Dietary Mannan Oligosaccharide Research Articles

An Antioxidant Supplement Function Exploration: Rescue of Intestinal Structure Injury by Mannan Oligosaccharides after Aeromonas hydrophila Infection in Grass Carp (Ctenopharyngodon idella).

Mannan oligosaccharides (MOS) are a type of functional oligosaccharide which have received increased attention because of their beneficial effects on fish intestinal health. However, intestinal structural integrity is a necessary prerequisite for intestinal health. This study focused on exploring the protective effects of dietary MOS supplementation on the grass carp’s (Ctenopharyngodon idella) intestinal structural integrity (including tight junction (TJ) and adherent junction (AJ)) and its related signalling molecule mechanism. A total of 540 grass carp (215.85 ± 0.30 g) were fed six diets containing graded levels of dietary MOS supplementation (0, 200, 400, 600, 800 and 1000 mg/kg) for 60 days. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila for 14 days. We used ELISA, spectrophotometry, transmission electron microscope, immunohistochemistry, qRT-PCR and Western blotting to determine the effect of dietary MOS supplementation on intestinal structural integrity and antioxidant capacity. The results revealed that dietary MOS supplementation protected the microvillus of the intestine; reduced serum diamine oxidase and d-lactate levels (p < 0.05); enhanced intestinal total antioxidant capacity (p < 0.01); up-regulated most intestinal TJ and AJ mRNA levels; and decreased GTP-RhoA protein levels (p < 0.01). In addition, we also found several interesting results suggesting that MOS supplementation has no effects on ZO-2 and Claudin-15b. Overall, these findings suggested that dietary MOS supplementation could protect intestinal ultrastructure, reduce intestinal mucosal permeability and maintain intestinal structural integrity via inhibiting MLCK and RhoA/ROCK signalling pathways.

Evaluation of the prophylactic potential of non-enterotoxigenic Escherichia coli (non-ETEC) vaccine immunization and dietary mannan oligosaccharide competitive exclusion benefits against ETEC infections in weaned pigs

Enterotoxigenic Escherichia coli (ETEC) strains expressing F4 and F18 fimbriae are the most common causative agents of post-weaning diarrhoea (PWD) in pigs. The growing global restriction on the use of antibiotics in food animals has encouraged research into the development of nutritional and feeding strategies as well as vaccination against PWD. The aim of this study was to evaluate the efficacy of a live oral F4ac+ F18ac+ non-ETEC vaccine candidate (VAC) to stimulate gut and systemic cellular immunity in 4-week old pigs over 5 weeks following immunization. The onset and duration of protective immunity against on-farm occurring PWD, growth performance, diarrhoea scoring and mortality, as well as the phenotypic proportions of immune cells, were determined. Faecal and ileal samples were taken for determining the microbial composition or phenotyping of naïve/memory T cells. Also, the effect of prebiotic supplement mannan oligosaccharide (MOS) in the prevention of small intestinal colonization by ETEC, and its potential adjuvanticity in combination with the vaccine (VAC+MOS) were assessed. The pigs supplemented with MOS or that received VAC had significantly higher body weight (BW) (P&lt;0.05) on Day 14, whereas the VAC+MOS treated pigs had significantly lower BW on Day 35. Treatment with VAC+MOS resulted in considerably reduced clinical PWD, in particular the incidence and severity of diarrhoea and mortality. The total bacterial load in the ileum was much lower in the pigs from all 3 principal groups (MOS, VAC, and VAC+MOS) than in the control (CON) group (19 x 107, 17 x 107 and 12 x 107 vs. 23 x 108 CFU/mL, respectively) on Day 35. The pigs from the principal groups had significantly higher proportions of tested immune cells (P&lt;0.05) on Days 28 and 35. The localization and frequency of naive CD45RA+ and memory CD45RC+ T lymphocytes indicated their different distribution patterns within particular tissue structures, such as the villi, crypts, epithelium, lamina propria and areas (interfollicular follicular and Peyer’s patches) of ileal mucosa. This may indicate their different functions in intestinal immune responses to intraluminal microbes and their products, vaccinal immunogens and/or immunomodulators/adjuvants. To conclude, active mucosal immunity is needed to protect pigs against PWD. Hence, oral vaccination of pigs against both F4 and F18 ETEC, in combination with prebiotic supplementation represents a sustainable, practical and effective approach in PWD control.

