Dietary Hydrolyzed Yeast Improves Growth, Gut Health, and Selective Gene Expression of Nile Tilapia (Oreochromis niloticus)

Effect of alpha-ketoglutarate supplementation on growth, antioxidant capacity, gene expression and amino acid profile in Nile tilapia (Oreochromis niloticus) under varying protein diets

Fertilization sources fallout: Unveiling the impacts on growth, metal accumulation, and physiological responses in Nile Tilapia, Oreochromis niloticus

The dietary presence of feed additives is crucial for boosting fish growth and immunity. Accordingly, this feeding trial aimed to investigate the effects of the separate and concurrent dietary supplementation of Spirulina platensis (SP) and bitter lemon (Citrus limon) peel essential oil (LEO) on the growth, immunity, antioxidant capacity, and intestinal health of Nile tilapia (Oreochromis niloticus). Four groups of male Nile tilapia were employed. The first group (control) was given the basal diet, while the second and third groups received the basal diet supplemented with LEO extract (1%) and SP (1 g/kg diet), respectively. The fourth group received the basal diet supplemented with a mix of LEO (1%) and SP at 1 g/kg. After two months of feeding, using LEO or/and SP improved the overall growth and immunological parameters, with their combination yielding the best outcomes. The supplementation of LEO or/and SP improved the Nile tilapia's growth metrics and transcriptomic levels of growth-regulating genes such as (oligo-peptide transporter 1 (Pep1), growth hormone receptors 1 (GHR1), and insulin-like growth factor (IGF1). The improved growth performance was linked to significant increases in the expression levels of mucin and fat metabolism-related genes. Moreover, fish supplemented with LEO, SP, or their combination showed enhanced non-specific immunological measures, including phagocytic and lysozyme activities and the mRNA copies of its regulating genes. Additionally, remarkable increases in the antioxidant enzyme activities and the mRNA levels of their related genes were detected. The complement (C3) gene's transcriptomic level was also significantly increased. Furthermore, the dietary supplementation of LEO, SP, or their combination improved the histological structures of the spleen, hepatopancreas, and intestine. The enhanced effects of LEO, SP, or their combination on fish immunity and growth are suggested to be due to their contents of bioactive compounds with anti-inflammatory, antioxidant, and antimicrobial properties. Thus, using the LOE and SP blends as feed additives is recommended for better growth and immunity of Nile tilapia.

This work was conducted to evaluate the effect of anise essential oil as a feed additive on growth performance and immunity of Nile tilapia (Oreochromis niloticus) exposed to two different challenges; reduced levels of dissolved oxygen (LDO) and/or infection with Aeromonas hydrophila. Juveniles were randomly distributed to six replicated experimental groups; groups 1, 2, and 3 were reared at normal levels of dissolved oxygen (NDO) (5 – 6 mg/l) and received 0, 1, and 2 ml/kg diet of anise essential oil, respectively. In addition, groups 4, 5, and 6 which were reared on LDO levels (2 – 3 mg/l) and received the same concentrations (conc.) of anise oil (0, 1, and 2 ml/kg diet, respectively). All groups were kept at a density of 30 fish/m3 and fed on a commercial basal diet (30% crude protein) for 60 days consecutively at rate of 3% body weight. Results cleared an enhancement of growth parameters of fish treated with anise oil, where final body weight, weight gain and average daily gain were increased and feed conversion ratio was decreased significantly than control groups even under hypoxic conditions. Moreover, groups that received anise oil showed stronger immunity against A. hydrophila infection synchronized with developed antioxidative capacity, where results indicated a significant increase in WBCs in all treated groups and globulin in a dose-dependent manner under hypoxic conditions. Additionally, using oil at a concentration of 2 ml/kg diet considerably raised superoxide dismutase (SOD) level under normal and hypoxic conditions and lowered the level of nitric oxide (NO) after challenge with bacteria at a concentration of 1 ml/kg diet at NDO and at 2 ml/kg diet at LDO.

