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This study was conducted to determine the effect of replacing fishmeal (FM) with fermented soybean meal (FSBM) for 12 weeks on the growth performance, feed utilization, immunological parameters, antioxidant enzymes assays and lipid peroxidation, digestive enzymes, and histopathological analysis of juvenile Litopeneaus vannamei (L. vannamei). By substituting 0.0%, 20%, 30%, and 40% FSBM for fishmeal (w/w), four isonitrogenous diets were generated. A total of 300 juvenile L. vannamei(1.59 ±0.01 g) were randomly allocated to the experimental fiber tanks at a rate of fifteen shrimp per tank, with three replicates for each treatment. Growth performance and feed utilization decline considerably (P < 0.05) with increasing amounts of FM replacement with FSBM in diets. In comparison to the juveniles fed the other experimental diets, the diet containing a moderate level of FM replacement (20% FSBM) considerably enhanced growth performance and feed consumption during the feeding trial. The 20% FSBM-fed group had the highest protein content. In contrast, raising FSBM levels significantly increased lipid content (P < 0.05) compared to the control. However, there were no statistically significant differences (P> 0.05) across FSBM treatments. Hemolymph plasma total protein (TP) concentration and lysozyme activity were substantially greater (P < 0.05) in 20% FSBM compared to 40% FSBM (P < 0.05). In addition, 20% FSBM exhibits a substantial (P < 0.05) increase in the activity of antioxidant enzymes (CAT SOD, GPX, and GR). In contrast, the control and 30% FSBM groups had considerably more lipid peroxidation marker (MDA) than the 20% and 40% FSBM groups. Hepatopancreas amylase activity was considerably elevated (P < 0.05) in the control group and with 40% FSBM. In addition, Hepatopancreas and intestinal protease and lipase activity increased significantly by 20% FSBM. Considerably more B-cells were present in the 40% FSBM diet than in the control diet, however they were significantly less prevalent in the 20% and 30% FSBM of diets (P < 0.05).

In the current study, white-leg shrimp (Litopenaeus vannamei) were fed on diets containing varying doses of Withania somnifera aqueous extract (WSAE) at a rate of 0 (control), 0.5, 1.0, and 2.0 g/kg feed for 56 days. After the feeding trial, shrimps in all groups were challenged with the exposure to Vibrio harveyi for ten days during which animals' mortality was observed. It is noted that the dietary WSAE linearly and quadratically stimulated shrimp's growth indices particularly at the treatment of 2.0 g/kg feed. Compared to the control group, the WSAE-fed L. vannamei had significantly higher villi length, villi width, and absorption area particularly in the treatment of 2.0 g/kg feed. Furthermore, L. vannamei fed on WSAE-enriched diets consumed more feed and exhibited higher total proteolytic activity, lipase, and α-amylase activities as compared with the control group. The dietary WSAE at escalating levels linearly and quadratically enhanced the antioxidant activity (serum superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total antioxidant capacity, and reduced glutathione) and the immune response (total hemocyte counts, total protein, lysozyme, and phagocytic activity). Similarly, the mRNA expression levels of cMn-SOD, CAT, and GPx genes were linearly and quadratically upregulated in the hepatopancreas of L. vannamei fed on WSAE-enriched diets (especially in the 2.0 g/kg feed treatment), while their lowest levels were significantly observed in the control group. On the other hand, malondialdehyde levels were significantly decreased in WSAE-supplemented shrimp groups, and its highest levels were observed in animals fed on the control diet. After the bacterial exposure, the survival rates of L. vannamei fed on 1.0 and 2.0 g WSAE/kg feed (61.3% and 66.7%, respectively) were higher than those in the control animals. Taken together, the results obtained herein indicate that inclusion of WSAE in diets of L. vannamei effectively enhanced the growth, antioxidant biomarkers, immune response, and resistance to the V. harveyi infection, particularly at the treatment of 2.0 g/kg feed.

