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Chlorella vulgaris (CV) has been investigated in aquaculture and shown as a potential functional feed additive. Therefore, this study tested the effects of dietary CV and Saccharomyces cerevisiae (SC) on the growth performance, blood biomarkers, and antioxidative capacity of common carp (Cyprinus carpio). Fish were allocated in four groups in triplicates, where each glass aquaria was stocked with 15 fish with 4.25±0.11 g/fish. Fish offered four test diets for 84 days: control (free from CV or/and SC), CV-supplemented diet (5 %), SC-supplemented diet (0.05 %; (10 × 109 CFU/g), and a mixture of CV and SC-supplemented diet (5 % CV+ 0.05 % SC), respectively. The results indicated that fish-fed CV or SC revealed enhanced growth performance (final weight, weight gain, and specific growth rate) and protein efficiency ratio, while the feed conversion ratio was reduced compared to the control. Fish-fed dietary SC or CV and SC mixture revealed higher villi length than the control. Besides, villi width and muscular thickness enhanced significantly in carps-fed CV and SC compared to the control. Fish-fed dietary CV and/or SC revealed lower moisture content and higher crude protein and total lipids than the control. The results indicated that fish-fed CV or SC revealed higher serum total protein than the control. On the other hand, the total cholesterol and triglyceride levels were markedly reduced in carps-fed dietary CV and/or SC compared to the control. The results indicated that fish-fed CV and/or SC revealed higher lysozyme activity, catalase, and glutathione peroxidase than the control. The superoxide dismutase of fish-fed CV or SC is higher than that of the control or CV and SC mixture. Additionally, the malondialdehyde levels (MDA) were markedly reduced in carp-fed dietary CV and/or SC compared to the control group. In conclusion, dietary C. vulgaris and/or S. cerevisiae can enhance growth performance and feed utilization in common carp. Besides, the biochemical blood markers and activated antioxidative capacity indicated that common carp fed C. vulgaris and/or S. cerevisiae revealed stable health status.

Fermented Spirulina platensis (FS) has recently attained attraction in human food due to its high functionality and rich content of bioactive compounds. Therefore, the current study investigated the potential roles of dietary FS on the growth performance, digestion capacity, antioxidative status, and immune response of Nile tilapia. Dietary FS at 0, 0.5, 1, 2, 4, and 8 g/kg were fed to Nile tilapia for 60 days. All formulated diets were isonitrogenous and isocaloric with 30.48 % crude protein and 6.63 % total lipids, respectively. The results indicated that the final weight (FW, P=0.004), weight gain (P=0.023), and specific growth rate (SGR, P=0.021) were influenced by dietary FS in a significant quadratic manner. Accordingly, the regression analysis revealed that the suggested doses of FS supplementation in Nile tilapia diets to show the highest FW and SGR are 4.26 and 3.98 g/kg, respectively. Furthermore, dietary FS enhanced the amylase (P=0.035) and lipase (P=0.004) activities in a quadratic manner. The elevated doses of dietary FS instigated prominent improvement of the villous height and goblet cell and increased branching of intestinal villi in the middle segments, particularly in fish fed 4 and 8 g/kg. The red blood cells (P=0.009), hemoglobulin (P=0.004), hematocrit (P=0.034), and white blood cells (P=0.014) were increased significantly with dietary FS in a quadratic manner. No marked effects were seen on the alanine transaminase, aspartate aminotransferase, urea, creatinine, total cholesterol, and triglycerides. Meanwhile, the total protein (P=0.039), albumin (P=0.021), and globulin (P=0.002) were increased significantly by dietary FS in a quadratic manner. The superoxide dismutase (P=0.005) and catalase (P=0.022) were increased, while malondialdehyde level (P=0.028) was decreased significantly with dietary FS in a quadratic manner. The lysozyme activity was higher in fish-fed FS at 0.5, 1, 2, 4, and 8 g/kg than in fish-fed FS at 0 g/kg. The phagocytic activity was higher in fish-fed FS at 2 and 4 g/kg than in fish-fed FS at 0, 0.5, and 8 g/kg without significant differences with fish-fed FS at 1 g/kg (P˃0.05). The regression analysis revealed that the suggested doses of FS supplementation in Nile tilapia diets to show the highest lysozyme activity and catalase activity are 3.52 and 3.79 g/kg, respectively. In conclusion, dietary FS enhanced growth performance, feed utilization, digestive enzyme activity, blood health, immunity, and antioxidative response. Overall, dietary FS can be added at 3.52–4.26 g/kg to enhance the productivity and well-being of Nile tilapia.

Betaine is one of the most widely used attractants in feed formulations. Its dietary inclusion in aquafeeds positively influences several growth performance metrics and feed utilization of aquatic animals. In this study, a meta-analysis was conducted to quantify the effects of dietary supplementation of betaine on the specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and survival (SUR) of several aquaculture species reared under different environmental conditions. Standardized mean differences (Hedge’s g) were computed to quantify the primary outcomes. Likewise, the influence of several moderators such as aquaculture species, feeding behavior, experimental duration, and percentage of betaine supplementation in aquafeeds on Hedge’s g effect sizes for SGR, FCR, PER, and SUR was determined by a mixed-effects model. The results indicated improved SGR, FCR, and PER in both carnivorous and omnivorous/herbivorous species fed on betaine-supplemented diets relative to the control. Although SUR was higher in control groups relative to the betaine-supplemented groups, no significant differences were noted. Higher values for betaine inclusion level tended to lower SUR whereas lower values improved the SUR. Furthermore, longer experimental durations exhibited higher values for SUR compared to shorter experimental durations. The dietary betaine requirement of aquaculture animals was estimated to be 0.99 % based on broken-line regression between the betaine inclusion level in aquafeed and SGR effect sizes.

Moringa oleifera is well known as a highly nutritious plant and a water purifier in fish culture. Tilapia fish has many impressive qualities making them very suitable for aquaculture. Therefore, this study aimed to evaluate the effect of supplementation of Moringa oleifera aqueous extract (MOAE) at varying concentrations (0, 100, 200, and 400 mg/kg diet for 90 days) on growth performance, hematological, and some biochemical parameters of Nile tilapia. Additionally, histological changes and immunohistochemical expression of caspase 3 in gills and livers were evaluated. Significant enhancements (P

Impairment of fish growth and immune system due to stress and disease are major constraints in aquaculture industry. Traditionally, antibiotic was used as prophylactic agent in the health management of aquaculture species. However, antibiotic only provide a temporary solution to the problem of disease outbreak. Over-reliance on antibiotic also has led to the increasing cases of antibiotic resistance among pathogenic bacteria from aquaculture sites and contamination of antibiotic residues into human food chain. Probiotic, prebiotic and symbiotic are therefore suggested as alternatives to prophylactic antibiotic to be used in the aquaculture industry. A potential prophylactic agent is polysaccharide that could be developed into an alternative antibiotic for aquatic animals. In this review paper, definition, sources, and mode of action of polysaccharide are presented. The roles of polysaccharides in fish farming with emphasis on growth improvement, immune system enhancement, disease resistance stimulation in tilapia farming, and the effects of polysaccharides on abiotic stressors are summarized and discussed.

Papaya is a sparsely branched tree and grows in many tropical and subtropical areas. Herein, this study compared the effects of papaya at 0.75 % as seeds meal (PSM), leaves meal (PLM), latex powder (PLP), or a mixture of them (PMIX) on the performances of Japanese quails. Two hundred unsexed Japanese quail (1st week-old) with an initial body weight of 21.08 ± 0.32 g were allocated into five experimental groups in cages with free access to water and test diets. Birds fed diets enriched with PSM, PLM, PLP, or PMIX for 55 weeks. The results showed that quail groups fed on papaya diets exhibited improved (P

ABSTRACT: The current study aimed to determine the effects of different levels of fermented Juncao grass (FG) on growth parameters, blood constituents, immunity, and antioxidative properties of broilers. A total of 240 (21-d-old) broiler chicks were randomly distributed to four dietary treatments of sixty birds, with six replicate pens and ten birds in each. Fermented grass was added to the basal diet at four levels with 0, 5, 10, and 15% FG. The results revealed that broilers fed 5% FG had significantly higher (P < 0.05) final body weight (FBW), average daily gain (WG) and average daily feed intake (ADFI). The best conversion ratio (FCR) was recorded for broilers supplemented with 5% FG compared to the group supplemented with 15% FG (P < 0.05). Increasing FG % decreased (P < 0.05) anti-inflammatory cytokines IL-4, IL-6, and IL-10. However, FG increased (P < 0.05) proinflammatory cytokines IFN-γ, IL-1, IL-2, IL-12, and TNF-α (P < 0.05). Moreover, IgA, IgG, and IgM levels increased (P < 0.05) with increasing FG %. In addition, increasing FG % in broiler rations significantly increased (P < 0.05) serum antioxidant levels of T-AOC, GSH-PX, SOD, CAT, NO and GSH, but decreased (P < 0.05) MDA levels compared to the control group. Conclusively, fermented Juncao grass would be considered a novel herbal feed additive for improving broiler performance, immunity, antioxidant, and health status. Nevertheless, further research at the molecular level is needed to quantify the effects of these herbal components on cellular and humoral immune functions in broiler chickens.