Effect of dietary mannan oligosaccharide (MOS) on growth, digestive enzymes activity, innate immunity and disease resistance against virulent Aeromonas hydrophila in peninsular carp Barbodes carnaticus (Jerdon, 1849)

Effect of dietary mannan oligosaccharide (MOS) on growth, digestive enzymes activity, innate immunity and disease resistance against virulent Aeromonas hydrophila in peninsular carp Barbodes carnaticus (Jerdon, 1849)

Mannan Oligosaccharide Enhanced the Growth Rate, Digestive Enzyme Activity, Carcass Composition, and Blood Chemistry of Thinlip Grey Mullet (Liza ramada).

Simple SummarySustainable aquaculture requires natural alternative substances with high potential in enhancing the performance and wellbeing of aquatic animals. In this regard, the present study tested the possibility of using mannan oligosaccharides (MOS) in the diets of grey mullet as functional additives. For 8 weeks, fish were fed with enriched diets containing 0, 0.5, 1, and 2% MOS. The results showed marked improvements in the growth performance, digestive enzyme activity, blood chemistry, and antioxidative capacity. In conclusion, dietary MOS at 0.5–1% is required to enhance the productivity of grey mullet.Mannan oligosaccharide (MOS) is prebiotic with high functionality in aquaculture. The current study investigated the potential roles of MOS on the growth performance, digestive enzyme activity, carcass composition, and blood chemistry of Thinlip grey mullet (Liza ramada). Four tested diets with 34.49% crude protein and 6.29% of total lipids were prepared and fortified with 0, 0.5, 1, and 2% MOS. Fish of initial weight = 5.14 ± 0.11 g/fish were distributed in 12 hapas (0.5 × 0.5 × 1 m) at 15 fish per hapa (triplicates) and fed the test diets to the satiation level two times a day (08:00 and 15:00) for eight weeks. At the end of the trial, all fish were weighed individually for growth performance calculation. Blood was collected to check blood chemistry traits, and intestines were dissected for digestive enzyme analysis. Fish treated with MOS had marked enhancement in the final body weight, feed conversion ratio, protein gain, and protein retention regardless of inclusion dose (p < 0.05). The weight gain, specific growth rate, and protein efficiency ratio were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). Insignificant influences of MOS were seen on the chemical composition of carcass components (moisture, crude protein, total lipids, and ash) (p > 0.05). Fish treated with MOS at 0.5 and 1% had marked enhancement in the amylase, lipase, and protease activities regardless of inclusion dose (p < 0.05). The blood total protein and albumin levels were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). The blood globulin was significantly enhanced in fish fed 1% MOS than fish treated with 0, 0.5, and 2% of MOS (p < 0.05). The blood lysozyme activity was meaningfully enhanced by including MOS at 1%, followed by fish treated with 0.5 and 2%, while the lowest values were in the control group (p < 0.05). Phagocytic activity and phagocytic index were markedly improved in fish treated with 1 and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Superoxide dismutase and glutathione peroxidase were markedly improved in fish treated with 1, and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Dietary MOS (0.5, 1, and 2%) meaningfully enhanced catalase activity while decreased the malondialdehyde concentration (p < 0.05). In summary, dietary MOS is required at 0.5–1% for enhancing the growth rate, feed efficiency, digestive enzyme activity, blood chemistry, and antioxidative capacity of grey mullet.

Effects of Dietary Mannan Oligosaccharides on Non-Specific Immunity, Intestinal Health, and Antibiotic Resistance Genes in Pacific White Shrimp Litopenaeus vannamei.