A 6-week feeding trial was conducted on One hundred and eighty (180) Cobb broilers to evaluate the effects of Neem (Azadirachta indica) decoction (AID) and Akakapenpen (Rauvolfia vomitoria) decoction (RVD) on body weight gain, carcass and organ characteristics and haematological values of broiler chickens. The leaves of Azadirachta indica and Rauvolfia vomitoria were harvested and dried in the sun until they became crispy but still greenish in coloration. They were washed and then boiled (40 g of chopped leaves in 9L of water). The decoctions were placed in separate sterilized bottles ready for use and were offered ad libitum. The birds were randomly distributed to the treatments with twenty (20) birds per replicate, with each treatment replicated three times in a Completely Randomized Design (CRD). The total replacement of antibiotics and coccidiostat resulted in non-significant depression (p<0.05) in final body weight and weight gain in experimental birds. However, feed intake was slightly affected (p<0.05) by administration of RVD to broilers. There was no significant effect of decoctions on water intake, feed conversion efficiency and mortality. Decoction had no significant influence on the dressing percentage, weights of crop (full), heart, proventriculus (full), intestines (full), feet and head. Decoction however, significantly affected gizzard (both full and empty), crop (empty), liver, kidney and proventriculus (empty). Liver and gizzard weights significantly increased with the inclusion of AID and RVD in water. Apart from WBC and Lymphocytes which were significantly influenced by decoction, the other blood parameters did not show any significant difference. This study suggests that AID and RVD replacement to antibiotics and coccidiostat may have beneficial effects on body weight gain and feed conversion efficiency. Total comparative profit derived from replacing antibiotics + coccidiostat with AID and RVD resulted in economic gains.

The optimal feeding regime for large yellow croaker Larimichthys crocea, with an emphasis on obviating raw fish diet in commercial farming

This study was carried out to investigate the effects of dietary energy levels ongrowth performance, blood parameter, and intestinal morphology of Pekin ducks inlow temperature. A total of 500, 21-d-old Pekin ducks (initial BW = 1,089± 5.21 g) were evenly assigned to five dietary treatments (2,950, 3,000,3,050, 3,100, or 3,150 kcal AME/kg, calculated on an as-is basis) with fourreplicates (pens) for each treatment (25 ducks per pen). During the experiment,hens were provided with feed and water ad libitum. Overall,increasing dietary energy levels corresponded to an increase of final bodyweight and body weight gain (linear, p < 0.01). Feedintake decreased (linear, p < 0.01) and feed conversionratio increased (linear, p < 0.01) with increasinglevels of energy. There were no significant differences (p< 0.05) in the level of leukocytes between groups. However, heterophilsdecreased (quadratic, p < 0.05) and lymphocytesincreased (linear, p < 0.01) as inclusion of dietaryenergy levels increased. The H/L ratio increased (linear, p< 0.01) with increasing dietary energy levels while serum corticosteronelevels decreased at overall experimental periods. Triglycerides increased(linear and quadratic, p < 0.05) with increasing dietaryenergy levels. There were no significant changes in villus height or crypt depthof the jejunum at overall experimental. In conclusion, increasing concentrationsof dietary energy levels up to 2,950–3,150 kcal/kg in diet. Additionally,3,150 kcal/kg dietary energy had been revealed more beneficial and could bepracticed as protective management for the Pekin ducks reared under low ambienttemperature (8°C to 10°C).

Growing concerns over antibiotic resistance and environmental sustainability have increased the demand for natural alternatives to in-feed antibiotics in poultry production. Biochar offers a novel, eco-friendly solution that may improve animal performance while supporting waste valorization. This study investigated the effect of biochar produced from pistachio by-product (PB) on growth, feed efficiency, and gut health in Japanese quails. Birds were assigned to five dietary treatments including a control diet without additives, a diet with 0.05% flumequine, and diets supplemented with 0.35%, 0.65%, or 1% PB biochar for 35 days. Feed intake, weight gain, feed conversion ratio (FCR), carcass traits, nutrient digestibility, intestinal histomorphology, and cecal microbial counts were evaluated. The results showed that final body weight and weight gain significantly increased in birds fed 0.65% biochar compared to the control and flumequine groups (P < 0.05). A trend towards a lower FCR was observed in birds fed 0.65% biochar compared with the control (P = 0.08). Except for the weight of the breast and thigh, none of the carcass traits and internal organs were affected by the treatments (P > 0.05). Preplanned comparisons between control and biochar-treated groups showed that PB biochar significantly increased Lactobacillus populations while reducing E. coli counts in the cecum (P < 0.05). Ileal digestibility of crude protein (CP) and crude fiber (CF) also enhanced with the inclusion of biochar in the diets compared to the control (P < 0.05). Dietary inclusion of PB biochar increased cecal and ileal villus height indicating improved gut morphology (P < 0.05). The optimal inclusion level of PB biochar was found to be 0.65%, which showed significant improvements in growth and digestibility. Overall, this study provides insight into the potential of PB biochar as a promising alternative to antibiotics.