Unstable outdoor farming conditions weaken fish's health status and immunity, leading to high susceptibility to infectious diseases and low productivity. Feed additives have been applied recently to enhance the growth performance and well-being of striped catfish. This study evaluated the effects of ginger (Zingiber officinale) on the growth performance, digestive enzyme activity, antioxidative response, and antibacterial capacity of striped catfish. Control and three test diets were supplemented with ginger rhizomes powder at 0.5 %, 1 %, and 1.5 %. After 90 days, the growth performance of striped catfish fed dietary ginger was marginally increased, with the highest being in the group receiving 1 % (p

The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector. However, the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to cost and sustainability issues remains a major challenge. Recently, insects have shown tremendous results as potential replacers of fishmeal in aquafeed. The present study aimed to review the utilization of insects in aquafeeds and their effects on aquatic animals' growth and feed utilization, immune response and disease resistance, and fish flesh quality and safety. While many insect species have been investigated in aquaculture, the black soldier fly (Hermetia illucens), and the mealworm (Tenebrio molitor) are the most studied and most promising insects to replace fishmeal in aquafeed. Generally, insect rearing conditions and biomass processing methods may affect the product's nutritional composition, digestibility, shelf life and required insect inclusion level by aquatic animals. Also, insect-recommended inclusion levels for aquatic animals vary depending on the insect species used, biomass processing method, and test organism. Overall, while an appropriate inclusion level of insects in aquafeed provides several nutritional and health benefits to aquatic animals, more studies are needed to establish optimum requirements levels for different aquaculture species at different stages of development and under different culture systems.

The aquaculture industry is expanding to meet the daily requirements of humanity from high-quality seafood. In this regard, intensive aquaculture systems are suggested, resulting in high production but being challenged with immunosuppression and disease invaders. Antibiotics were used for a long time to protect and treat aquatic animals; however, continuous use led to severe food safety issues, reducing the natural immunity response and high resistance to harmful bacterial strains. Therefore, natural functional additives were introduced to reduce or even replace chemotherapies. More specifically, marine-derived substances showed effective immunostimulant and antioxidative roles when introduced to aquatic animals. Bioactive molecules derived from algae, crustaceans, and fish, including astaxanthin, carotenoids, chitosan, fucoidan, lectins, and polyunsaturated fatty acids (PUFAs), are the most applied additives in aquaculture. In addition, marine-derived biomolecules were introduced to several other sectors, such as nutraceuticals, pharmaceuticals, cosmetics, and agriculture. Marine-derived substances are lipid-soluble biomolecules known for their ability to cross the cellular membranes, thereby causing pigmentation roles. Consequently, marine-derived biomolecules are involved in antioxidative and immune activation effects and, thereby, high performances and productivity of aquatic animals. In the literature, there are available knowledge about the possibility of using marine-derived biomolecules in aquaculture. This article presents information about the sources, mode of action, and effects of marine-derived biomolecules on aquatic animals to fortify the scientific community with enough details about friendly natural substances for sustainable aquaculture.

Sodium butyrate (SB) is an active organic acid usually applied in aquaculture. Hence, the effects of SB were investigated on the growth performance, digestive enzyme activity, and blood biochemistry of Thinlip Grey Mullet (Liza ramada) in this study. Five test diets with an average protein level of 30.33 % and energy of 18.22 MJ/kg were formulated to include SB supplementation at 0, 0.5, 1, 2, and 4 g/kg. In 15 enclosures (0.5 ×0.5 ×1 m), 225 fish were divided equally, where each hapa was stocked with 15 fish with an average weight of 7.79 ± 0.04 g/fish. Every three hapas represented one experimental group (triplicates). Fish were kept under average water temperature (25.12 ± 0.33 °C), salinity (11.46 ppt), and total ammonia (0.16 ± 0.01 mg/L) during the trial. The enclosures were fixed in a concrete tank with running water in a flow-through system, and fish were fed the control diet at 3 % of the body weight twice daily (08:00 and 15:00) for 60 days. At the end of the trial, all fish were fasted for 24 h, weighed and counted, then blood samples collected, and intestines and livers were dissected. The results revealed that fish-fed SB had higher growth performance, feed intake, protein efficiency ratio, and protein productive value than fish-fed SB-free diet (P

Population genetic data collected from variable regions in human genome have been extensively used for studying human origins and migration patterns, estimating the probative value of DNA evidence and in disease association studies. Here, we illustrate the value of population genetic data in the genomic era with an emphasis on their role in health science and practice. This commentary is intended to show the value of an ethnicity-based approach to medicine and the role of genetics via accumulated population genetic data as its rational support basis. For this specific reason, we feel that new genome-based knowledge and resources need to be disseminated urgently to health professionals, researchers, policy makers and the public, so that it may be fully integrated into health-related policy and decision making. Ideally, all population genetic databases should be freely accessible, but this creates several technical issues which need to be properly considered. Those highlighted here include such as factors sample size, marker type, population descriptions and genotyping coverage.

Adding medicinal herbs to aquafeed is recommended for feasible aquaculture activity. This study tested for 90 days the effect of dietary sage (Salvia officinalis L.) on the growth performance, feed efficacy, blood indices, non-specific immunity, and intestinal microbiota of European sea bass (Dicentrarchus labrax; n = 300 fish). Fish with an initial weight of 12 ± 0.1 g/fish were distributed in five treatments and fed sage at 0, 2, 4, 6, and 8 g/kg. Dietary sage at 2 g/kg diet improved the growth, feed consumption, and growth hormone secretion in European sea bass. The blood parameters in European sea bass fed on experimental diets showed normal levels for healthy fish. Significantly higher lysozyme and phagocytic activities were recorded with sage supplement at the 4 g/kg diet compared to other groups. Regarding overall bacterial count, fish given a sage-free diet (the control) showed more significant microbiota numbers, Vibrio, Escherichia coli, and acid-fermentative bacteria. Remarkably, fish fed on diets fortified with sage displayed lower records of the total bacterial count, Vibrio, and Escherichia coli than the control. Moreover, fish fed a diet enriched with high levels of sage (6 or 8 g/kg) showed increased acid-fermentative bacteria. The regression analysis showed that the optimum quantity of sage at 3.6 – 4.1 g/kg diet is recommended based on the weight gain, specific growth rate (SGR), phagocytic activity, feed conversion ratio (FCR), and lysozyme activity. In conclusion, the dietary incorporation of sage (2 – 4 g/ kg diet) enhanced growth, feed efficacy, blood indices, non-specific immune responses, and sustained healthier gut flora in European sea bass.