This study was conducted to comprehensively investigate the beneficial effects of a mannan oligosaccharide product (hereinafter called MOS) on Litopenaeus vannamei and optimum level of MOS. Five isonitrogenous and isolipid diets were formulated by adding 0%, 0.02%, 0.04%, 0.08%, and 0.16% MOS in the basal diet. Each diet was randomly fed to one group with four replicates of shrimp in an 8-week feeding trial. The results showed that dietary MOS improved the growth performance and the ability of digestion of shrimp. Dietary MOS significantly increased the activity of total superoxide dismutase, catalase, and glutathione peroxidase and decreased the content of malondialdehyde in plasma of shrimp. Dietary MOS significantly increased the activity of alkaline phosphatase and lysozyme in plasma and the hemocyte counts. Dietary MOS significantly upregulated the expression of Toll, lysozyme, anti-lipopolysaccharide factor, Crustin, and heat shock protein 70 in the hepatopancreas. And dietary MOS significantly upregulated the expression of intestinal mucin-2, mucin-5B, and mucin-19, while it decreased the expression of intestinal mucin-1 and macrophage migration inhibitory factor. Dietary MOS improved the bacterial diversity; increased the abundance of Lactobacillus, Bifidobacterium, Blautia, and Pseudoalteromonas; and decreased the abundance of Vibrio in the intestine. Shrimp fed MOS diets showed lower mortality after being challenged by Vibrio parahaemolyticus. Notably, this study found a decrease in antibiotic resistance genes and mobile genetic elements after MOS supplementation for the first time. The present results showed that diet with MOS supplementation enhanced the organismal antioxidant capacity and immunity, improved intestinal immunity, optimized intestinal microecology, mitigated the degree of antibiotic resistance, and increased the resistance to V. parahaemolyticus in L. vannamei, especially when supplemented at 0.08% and 0.16%.

Mannan Oligosaccharides Application: Multipath Restriction From Aeromonas hydrophila Infection in the Skin Barrier of Grass Carp (Ctenopharyngodon idella).

The objective of this study was to evaluate the efficacy of dietary Mannan oligosaccharides (MOS) supplementation on skin barrier function and the mechanism of on-growing grass carp (Ctenopharyngodon idella). Five hundred forty grass carp were fed for 60 days from the growing stage with six different levels of MOS diets (0, 200, 400, 600, 800, and 1,000 mg kg-1). At the end of the growth trial, the 14-day Aeromonas hydrophila challenge experiment has proceeded. The obtained data indicate that MOS could (1) decline skin lesion morbidity after being challenged by the pathogenic bacteria; (2) maintain physical barrier function via improving antioxidant ability, inhibiting excessive apoptosis, and strengthening the tight junction between the epithelial cell and the related signaling pathway (Nrf2/Keap1, p38MAPK, and MLCK); and (3) regulate immune barrier function by modulating the production of antimicrobial compound and expression of involved cytokines and the related signaling pathway (TOR and NFκB). Finally, we concluded that MOS supplementation reinforced the disease resistance and protected the fish skin barrier function from Aeromonas hydrophila infection.

Effect of dietary mannan oligosaccharides and fructo-oligosaccharides on physico-chemical indices, antioxidant and oxidative stability of broiler chicken meat

