The Immunostimulatory Effects of Commercial Feed Additives on Growth Performance, Non-specific Immune Response, Antioxidants Assay, and Intestinal Morphometry of Nile tilapia, Oreochromis niloticus

Dietary effects of Saccharomyces cerevisiae and Allium sativum on growth, antioxidant status, hepatic and intestinal histoarchitecture, expression of growth- and immune-related genes, and resistance of Oreochromis niloticus to Aeromonas sobria

This study investigated the benefits of yeast, Saccharomyces cerevisiae and/or garlic, Allium sativum supplementation in diets of Nile tilapia with regard to growth, antioxidant status, hepatic and intestinal histoarchitecture, expression of growth- and immune-related genes, and resistance to Aeromonas sobria infection. Fish (with an initial weight of 9.43 ± 0.08 g) were allocated to twelve hapas, organized into four triplicate treatment groups defined as control (no supplementation), yeast (4 g/kg diet), garlic (30 g/kg diet), and a mixture of both. This trial continued over a 60-day feeding period. Results revealed that combined treatment (yeast + garlic) demonstrated the most promising outcomes regarding growth, with significantly higher final body weights, weight gains, and specific growth rates compared to other groups. Moreover, this combination enhanced hepatic antioxidant status, as evidenced by elevated levels of reduced glutathione and activities of catalase and superoxide dismutase enzymes, reflecting improved defense against oxidative stress. Histological assessments of the livers and intestines demonstrated structural enhancements in yeast and garlic treatments, suggesting improvements in organ health. In comparison to the control, the gene expression analyses unveiled increased expression of growth-related (igf-1 and ghr1) and immune-related (il-10, lyz, and hep) genes in the test groups, indicating a possible reinforcement of the growth and immune responses. The combined treatment also showed the highest resistance to A. sobria infection, as evidenced by improved survival rates and lower mortality compared with the other groups. These findings highlight the benefits of a combination of both yeast and garlic as a dietary supplementation regimen. In conclusion, this study suggests that the combined treatment regimen could be considered an effective strategy to promote the health and productivity of Nile tilapia under production conditions.

Effect of Fish-Based Diet on Malnourished Children: A Systematic Review

Background

Malnutrition in children is mainly caused by the lack of protein and fat intake which harms their ability to grow and survive. Accurate data on the benefits of fish-based foods on the nutritional status of children is limited. The present systematic review aimed to provide an overview of published articles on the nutritional value of fish-based foods for children.

Methods

A systematic review was performed during 2000-2021 by searching Science Direct, Cochrane Library, PubMed, ProQuest, and Wiley Online Library databases. The full text of selected articles in English was screened based on the inclusion and exclusion criteria. Included articles were all experimental studies (randomized control trial, quasi-randomized trial) or mixed methods studies involving malnourished children. The study was reported under the preferred reporting items for systematic reviews and meta-analyses guidelines. The risk of bias was assessed using the Cochrane tool.

Results

A total of 330,859 articles were screened, out of which eight articles were included in the systematic review. Interventions included fish-based foods and beverages such as wafer bars, Jemawut-tuna cookies, Amizate in chocolate drink, dried fish powder, flaxseed oil supplemented with fish oil capsules, and porridge fortified with fish powder. Primary or secondary outcomes were the determination of zinc level, height growth, erythrocyte n-3 polyunsaturated fatty acid content, safety and acceptability, intestinal integrity, and cognitive development. The results showed that dried fish powder produced the most significant effect on body weight.

Conclusion

The consumption of dried fish powder had positive effects on the recovery of malnourished children.

Nutritional impact of nano zeolite, probiotic, and fatty acids as feed additives on health status of Nile tilapia (Oreochromis niloticus)

For human consumption, fish is a good and affordable source of several crucial elements. Growing aquaculture management and output is always necessary. Therefore, this study was designed to evaluate the effect of probiotics, nano zeolite, and/or medium chain fatty acids (MCFA) on fish health and the chemical composition of the fish body. The experimental fish were distributed into eight groups. T1: Control group fed the basal diet without feed additives, T2: Nano zeolite at a rate of 2 mg/kg diet, T3: Pedococcus at a rate of 2 gm kg diet, T4: Medium chain fatty acids used according to produced company recommendation at a rate of 3.5 gm/kg diet, T5: Nano zeolite (2 mg/kg diet) + Pedococcus (2 mg/kg diet), T6: Nano zeolite (2 mg/kg diet) + Medium chain fatty acids (3.5 gm/kg diet), T7: Pedococcus (2 mg/kg diet) + Medium chain fatty acids (3.5 gm/kg diet), and T8: Nano zeolite (2 mg/kg diet) + Pedococcus (2 mg/kg diet) + Medium chain fatty acids (3.5 gm/kg diet). The obtained results showed an insignificant difference in the body composition of Nile tilapia fish fed feed additives alone or in combination. Moreover, the feed additives did not affect the health status of fish, as indicated by normal liver and kidney functions.