A 30-day feeding trial was performed to assess the potential of the dietary supplementation of Coenzyme Q10 (CoQ10) and lipoic acid on acclimatized European seabass larvae with a preliminary weight and length of 2.7 mg and 12.42 mm (25 dph = days post-hatching). Seven experimental groups were fed on the basal micro-diet (56 % crude protein and 13 % crude lipid) without any supplement in the control group or with the addition of CoQ10 at levels of 5, 10, and 15 mg/kg or α-lipoic acid at levels of 50, 100, and 150 mg/kg, respectively. Larvae fed on a diet enriched with CoQ10 at levels of 5 and 10 mg/kg showed the highest values for final weight, weight gain, specific growth rate (SGR), the protein efficiency ratio (PER), and the lowest value for feed conversion ratio (FCR) as well as no morphological or histological abnormalities. Also, the group fed a diet supplemented with CoQ10 at 5 mg/kg gave the highest values for final length and survival. The survival rate ranged from 54.59 % to 79.82 % and the lowest rate was in the group fed a diet enhanced with lipoic acid at 150 mg/kg. Meanwhile, the lowest records for final weight, weight gain, protein efficiency ratio, and the presence of morphological and histological abnormalities were in groups fed on the control diet and with high levels of lipoic acids (100 and 150 mg/kg). Moreover, all lipoic acid groups showed deleterious signs in the histological structure of the intestine and liver. However, significantly lower values of catalase (CAT) and glutathione peroxidase (GPx) were found in the fish group fed on the basal diet, while the peak values were in groups fed on diets fortified with CoQ10 at 5 and 10 mg/kg. In addition, larvae fed CoQ10 at levels of 5 or 10 mg/kg performed better in terms of CAT and GPx activities than that fed lipoic acid at levels of 100 or 150 mg/kg. Furthermore, the control group displayed lower levels of insulin-like growth factor 1 (IGF-1), CAT, and GPx -related gene expressions while considerable upregulations of IGF-1 and GPx were noted in larvae groups fed on diets improved with CoQ10 at levels of 5 or 10 mg/kg and lipoic acid at 50 mg/kg compared to the others. Also, upregulations in CAT were found with CoQ10 at levels of 5 or 10 mg/kg compared to their counterparts in the other groups. In conclusion, dietary CoQ10 at 5 or 10 mg/kg improves the performance and well-being of European seabass.

Abstract Salmonella is one of the most hazardous diseases in poultry farms. Markedly, the application of active immunostimulants is illustrated as potential protective agents against infection in poultry farms. Thus, this work aimed to explore inter‐ and intra‐breed variation in response to acute and subchronic Salmonella enteritidis infection in two‐layer breeds (one commercial [Hy‐line strain] and another native [Fayoumi breed]). Besides exploring the possible protective effect of a commercial immune modulator (STIMULAN) on the two breeds during the acute infection. The ELISA antibody titer in sub‐chronic infections and the expression analysis of some selected genes (IL‐1β, LITAF, TGF‐β, HSP90 and HSP70) are used as the clinical signs for acute infections to assess the possible protective role of a commercial immunomodulator (STIMULAN). Five groups were used during the acute experiment: G1—control; G2a—susceptible; G2b—resistant birds, G3—which received STIMULAN and G4—which received the infection + STIMULAN. The groups with sub‐chronic infections include G1 (control), G2 (high antibody titer) and G3 (low antibody titer). The gene expressions among the susceptible birds during acute infection of both breeds are nearly similar. They only differ in the expression of HSP90 in the Fayoumi breed. However, the resistant birds vary in their gene expression profile. The effect of STIMULAN as a feed additive in non‐infected birds was an up‐regulation of LITAF, TGF‐β, HSP90 in Fayoumi. Moreover, a powerful stimulatory role was observed when both breeds were infected. Both breeds were asymptomatic during the sub‐chronic infection. Although, the increased expression of inflammatory‐related genes in the Hy‐line was considered as an indication of infection persistence. Fayoumi is capable of immune clearance for this infection. Thus, the Fayoumi breed is more resistant to acute Salmonella infection. HSP90 plays a vital role in its resistance. We recommend the use of STIMULAN as an immunomodulator during Salmonella infection.

Protein ingredients in aquafeed are one of the most important factors responsible for the development and sustainability of aquaculture. Currently, because of high costs and fluctuating production, some animal and plant protein sources are unable to satiate the increasing demand from the fish feed manufacturers. Aquatic animals’ nutritional requirements have been accorded particular focus with less costly feedstuff in aqua feed given extra weightage. There has been increasing attention in recent years on finding methods to recycle the animal and plant by-products for feed preparation. Due to its vital amino acid content as well as high protein composition, palm date meal (PDM) which is a renewable and sustainable resource is expected to be a viable raw material option for replacing protein ingredients (e.g., fish meal and soybean meal) or as a supplement in fish feed. PDM is an agro-industry by-product which left from dates as waste in several countries. This article reviewed the current research including the source, derivatives, and the potential of PDM as a possible alternative to the conventional plant and animal protein sources. Also, the added value of using PDM waste in aquafeed to reduce the feed cost, enhance this e growth rate of fish, improve the health and well-being of fish, and subsequently sustain the aquaculture industry. Therefore, this review paper will illuminate the possibility of PDM as a promising feed source and also the present knowledge and future perspectives about the application of PDM in aquaculture.

Farmed fish and shrimp are continuously challenged by multiple stressors during their life stages, such as hypoxia, pH fluctuations, different salinities, high nitrite, un-ionized ammonia, injury during handling, inadequate nutrition, or food shortage, which can eventually adversely impact their health, welfare, and growth rates. Besides, these stressors can weaken production and decrease their resistance to diseases. Scientists and researchers have been making concerted efforts to find new, safe, and inexpensive supplements to mitigate the negative influences of stressors and thereby enhance the productivity of farmed aquatic animals. Some microalgae are microscopic unicellular organisms that were found to be promising feed supplements due to their richness in important nutrients such as minerals and vitamins. Moreover, some microalgae contain several bioactive phytochemicals that exhibit anti-inflammatory, antioxidant, and immunomodulatory properties. Several field-controlled studies provided evidence that using microalgae as feed supplements led to improved growth, physiological functions, immunity, antioxidant capacity, and disease resistance in farmed finfish and shellfish species. This review article emphasizes the beneficial role of the cyanobacterium Arthrospira platensis and seven microalgal species, including Chlorella vulgaris, Parietochloris incisa, Dunaliella salina, Aurantiochytrium sp., Haematococcus pluvialis, Tetraselmis sp., and Nannochloropsis oculata in mitigating stress effects in farmed finfish and shellfish species. The conclusions of this article throw light on the potential benefits of using microorganisms in aquaculture.

The present study was performed to examine the effects of aquatic fern (Azolla caroliniana) (AQF) on growth performance, skin mucus and serum immunities, and disease resistance of Nile tilapia reared in a biofloc system. Three hundred Nile tilapia fingerlings (average 10.48 ± 0.56 g fish-1) were distributed into 15 glass tanks (150 liters tank−1) at a concentration of 20 fish tank−1. A completely randomized design was used in triplicates, where the control group was fed 0 g kg−1 AQF (AQF1), while AQF2, AQF3, AQF4, and AQF5 were fed 25, 50, 100, and 200 g kg−1 AQF, respectively. Growth and immunological specimens were collected every 4 weeks, while disease resistance was conducted after 8 weeks post-feeding. The results showed that dietary administration of AQF significantly promoted the growth rate and feed efficiency of Nile tilapia, with the maximum level noticed in fish fed 100 g kg−1 AQF. However, no significant differences were observed between the AQF1 and AQF5 diets. Similarly, incorporation of AQF resulted in significantly higher skin mucus and serum immunities than the control, except for AQF5. The highest values were observed in fish fed the AQF5 diet. The challenge test showed that in contrast to the control (26.67%), the AQF administrated diets led to significantly higher survivability by 60% (AQF2), 66.67% (AQF3), 83.33% (AQF4), and 53.33 for AQF5. The relative percent survival (RPS) was 45.45%, 54.55%, 77.27%, and 36.36% in AQF2, AQF3, AQF4, and AQF5, respectively. The highest RPS against S. agalactiae was noted in the AQF4 diet. In conclusion, dietary supplementation of 100 g kg−1 AQF can be potentially used as a growth promoter and immunostimulant in Nile tilapia aquaculture.