This trial was conducted to evaluate grape seed proanthocyanidins (GSPs) on alleviating the effects of dietary cadmium (Cd) induced growth retardation and oxidative stress in hepatopancreas of juvenile tilapia (Oreochromis niloticus). Two hundred and forty fish were randomly divided into four groups with four replicates in each group and 15 fish in each replicate. The four groups were: control group (fed with a basal diet), Cd group (fed with a basal diet+100 Cd mg/kg), Cd+ GSPs group I (fed with a basal diet+100 mg Cd/kg+400 mg GSPs/kg), and Cd+ GSPs group II (fed with a basal diet+100 mg Cd/kg+800 mg GSPs/kg). The trial period was 49 days. Final body weight and weight gain rate of Cd group were significantly affected (P&lt;0.05) compared with the control group. There was a significant difference in final body weight, weight gain rate, and feed conversion rate between the Cd (control) group and the two GSPs groups (P&lt;0.05). Feeding rate and survival rate of all groups was similar (P&gt;0.05). Levels of malondialdehyde, glutathione, and total antioxidation capacity and activities of superoxide dismutase, catalase, and glutathione peroxidase in hepatopancreas of the Cd group were affected significantly (P&lt;0.05). No significant differences in malondialdehyde level and antioxidant potential parameters (except glutathione peroxidase in Cd+GSPs group II) were found between control group and all GSPs supplemented groups (P&gt;0.05). Results indicate that dietary GSPs supplementation may alleviate dietary Cd-induced growth retardation and oxidative stress in hepatopancreas of tilapia.

Foram utilizadas 540 codornas fêmeas, com idade inicial de sete dias e peso médio de 21,50 g, durante 35 dias. O delineamento foi em blocos ao acaso, com cinco repetições e 18 aves por unidade experimental. Os tratamentos consistiram de seis relações metionina mais cistina digestível: lisina digestível (0,48, 0,53, 0,58, 0,63, 0,68 e 0,75). Foram estudadas as variáveis peso final (g), ganho de peso (g), consumo alimentar (g), conversão alimentar (g/g), empenamento (%), composição química corporal (matéria seca, água, proteína e extrato etéreo) e deposição de proteína e gordura corporais. Os tratamentos influenciaram de forma quadrática o consumo alimentar, a conversão alimentar, o empenamento, a composição química (matéria seca, água, proteína e extrato etéreo) e a deposição de proteína corporal, e linearmente o peso final e o ganho de peso das codornas. A melhor relação metionina mais cistina digestível: lisina digestível para as codornas japonesas em crescimento foi de 0,66, sendo a exigência em metionina mais cistina digestível estimada em 0,758%, para consumo de 91,43 mg de metionina mais cistina digestível.

