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The present investigation aimed to evaluate the effect of dietary chitosan supplementation on growth performance, body composition, immune response and histopathology of Nile tilapia, and also the in vitro antibacterial activity of chitosan against Streptococcus agalactiae (S. agalactiae). About 180 fish (average body weight 39.3 ± 0.3 g) were randomly divided into three groups according to chitosan supplementation: control group (basal diet without chitosan), Ch3 group (3 g chitosan/kg diet) and Ch5 group (5 g chitosan/kg diet). Growth performance parameters and body proximate composition were measured before infection but biochemical parameters and lysozyme and antibacterial activities before and after experimental infection. Results of the present investigation showed dietary chitosan (5 g chitosan/kg diet) significantly (p

The present study was intended for investigating the effect of lead acetate toxicity (5 or 10 mg lead acetate/liter water), Dunaliella algae (11 g/kg diet)-supplemented diet and their interaction i...

The present trial was performed to evaluate the effect of dietary incorporation of dried Spirulina, Chlorella and their mixture on the immune status of Nile tilapia (Oreochromis niloticus) before and after artificial infection with pathogenic bacterium Aeromonas hydrophila (A. hydrophila). Two hundred and forty fish were divided into four groups: (a) a control group fed on a basal diet only, (b) a second group fed on a diet containing Spirulina 15%, (c) a third group fed on a diet containing Chlorella 15%, and (d) a fourth group fed on a diet containing a mixture of both Spirulina 15% and Chlorella 15%. At the end of the experiment (9 weeks), the four groups were experimentally infected with A. hydrophila for 7 days. Antioxidant enzymes, lysozyme and bactericidal activities and histopathological changes were determined just before the challenge test and 7 days post‐challenge. Significant (p ≤ 0.05) increases in fish body protein% before the challenge test and increases in serum antioxidant enzymes, lysozyme and bactericidal activity in the Chlorella and algal mixture groups before and after the challenge test were observed. Spirulina, Chlorella and their mixture groups significantly decreased serum malondialdehyde compared to the control group before and after the challenge test. Using Spirulina, Chlorella and their mixture mitigated the necrotic and degenerative changes induced by A. hydrophila and revealed well‐developed and multiple melanomacrophage centres. Thus, dietary Spirulina, Chlorella and their mixture inclusion in Nile tilapia fish proved to have a protective effect against A. hydrophila infection.

This paper was designed to analyze the effect of ochratoxin A (OTA) contaminated feed on the growth outcomes, certain serum biochemical, histopathology, and OTA residue in the dorsal muscle, liver, and kidney in Nile tilapia. Also, to improve the drastic effect of OTA through dietary supplementation of hydrated sodium aluminum silicates nanoparticles or nano copper. For performing the present study, 270 fish were randomly allotted into 6 equal groups according to ochratoxin and nanoparticles of hydrated sodium aluminum silicates or copper oxide. The results indicated that supplementation of two levels of both nanoparticles (aluminum silicate or copper) as a mycotoxin adsorbent could prevent ochratoxicosis in Nile tilapia fish. In addition, they maintained optimal growth performance, feed efficiency without bad effect on serum profiles and vital organs function of fish in a dose-dependent manner. Histopathologically, the most interesting finding was the precipitation of calcium salts known as nephrocalcinosis, within the tubules, upon the degenerative tubules and tunica intima and media of the blood vessels in the control positive group. These pathological lesions were mitigated by nanoparticle supplementation. Thus increase the safety of fish products.

We studied the impact of using fodder enriched with the cyanobacterium Spirulina platensis or the green alga Chlorella vulgaris or a consortium containing both of them on growth, biochemistry profile and immune status of the Nile tilapia (Oreochromis niloticus) fish. A set of 240 males challenged with Aeromonas hydrophila one week before the end of 9 weeks experimental period. The fodder supplemented with 15% (w/w) of Spirulina platensis, 15% of Chlorella vulgaris or 15% of their (1/1) mixture. Growth performance was measured all over 9 weeks. Challenge test was performed by infection with the pathogen after 8 weeks of growth. The serum total contents of protein, albumin, globulin, urea, creatinine and activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALK) and lactate dehydrogenase (LDH) were measured at 7 days before and after the infection. The results revealed significant increases in body weight of the Chlorella and their mixture (Chlorella and Spirulina) treated groups compared with the untreated control and the only Spirulina treated ones (p ≤ 0.05). Without infection, the serum total protein and serum globulin significantly increased by supplementation with the Spirulina, Chlorella and both compared to the uninfected control group. The serum albumin significantly decreased with Chlorella and the mixture supplementations. Lactate dehydrogenase (LDH) in the fish serum generally decreased with application of the enriched feed compared with the control. After infection, serum total protein and globulin significantly increased by the feed supplementations compared with the control group while the serum albumin insignificantly increased by supplementation with Chlorella and Spirulina. ALT, AST, ALK, LDH, urea and creatinine in the fish serum decreased with the microalgae additives compared with the control.

