Evaluation of Spray-Dried Bovine Hemoglobin Powder as a Dietary Animal Protein Source in Nile Tilapia, Oreochromis niloticus

Alkalinity exposure induced growth inhibition, intestinal histopathological changes, and down-regulated nutrient transporter expression in Nile Tilapia: The ameliorative role of dietary camel whey protein hydrolysates

Alkaline stress impairs fish productivity and performance and, therefore, is considered one of the major challenges facing aquaculture. In this work, the effects of supplementing diets with camel whey protein hydrolysates (WPH) on growth, digestion, antioxidant capacity, and gene expression were investigated in Nile tilapia (Oreochromis niloticus) under alkaline stress. A total of 160 fish (16.17 ± 0.29 g) were equally assigned into four treatments, with 10 fish in each replicate. The control (C) and WPH groups received the basal diet supplemented with 0 and 75 g/kg WPH, respectively, and were reared in freshwater with an alkalinity of 1.4 mmol NaHCO3/L. The alkaline-exposed (AK) and AK + WPH groups were subjected to alkaline water (alkalinity = 23.8 mmol NaHCO3/L) and fed basal and WPH diet, respectively. Alkaline stress depressed the growth performance, digestive enzyme activity, intestinal Lactobacillus count, intestinal morphometrics, growth hormone level, and antioxidant enzyme activity but enhanced leptin hormone level and malondialdehyde (MDA) concentrations in Nile tilapia. Alkaline stress also downregulated the transcription of key intestinal transporter genes. Dietary supplementation with WPH significantly improved growth, digestive enzyme activity, antioxidant capacity, and the gene expression profile of Nile tilapia under alkaline stress. Based on the current results, it was concluded that WPH diet could mitigate negative effects caused by alkaline stress in Nile tilapia, which might support its application as an effective functional protein replacement candidate in aquaculture.

Antagonistic Effect of Zinc Oxide Nanoparticles Dietary Supplementation Against Chronic Copper Waterborne Exposure on Growth, Behavioral, Biochemical, and Gene Expression Alterations of African Catfish, Clarias gariepinus (Burchell, 1822)

The harmful impact of waterborne copper (Cu) as a common abiotic stressor in aquatic environments has gained much more interest. The present study aimed to investigate the utilization of zinc oxide nanoparticles (ZnONPs) dietary supplementation to mitigate the chronic toxicity of Cu in African catfish (Clarias gariepinus). Two hundred and forty fish (92.94 ± 0.13 g) were assigned into six groups for 60 days. Control (C), ZnONPs20, and ZnONPs30 groups were fed on basal diets fortified with 0, 20, and 30 mg kg-1 ZnONPs without Cu exposure. Cu, Cu + ZnONPs20, and Cu + ZnONPs30 groups were exposed to Cu at a dose of 10 mg L-1 and fed on basal diets fortified with 0, 20, and 30 mg kg-1 ZnONPs, respectively. The results revealed that the Cu-exposed fish experienced abnormal clinical signs and behavioral changes. The growth indices and acetylcholine esterase activity were significantly decreased (P < 0.05) in the Cu group. Meanwhile, hepatorenal and serum stress indices (P < 0.05) were significantly elevated with chronic Cu exposure. In addition, a higher expression of stress (P < 0.05) (heat shock protein 60 and hypoxia-inducible factor-1 alpha) and apoptotic-related genes (C/EBP homologous protein, caspase-3, and Bcl-2 Associated X-protein) with down-regulation (P < 0.05) of the anti-apoptotic-related genes (B-cell lymphoma 2 and proliferating cell nuclear antigen) was noticed in the Cu-exposed fish. Histopathological alterations in the gills, liver, kidney, and spleen were markedly reported in the Cu-exposed group. The dietary supplementation with ZnONPs significantly alleviated the negative impacts of chronic waterborne-Cu exposure on growth performance, physiological changes, gene expression, and tissue architecture, especially at 30 mg kg-1 diet level. In particular, the inclusion of ZnONPs at the 30 mg kg-1 diet level produced better outcomes than the 20 mg kg-1 diet. Overall, ZnONPs could be added as a feed supplement in the C. gariepinus diet to boost the fish's health and productivity and alleviate the stress condition brought on by Cu exposure.

