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The current study investigated the effects of dietary curcumin nanoparticles (C-NPs) on the performance, hemato-biochemical profile, digestive enzymes activities, antioxidant status, humoral immunity, and liver and intestinal histology of Nile tilapia (Oreochromis niloticus). Fish (4.3 ± 0.5 g) were fed with diets enriched with 0.0 (control), 15, 30, 45, and 60 mg C-NPs/kg diet up to apparent satiety thrice a day for 60 days. The growth-stimulating effects of dietary C-NPs were significantly observed in terms of final weight, weight gain %, specific growth rate, and feed intake. Compared with the control group, serum amylase, lipase, and proteases activities of Nile tilapia significantly (P < 0.05) increased alongside the increase in dietary levels of C-NPs in a dose-dependent manner. The counts of red blood cells and white blood cells as well as hemoglobin and hematocrit levels of Nile tilapia fed with 30–60 mg C-NPs/kg diet were statistically (P < 0.05) higher than fish in the control group with no significant differences among them (P > 0.05). Moreover, lymphocytes and monocytes significantly (P > 0.05) increased; meanwhile neutrophils significantly (P > 0.05) decreased as C-NPs levels in diets increased. In a similar trend, antioxidant (malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase) and humoral immunity (lysozyme and total immunoglobulin) biomarkers were significantly higher in C-NPs-fed fish. Liver histology showed improvements in the cell architecture of fish fed with C-NPs containing diets up to 45 mg/kg diet. Compared with the control diet, feeding Nile tilapia with C-NPs diets resulted in a higher villi length/width and absorption area. According to the regression curves, the current study recommends using the dietary C-NP with optimum values of 45–55 mg/kg diet to improve the performance, digestive enzymes, antioxidant activities, and immunity response of Nile tilapia.

years (FAO, 2016). In the year 2012, it was estimated that 24.3 million tons of aquaculture species which fed commercially manufactured aquaculture feed. Aquaculture feed production has been growing at an average year rate of 10.3% since year 2000 and there is and expected consumption of aquaculture diets of 65.4 million tons by 2020 and 87.1 million tons by 2025 (Tacon and Metian, 2015). The probiotics represent a new era in aquaculture and both commercial and scientific interest in this topic is increasing. Indeed, probiotics are commonly used as therapeutic and prophylactic supplements (Nayak, 2010; Hoseinifar et al., 2014). Probiotics when administered in suitable amounts; give benefits to the health of the animal by improving the balance of the microbiota in the intestine (Verschuere et al., 2000). Probiotics are becoming an internal part of aquaculture practices to obtain high production. Probiotics offer benefits with regard to improving immune status and fish production (Cerezuela et al., 2011). The addition of prebiotics to diets has been applied in aquaculture practices and it plays a role in promoting growth, digestive enzyme activity, immune responses and the composition of beneficial bacteria in the fish digestive tract (Zhou et al., 2010; Soleimani et al., 2012; Zhang et al., 2012; Akrami et al., 2013). Prebiotics and probiotics demonstrated positively modulate the intestinal microflora and could improve fish health. The use of these products in aquaculture is widely accepted. However, some results on their efficiency from a few studies have been conflicting (Gatesoupe, 2005; Grimoud et al., 2010). Supplementation with enzymes is effective to eliminate the anti-nutritional factors and improve the utilization of feeds energy and amino acids, resulting in improved fish growth performance (Lin et al., 2007) and the intestinal health (Castillo and Gatlin, 2015). Exogenous proteases may compensate for the deficiency of endogenous enzymes and help in the breakdown of proteins improving digestibility (Shi et al., 2016) and carbohydrates are used to help in the breakdown of hemicelluloses which are part of the cell wall (Ebringerová, 2005). Enzyme can improve nitrogen and amino acid utilization by increasing the access to proteins for digestive proteases (Tahir et al., 2008) and the addition of beta mannanase decreases the immune related signal caused by beta mannans (Arsenault et al., 2017). Proteases are primary enzymes which have been isolated from various parts of Nile tilapia digestive tract (Tengjaroenkul et al., 2000; Hinsui et al., 2006). On the other hand variations in the quality and quantity of nutrients used in diets may modify enzymatic profile and activity in the animal's digestive tract (Lundstedt et al., 2004). Thus, feed composition might induce biological adaptations, including an increase in nutrient absorption (Moraes and Bidinotto, 2000). Digestive enzymes have been investigated to understanding nutritional requirements and the effects of feed composition on enzyme activity in order to ...