Aims: Detect of some parasites and bacteria which cause diseases problems in some ornamental fish ; Fantail, Angel fish, Koi carp , Molly , Swordtail and Guppy. Methods and Results: one hundred and fifty apparently infected ornamental fish collected (25 of each species) from private ornamental fish shops, were examined in live condition for detection of any parasitic infestation and any abnormalities. Bacteriological examination of the previously mentioned fishes resulted in the detection of three bacterial species; Pseudomonas fluorescence, Aeromonashydrophila andStaph aureus with total prevalence 11.3%,10%, and 2% respectively. The most isolated strain (Pseudomonas fluorescence )was identified by PCR technique, while parasitic infestation resulted in detection of Protozoal infestation with the prevalence of; Ichthyophthirius multifiliis16.6% Trichodinaacuta 15.3% andChilodonella 7.3%. Monogenia infestation (Gyrodactylus sp.) 16.3% and Crustacean infestation (Argulusfoliaceus 20% andLerneacyprinacea 3.3%). Antimicrobial sensitivity test of Aeromonashydophilla suggested to be treated with Ciprofloxacin, Trimethoprim + sulphamethoxazole, Tetracycline, Amoxicillin or Gentamycin, Pseudomonas fluorescence suggested to be treated with Ciprofloxacin, Tetracycline or Streptomycin while S. aureus suggested to be treated with Ciprofloxacin, Ampicillin, Gentamycin or Amoxicillin.Eventually. Treatment of infested parasitic fishes was done by sodium chloride solution at conc. of 2.5% for 15 minutes showed a successful effect on the second day of treatment. Conclusions: addition of these antimicrobials with balanced ration for fish and good water quality will help on control and treatment of such condition of infection. Significance and Impactof Study: this study shows us the most important parasites and bacteria which cause diseases problems in some ornamental fish and the suitable treatment of it .

The present study aimed to investigate the effect of low phosphorus diet with or without different levels of phytase enzyme supplementation on growth performance, body composition, nutrient retention efficiency, gene expression, and health status of A. hydrophila challenged fish. A total of 240 monosex males of Nile tilapia (Oreochromis niloticus) with an average body weight of 23.19 ± 0.15 g/fish were used. Fish were randomly chosen and divided into 4 equal groups (60 fish per group), with 3 subgroups containing 20 fish as a replicate. Group 1, was fed on a diet containing 100% P, group 2, was fed on a diet containing 50% P, group 3 and 4, were fed on low P with 500 or 1000 units of phytase/Kg respectively. It was observed that the 50% phosphorus diet significantly reduced body weight, feed intake, feed conversion ratio (FCR), and protein efficiency ratio (PER) compared to Nile tilapia fish fed on the diet containing 100% phosphorus. In contrast, fish fed on the diet containing 50% phosphorus supplemented by 500 or 1000 phytase units/kg significantly (P ≤ 0.05) increased final body weight (FBW), total body gain (TBG), average daily gain (ADG), and weight gain compared to Nile tilapia fed on the same diet or fed on the diet containing normal phosphorus without phytase supplementation. Different phosphorus and phytase supplementation levels had no significant effect on serum total protein, albumin, and globulin concentrations, meanwhile, phytase supplementation increased serum calcium and phosphorus levels. Nile tilapia fed on phytase supplementation had an increase in body protein, lipid content, and nutrient utilization efficiency compared to Nile tilapia fed on the diet containing 100% phosphorus. Nile tilapia fed on low dietary phosphorus showed an increase in mortality after infection and a decrease in phagocytosis and neutrophil compared to fish fed on normal phosphorus. Phytase supplementation, made immune response parameters return to its normal values and the pathological lesions of liver, spleen, stomach, and intestine were reduced. Moreover, normal phosphorus significantly up-regulated lipoprotein lipase (LPL) mRNA expression and down-regulated fatty acid synthase (FAS) mRNA in Nile tilapia's liver while low phosphorus with or without phytase supplementation reduced LPL expression and relatively up-regulated FAS.

Two hundred and seventy monosex males Nile Tilapia (Oreochromis niloticus) with an average body weight of 16.65±0.2 g/fish were used to investigate the effect of dietary replacement of inorganic iron by different levels of Fe-NPs on growth performance, body composition and health status of A. hydrophila challenged Nile tilapia fish. Fish maintained on 30% protein level, Six different experimental diets supplemented with 0.0 (T1), 85.0 mg inorganic Fe/kg (T2) and 85.0, 63.75, 42.5 and 21.25mg Fe-NPs/kg (T3-T5) were fed to triplicates groups of fish. It was found that the final body weight, weight gain, SGR, FCR and PER were significantly improved in the fish fed on the iron-supplemented diets compared to those fed on the iron-deficient diet (T1). Blood pictures and serum biochemical were significantly increased before and after A. hydrophila infection in the iron-supplemented groups compared to the iron-deficient diet group. The dietary administration of iron NPs improved the antioxidant enzymatic activities (CAT and TAC) irrespective of the different iron sources in the basal diet. Moreover, it was observed that the diets containing 63.75 and 42.5 mg/kg of Fe-NPs exhibited the best survival rate compared to the other groups.