, 40, and 50 thousand fish / pond. The water quality measurements were sustained at recommended limits, temperature ranged from 23 to 29ºc and the pH from 7.5 to 8.8, while the dissolved oxygen was kept at range from 5.4 to 7.9 mg/l. The growth measurements revealed that the Fing 50 treatment had superior total production, though the percentage of larger fish were accomplished by both group Fing 40 and Fing 30. This was reflected by economics of production, where the highest return was generated by treatments Fing 40, followed by Fing 50, and the best return on costs was in favor of the Fing 30 treatment. In reference to this study findings, a stocking density of 30 and 40 thousand monosex tilapia fingerlings are recommended for culture in earthen ponds under the similar conditions in Egypt.