The aim of this study was to evaluate the effect of total ammonia (TAN) on growth, survivability, some blood biochemistry and histological evaluation of the kidney, liver, skin and muscles of red tilapia fingerlings for 56 days. A total of 180 fish were held at a rate of 10 fish fiberglass -1 tank with capacity of 100 liters welled water (salinity 27.3 ppt). Treatments of 0.1, 0.9, 1.8, 2.9 and 3.5 mgL -1 of TAN were carried out in this study. Fish fed pellets containing 34.7% crude protein. The results showed that fish exposed to 3.5 mg TAN L -1 recorded the lowest final body weight and survival rate, these results inversely related with increasing TAN levels. Fish subjected to treatment of 3.5 mg TAN L -1 achieved the highest values of serum urea, uric acid and creatinine. The histological investigation of kidney, liver and skin of fish exposed to 3.5 mg TAN L -1 showed severe damages in renal tubules, large amount of hemorrhage between renal tubules, vacuolation in hepatic cytoplasm, hepatic congestion, hepatic necrosis, laceration of skin, inflammation in muscle fibers and splitting of large muscle fibers. Based on the results of the present study, it is recommended that increased levels of ammonia should be avoided and eliminating the causes in aquaculture ponds in order to obtain the highest production performance and increase survival rates and maintain fish health and vitality.

This study was conducted to investigate the effects of replacing commercial feed with vinegar-immersed poultry viscera on growth performance, physiological status and bacterial load of the catfish, Clarias gariepinus. Fish were fed on a commercial diet (T1), poultry viscera (T2) and poultry viscera immersed in commercial vinegar (T3). Catfish with an average body weight of 520g were stocked in circular fiberglass tanks each of 2 m 3 water volume for 98 days. Water quality parameters, growth performance, feed utilization, flesh composition, serum analysis and bacterial load of feed, water and fish, were measured. Ammonia content in rearing water decreased significantly in T3 compared to T2. There were not any significant differences detected (P>0.05) in survival and growth performance, while significant (P≤0.05) differences in feed utilization and wholebody composition were detected among treatments. The quality indices of fish in terms of flesh composition were in favor of T3. A decrease in the serum's total protein and albumin and an increase in the serum's globulin and cholesterol levels were observed when fish was fed on poultry viscera only. Pathogenic bacterial load in feed, rearing water and fish intestine were at their lowest limit in T3. This study shows that C. gariepinus can feed on poultry viscera immersed in commercial vinegar as an alternative feedstuff source to commercial high-priced feed. The ecological impacts of treating environmentally hazardous by-products, like poultry viscera and converting it to a high value by-product are a matter of interest for both aquaculurists and environmentalists alike. More research work is needed to take advantage of the current results in a commercially applicable scale. Egyptians dating back to ancient times consider catfish one of the most favorite fish types. Many images of Catfish appeared on the walls of ancient Pharaonic temples. In 2015, the total catfish production in Egypt was 37,914 tons/year, of which 7,455 tons/year were obtained from aquaculture (GAFRD, 2015). African Catfish require about 40% CP in their diet and the best results have been achieved with crude protein value ranging from 35 to 50% for all African Catfish species (Adebayo and Quadri, 2005). Nutrition is one of the most important factors in fish farming because it contributes to up to 50% of fish production costs (Omoruwou and Edema, 2011). Feeding is one of the major constraints facing aquaculture. The importance of fish meals in the production of animal feeds cannot be disputed, but forms the highest cost and therefore raises the price of the feed exponentially (Olaniyi and Salau, 2013). The feeding can be harmful to the fish's health and may cause a remarkable drop in water quality, reduce growth, decrease feed utilization and increase susceptibility to infection (Priestley et al., 2006). Therefore, there is the need to balance between rapid fish growth and the optimum use of the supplemented feed in order to be economically viable and for the fish to be in good health (Wuraola1 and ...