Effects of exogenous bile acids (BAs) on growth, lipid profile, digestive enzymes, and immune responses of thinlip mullet, Liza ramada

An eight-week trial was designed to explore the dietary effects of commercially purchased exogenous bile acids (BAs) on growth, whole-body composition, lipid profile, intestinal digestive enzymes, liver function enzymes, oxidative stress biomarkers, and serum immunity of thinlip mullet, Liza ramada. Four triplicate groups (10.50 ± 0.05 g) were fed four soybean meal (SBM)-based diets supplied with several BAs levels at 0 (control), 50, 130, or 350 mg/kg feed. Results indicated that the growth was significantly increased in groups fed BAs-based diets, especially at 130 mg/kg feed. The body composition analysis showed that feeding fish on diets supplied with BAs up to 130 mg/kg decreased moisture (%) alongside increased crude protein (%). However, the body composition of fish fed a diet with 350 mg BAs/kg had the lowest moisture (%) and the highest crude protein (%). Moreover, there were significant increases in the intestinal (protease, α-amylase, and lipase) enzyme activities in the groups supplied with BAs up to 130 mg BAs/kg. Liver function enzymes (aspartate aminotransferase and alanine aminotransferase enzyme activities) were significantly decreased in BAs-supplemented groups compared to those fed the BAs-free group. On the other hand, the control group had higher total cholesterol, triglycerides, and low-density lipoprotein alongside the lower high-density lipoprotein than BAs-supplemented groups, especially at 350 mg BAs/kg feed. BAs significantly decreased hepatic malondialdehyde concentrations and increased the activity of hepatic catalase, superoxide dismutase, and total antioxidant capacity compared with those reared on the control diet. Serum lysozyme, respiratory burst, and alternative complement activities were significantly increased in BAs-supplied groups, particularly in the group supplied with 130 mg BAs/kg compared to those fed on the control diet. Accordingly, our findings recommend that including 130 mg BAs/kg in an SBM-based diet enhanced the growth, digestive enzyme activities, and liver functions, alleviated oxidative stress, boosted serum immunity, and lowered lipid metabolites in thinlip mullet. These findings will be beneficial for improving the quality of feed prepared for feeding mullets and an effective alternative strategy to support mullet farming.

Effects of L-ascorbic acid on growth, non-specific immunity, antioxidant capacity, and intestinal and hepatopancreatic histology of red swamp crayfish, Procambarus clarkii

This study investigated the dietary effects of coated L-ascorbic acid (LA) on growth, feed utilization, survival, serum biochemical indices, immunity, antioxidant capacity, and intestinal and hepatopancreatic histology of the pre-adult red swamp crayfish. Four isoproteinous and isolipidic diets were formulated to contain several LA levels as 0, 1300, 1600, and 1900 mg/kg and designated as control (LA0), LA13, LA16, and LA19, respectively. However, the analyzed LA concentrations in diets were 0.00, 199.57, 360.45, and 487.50 mg/kg in LA0, LA13, LA16, and LA19, respectively. Triplicate treatments of crayfish (21.60 ± 0.14 g) were fed the test diets and reared in fiberglass tanks with a density of 20 individuals per each for eight weeks. Results revealed that all LA treatments had significantly enhanced growth performance compared to the control. Of interest, the LA16 treatment recorded the highest final tank biomass, biomass gain, total feed intake, condition factor, and muscle yield among the other treatments. The tank feed conversion ratio was significantly decreased in LA treatments compared to the control. Moreover, dietary LA16 and LA19 had significantly higher survival rates (93.3%) compared to (85.0%) in the LA0 group. All dietary doses of LA significantly increased serum parameters (total protein, albumin, globulin, lysozyme activity) and respiratory burst activity compared to the LA0 treatment. Dietary LA16 significantly boosted the hepatopancreatic antioxidant capacity, manifested by decreased malondialdehyde concentrations, increased catalase, superoxide dismutase, and glutathione peroxidase enzyme activities, and reduced glutathione content compared to the LA-free diet. A normal histoarchitecture of the hepatopancreatic tubules was found in all LA treatments except with some minor degenerative changes in the tubular lumen, and hepatopancreatic cells associated with enlarged nuclei were found in the LA19. However, normal intestinal histoarchitecture was found in all treatments with no recorded intestinal lesions. Of interest, the polynomial regression performed on the analyzed LA concentrations suggested that 380 mg/kg would be suitable to provide maximal biomass gain for pre-adult crayfish. In conclusion, results revealed that coated LA could enhance the growth, immunity, and antioxidant capacity of pre-adult red swamp crayfish, suggesting its potential as a functional and necessary micronutrient for crayfish diets.