The current work assessed the inclusion impacts of oilseed camelina meal (CM) as a protein source in red sea bream (Pagrus major) diets. A 45 day assessment period with 180 juveniles (6.47 ± 0.17 g) were allocated in triplicates to 4 experimental groups and fed formulated diets in which fish meal (FM) was subrogated at graded series of 0% (T1), 20.5% soybean meal (T2), 20.5% camelina meal (T3), and 33% camelina meal (T4). No noticeable alterations were observed in specific growth rate, feed intake, survival rate, hepatosomatic index, and Fulton's condition factor among the experimental groups. Fish fed the T4 diet showed considerably reduced (P 0.05) in glucose, total bilirubin, total protein, total cholesterol, triglyceride, glutamyl oxaloacetic transaminase, and glutamic pyruvate transaminase. Hematocrit levels decreased noticeably (P

Barberry fruit (BF) has a long history as a folk remedy due to its antimicrobial, anti-inflammatory, antioxidant, and cholagogic properties. This study was performed to determine the dietary effect of BF extract on serum and skin mucus immune parameters, antioxidant status, and stress-selected gene expression in Siberian sturgeon. One hundred and fifty fish (30 ± 1 g initial weight) were fed with different levels of BF extract including 0 (control), 150, 300, 600, and 750 mg kg−1 for 8-week. After the feeding trial, the counts of white blood cells and lymphocytes were increased in BF-added groups compared to the control group (P < 0.05). The highest levels of serum complement component 4, lysozyme activity, and alternative complement were obtained in 750 mg kg−1 BF extract treatment (P < 0.05). The highest activities of protease, alkaline phosphatase, and esterase were obtained in the skin mucus samples of the fish fed with 750 mg kg−1 BF extract (P < 0.05). The group fed diets supplemented with 600 and 750 mg kg−1 BF extract showed the highest mucus lysozyme activity (P < 0.05). The activities of glutathione peroxidase and superoxide dismutase were increased in fish treated with different levels of BF extract (P < 0.05), while malondialdehyde content was decreased in BF-added groups compared to the control group (P < 0.05). Heat shock protein and cytochrome P450 mRNA expressions were lowest in the 750 mg kg−1 BF extract treatment group, while the highest levels of both genes were found in the control group (P < 0.05). The results showed marked improved antibacterial capacity of Siberian sturgeon fed dietary BF against Streptococcus iniae, Yersinia ruckeri, Escherichia coli, Listeria monocytogenes, Aeromonas hydrophila, and Lactococcus garvieae. This study unveiled the promising results of dietary BF extract, especially at 750 mg kg−1, in the regulation of immune and antioxidant defense systems along with the stress responses in Siberian sturgeon.

Medicinal plants are the most utilized and validated feed additives in the aquaculture industry. This study investigated the dietary effects of anise (Pimpinella anisum L.) in European sea bass (Dicentrarchus labrax). Fish were treated with anise at 0, 1.5, 2.5, and 3.5 g per kg diet for successive 120 days. The results showed a marked enhancement in the growth performance and reduced feed conversion ratio in fish-fed anise compared to the control group (p

This study aimed to investigate the effects of Amla (Phyllanthus emblica) fruit extract (AFE) on the growth, skin mucosal and serum immunity, and disease resistance of Nile tilapia (Oreochromis niloticus) against Streptococcus agalactiae. Three hundred fish (10.48 ± 0.56 g fish-1) were distributed in 15 tanks with 20 fish per tank and fed basal diet supplemented with 0, 5, 10, 20, and 40 mg kg-1 AFE for eight weeks. The completed randomized design with three replications was applied. Growth performance, peroxidase, alternative complement, phagocytosis, and respiratory burst activities were determined at weeks 4 and 8. The challenge study was conducted at the end of the experiment. Based on the results, Nile tilapia fed the AFE diets significantly enhanced skin mucus lysozyme and peroxidase activities (P ≤ 0.05) post-feeding. The highest levels were observed in the group that received 20 mg kg-1 of AFE (P ≤ 0.05), whereas the control group presented the lowest levels of lysosome and peroxidase activities. Similarly, incorporation of 20 mg kg-1 of AFE brought about the maximum levels of (P ≤ 0.05) serum lysozyme, peroxidase, alternative complement, phagocytosis, and respiratory burst activities in contrast to the other treatments; whereas fish fed the control diet generated the lowest immune parameter values (P ≤ 0.05). In the challenge study, the Nile tilapia’s relative percent survival (RPS) was 52.38%, 61.90%, 80.95%, and 47.62% in Diet 2, Diet 3, Diet 4, and Diet 5, respectively. Fish fed 20 mg kg-1 AFE showed significantly (P

Mycotoxicosis is a severe challenge in the aquafeed industry and is involved in low productivity and high economic loss. On this occasion, available dietary supplements, including probiotics, may relieve the impacts of mycotoxicosis on the performances of aquatic animals. In this study, four test diets were prepared to test the effects of Bacillus subtilis (BS), ochratoxin A (OTA), and their mixture (BS/OTA) on the performances of Mullet (Liza ramada). Fish of similar initial weight (11.38 ± 0.24 g) were divided into four groups stocked in triplicate hapas (0.5 ×0.5 ×1 m) at 15 fish per hapa. Fish fed the control diet (without BS or OTA), BS (2 × 106 CFU/g), OTA (1 mg/kg) or BS (2 × 106 CFU/g) and OTA (1 mg/kg) (BS/OTA). After eight weeks, the final weight (FBW) and specific growth rate (SGR) were markedly enhanced by dietary BS and reduced by OTA contamination, while the feed conversion ratio (FCR) was meaningfully reduced by dietary BS and increased by OTA. The hemoglobin (Hb), packed cell volume (PCV), red blood cells (RBCs), and white blood cells (WBCs) were markedly lowered by OTA toxicity. Fish fed BS, or BS/OTA diets showed no significant differences with the control in terms of Hb, PCV, RBCs, and WBCs (p ˃ 0.05). The BS-fed fish showed the same normal intestinal and liver structure with an improved appearance of intestinal villi. The OTA-exposed fish showed deterioration of intestinal mucosa and stunted growth of intestinal villi with severe liver vascular dilatation and congestion in addition to hepatocytes degeneration. The combination of BS with OTA alleviated the pathological effect of individual OTA on the intestinal villi, improved intestinal morphology, and restored the normal hepatic structures with mild periductal inflammatory reaction around the bile duct. The blood total protein and albumin levels were markedly increased by dietary BS and lowered by OTA. Fish fed BS/OTA diet had higher alanine aminotransferase (ALT), aspartate aminotransferase (AST), and urea than fish fed the control but lower than those contaminated with OTA. The catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were markedly increased by dietary BS and lowered by OTA toxicity. However, the malondialdehyde (MDA) level was decreased by dietary BS and increased by OTA toxicity. Interestingly, fish fed the control and BS/OTA diet had similar FBW, SGR, FCR, survival rates, Hb, PCV, RBCs, WBCs, creatinine, CAT, GPx, SOD, and MDA levels. In conclusion, dietary B. subtilis relieved the negative impacts of OTA contamination via protecting fish's intestine, liver, and kidney function.

The increment in world population has led to the increasing demands for fish supply as principal source of animal protein that represents about 17% of animal protein consumption globally. The world aquaculture industry has expanding remarkably but limited source of fishmeal and fish oil which known as important ingredients in fish feed has led to seeking of alternative sources for their replacement in aquafeed formulation. Many potential and cheaper ingredients derived from vegetable oils or agricultural by-products have been investigated to replace fish meal and fish oil which shown promising results in fish productivity and fish health status including olive oil by-products. Varies depending on its type, olive oil composes of antioxidants, healthy type of fats such as MUFA and PUFA, and high in vitamins that provide human health benefits for heart and liver, help in many diseases and reducing the risk of cancer. In agriculture industry, olive and olive oil production processes have resulted to by-products such as olive mill wastewater (OMW), olive leaf and olive pomace. The inclusion of these by-products in animal feeds is the solution for agricultural waste management. The first report of utilization of olive oil by-products in fish feed was documented in 2004 and since then, many researches has been conducted to investigate fish health benefits that showed improvement in fish carcass composition and fish immunity depending on type of by-products used and fish species. Additionally, antioxidant contents in olive oil extract were reported could provide antimicrobial, antifungal and antioxygenic characteristics which potentially improve the fish health. This review discussed the opportunities and challenges in application of olive oil by-products in aquafeed which provides significant prospects in fish growth performance that could boost aquaculture industry development.