The objective of this present study was to investigate the potentiality of prebiotics (mannan oligosaccharides-MOS and fructo-oligosaccharides-FOS) in replacement of antibiotic growth promoter and their relationship with physico-chemical indices, antioxidant and oxidative stability and carcass traits of broiler chickens meat. Accordingly, 240 day-old broiler chicks of uniform body weight divided in 6 treatment groups with 5 replicate each (5 × 6 = 30) having 8 birds in each replicate. Six corn based dietary treatments were formulated viz. T1 (control diet), T2 (T1 + Bacitracin methylene di-salicylate @ 0.002%), T3 (T1 + 0.1% MOS), T4 (T1 + 0.2% MOS), T5 (T1 + 0.1% FOS), and T6 (T1 + 0.2% FOS). Significant (p < 0.05) increase in cut up part yields (%) and reduction in cholesterol and fat content in T4 (0.2% MOS) group. The water holding capacity (WHC) and extract release volume (ERV) were increase (p < 0.05) in 0.1 or 0.2% MOS supplemented group. DPPH (1, 1-diphenyl-2-picrylhydrazy) was higher (p < 0.05) and lipid oxidation (free fatty acid and thio-barbituric acid reactive substances) was lower (p < 0.05) in T4 group. The standard plate count (SPC), staphylococcus and coliform counts were decreased (p < 0.05) in T3 or T4 group. Thus, it can be concluded that mannan oligosaccharides (MOS) may be incorporated at 0.2% level in diet for improved physico-chemical indices, antioxidant and oxidative stability and carcass characteristics of broiler chickens meat and it may be suitable replacer of antibiotic growth promoter.

Effects of Dietary Mannan Oligosaccharide on Growth Performance, Feed Utilization, Body Composition and Haematological Parameters in Asian Catfish (Clarias batrachus) Juveniles

The influence of dietary supplementation of mannan oligosaccharide (MOS) on growth performance, feed utilization, body composition and haematological parameters were evaluated in Asian catfish (Clarias batrachus) juveniles. Triplicate groups of juveniles Asian catfish (21.23 ± 1.01 g) were fed twice per day at 3 % of body weight for 12 weeks, with 0 (control), 0.2, 0.4 or 0.6% MOS diets. Compared to control, those fed with MOS supplemented diets had significantly improved (P&lt;0.05) specific growth rates, protein efficiency ratio and survival rate. Significantly lower hepatosomatic index was noted in 0.2% and 0.4% MOS diets compared to those fish fed control. Similarly, intraperitoneal fat was significantly lowest in those fish fed with 0.4% diet over the control group. The highest protein content was (81.86±0.36) in fish fed with 0.4% MOS diet, whereas ash content was highest (7.33±1.23) in fish group fed with 0.6% MOS. Significantly decreased erythrocyte sedimentation rate and increased packed cell volume were observed when the fish fed with 0.4% and 0.6% MOS diets compared to the remaining treatments. MOS supplemented diets showed significant influence on the white blood cell count compared to the control. Thus, 0.4% MOS is sufficient to improve growth and haematological parameters in Asian catfish.

Effects of mannan oligosaccharides and fructooligosaccharides on the growth and nonspecific immune responses of juvenile freshwater prawn Macrobrachium acanthurus

The freshwater prawn Macrobrachium acanthurus represents a valuable resource for fishermen's communities in Mexico, although the information of its culture conditions and nutrition is still scarce. Prebiotics are defined as non-digestible components that are metabolized by specific health-promoting bacteria in the host's digestive system, improving the health status and growth performance of cultured aquatic organisms. Fructooligosaccharides (FOS) and mannan oligosaccharides (MOS) are among the most used prebiotics in aquaculture. The present work aimed to determine the effects of dietary FOS and MOS in the growth performance, immune responses, and sexual maturity of juvenile freshwater prawn Macrobrachium acanthurus. Juveniles (0.06 ± 0.001 g) were fed with diets supplemented with a 3 g kg-1 diet of commercial FOS and MOS for 80 days. At the end of the feeding trial, the following indices were calculated: weight gain, specific growth rate, and feed conversion efficiency, as well as superoxide dismutase and lysozyme activities in hepatopancreas tissue. The growth performance, survival, juveniles' protein contents did no show significant differences among the groups. No differences were detected in superoxide dismutase and lysozyme activities among experimental groups. Around day 60 of the feeding trial, the females fed with the prebiotics maturated, and by the end of the trial, several of them were carrying eggs. It seems that prebiotics might have a role in sexual maturation, but further research is necessary to establish if prebiotics influences the early maturation of M. acanthurus.