Nano-selenium impacts on growth performance, digestive enzymes, antioxidant, immune resistance and histopathological scores of Nile tilapia, Oreochromis niloticus against Aspergillus flavus infection

The present study examined the impacts of varying amounts of selenium nanoparticles (Se-NPs) as a natural antioxidant and metabolic regulator on growth performance, antioxidant capacity, digestive enzymes and immune resistance of Oreochromis niloticus challenged to Aspergillus flavus infection. For 60 days, fish were fed the experimental diet of 30% crude protein up to apparent satiation three times a day. Se-NPs were added to the control diet at different levels of 0.0 (control), 0.5 (T1), 1.0 (T2) and 1.5 (T3) mg/kg diet to fed monosex Nile tilapia fingerlings with average initial weight (4.5 ± 0.5 g). Fish were randomly distributed in 12 tanks 100 L at a density of 20 fish per tank after 2-week acclimation to represent four treatments in triplicates. The results indicated that the growth indices, feed efficiency and survival rate were significantly enhanced (P < 0.05) by incorporating Se-NPs up to 1 mg/kg diet. Furthermore, the haemato-biochemical parameters, digestive enzymes activity and antioxidant capacity of the fish were significantly improved (P < 0.05) at T2. When the fish were challenged with Aspergillus flavus, a decreasing mortality rate was observed, which clearly shows that selenium nanoparticles boosted the fish’s immune response at T2. The intestinal morphology as villus length, villus width, muscular fibres layer thickness and absorption intestinal zone after challenged with A. flavus infection were considerably enhanced (P < 0.05) by incorporating all Se-NP levels. Histopathological score significantly improved (P < 0.05) for the hepatopancreatic, intestinal, gills and muscle tissues at T2. The present study concludes that selenium nanoparticles up to 1.0 mg/kg diet can be efficiently used in tilapia feed to help boost fish production, immune system response and histopathological parameters.

Heat inactive Bacillus subtilis var. natto regulate Nile tilapia (Oreochromis niloticus) intestine microbiota and metabolites involved in the intestine phagosome response

In this study, we evaluated the intestinal microbiota, intestinal and fecal metabolites production and the intestinal RNA-seq analysis of the Nile tilapia intestine after feeding with 10⁵and 10⁷ of the inactive Bacillus subtilis var. natto. First, we assessed the influence of heat inactive Bacillus subtilis var. natto on the growth performance, biochemical blood analysis, and evaluated the liver/body, spleen/body and intestine/body ratio. This evidence was known feeding with inactive Bacillus subtilis var. natto was able to improve the growth performance after 4 weeks, but not to affect the inflammatory biochemical blood parametres total protein (T-pro), albumin (Alb), Alb/T-pro ratio, creatine-phospho-kinase (CPK) and lactate dehydrogenase (LDH). Further, in the intestine microbiota, the Lactobacillaceae, Firmicutes, Chromatiales, and Rhodobacteria, was significantly higher than the control and the Firmicutes/Bacteroidetes ratio (F/B), which was indicated with a significantly increased. The intestine tissue metabolites OPLS-DA analysis indicated that the prominent bioactive metabolites changed. The peonidin-3-glucoside, l-Tyrosine, 1-Deoxy-1-(N6-lysino)-d-fructose was significantly increased. The feces metabolite OPLS-DA analysis indicated that the palmitelaidic acid, 5-KETE, tangeritin was significantly increased. In the transcriptome, the Gene Ontology (GO) analysis was found to enhance the intestine intestinal immune network. Combine of these evidence, feeding of the heat inactive Bacillus subtilis var. natto exactly improved the O. niloticus growth performance and regulation of the microbiota to promote the metabolites. In the transcriptome analysis, it was found to involve in the intestine immune phagosome response. Summarized of this study, the heat inactive Bacillus subtilis var. natto was reported to affect Nile tilapia intestine microbiota, and could positively regulate the intestine and fecal metabolites production to improve the intestine immune network.