Ammonia exposure can be considered more stressful for aquatic animals when it coincides with high temperature. This study was conducted to detect the effects of ammonia exposure and heat stress and their interactions on the histological features of gills and liver tissues and the expression responses of immune and antioxidative related genes in Nile tilapia. Thus, 180 fish were divided into four groups (triplicates), where the first and third groups were kept in clean water without total ammonium nitrogen (TAN) exposure. At the same time, the second and fourth groups were exposed to 5 mg TAN/L. After seven days, the water temperature was raised in the third (without ammonia toxicity) and fourth (exposed with 5 mg TAN/L) groups up to 32 °C and kept under these conditions for 24 h. While the first (without ammonia toxicity) and second (exposed with 5 mg TAN/L) groups were kept under optimum water temperature (27.28 °C) then gills and liver tissues were dissected. Marked upregulation of keap1 was seen in the gills of fish exposed to ammonia/heat stress. The expression of mRNA levels for nrf2, nqo-1, cat, and gpx genes were downregulated in all stressed groups, with the lowest was recorded in the ammonia/heat stress group. The transcription of ho-1 was upregulated in the ammonia and heat stress groups while downregulated in the ammonia/heat stress group. The transcription of the complement C3 gene was downregulated in the livers of heat stress and ammonia/heat stress groups, while the lysozyme gene was downregulated in the ammonia/heat stress group. The mRNA expression levels of nf-κB, il-1β, and tnf-α genes were higher in the ammonia group than in the heat stress group. The highest transcription level of nf-κB, il-1β, tnf-α, il-8, and hsp70 genes and the lowest C3 and lysozyme genes were observed in fish exposed to ammonia/heat stress. The co-exposure to ammonia with heat stress triggered degeneration of primary and secondary gill filaments with telangiectasia and vascular congestion of secondary epithelium while, the liver showed hepatic vascular congestion and visible necrotic changes with nuclear pyknosis. In conclusion, the combined exposure of ammonia and heat stress induced oxidative stress, immunosuppression, and inflammation in Nile tilapia.

The development of plant ingredients as an alternative to fish meal (FM) has received sustained interest in the aquaculture sector. The study investigated the replacement of FM with different percentages of dietary fermented soy pulp (FSP) to assess the growth performance, haematology, blood biochemical, liver, and gut morphology of African catfish. Five isonitrogenous (32 % crude protein) diets were prepared with FSP by replacing 0 % FSP (D1), 25 % FSP (D2), 50 % FSP (D3), 75 % FSP (D4) and 100 % FSP (D5) of FM component of the diets. The results showed a significant difference (p < 0.05) in growth parameters where the fish fed D3 diet showed the highest weight gain, specific growth rate, and condition factor compared with other diets. The mean values of Red Blood Cell (RBC) and Lymphocytosis (LYM) were significantly highest (p < 0.05) in fish fed the D3 diet. The albumin (ALB), globulin (GLOB), and total protein (TP) were significantly lower (p < 0.05) in the control diet compared with the experimental diets. In addition, the D3 diet provides the highest total lactic bacteria (LAB) and total bacteria (TB) compared with other diets. FSP as a protein replacement of the FM had a significant effect (p < 0.05) on villus length, width, and crypt depth in fish's anterior and posterior gut. The histological study of the intestinal revealed that the gut of the D3 diet had an intact epithelial barrier with goblet cells arrangement and very well-organized villus structure, tunica muscularis compared with the other treatments. In conclusion, the replacement of 50 % FM with FSP could be used in the aquafeed industry for better growth and health status of African catfish and possibly for freshwater species.

In aquaculture, fish are stressed with several factors involved in impacting the growth rate and health status. Although Nile tilapia can resist brackish water conditions, hypoxia status may impair the health condition of fish. Nile tilapia were exposed to salinity water at 0, 10, and 20‰ for four weeks then the growth behavior was checked. The results showed meaningfully lowered growth rate, feed utilization, and survival rate when fish kept in 20‰ for four weeks. Then fish were subdivided into six groups (factorial design, 2 × 3) in normoxia (DO, 6 mg/L) and hypoxia (DO, 1 mg/L) conditions for 24 h. High salinity (10 and 20‰) combined with hypoxia stress-induced inflammatory features in the intestines, gills, and livers of fish. The activities of SOD, CAT, and GPX were increased in the intestines, gills, and livers of fish grown in 10 and 20‰ and exposed with hypoxia stress. Fish grown in 20‰ and stressed with hypoxia had the highest ALT, AST, and ALP levels (p

The present study evaluated the enhancement of the growth rate, intestinal health, immune-related genes, and resistance against suboptimal water temperature in common carp (2.01 ± 0.02 g) by dietary paraprobiotics. Fish were fed dietary heat killed Lactobacillus plantarum (LP20) at 0 (control), 50, and 100 mg/kg for 2 months. After the feeding trial fish were exposed to suboptimal water temperature averaged 13.22 ± 0.44 °C for 48 h. The final body weight, weight gain, specific growth rate, and feed conversion ratio of fish fed LP20 at 100 mg/kg were significantly enhanced (P < 0.05). The villi length and width were increased in fish fed LP20 at 50 and 100 mg/kg when compared to the control (P < 0.05). The crypt depth was increased by increasing LP20 in a dose dependent manner with the highest value in the group of fish fed 100 mg/kg (P < 0.05). The number of goblet cells showed higher number in fish fed LP20 at 50 and 100 mg/kg than the control group (P < 0.05). The expression of catalase (CAT) gene did not show any changes in transcription before the thermal stress however after thermal stress fish fed 50 mg/kg had upregulated CAT followed by those fed 100 mg/kg. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) gene expressions showed upregulations in fish fed 50 mg/kg before the thermal stress but after the thermal stress fish fed 100 mg/kg had the highest level of mRNA transcriptions for GPx and SOD genes. In the same manner, the expression of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin 10 (IL-10) were significantly upregulated in fish fed LP20 at 50 mg/kg before the thermal stress whereas the expression of these genes was upregulated in fish fed 100 mg/kg. In conclusion, using LP20 at 50−100 mg/kg resulted in enhancing the growth rate, intestinal morphometry, immune and antioxidative related genes. Accordingly, common carp showed high resistance against suboptimal water temperature stress.

Nucleotides (NT), as a modern feed additive, are effective in many vital functions of cultured aquatic organisms. An experiment was performed to evaluate the effects of dietary nucleotides on the growth performance, carcass composition, liver enzymatic profile, liver, intestine, and spleen histology in European sea bass, Dicentrarchus labrax (initial weight 29.56 ± 0.083 g/fish). Four isonitrogenous (46 % crude protein) and isolipidic (16 % crude lipid) experimental diets were supplemented with different levels of nucleotides, representing N0, N500, N1000, and N1500 treatments, respectively. Each diet was fed to three net enclosures (experimental net cage: 1 × 1 × 1 m) with 0.5 m3 water volume, and each net enclosure contained eight fish. The fish were fed to satiation for 56 days. The results showed significant (P < 0.05) differences in growth performance and feed utilization indices in favor of N500 among all the treatments (P < 0.05). Seabass fed N0 and N1500 had the significantly lowest results. No significant (P < 0.05) differences in survival were detected. Fish fed diets supplemented with nucleotides exhibited significantly lower values of alkaline phosphatase activity (ALP), aspartate aminotransferase activity (AST), alanine aminotransferase activity (ALT), and bilirubin (BIL) compared with the control. The intestine, liver, and spleen histology showed the best development in N500 fed group fish compared with the other treatment, mainly N0 and N1500. In conclusion, the present experiment showed that 500 mg/kg of dietary nucleotides is the optimum level for the best growth performance, health condition, and digestive organs development of D. labrax.

Nile tilapia (Oreochromis niloticus) is a well-known economic fish species and can grow well under optimum environmental conditions. However, stressful rearing conditions are expected to deteriorate the performance and health condition of fish. Hence, the present study investigated the physiological and ion changes of Nile tilapia under salinity stress. Fish of 200 ± 20 g were divided into three groups where the control group reared in water with 0 ppt salinity, while the second and third groups were raised in water with low salinity (10 ppt) and high salinity (15 ppt), respectively. Blood dissolved oxygen and gases (pH, PO2, PCO2, TCO2, and HCO3−) significantly differed in different groups after 5 and 10 days (P < 0.05). The salinity stress affected the Hb, PCV, Na+, K+, Ca++, and lactate significantly (P < 0.05). Serum cortisol, triiodothyronine, and free triiodothyronine concentrations after 5 and 10 days were significantly affected (P < 0.05) in salinity stressed groups compared to the control group. Serum malondialdehyde showed a significant increase (P < 0.05) after 5 days in the stressed groups, then became non-significant after 10 days compared to the control group. The relative gene expression of Na+-K+-ATPase and cytosolic carbonic anhydrase were significantly upregulated in salinity stressed groups (P < 0.05). The histopathological images of Nile tilapia exposed to high salinity stress revealed damage in gills, liver, and kidney tissues, which confirmed the harmful effects of increased salinity. Thus, the obtained results demonstrated that the adverse effects of high salinity stress on the health status of Nile tilapia.