In this study, Nile tilapia fingerlings with average body weight (8.6 ± 0.06 g) were exposed to zinc (Zn) toxicity and tested its amelioration with miswak (Salvadora persica L.) (SP) supplemented diet. Five fish groups were fed on diets with SP at 0, 0.25, 0.5, 1.0, and 2.0% (T1, T2, T3, T4, and T5, respectively) diet without Zn exposure, while another five groups were exposed to Zn at 7 mg/L and co-supplemented with SP at 0, 0.25, 0.5, 1.0, and 2.0 % (T6, T7, T8, T9, and T10, respectively). After 12 weeks, fish-fed 1.0% SP diet (T4) achieved the highest growth and feed performances, while the lowest one was in Zn-exposed fish (T6) (P < 0.05). T6 and T7 groups showed the most inferior carcass protein and ash contents, while T4 and T5 showed the highest lipid content (P < 0.05). The level of Zn residue increased in fish exposed to Zn (P < 0.05). Fish exposed to Zn and fed SP showed high blood urea, catalase, ALT, AST, and total superoxide dismutase (T-SOD), while the malondialdehyde (MDA) was decreased (P < 0.05). Interestingly, miswak resulted in elevated catalase and T-SOD and reduced MDA in fish without Zn exposure (P < 0.05). Zn exposure causes abnormal histopathological characteristics in gills, hepatopancreas, posterior kidney, and musculature tissues of tilapia, while fish-fed SP showed regular, healthy, and protected histopathological characters. The results suggested that SP can induce the antioxidant responses that prepare Nile tilapia for a further suppressive oxidative condition (i.e., Zn exposure).

This study evaluated the effectiveness of dietary Ziziphus mauritiana leaf powder (ZLP) to control Aeromonas hydrophila infection in Nile tilapia and reduce damage to vital immune organs. Four experimental groups were fed a diet supplemented with ZLP at concentrations of 0, 5, 10, and 20 g/kg (w/w) for 6 weeks. At the end of the feeding trial, all groups were intraperitoneally injected with pathogenic A. hydrophila. It was found that Z. mauritiana significantly (P

Astudy was undertaken to determine the effect of the dietary lipid levels on growth performance , feed utilization and body composition of Nile tilapia larvae. Four isonitrogenous diets (40% crude protein) and dietary lipid levels (4, 6, 8 and 10% DM) were fed to satiation Nile tilapia larvae for 9 weeks. The best survival, weight gain, specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR) and feed efficiency were observed for larvae fed 8% lipid level. While the poorest survival, specific growth rate (SGR), protein efficiency ratio (PER), lowest weight gain, specific growth rate (SGR), feed efficiency and highest feed conversion ratio (FCR), were observed with larvae fed 4% lipid level. The lipid content of fish were positively correlated with dietary lipid level. The body protein content increased with increasing the protein levels in the diet. It could be concluded that the requirement of lipid for Nile tilapia fry was 8% lipid under the present experimental condition.

The present study was carried out to study the possibility of early weaning of gilthead sea bream (Sparus aurata) larvae. Therefore seabream larvae divided into different groups and weaned at 35, 40, 45, 50, 55and 60 days post hatching (dph). At the end of the experiment the mean wet weight and length of gilthead seabream were recorded for larvae. Showed that, the late weaning (50, 55 or 60 dph) significantly increased the wet weight and length of larvae compared to larvae groups that early weaned (35 and 40 dph) and the same trend was also observed for larvae after 60 dph. During the entire experimental period the highest SGR values were recorded for groups 60 and 55 dph (3.75 and 3.19), while the lowest SGR recorded for group 35 dph (1.59) indicating that, the late weaning age released the best SGR was compared to the early weaning of gilthead seabream larvae . The obtained results indicated that the late weaning of larvae (60 dph) significantly increased each of protein and fat content of larvae when compared to the early weaning of larvae (35 dph). In conclusion, it can be concluded that, the early weaning could not only improve the growth performance, but also keep the survival rate within the same limits for the original late weaning age.