Subchronic Exposure to Polystyrene Microplastic Differently Affects Redox Balance in the Anterior and Posterior Intestine of Sparus aurata

Microplastics (MPs) are pollutants widely distributed in aquatic ecosystems. MPs are introduced mainly by ingestion acting locally or in organs far from the gastroenteric tract. MPs-induced health consequences for fish species still need to be fully understood. We aimed to investigate the effects of the subchronic oral exposure to polystyrene microplastics (PS-MPs) (1-20 μm) in the gilthead seabreams (Sparus aurata) used as the experimental model. We studied the detrimental impact of PS-MPs (25 and 250 mg/kg b.w./day) on the redox balance and antioxidant status in the intestine using histological analysis and molecular techniques. The research goal was to examine the anterior (AI) and posterior intestine (PI) tracts, characterized by morphological and functional differences. PS-MPs caused an increase of reactive oxygen species and nitrosylated proteins in both tracts, as well as augmented malondialdehyde production in the PI. PS-MPs also differently affected gene expression of antioxidant enzymes (i.e., superoxide dismutase, catalase, glutathione reductase). Moreover, an increased up-regulation of protective heat shock proteins (HSPs) (i.e., hsp70 and hsp90) was observed in PI. Our findings demonstrate that PS-MPs are responsible for oxidative/nitrosative stress and alterations of detoxifying defense system responses with differences in AI and PI of gilthead seabreams.

Assessment of Thepax and Bio Boost for promoting microbial growth in common carp intestines Cyprinus carpio

The study aimed to evaluate the effect of Thepax and BioBoost as food additives on the microorganisms in the intestines of fish. From March 4 to October 22, the total number of common carp was 900 fish with an average weight of 163.41 ±10.16 g and a density of 100 fish/cage; three replicates were used for each treatment. The fish were fed three times daily. The included T1(0%additive), T2(1g/kgThepax)and T3 (1 g/kgBioBoost). The highest final weight value is Thepax treatment (2209.34 g), followed by Bio Boost and control. Microorganisms showed significant differences (P<0.05) in T2 for Lactobacillus sp. (10² x 65 CFU/ml) followed by T3 (10² x 55 CFU/ml) and control T1 (10² x 23 CFU/ml), also for Cellulomonas sp. in T2 (10² x 54 CFU/ml) followed by T3 (10² x 39 CFU/ml) and control T1 (10² x 7 CFU/ml). At the same time, Aeromonas sp. bacteria was higher in T1 (10² x 34 CFU/ml) over the treatments of T2 and T3 (10² x 2 CFU/ml) for both. We concluded the best additive was 1 g of Thepax / kg of feed in the recommended diets for common carp. Keywords: Thepax; Additives; Microorganisms; Intestines; Bacteria; Lactobacillus; Endo Bio Boost

Fish Nutritional Value as an Approach to Children's Nutrition

Fish is a relatively cheap and accessible source of animal protein for human consumption even in rural communities. It is critical for global food and nutrition security, and its consumption continues to increase. As a highly nutritious food, fish consumption is highly recommended for children and expectant mothers for normal growth and development. The present paper explores the nutritional value of fish as approach to nutrition in children and its benefits. The findings reveal that fish is a valuable source of essential amino acids (EAA) and polyunsaturated fatty acids (PUFAs) that play important physiological functions for maintenance and development of fetuses, neonates, and infant brains. Therefore, it could be a valuable tool in the fight against food insecurity and malnutrition. However, fish and fish products are also highly susceptible to contamination by various organic and inorganic compounds that threaten public health. Particularly, heavy metals and biogenic amines (BAs) have shown adverse effects when contaminated fish is consumed, and the effects in children have been worse. Hence, while fish consumption is highly recommended for children's nutrition, the safety and quality of the product should always be checked to safeguard public health.

A review on the use of dried distiller’s grains with solubles (DDGS) in aquaculture feeds

Distiller’s dried grains with soluble (DDGS) to replace fishmeal (FM) or other plant protein sources and its effects on an aquatic animal’s growth performance and health system is rarely discussed. In recent times FM use in aquafeed has been a problem for the aquaculture industry because of the depletion of fish resources in the ocean and the high cost of FM. For that reason, researchers are focusing on reducing the cost of aquafeed production by lowering the inclusion of FM in aquafeed. One of the low-cost alternative protein sources to replace FM is DDGS. The present review discusses the compilation of available literature review and other works on the use of DDGS to replace FM in aquafeed and how it improves the growth performance, immune health system, and disease resistance in an aquatic animal. It focuses on the production of DDGS, the nutritional composition of DDGS, the chemical and physical characteristics of DDGS, and the effects of the DDGS inclusion in aquafeed on the aquatic animal. Apart from improving the growth performance of the aquatic animal when included in aquafeed, it also helps improve the immune health system of the animal. It also helps boost the immune system of the aquatic animal to fight diseases and increase disease resistance when included in aquafeed. Furthermore, DDGS also contains some constituents like carotenoids that help improve the meat quality of the animal when included in aquafeed. The current review also discusses the management and use of technology to improve the aquaculture industry, educate farmers on reducing diseases during the culturing periods, and increase productivity and profit in a friendly environment.