This study aimed at investigating the potential role of β-glucan in improving the immunity, anti-inflammatory and histopathology disorders induced by chlorpyrifos in Nile tilapia. Fish were allocated in four group where the control fed the basal diet without chlorpyrifos toxicity and chlorpyrifos group fed the basal diet and subjected to chlorpyrifos (15 μg/L water). The third group fed dietary β-glucan (1 g/kg diet) without chlorpyrifos toxicity and the fourth group fed dietary β-glucan and exposed to chlorpyrifos (β-glucan/chlorpyrifos). Results revealed that the exposure to chlorpyrifos tended to decrease final body weight (FBW), weight gain (WG), specific growth rate (SGR), and survival but increased the feed intake (FI) and feed conversion ratio (FCR). Administration of β-glucan tended to increase FBW, WG, SGR, survival, and FI but did not change the FCR. Exposure to chlorpyrifos did not change the blood alkaline phosphatase (ALP) but increased aspartate aminotransferase (AST), alkaline phosphatase (ALP), and cortisol levels whereas β-glucan administration markedly decreased ALP, AST, ALT, and cortisol levels and β-glucan/chlorpyrifos treatment declined the levels of these variable close to the baseline values. Compared to the control, chlorpyrifos administration tended to decrease the lysozyme and phagocytic index but no change was observed in phagocytic activity. β-Glucan administration greatly increased the levels of lysozyme, phagocytic activity and phagocytic index, and β-glucan tended to alleviate the negative effect of chlorpyrifos on the mentioned parameters. The chlorpyrifos exposure caused congestion and telangiectasia in gills, catarrhal enteritis followed by degeneration and sloughing of the apical part of the intestinal villi with diffused lymphocytic infiltration, and fatty degeneration and vacuolation of hepatocytes in addition to congestion of blood sinusoids in liver. However, the histopathological structure of these organs was normal with dietary β-glucan. In conclusion, β-glucan administration alleviated the adverse effects of chlorpyrifos on the immune and anti-inflammatory response as well as histopathology of gills, liver, and intestine of Nile tilapia.

The study aimed at evaluating the possible feeding strategies of selenium (Se) nanoparticles on the performances of European seabass (Dicentrarchus labrax). The first group fed the basal diet continuously (control) while the second group offered Se (1 mg/kg diet) every day (R1). The third group fed the basal diet one day then Se diet every other day (R2), and the fourth group basal diet for two days then fed Se diet every two days (R3). The FBW, WG, and SGR were significantly improved in the R1 group than fish in the other groups (P

Infectious diseases usually occur in response to the highly intensive rearing conditions in fish farms. The use of feed additives is still one of the most practical options in the field of aquaculture. Therefore, this study aimed at evaluating the impact of raffinose on the growth rate, antioxidative status, and immunity of Nile tilapia. For 60 days, fish fed five test diets with raffinose at 0, 0.5, 1, 1.5, and 2 g/kg. The FBW was increased by feeding raffinose at 0.5 or 1 g/kg levels over the control, whereas no significances were observed among the other groups. Feeding tilapia with raffinose at 1 g/kg increased the WG and SGR and decreased the FCR with regards to the control. The activity of SOD was enhanced by feeding raffinose at all levels, while GPX and SOD were improved by 1 or 1.5 g/kg levels over the control. On the contrary, the concentration of MDA was decreased by raffinose, and the lowest levels were observed by 1 or 1.5 g/kg levels. The lysozyme activity was increased by level 1 g/kg over the other levels without significant differences with 1.5 g/kg. The phagocytic activity and index were also boosted by feeding raffinose at 1, 1.5, and 2 g/kg levels over 0 and 0.5 g/kg. Taking together, dietary raffinose increases Nile tilapia growth performances, and immune responses and 0.85–1.37 g raffinose per kg diet is recommended for this species nutrition.

The present study was designed to evaluate the effects of ethanolic extracts of Hypericum perforatum (HP), Origanum vulgare (ORG), and Melissa officinalis (MOF) on Nile tilapia (Oreochromis niloticus) juveniles. Fish (16.92 ± 0.28 g) were randomly divided into seven groups fed on diets with 0 % (CTR), and two levels (0.2 % and 0.5 %) from each plant extract for 60 days. Final body weight, weight gain %, specific growth rate, and feed conversion ratio were significantly improved in the groups fed with ORG and MOF at 0.5 % (P < 0.05). Moreover, ORG 0.5 % and MOF 0.5 % groups showed a significant increase in RBCs and WBCs counts as well as the hematocrit and hemoglobin values (P < 0.05). Besides, significant enhancement was noticed in the levels of intestinal digestive enzymes in the MOF 0.5 % group (P < 0.05). Activities of hepatic superoxide dismutase, glutathione peroxidase, catalase were significantly improved, meanwhile, the hepatic malondialdehyde levels were significantly decreased in all groups fed on phytogenic diets compared to the CTR group (P < 0.05). Furthermore, ORG 0.5 % and MOF 0.5 % groups showed a significant increase in serum total protein, and alternative complement activity (ACH50) (P < 0.05). Attractively, serum lysozyme levels were significantly increased while serum endotoxin values decreased in all groups fed on phytogenic diets. Furthermore, the MOF 0.5 % group showed the highest activities of skin mucus lysozyme, ACH50, and protease (P < 0.05), meanwhile mucosal total immunoglobulins were the highest in ORG 0.5 % and both levels of MOF. ORG 0.5 % and MOF 0.5 % groups showed the highest protection levels of fish following challenge with pathogenic Aeromonas hydrophila. Conclusively, this comparative study showed that both ORG and MOF extract at a 0.5 % level can effectively improve the growth, health, and immune status of Nile tilapia juveniles.

The current study aimed to evaluate whether clenbuterol, a β2-adrenergic agonist, supplementation in Nile tilapia (Oreochromis niloticus) diets can influence growth and blood parameters. Besides, assessment of adipogenic genes as fatty acid synthase (FAS) and lipoprotein lipase (LPL) which is a key enzyme in the regulation of the flux of fatty acids in liver, muscle, and adipose tissue as well as muscle growth-regulating genes as myostatin (MYO) in muscle and insulin-like growth factor-1 (IGF-1) in liver. The fish were allocated into three equal groups; control group that fed basal diet only and the other two groups fed a basal diet containing clenbuterol at two doses 5 ppm and 10 ppm/kg diet for 30 consecutive days. Results revealed that clenbuterol supplementation significantly increased body weight, decreased liver, spleen and abdominal fat weights, and decreased total circulatory cholesterol and triacylglycerol levels. Moreover, clenbuterol inhibits lipogenesis by downregulation of FAS gene expression by dose and time-dependent manner in the liver while enhanced lipolysis in both the liver and in the adipose tissue. Moreover, lipolysis was reduced in muscle by dose 10 ppm on day 30. Furthermore, clenbuterol presented higher gene expression of MYO and IGF-1 in muscle and liver respectively by dose 5 ppm at day 15 on the other hand, these findings were reversed by day 30 compared with control. In conclusion, clenbuterol efficacy was apparent in a dose and time response pattern to boost growth and reduce fat deposition rates, indicating for the first time that clenbuterol has a profitable growth impact on Nile tilapia.

Probiotics and herbals are highly recommended in aquaculture; however, little is known about their combined effects. Therefore, the present study evaluated the possible synergistic impacts of Spirulina platensis (SP) and Bacillus amyloliquefaciens (BA) on the growth performance, histomorphology, and immune response of Nile tilapia (Oreochromis niloticus). A control and three test diets were enriched with SP, BA, or both SP and BA and fed for tilapia for 60 days. The obtained results displayed higher final body weight, weight gain, and specific growth rate in fish fed SP or/and BA with respect to the control with the highest being in fish fed both SP and BA (P

The present study was conducted to replace fish meal with alternative plant protein sources in aquafeeds. Therefore, soybean meal (SBM), corn gluten meal (CGM), and mix of SBM + CGM were used as alternatives to fish meal (FM) with or without betaine (B) in Nile tilapia diets. Positive control diet using FM and six other diets were formulated to contain SBM, SBM + B, CGM, CGM + B, SBM + CGM, or SBM + CGM + B. Dietary B improved fish growth and body protein content in comparison to the control and equal to fish fed FM-based diet. Reduced FCR and body fat content were observed in the case of fish fed FM, SBM + B, CGM + B, or SBM + CGM + B diets. The survival rate was significantly increased in the group of fish fed SBM + CGM + B when compared to fish fed CGM diet (P = 0.013) while no significant differences were reported among the other groups (P > 0.05). Markedly increased intestinal villi length and the number of goblet cells were found in FM, SBM+B, CGM+B, and SBM+CGM+B groups (P