Identification of novel antioxidant and anti-inflammatory peptides from bovine hemoglobin by computer simulation of enzymolysis, molecular docking and molecular dynamics

Due to the structural diversity and complex mechanisms of action of bioactive peptides, screening for specific functional peptides is often challenging. To efficiently screen bioactive peptides with antioxidant and anti-inflammatory effects from bovine hemoglobin, we employed bioinformatics methods to perform virtual enzymatic hydrolysis using online tools and predicted the bioactivity, toxicity, and sensitization scores of the resulting peptides. Molecular docking and molecular dynamics simulations with Keap1 and TLR4 were subsequently conducted to screen for antioxidant and anti-inflammatory peptides. Finally, peptides ARRF and ARNF were synthesized using the Fmoc solid-phase method. The oxidative stress and inflammation model in RAW264.7 cells was induced using lipopolysaccharide (LPS), followed by treatment with peptides ARRF and ARNF to verify their antioxidant and anti-inflammatory activities. The results demonstrated that 529 bovine hemoglobin oligopeptides were produced following virtual enzymatic hydrolysis, of which nine were identified as eligible based on predictions of biological activity, toxicity, solubility, and sensitization. Molecular docking results indicated that the oligopeptides ARNF, QADF, and ARRF exhibited favorable interactions with Keap1, while ARNF, RRF, and ARRF showed strong interactions with TLR4. The primary active sites binding to the Keap1 receptor included Val465, Thr560, and Gly464. The main active sites binding to the TLR4 receptor were Asn309, Asn305, and Glu286. Hydrogen bonding, electrostatic interactions, and hydrophobic interactions were identified as the primary modes of interaction between the oligopeptides and the Keap1 and TLR4 receptors. Molecular dynamics simulations further confirmed that the selected bovine hemoglobin peptides could stably bind to Keap1 and TLR4 receptors. Cell experiments demonstrated that ARRF and ARNF effectively ameliorated LPS-induced oxidative stress and inflammation in RAW264.7 cells.

Conclusion

Compared to traditional methods, this study promptly screens bovine hemoglobin antioxidant and anti-inflammatory peptides, offering a novel approach for rapidly identifying food-derived bioactive peptides.

Simultaneous Determination of Animal Products from Ruminant, Pig, Poultry, and Fish in Feedingstuff by Targeted High-Resolution LC-MS/MS

The prohibition of processed animal proteins (PAPs) has been relaxed gradually since 2007. The official control method for PAPs in feedingstuff, a combination of light microscopy (LM) followed by PCR, is no longer sufficient. Thus, a targeted LC-MS/MS method was developed, which enables a tissue-specific distinction between egg and dairy products, gelatine, and PAPs derived from blood or muscle tissue of the species ruminants, pigs, poultry, and fish. Tissue-specific proteins were analyzed after tryptic digestion to peptides with high-resolution ESI-QTOF-MS. A targeted method was developed based on untargeted proteomics approaches and the selection of specific peptides (45 unique peptides in total). Proficiency testing of blank and spiked samples revealed excellent results for trueness and selectivity. Furthermore, sensitivity was achieved at a level of 0.1% (w/w) for assessed peptides. Summing up, the developed method seems to be suitable for routine analysis after verification by ring trials.

Effect of dietary intervention with Capsicum annuum extract on growth performance, physiological status, innate immune response, and related gene expression in Nile tilapia

The red pepper (Capsicum annuum) has gained great attention recently because of its biological and pharmacological characteristics. The present approach aimed to evaluate the effects of C. annuum alcoholic extract (CAE) supplementation on Nile tilapia (Oreochromis niloticus) growth performance, physiological status, some metabolic, immune, and regulatory genes expression, and resistance against Streptococcus agalactiae infection. Fish (22.26 ± 0.19 g) were assigned to four treatments (five replicates, each with 10 fish replicate-1) and fed tested diets for 60 days. The experimental diets were supplemented with CAE at 0, 0.4, 0.8, and 1.6 g kg-1, expressed as CAE0, CAE0.4, CAE0.8, and CAE1.6, respectively. The findings exhibited that CAE dietary supplementation improved growth performance, feed utilization, elevated growth hormone level, and digestive enzyme activities (amylase and protease), and lowered leptin hormone in a level-dependent manner. Boosting the mRNA expression of the transporter proteins (solute carrier family 15 member 2 and solute carrier family 26 member 6) and insulin-like growth factor-1 genes with a decrease in the myostatin gene expression was noticed in the CAE-fed groups. The innate immune (serum bactericidal activity %, complement 3, and phagocytic activity %) and antioxidant (glutathione peroxidase and total antioxidant capacity) parameters were significantly (p < 0.05) improved, and the serum malondialdehyde level was significantly decreased by CAE dietary inclusion. A marked upregulation in the mRNA expression of interleukins (il-1β, il-6, il-8, and il-10), transforming growth factor-β, glutathione peroxidase, and glutathione synthetase genes were observed in CAE-fed groups. Dietary CAE decreased the cumulative mortalities after the challenge with S. agalactiae by 20, 13.33, and 10% in CAE0.4, CAE0.8, and CAE1.6, respectively, compared to the control (40%). Overall, dietary supplementation with CAE could improve growth performance and physiological status, and modulate the expression of several regulatory genes in Nile tilapia. The recommended level of CAE is 1.6 g kg-1 to augment growth and health status.