This study evaluated the effectiveness of dietary Ziziphus mauritiana leaf powder (ZLP) to control Aeromonas hydrophila infection in Nile tilapia and reduce damage to vital immune organs. Four experimental groups were fed a diet supplemented with ZLP at concentrations of 0, 5, 10, and 20 g/kg (w/w) for 6 weeks. At the end of the feeding trial, all groups were intraperitoneally injected with pathogenic A. hydrophila. It was found that Z. mauritiana significantly (P 0.05) upregulated (lysozyme, interleukin 1 beta) and superoxide dismutase gene expressions as well as improved the activity of serum lysozyme and liver antioxidant enzymes. The fish that were fed a ZLP-supplemented diet also exhibited significantly higher survival rates after A. hydrophila challenge than those that were fed a ZLP-free diet (P 0.05). Supplementation of 10 g/kg ZLP most effectively reduced the histopathological alterations caused by A. hydrophila challenge in the liver, spleen, kidney, and muscle of the fish. In conclusion, ZLP can be effective in controlling A. hydrophila infection in Nile tilapia (particularly at a concentration of 10 g/kg) through enhancement of its immune and antioxidant status.

Currently, the use of phytogenic additives and nanoparticles formulation in fish diets raises great worldwide interest. However, studies on the outcomes of their combination in farmed fish feeding are scarce. Hence, an experiment was planned to examine the effect of chitosan nanoparticle (ChNP), thymol (THY) or their mixture (THY + ChNP) supplementation on growth, whole-body composition, hematological profile, biochemical parameters, intestinal bacterial count, digestive enzymes, and intestinal histomorphology of Oreochromis niloticus. Fish (4.97 ± 0.02 g) were randomly distributed into 4 different treatments. The control group was fed a basal diet, while the other three groups were fed diets supplemented with THY (0.5 g/kg diet), ChNP (5 g/kg diet), and THY + ChNP at the same levels. Results showed that interaction synergistic effect was apparent between the supplemented THY and ChNP on the enhancement of feed and protein utilization, lymphocyte count, HCT, MCV, and MCHC values together with catalase, lipase, and protease activities. The individual THYor ChNP addition to the fish diet significantly improved growth performance indicators, feed utilization, erythrogram profile, oxidative stress parameters, lipase enzyme activity, and lipid sedimentation. Intestinal villus length was significantly increased in ChNP and THY + ChNP supplemented groups. A significant drop of the total anaerobic and aerobic intestinal bacterial count was apparent in THY and ChNP supplemented groups. Conclusively, although the individual addition THY or ChNP improved growth and some health indications, a notable synergistic interaction was obvious following their co-addition in most indicators.

An experiment was conducted to evaluate the effect of dietary cinnamon nanoparticles (CNP) on the growth performance, antioxidant and digestive enzymes activities, and innate immunity of Nile tilapia, Oreochromis niloticus (L.). Fish (9.7 ± 0.3 g) were fed on diets enriched with 0.0, 0.25, 0.5, 1.0, 3.0, 5.0, and 10.0 g CNP/kg diet for 8 weeks. After the feeding trial, fish were challenged against hypoxia stress or pathogenic bacteria (Aeromonas hydrophila) infection. Fish performance was significantly improved with increasing CNP levels over the control diet. Furthermore, only crude protein contents in whole-fish body were significantly higher in CNP-fed fish than those fed the control diet. Antioxidant-stimulated activity was observed with dietary CNP where malondialdehyde (MDA) level and activities of superoxide dismutase (SOD) and catalase (CAT) increased significantly, whereas glutathione peroxidase (GPx) activity decreased significantly in CNP-fed fish. Likewise, CNP supplementation induced the secretion of protease, lipase, and amylase, which were maximized at 3.0–10.0 g CNP/kg diet. All innate immunity variables i.e. nitrous oxide (NO), nitro blue tetrazolium (NBT), and lysozyme activity were significantly higher in CNP-fed fish than the control one. No fish mortality was observed during hypoxia stress among all treatments, but CNP administration protected the fish against A. hydrophila infection. No mortality was observed in fish fed 3.0–10.0 g CNP/kg diet after bacterial challenge; meanwhile the mortality of fish fed the control diet was 66.7%. This study evoked that dietary CNP enhanced the performance, antioxidant and digestive enzymes activity, and innate immunity of Nile tilapia and its optimum level is 3.0 g CNP/kg diet.