Varied levels of Saccharomyces cerevisiae-fermented date palm seed meal (DSM) were included in Nile tilapia (26.95 ± 0.01 g) diets. Five diets were prepared to include fermented DSM at 0, 5, 10, 15 and 20 % and fed for fish for 8 weeks. The obtained results revealed that yeast fermented DSM significantly affected the final body weight, weight gain, specific growth rate, and feed conversion ratio in a dose dependent manner (P = 0.001, P = 0.002, P = 0.004, P = 0.01, respectively). Dietary yeast fermented DSM significantly increased the lipase, amylase, and protease activities (P = 0.011, P = 0.02, P = 0.031, respectively). In the anterior segment of the intestine, villus length and the number of goblet cells were significantly affected by the inclusion of yeast fermented DSM (P = 0.001 and P = 0.008). In the middle area, only the villus length, internal villi distance, and goblet cells number were affected significantly by the inclusion of yeast fermented DSM (P = 0.001, P = 0.02, P = 0.047, respectively). Posterior intestinal morphometry showed significantly increased villus length and number of goblet cells when fish fed yeast fermented DSM in a dose dependent manner (P = 0.028 and P = 0.04). Most of the measured blood parameters showed insignificant (P > 0.05) differences except for total blood protein, globulin, albumin, RBCs, and WBCs which were significantly affected by the inclusion of yeast fermented DSM (P = 0.001, P = 0.001, P = 0.007, P = 0.042, P = 0.001, respectively). Furthermore, dietary yeast fermented DSM significantly altered the lysozyme and phagocytic activities (P = 0.03 and P = 0.005). Based on the polynomial regression analysis the inclusion of yeast fermented DSM at 11.44–17.44 % can be used effectively in tilapia’ diets for improving the growth, digestion activity, and immune response.

This study investigated the influence of probiotic Pediococcus acidilactici MA 18/5 M on the metabolic enzyme activities and mRNA levels of growth, immunity, and antioxidative-related genes in zebrafish. Zebrafish fed with diets containing P. acidilactici MA 18/5 M at 0, 107, 108, and 109 CFU/g levels for eight weeks. The obtained results revealed that the creatine phosphokinase, lactate dehydrogenase, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase remained unchanged in all groups (P > 0.05). Dietary P. acidilactici enhanced protease activity relative to the control group (P

The present study investigated the impact of stocking density and dietary carbon sources on the growth, oxidative status and stress markers of Nile tilapia (Oreochromis niloticus) reared under biofloc conditions. Six groups were established at three levels of stocking densities [20, 40 and 60 fish (50.47 ± 0.05 g) per m3] and fed the basal diet without carbon sources or with broken rice flour (BRF) or broken wheat grain flour (BWGF) in biofloc units. Water quality [pH, biological oxygen demand (BOD), Total ammonia-nitrogen (TAN), and nitrite-nitrogen (NO2)] values were increased significantly (P < 0.05) as the density increased and recorded the highest values in group (60 fish per m3) while dissolved oxygen decreased. Biofloc volume and bacterial counts were significantly (P < 0.05) lower in 20 fish m−3 and the highest values were in 40 fish per m3. Significantly increased growth and feed utilization were recorded in 40 fish per m3 fed with BRF. The lipid content lowered significantly (P < 0.05) in 60 fish m-3 group. Red blood cells count, hemoglobin and hematocrit values were reduced in fish stocked in high density while alanine transaminase (ALT) and aspartate transaminase (AST) increased in fish reared in low density. Glucose, cortisol, catalase and superoxide dismutase increased in fish reared at 20 fish m-3 and fed the basal diet. Thus, using of BRF for fish reared at 40 fish per m3 promotes growth and health status of Nile tilapia cultured in a biofloc system. Keywords: Biofloc, Carbon source, Growth performance, Stress markers, Nile tilapia, Stocking density

The present study was conducted to assess the possible effects of gotu kola (Centella asiatica) powder (GKP) on skin mucus and serum immune response, as well as growth performance of Nile tilapia, Oreochromis niloticus. Three hundred twenty Nile tilapia fingerlings (average weight of 17.84 ± 0.08 g) were divided into four treatments and fed four levels of gotu kola powder (GKP) as following 0, 5, 10, and 20 g kg−1 diet for 61 days. Completed Randomised Design with four replications was applied. The results showed that fish fed 5 g kg−1 GKP significantly improved skin mucus lysozyme (SMLA) and skin mucus peroxidase activities (SMPA) (P 0.05). For serum immunity, dietary administration of GKP showed significantly improved serum lysozyme and serum peroxidase activities compared to control group (P

The current study evaluated the effects of dietary mannanoligosaccharide (MOS) on red sea bream (Pagrus major) performances. Fish fed five dietary levels of MOS at 0, 0.5, 1, 1.5 or 2 g/kg for 60 days. The results showed that MOS supplementation significantly increased the final body weight, weight gain, and specific growth rate with decreased feed conversion ratio especially in fish fed 1.5 g per kg diet (P

Dietary cinnamon has several bioactive compounds with growth-promoting and immunomodulation potential and is suggested for finfish species. This study evaluated the inclusion of cinnamon at 0, 10, 15, and 20 g/kg in European sea bass (Dicentrarchus labrax) diets. After 90 days, the highest final weight, weight gain, specific growth rate, protein efficiency ratio, and the lowest feed conversion ratio were seen in fish treated with 10 g/kg (p < 0.05). Further, the measured growth hormone in the blood indicated that fish treated with 10 g/kg had a higher level than fish 0 and 20 g/kg. After the feeding trial, fish treated with cinnamon at varying levels had higher lipid content than fish before the feeding trial (p < 0.05). Lower Vibrio spp. and Faecal Coliform counts were observed in fish treated with cinnamon than fish fed a cinnamon-free diet (p < 0.05). The hematocrit level was markedly (p < 0.05) increased in fish fed cinnamon at 10 g/kg compared to the control without significant differences with fish fed 15 and 20 g/kg. Hemoglobin was significantly increased in fish treated with cinnamon at 10, 15, and 20 g/kg compared to fish fed a cinnamon-free diet (p < 0.05). Red and white blood cells (RBCs and WBCs) were meaningfully (p < 0.05) increased in fish treated with cinnamon compared with the control. Markedly, fish treated with cinnamon had higher serum total lipids than the control with the highest value in fish treated with 15 g/kg (p < 0.05). The lysozyme activity was markedly higher in fish treated with 15 g cinnamon/kg than fish fed 0, 10, and 20 g/kg (p < 0.05). Moreover, phagocytic activity was significantly higher in fish treated with cinnamon at 10, and 15 g/kg than fish fed 0 and 20 g/kg (p < 0.05). In conclusion, dietary cinnamon is suggested at 10–15 g/kg for achieving the high production and wellbeing of European sea bass.

The need to replace antibiotics in aquafeed is increasing, and alternative safe substances are now encouraged for sustainable aquaculture activity. Curcumin is regarded as a multifunctional feed additive with growth-promoting and immunostimulant potential. Thus, this study evaluated dietary inclusion of curcumin at rates of 0, 1.5, 2, 2.5, and 3% in the diets of Gilthead seabream for 150 days. The results showed an improved final body weight, weight gain, specific growth rate, and feed conversion ratio in fish treated with curcumin, in a dose-dependent manner. The highest growth performance was observed in fish fed a diet supplemented with 3% curcumin. The results also showed lowered activity of pathogenic bacteria (Vibrio spp. and Faecal coliform) in the intestines of Gilthead seabream fed a diet with curcumin inclusion, in a dose-dependent manner. The hematological indices were within the normal range for healthy fish, without meaningful effects except for hematocrit, hemoglobin, red blood cells (RBCs), and white blood cells (WBCs), which were markedly increased by dietary curcumin. Phagocytic activity was obviously enhanced by dietary curcumin, compared with the control. The biochemical blood metabolites related to liver function (alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT)), renal tissue (urea), and total cholesterol were within the normal values, without significant differences. Overall, the inclusion of curcumin at a rate of 2–3% improved the growth performance and well-being of Gilthead seabream.