Modulation of the growth performance and innate immunity of loaches (Paramisgurnus dabryanus) upon dietary mannan oligosaccharides

Different levels of mannan oligosaccharides (MOs) (100, 300 and 500mgkg-1) were incorporated into a basal diet to formulate three diets, which were used to test the growth performance and innate immunity of loaches. The basal diet without any MOs served as the control. Loaches fed with MO-containing diets for 70days showed a higher specific growth rate, condition factor, survival rate, intestine weight index, intestine length index, intestine Lactobacillus population, intestine Bifidobacterium population, phenoloxidase activity, superoxide dismutase activity, glutathione peroxidase activity, acid phosphatase activity, alkaline phosphatase activity, lysozyme level, complement 3 and resistance to Aeromonas hydrophila than the loaches in the control group. The feed conversion ratio, intestine Escherichia coli population, malondialdehyde level, aspartate aminotransferase level and alanine aminotransferase level showed an opposite trend. The optimal dose of dietary MOs required for the maximum growth of loaches was 300mgkg-1. Results indicated that dietary MOs promoted the growth performance and innate immunity of loaches and could be used as a dietary supplement for loaches.

Bioactive Peptides from Sesame Meal for Broiler Chickens: Its Influence on the Serum Biochemical Metabolites, Immunity Responses and Nutrient Digestibility

This study was conducted to evaluate and compare the effects of bioactive peptides derived from sesame meal (BPSM), avilamycin as an antibiotic and mannan-oligosaccharides (MOS) as a prebiotic supplementation on the some serum metabolites, immune response, and ileal nutrient digestibility of broiler chickens. A total of 300 broiler chickens were randomly placed in 6 treatments with 5 replicates of 10 birds each, for 32 days. The experimental treatments consisted of a basal corn-soybean meal or control diet, control diet + 10 mg/kg avilamycin, control diet + 2 gr/kg MOS, control diet + 50, 100 and 150 mg/kg BPSM. According to the results, dietary treatments had no effects on the serum concentration of IgG and IgM (immunity indices), cholesterol, triglyceride, low density lipoprotein (LDL) and enzyme activity of aspartate aminotransferase (AST) as an index for liver health (P > 0.05). While the blood concentration of albumin increased in broiler chickens fed diet containing 100 mg/kg BPSM (P < 0.05).In nutrient digestibility, addition of 100 mg/kg of BPSM and MOS increased the ileal digestibility coefficients of crude protein and ether extract in broiler chickens (P < 0.05). Likewise, ileal digestibility of vital amino acids including histidine, methionine, and tyrosine improved in broiler chickens, which received 100 mg/kg BPSM diet, while threonine digestibility increased in broilers fed MOS diet (P < 0.05). Body weight gain and food conversion ratio improved (P < 0.05) in the birds received MOS and 100 mg/kg BPSM, respectively. Considering the results of this study, it is concluded that BPSM can be used as a diet supplement in broiler chickens with no negative effect on the immune response and nutrient digestibility.

Dietary mannan oligosaccharide enhances growth and survival of juvenile tiger shrimp Penaeus monodon against experimental challenge with Vibrio harveyi and white spot syndrome virus