The present study was conducted to investigate the effects of Ziziphus mauritiana leaf powder (ZLP) on growth performance, intestinal histomorphology and growth-related gene expression of Nile tilapia (Oreochromis niloticus). ZLP was incorporated into the basal diet at 5, 10 and 20 g per kg diets (w/w) and fed to fish for 12 weeks. The obtained results revealed significantly (P

Acidifiers could be used as feed additives to stimulant performance, health, and immunity of fish fed plant-based diets. In the present study, sodium butyrate (SB) was incorporated in practical diets for Nile tilapia, Oreochromis niloticus (L.) to alleviate the adverse effects of high contents of plant ingredients in fish diets. However, Gustor BP-70 (Norel Misr), which is a protected SB (70%) coated with 30% of vegetable fat, was incorporated in a practical fish diet at levels of 0.0, 2.5, 5.0, 7.5, and 10.0 g/kg diet. Fish (5.4 ± 0.5 g) were fed the tested diets manually up to apparent satiation twice a day for 90 days in quadruplicates. At the end of the feeding trial, fish were intraperitoneally injected by pathogenic bacteria, Aeromonas hydrophila and kept under observation for 10 days to record any irregular clinical signs and daily fish mortality. Dietary SB showed stimulating-effects on fish growth, feed utilization, and innate immunity of Nile tilapia. Likewise, activities of serum lysozyme and respiratory burst as well as bactericidal and agglutination activities were significantly improved due to dietary SB supplementation in a dose-dependent trend. After A. hydrophila infection, no fish mortality was detected in fish fed 7.5–10.0 g SB/kg diet, whereas fish fed the control diet showed highest mortality (85.0%). Based on the regression curve, it could recommend the use of 6.25 g SB/kg diet as a feed supplement for Nile tilapia to enhance its performance, immunity, and resistance against the possible infection by pathogenic bacteria A. hydrophila.

Aims The aim of this study was to determine the effect of phenolic compounds of Roselle calyx (Hibiscus sabdariffa Linn) on growth performance, feed utilization, whole-body composition, blood profile, and immunity against Aeromonas hydrophila in Nile tilapia, Oreochromis niloticus. Background H. sabdariffa extracts have demonstrated to have a broad range of therapeutic effects such as antioxidant, antiobesity, anticancer, inhibition of the contractility of rat bladder and uterus, antibacterial, antihypertensive, and antimicrobial activities due to the presence of phenolic compounds. Materials and methods Fifteen fish with the same initial weight (5.45 ± 0.01 g/fish) were selected and randomly distributed into four experimental treatments in triplicates. The chemical profiles of phenolic constituents were analyzed using high-performance liquid chromatography to determine the major phenolic compounds. Results and discussion The diet containing 1% Roselle calyx showed the highest growth performance and feed utilization in comparison with other dietary treatments. The main phenolic compounds were ferulic acid, rosmarinic acid, apigenin, carnosic acid, cinnamic acid, caffeic acid, chlorogenic acid, p-Coumaric acid, and quercetin-7-O-glucoside, in addition to anthocyanins such as delphinidin-3-glucoside, sambubioside, cyanidin-3-monoglucoside, and cyanidin-3-sambubioside. Conclusion Roselle calyx was found to have an antibacterial activity antagonistic to pathogenic A. hydrophila infection in fish. Lysozyme and bactericidal activities of fish increased significantly in fish fed on Roselle calyx-enriched diets.