The current investigation assessed the impacts of sub-lethal concentrations of silicon dioxide nanoparticles (SiO2NPs) on hepato-renal functions, histopathological characteristics, and gene transcription in gills and liver of Nile tilapia juveniles. Fish were exposed to 20, 40, and 100 mg/L of SiO2NPs for 3 weeks. Pairwise comparisons with the control group showed a significant dose-dependent elevation in serum ALP, ALT, and AST enzyme activities as well as blood urea and creatinine levels in SiO2NP-intoxicated groups. Exposure to 100 mg/L SiO2NPs significantly upregulated expression of HSP70, TNF-α, IL-1β, and IL-8 genes in the gills as compared to the control group. Moreover, exposure to 100 mg/L SiO2NPs significantly upregulated the expression SOD, HSP70, IL-1β, IL-8, and TNF-α genes in the hepatic tissues as compared to the control group. Exposure of fish to 20 mg SiO2NPs/L significantly increased the mRNA expression levels of IL-12 in both the gills and liver tissues. Notably, all tested SiO2NP concentrations significantly upregulated the transcription of CASP3 gene in gills and liver of Nile tilapia as compared to the control group. Interestingly, varying histopathological alterations in renal, hepatopancreatic, and branchial tissues were observed to be correlated to the tested SiO2NP concentrations. In conclusion, our results provide additional information on the toxic impacts of SiO2NPs in Nile tilapia at the hematological, tissue, and molecular levels.

The present study aimed to evaluate the effect of dietary fermented extracts sourced from Saccharomyces cerevisiae (nucleotides, β-glucans and MOS) (Hilyses®) on the production and health of Nile tilapia (Oreochromis niloticus) broodstock, as well as on seed survival and performance. The trial was performed in a hatchery along the spawning season and continued in the laboratory to monitor the performance in fry and fingerlings. The broodstock were divided into two groups, (C) fed a basal diet and (H) fed 0.4% Hilyses. Blood and histological parameters, antioxidant power, cortisol level and the expression of some immune-related (TLR-2, IL-1β and TNF-α) and growth-related genes (MUC-2 and IGF-1) were measured. The obtained seeds were subdivided into four treatments: (C-C) fed a basal diet, (C-H) fed 0.4% Hilyses, (H-C) fed a basal diet and (H-H) fed 0.4% Hilyses. Results revealed that the dietary inclusion of Hilyses in the broodstock increased seed production, survival, hematological parameters, and antioxidant power. Moreover, it improved the intestinal microstructure and upregulated the immune- and growth-related genes. The growth indices of fry and fingerlings were significantly increased in all Hilyses-treated groups (p < 0.05). The performance in the (H-H) group significantly surpassed those of all groups. Therefore, dietary fermented yeast could be used as a strategic solution to sustain tilapia production.

The current study aimed at assessing the recuperative roles of dietary Spirulina platensis on the antioxidation capacity of Nile tilapia (Oreochromis niloticus) exposed to sodium sulphate for eight weeks. In brief, fish were allocated into four groups with three triplicates per group, where a group fed on a commercial basal diet served as control, a group was intoxicated with sodium sulphate (SS) 5.8 mg/L, another group was fed a diet supplemented with 1% S. platensis (SP), and the last group was fed 1% SP and concomitantly intoxicated with 5.8 mg/L sodium sulphate (SP/SS). Tissue antioxidative indices of each fish were measured as follows: glutathione peroxidase (GSH-Px) activity in muscles, catalase (CAT) and superoxide dismutase (SOD) activities in gills, and total antioxidant capacity (T-AOC) in the liver and kidney. Moreover, the expression of hepatic SOD, GSH-Px, and glutathione-S-transferase (GST) genes was also determined. It was found that tissue CAT, SOD, and GSH-Px activities as well as the T-AOC levels were significantly decreased in the SS group (p < 0.05). Moreover, there was a significant downregulation of hepatic SOD, GSH-Px, and GST genes in SS-exposed fish (p < 0.05). Interestingly, simultaneous dietary supplementation with SP provided a marked attenuation of the tissue antioxidative parameters when compared with the SS and control groups. To conclude, the present study exemplifies that dietary SP supplementation could be a beneficial abrogation of SS-induced tissue oxidative stress in the exposed fish.

Marine-derived substances are known for their beneficial influences on aquatic animals’ performances and are recommended to improve intestinal health, immunity, and anti-oxidative status. The present study investigates the role of chitosan nanoparticles on the intestinal histo-morphometrical features in association with the health and immune response of Grey Mullet (Liza ramada). Chitosan nanoparticles are included in the diets at 0, 0.5, 1, and 2 g/kg and introduced to fish in a successive feeding trial for eight weeks. The final body weight (FBW), weight gain (WG), and specific growth rate (SGR) parameters are significantly increased while feed conversion ratio (FCR) decreases by chitosan nanoparticles compared to the control (p < 0.05). The morphometric analysis of the intestines reveals a significant improvement in villus height, villus width, and the number of goblet cells in chitosan-treated groups in a dose-dependent manner. Additionally, there is a positive correlation between the thickness of the enterocyte brush border and the chitosan dose, referring to an increasing absorptive activity. Histologically, the intestinal wall of Grey Mullet consists of four layers; mucosa, sub-mucosa, tunica muscularis (muscular layers), and serosa. The histological examination of the L. ramada intestine shows a normal histo-morphology. The epithelial layer of intestinal mucosa is thrown into elongated finger-like projections, the intestinal villi. The values of hemoglobin, hematocrit, red blood cells (RBCs), total protein (TP), albumin, and globulin are significantly increased in fish fed 1, and 2 g/kg of chitosan nanoparticles compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest levels of TP and albumin are observed in fish fed 1 g/kg diet (p < 0.05). The lysozyme activity and phagocytic index are significantly enhanced by feeding chitosan nanoparticles at 0.5, 1, and 2 g/kg, whereas the phagocytic activity is improved in fish fed 1 and 2 g/kg (p < 0.05). The highest lysozyme activity and phagocytic index are observed in fish fed 1 g/kg. SOD is significantly activated by feeding chitosan nanoparticles at 1 g/kg. Simultaneously, glutathione peroxidase (GPx) and catalase (CAT) activities also are enhanced by feeding chitosan at 1 and 2 g/kg, compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest GPx and CAT activities are observed in fish fed 1 g/kg (p < 0.05). Conversely, the malondialdehyde (MDA) levels are decreased by feeding chitosan at 1 and 2 g/kg, with the lowest being in fish fed 1 g/kg (p < 0.05). To summarize, the results elucidate that L. ramada fed dietary chitosan nanoparticles have a marked growth rate, immune response, and anti-oxidative response. These improvements are attributed to the potential role of chitosan nanoparticles in enhancing intestinal histo-morphometry and intestinal health. These results soundly support the possibility of using chitosan nanoparticles at 1–2 g/kg as a feasible functional supplement for aquatic animals.

Olive cake meal (OCM) is characterized by its high nutritional value and is used as an alternative source of protein and fats in poultry diets. However, due to the high percentage of fiber in OCM, beneficial bacteria cells are used to improve the digestion rates. Therefore, the influence of OCM and Bacillus licheniformis (BL) on the growth, nutrient utilization, blood chemistry, and muscle fatty acid profile of broilers was exclusively examined in this study. Three hundred and sixty birds were randomly divided into six experimental groups (6 replicates/10 birds each): Control, OCM (2%), OCM (4%), BL, OCM (2%)/BL, and OCM (4%)/BL groups. Although feed intake was not meaningfully influenced by dietary treatments, weight gain was enhanced and feed conversion ratio was reduced (p < 0.05). The abdominal fat was lowered in broilers fed OCM (2%), OCM (4%), OCM (2%)/BL, and OCM (4%)/BL diets without a difference to those fed BL only (p < 0.05). Interestingly, blood total protein, albumin, Newcastle disease (ND) titer, and high-density lipoprotein (HDL) cholesterol were significantly increased, while total cholesterol was decreased by the mixture of OCM and BL (p < 0.05). Muscle oleic and linoleic acids, as well as vitamin E, increased significantly in broilers fed both OCM (4%) and BL, while linolenic acid increased in all groups except those fed BL and control diets (p < 0.05). Liver malondialdehyde (MDA) was decreased by feeding BL or both OCM at 2% or 4% and BL (p < 0.05). In conclusion, the inclusion of BL to OCM diets resulted in improved fat utilization and, accordingly, enhanced growth, nutrient utilization, and antioxidative response in broilers. Based on the obtained results, it is recommended to use BL to improve the nutritional value of OCM and to increase the feed utilization of OCM by broilers.