Phytochemicals are used in fish farming to reduce stress and combat diseases during intensification. Recently, nanotechnology has represented a paradigm shift in the aquatic feed industry to improve the solubility, availability, and efficacy of phytochemicals. The purpose of this research was to investigate the effects of dietary supplementation with nano-curcumin (CUNE) on the growth, feed utilization, body composition, blood biochemistry, antioxidant status, disease resistance to Vibrio parahaemolyticus (V. parahaemolyticus), and the expression of insulin-like growth factor 1 (IGF-1), growth hormone (GH), interleukin-10 (IL-10), and interlukin-1β (IL-1β) genes in European Seabass (Dicentrarchus labrax) fingerlings. Fish (6.02±0.01) were randomly divided into four equal groups and fed varying levels of CUNE: 0 (CUNE0), 50 (CUNE1), 60 (CUNE2), and 70 mg/kg (CUNE3) of nano-curcumin for 56 days, respectively. The inclusion of dietary CUNE significantly improved the growth indices (final body weight and weight gain, and specific growth rate) and feed utilization (improved feed intake and lower FCR) of European seabass fingerlings (p<0.05). However, CUNE inclusion had no significant effect on body composition including the percentages of dry mater, crude protein, crude lipid, and ash (p>0.05). All CUNE groups established an enhancement in blood hematology in a dose-dependent manner, with CUNE3 demonstrating the highest values. CUNE supplementation (70 mg/kg diet) produced the highest levels of total protein, albumin, globulin, and triglycerides, as well as the lowest levels of glucose, and hepatic enzymes (ALT, AST, and ALP; p<0.05) compared to other groups. Furthermore, the CUNE-supplemented groups showed significant improvements in superoxide dismutase, catalase, and glutathione peroxidase, while reducing malondialdehyde (p<0.05). Additionally, the consumption of CUNE increased the expression of IGF-1, GH, and IL-10 genes in a dose-dependent manner (p<0.05). Interestingly, fish fed 70 mg of CUNE in their diets had lower expression of the IL-1β gene compared to the other groups (p<0.05). When the fish were challenged with V. parahaemolyticus, the addition of CUNE in their diets resulted in reduced mortality rates. Therefore, nano-curcumin could be considered as a natural feed additive to promote growth, feed utilization, and bacteria resistance via supporting antioxidant status, serum metabolites, and the regulation of GH, IL-10, and IGF-1 in the hepatic tissues of European seabass fingerlings.

Ameliorative effects of dietary Chlorella vulgaris and β-glucan against diazinon-induced toxicity in Nile tilapia (Oreochromis niloticus)

The present study was conducted to administer a commercial multi‐strain probiotic (MP), Yilibao (Bacillus velezensis:Bacillus cereus:Lactobacillus casei = 2:2:1), in Nile tilapia, Oreochromis niloticus. In terms of aerobic Bacillus spp. counts, we produced five diets containing 0, 0.34, 1.68, 3.36 and 6.72 g/kg of MP dry product (Control, T1, T2, T3, T4). Seven hundred and fifty tilapia juveniles (13.26 ± 0.01 g) distributed into 25 tanks in five replications were fed their diet for eight weeks. Results showed that fish fed T3 and T4 diets displayed significantly higher final body weight and weight gain (p < .05). Further, all MP‐treated fish exhibited remarkably decreased plasma lipid profiles (cholesterol, triglycerides) (p < .05) and fish fed T3 and T4 diets displayed significantly higher plasma myeloperoxidase activity and complement C3 content (p < .05). Additionally, fish fed T3 and T4 diets exhibited significantly promoted total antioxidant capacity, glutathione peroxidase activity, glutathione level and declined malondialdehyde content in the plasma and/or liver (p < .05). Moreover, significantly elevated chymotrypsin activity, villus height and intraepithelial lymphocytes counts were found in fish fed T3 and T4 diets (p < .05). As fish fed T3 and T4 diets surpassed the other treatments in growth, immune–antioxidative status and gut health, the recommended dose for tilapia is 3.36–6.72 g/kg.

This experiment was conducted to study the association of Ghrelin gene polymorphisms and expression levels with some productive and carcass traits of broiler chickens. Two hundred broiler chicks, one day old Ross308, were wing-tagged and reared under conventional conditions. Blood samples were collected individually of all birds to study of ghrelin gene polymorphisms by PCR-RFLP technique. Proventriculus was collected at 35 days of age from thirty birds of each groups sorted according to high, moderate and low growth rate to measure ghrelin gene expression by real-time RT-PCR. Result revealed that final body weight and weight gain were not significantly influenced by ghrelin gene , whereas body weight and weight gain of males and females with high ghrelin gene expression were significantly (p&lt;0.01) higher than those of moderate and low ghrelin gene expression at 21 and 35 days of age. Ghrelin gene polymorphisms had no significant (p&gt;0.05) influence on carcass traits and edible organ weights, while significant (P &lt; 0.01) differences were existed among high, moderate and low ghrelin gene expression groups in carcass weight, breast, wing, neck and back relative weights. It is concluded that PCR- RFLP technique revealed no significant effect for ghrelin gene polymorphisms on productive and carcass traits, whereas ghrelin gene expression had significant effect on productive traits.

Dietary glutamine improves growth and intestinal morphology of juvenile GIFT tilapia (Oreochromis niloticus) but has limited effects on innate immunity and antioxidant capacity