A 45-days feeding trial was conducted on juvenile tiger shrimps Penaeus monodon of size 0.997±0.098 g with diets containing Mannan oligosaccharides (Mos) at three graded levels (0.1, 0.2 and 0.3%). Maximum weight gain (1.353 g) was achieved in shrimps fed with 0.3% Mos concentration, followed by 0.2% Mos (1.224 g). Best feed conversion ratio (FCR) of 2.406 was registered in 0.3% Mos groups. Results indicate that there was a significant difference (p&lt;0.01) in weight gain and FCR among the treatments. However, no statistical differences were observed on the specific growth rate (SGR), mean feed intake and survival rate. Feeding trial was followed by a 10 days challenge study with Vibrio harveyi by intramuscular injection and white spot syndrome virus (WSSV) by feeding WSSV infected tissues. Significantly higher survival rate was observed in the shrimp groups fed with 0.3% Mos (66.67%) than the other treatments when challenged with V. harveyi. Tiger shrimps fed with 0.3% Mos challenged with WSSV showed a significantly higher survival rate (66.67%), followed by 0.2% Mos (50%), 0.1% Mos (25%) and control (25%) on day 5 post-challenge. However On day 10 post-challenge with WSSV, except in the groups fed with 0.3% Mos (16.67% survival), 100% mortality was noticed in all other diet groups. Therefore, it is concluded that dietary administration of Mos at 0.3% would enhance the growth and survival of tiger shrimp against V. harveyi. With respect to WSSV challenge, it appears that, though Mos at 0.3% had a positive effect on the shrimp, higher survival was not observed. Whether additional increment in Mos supplementation in the diet would positively affect the survival of tiger shrimps post-WSSV challenge, needs to be investigated further.

Dietary Mannanoligosaccharide Supplementation Improves Growth Performance, Intestinal Integrity, Serum Immunity, and Antioxidant Capacity of Partridge Shank Chickens.

Herein, we assessed the impact of dietary addition of konjac mannanoligosaccharide (MOS) on the growth, intestinal morphology, serum immune status, and oxidative status in Partridge Shank chickens. For the experiment, one-day-old chicks (n=192) were randomized into six replicates (n=8/replicate) and fed four different diets: a basal diet containing 0 (Control group), 0.5, 1, or 1.5 g MOS per kg of diet (g/kg) for 50 d. Relative to the control, the group fed 0.5 g/kg MOS decreased feed consumption from 22nd to 50th d and 1st to 50th d (P<0.05). By adding MOS, the height of the intestinal villus and the villus height to crypt depth ratio were increased (P<0.05); 1.5 g/kg MOS was the best dosage for these parameters. Jejunal and ileal goblet cell density increased following MOS supplementation at 21 d (P<0.01) and 50 d in the jejunum (P<0.05), respectively. Moreover, adding MOS to the diet increased the contents of IgA and IgM at 21 d (P<0.05) and total antioxidant capacity (P<0.05) at 50 d in the serum but decreased malondialdehyde content (P<0.01) at 21 d in the group fed 0.5 and 1.5 g/kg MOS. The findings suggested that MOS supplementation could affect feed consumption, intestinal health, serous immunity, and antioxidant capacity of Partridge Shank chickens.

Mannan oligosaccharides supplementation enhanced head-kidney and spleen immune function in on-growing grass carp (Ctenopharyngodon idella)

This research investigates the influences of dietary mannan oligosaccharides (MOS) on the head-kidney and spleen immune function in on-growing grass carp (Ctenopharyngodon idella) and its related mechanism. Fish were fed during 60 days at different levels of MOS (0, 200, 400, 600, 800 and 1000 mg kg−1). Subsequently, 14 days after the feeding trial was injected intraperitoneally with Aeromonas hydrophila, the immune function was studied. The results are as follows: (1) appropriate MOS supplementation could increase the content of antibacterial compound and immunoglobulin (Ig), up-regulate antimicrobial peptides transcriptional levels in these two organs; (2) appropriate MOS supplementation attenuated inflammatory response in these two organs by regulating cytokines (pro- and anti-inflammatory cytokines) and related signalling pathways (NF-κB and TOR). The interesting points though, was, no differences were found in liver-expressed antimicrobial peptide (LEAP)-2A, interleukin (IL)-8, IL-4/13B, IκB kinase (IKK) α and nuclear factor kappa B (NF-κB) p52 gene expression in these two organs. Consequently, the present research suggests that MOS supplementation can enhance head-kidney and spleen immune function. Finally, we obtained these appropriate MOS dose (538.5 and 585.8 mg kg−1) by quadratic regression analysis of lysozyme activity (head-kidney) and phosphatase activity (spleen), respectively.

Effect of Trichoderma reesei Degraded Date Pits on Antioxidant Enzyme Activities and Biochemical Responses of Broiler Chickens.