Potential role of dietary Boswellia serrata resin against mancozeb fungicide-induced immune-antioxidant suppression, histopathological alterations, and genotoxicity in Nile tilapia, Oreochromis niloticus

This study was established to look into the toxicological consequences of chronic exposure to a fungicide (mancozeb; MAZ) on the immune-antioxidant response, gene expressions, hepato-renal functions, and histological pictures of Nile tilapia (Oreochromis niloticus). Additionally, the effectiveness of Indian frankincense resin extract (IFRE) to mitigate their toxicity was taken into account. Fish (n =240; average body weight: 22.45 ± 2.21 g) were randomized into four groups for eight weeks in six replicates (control, IFRE, MAZ, and IFRE + MAZ), where ten fish were kept per replicate. The control and IFRE groups received basal diets that included 0.0 and 5 g/kg of IFRE without MAZ exposure. The MAZ and IFRE+MAZ groups received the same diets and were exposed to 1/10 of the 96-h of LC50 of MAZ (1.15 mg/L). The outcomes displayed that MAZ exposure resulted in a lower survival rate (56.67 %) and significantly decreased levels of immune-antioxidant variables (antiprotease, complement3, phagocytic activity, lysozyme, glutathione peroxidase, superoxide dismutase, and total antioxidant capacity) compared to the control group. The MAZ-exposed fish showed the greatest levels of lipid peroxide (malondialdehyde), alkaline phosphatase, alanine amino-transferase, and stress indicators (cortisol and glucose). Additionally, histopathological alterations, including vacuolation, severe necrosis, degeneration, and mononuclear cell infiltrations in the hepatic, renal, and splenic tissues resulted, besides a reduction in the melanomacrophage center in the spleen. A down-regulation of immune-antioxidant-associated genes [toll-like receptors (TLR-2 and TLR-7), nuclear factor kappa beta (NF-κβ), transforming growth factor-beta (TGF-β), phosphoinositide-3-kinase regulatory subunit 3 gamma b (pik3r3b), interleukins (IL-1β and IL-8), glutathione synthetase (GSS), glutathione peroxidase (GPx), and superoxide dismutase (SOD)] were the consequences of the MAZ exposure. Remarkably, the dietary inclusion of IFRE in MAZ-exposed fish augmented the immune-antioxidant parameters, including their associated genes, decreased stress response, and increased survival rate (85 %) compared with the MAZ-exposed fish. Moreover, dietary IFRE improved hepato-renal function indices by preserving the histological architecture of the hepatic, renal, and splenic tissues. The insights of this study advocate the use of an IFRE-dietary addition to protect Nile tilapia from MAZ toxicity, which provides perspectives for future implementations in enhancing fish health for sustainable aquaculture.

Using Azadirachta indica protein hydrolysate as a plant protein in Nile tilapia (Oreochromis niloticus) diet: Effects on the growth, economic efficiency, antioxidant-immune response and resistance to Streptococcus agalactiae