The long-term use of antimicrobials as growth promoters in poultry feed leads to antimicrobial resistance in pathogens. Thus, alternatives to antibiotics are essential for reasons associated with both safety and cost-effectiveness. Underutilized plant sources need to be developed to replace antibiotics in broiler feed. Several feed resources have been introduced so far, but they have yet to be applied widely. Date pits are a major by-product of the date industry (6–8%) and have the potential antioxidant to replace antibiotics. In this study, fresh date pits were degraded using the mold Trichoderma reesei under solid-state degradation (SSD), resulting in degraded date pits (DDP). A total of 180 Brazilian “Cobb 500” broiler chicks were divided into six feed treatments in triplicate groups. The treatments were corn-soy basal diet (positive control; C+), corn-soy + 20% oxytetracycline at 0.05% (negative control; C–), corn-soy + 10% DDP, corn-soy + 0.2% mannan-oligosaccharides (MOS), corn-soy + 0.1% mannose, and corn-soy + 0.2% mannose. The antioxidant and biochemical effects of DDP, MOS, and mannose were determined in the blood serum, liver, and intestine of broilers at age 21 and 42 days. The results indicated that the contents of antioxidants such as flavonoids and phenolics, as well as the MOS content in DDP, were increased by the degradation process. Additionally, mannose, glucose, arabinose, rhamnose, and glucuronic acid were significantly increased in DDP after degradation. The activity of antioxidant enzymes (GPx—glutathione peroxidase, catalase, and SOD—superoxide dismutase) in the serum, liver, and intestine of broilers fed with diets containing 10% DDP and 0.2% MOS was increased significantly compared to the control group. Malondialdehyde activity was decreased, whereas the mean corpuscular hemoglobin level and the iron content were significantly upregulated in the broilers fed with 10% DDP, 0.1% mannose, and 0.2% MOS diets compared with the control. Thus, DDP can be used to improve the antioxidant status and has a prebiotic-like effect in broiler chicken performance.

Beneficial impacts on growth, intestinal health, immune responses and ammonia resistance of pacific white shrimp (Litopenaeus vannamei) fed dietary synbiotic (mannan oligosaccharide and Bacillus licheniformis)

The impacts of dietary mannan oligosaccharide (MOS) and Bacillus lincheniformis (B. lincheniformis) on growth performance, immune responses, intestinal health and ammonia resistance of Litopenaeus vannamei were explored. Four resultant diets (control diet (CON), 0.2 % MOS (MOS), 0.1 % B. lincheniformis (BL), 0.2 % MOS plus 0.1 % BL (SYN)) were produced to feed shrimps for 8 weeks. Results showed that significantly higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and protein productive value (PPV) were found in shrimp fed the SYN diet (P < 0.05). The villus number (VN) and villus height (VH) of shrimps fed the SYN diet were significantly higher than those of shrimps fed the CON diet (P < 0.05). Moreover, significantly thicker submucosa (SM) of shrimp fed the MOS diet than that of shrimps fed BL and CON diets were found (P < 0.05). Intestinal acetic acid content was significantly higher in shrimps fed supplemented diets (P < 0.05). Meanwhile, the propionic acid content in shrimps fed BL and SYN diets were significantly higher than those in shrimps fed the other diets (P < 0.05). The expression levels of catalase (CAT), glutothion peroxidase (GPX), superoxide dismutase (SOD), penaeidin -3a (Pen-3a) and heat shock protein (Hsp-70) were significantly upregulated by supplemented diets at some time points (P < 0.05). The survival rates of shrimps fed supplemented diets after ammonia challenge were significantly higher (P < 0.05). The expression levels of CAT, SOD, Pen-3a and Hsp-70 in shrimps fed supplemented diets were upregulated after ammonia challenge. In conclusion, dietary synbiotic could enhance growth performance, feed utilization and intestinal morphology, while dietary MOS and/or B. lincheniformis supplementation could positively influence the intestinal SCFAs content, increase immune responses and ammonia resistance of Litopenaeus vannamei.