A feeding trial for 90 days was conducted on Nile tilapia (Oreochromis niloticus) (average weight: 25.50 ± 0.05 g) to evaluate the effect of dietary inclusion of Azadirachta indica seed protein hydrolysate (AIPH). The evaluation included the impact on the growth metrics, economic efficiency, antioxidant potential, hemato-biochemical indices, immune response, and histological architectures. A total of 250 fish were randomly distributed in five treatments (n = 50) and received diets included with five levels of AIPH (%): 0 (control diet, AIPH0), 2 (AIPH2), 4 (AIPH4), 6 (AIPH6) or 8 (AIPH8), where AIPH partially replace fish meal by 0, 8.7%, 17.4%, 26.1%, and 34.8%, respectively. After the feeding trial, a pathogenic bacterium (Streptococcus agalactiae, 1.5 × 108 CFU/mL) was intraperitoneally injected into the fish and the survival rate was recorded. The results elucidated that AIPH-included diets significantly (p < 0.05) enhanced the growth indices (final body weight, total feed intake, total body weight gain, and specific growth rate) and intestinal morpho-metrics (villous width, length, muscular coat thickness, and goblet cells count) in comparison to the control diet, with the AIPH8 diet recording the highest values. Dietary AIPH inclusion significantly improved (p < 0.05) the economic efficacy indicated by reduced feed cost/kg gain and increased performance index. The fish fed on the AIPH diets had noticeably significantly higher (p < 0.05) protein profile variables (total proteins and globulin) and antioxidant capabilities (superoxide dismutase and total antioxidant capacity) than the AIPH0 group. The dietary inclusion of AIPH significantly (p < 0.05) boosted the haematological parameters (haemoglobin, packed cell volume %, and counts of red blood cells and white blood cells) and immune indices (serum bactericidal activity %, antiprotease activity, and immunoglobulin M level) in a concentration-dependent manner. The blood glucose and malondialdehyde levels were significantly (p < 0.05) lowered by dietary AIPH (2%-8%). The albumin level and hepatorenal functioning parameters (aspartate aminotransferase, alanine aminotransferase, and creatinine) were not significantly (p > 0.05) altered by AIPH diets. Additionally, AIPH diets did not adversely alter the histology of the hepatic, renal or splenic tissues with moderately activated melano-macrophage centres. The mortality rate among S. agalactiae-infected fish declined as dietary AIPH levels rose, where the highest survival rate (86.67%) was found in the AIPH8 group (p < 0.05). Based on the broken line regression model, our study suggests using dietary AIPH at the optimal level of 6%. Overall, dietary AIPH inclusion enhanced the growth rate, economic efficiency, health status, and resistance of Nile tilapia to the S. agalactiae challenge. These beneficial impacts can help the aquaculture sector to be more sustainable.

Microbiota plasticity in tilapia gut revealed by meta-analysis evaluating the effect of probiotics, prebiotics, and biofloc

Tilapia species are among the most cultivated fish worldwide due to their biological advantages but face several challenges, including environmental impact and disease outbreaks. Feed additives, such as probiotics, prebiotics, and other microorganisms, have emerged as strategies to protect against pathogens and promote immune system activation and other host responses, with consequent reductions in antibiotic use. Because these additives also influence tilapia's gut microbiota and positively affect the tilapia culture, we assume it is a flexible annex organ capable of being subject to significant modifications without affecting the biological performance of the host. Therefore, we evaluated the effect of probiotics and other additives ingested by tilapia on its gut microbiota through a meta-analysis of several bioprojects studying the tilapia gut microbiota exposed to feed additives (probiotic, prebiotic, biofloc). A total of 221 tilapia gut microbiota samples from 14 bioprojects were evaluated. Alpha and beta diversity metrics showed no differentiation patterns in relation to the control group, either comparing additives as a group or individually. Results also revealed a control group with a wide dispersion pattern even when these fish did not receive additives. After concatenating the information, the tilapia gut core microbiota was represented by four enriched phyla including Proteobacteria (31%), Fusobacteria (23%), Actinobacteria (19%), and Firmicutes (16%), and seven minor phyla Planctomycetes (1%), Chlamydiae (1%), Chloroflexi (1%), Cyanobacteria (1%), Spirochaetes (1%), Deinococcus Thermus (1%), and Verrucomicrobia (1%). Finally, results suggest that the tilapia gut microbiota is a dynamic microbial community that can plastically respond to feed additives exposure with the potential to influence its taxonomic profile allowing a considerable optimal range of variation, probably guaranteeing its physiological function under different circumstances.

Chemical Composition and Functional Properties of Spray-Dried Animal Plasma and Its Contributions to Livestock and Pet Health: A Review

Spray-dried animal plasma (SDAP) is a functional ingredient derived from healthy animal blood, used as a nutritional additive in livestock and pet nutrition. SDAP is rich in macronutrients, micronutrients, and bioactive compounds such as immunoglobulins, albumin, growth factors, peptides, transferrin, and enzymes. This review focuses on the chemical composition of SDAP from porcine, bovine, and poultry sources, including protein quality and mineral profile. SDAP enhances performance and health in monogastric farm animals, aquaculture, and pets. It promotes growth rates and feed intake due to its high digestibility and superior amino acid profile compared to other protein sources. In pigs, SDAP's positive effects stem from tissue-specific actions in the gastrointestinal tract, impacting digestion, immunity, and barrier function. For poultry, SDAP shows promise as a substitute for antibiotic growth promoters, particularly in chick starter diets. SDAP contains functional proteins that regulate immune response, enhance intestinal health, and aid in stress conditions. It is also used as a binder in pet food, providing high protein content and other desirable properties. SDAP meets the dietary requirements of carnivorous pets, appealing to owners seeking animal-derived protein sources. Additionally, SDAP may help prevent cognitive impairment in senior dogs and cats.