The effect of mannanoligosaccharide on the growth performance, histopathology, and the expression of immune and antioxidative related genes in Nile tilapia reared under chlorpyrifos ambient toxicity

The role of mannanoligosaccharide (MOS) in reducing the adverse effects of chlorpyrifos (CPF) toxicity in tilapia was evaluated in the present study. Fish were allotted into four groups and fed the basal diet or MOS and exposed to CPF (control, CPF, MOS, and MOS/CPF) for 30 days. Fish fed MOS revealed higher growth and survival rates and lower FCR than CPF-intoxicated fish (P < 0.05). The Hb, PCV, RBCs, and WBCs variables were lowered by CPF toxicity and increased by MOS (P < 0.05). The values of total protein (sTP), albumin (ALB), globulin (GLB), lysozyme (LZM), and phagocytic activities (PA) decreased whereas, ALP, ALT, AST, urea, bilirubin (BIL), and creatinine (CR) were increased by CPF toxicity. However, dietary MOS increased the sTP, ALB, GLB, LZM, and PA and decreased the ALP, ALT, AST, BIL, and CR. The PA and phagocytic index displayed higher levels by MOS feeding than the other groups (P < 0.05). The lowest mRNA level of GPX1 (cellular GPX) gene was observed in fish of the CPF group, while the highest level was shown in the MOS/CPF group (P < 0.05). Fish in the control and CPF groups displayed downregulated CAT whereas the expression of GPX and CAT genes was higher in fish of the MOS/CPF group than fish in the MOS group (P < 0.05). MOS upregulated the expression of HSP70 gene with CPF toxicity. Fish of the CPF and MOS/CPF groups displayed upregulated CASP3, IFN-γ, and IL-8 genes. Fish of the CPF group exhibited the lowest IL-1β, while fish of the MOS/CPF group showed upregulated IL-1β. The intoxication with CPF induced histopathological inflammations in the gills, intestine, and liver tissues, while dietary MOS protected against inflammation. In summary, dietary MOS is recommended as an immunostimulant to counteract the inflammatory impacts of waterborne CPF toxicity in Nile tilapia.

Protective effects of dietary mannan oligosaccharide on heat stress-induced hepatic damage in broilers.

Heat stress is a major concern in broiler's production, which can damage liver of broilers. This study investigated the protective effects of mannan oligosaccharide (MOS) on heat stress-induced hepatic injury in broilers. A total of 144 day-old male chicks were allocated into three treatment groups. Broilers raised under normal ambient temperature were fed a basal diet (control group), and broilers under heat stress (32-33°C for 8h daily) were given the basal diet supplemented without MOS (heat stress group) or with 1g/kg MOS (MOS group) for 42days. Compared with the control group, heat stress reduced liver weight, whereas increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in the serum. It also reduced glutathione peroxidase (GSH-Px) activity in the serum and liver, GSH content, and superoxide dismutase (SOD) activity in the liver, but increased malondialdehyde (MDA) concentration in the serum and liver. Dietary MOS decreased serum ALT activity in heat-stressed broilers. MOS inclusion also decreased serum MDA content, but elevated hepatic GSH-Px and SOD activities, with MDA content and GSH-Px activity still being different from the control group, and SOD activity being similar to the control group. Heat stress increased concentrations of tumor necrosis factor α (TNF-α) in the serum and liver, interleukin-1β (IL-1β) in the liver, and mRNA abundances of HSP70, TLR4, MyD88, TNF-α, and IL-1β in the liver of broilers. Serum TNF-α content and mRNA abundances of hepatic TLR4 and TNF-α in MOS group were lower than the heat stress group, whereas these indexes were still higher than the control group. Our results indicated that dietary MOS ameliorated hepatic damage in heat-stressed broilers through alleviation of oxidative stress and inflammation.

Mannan oligosaccharides improved growth performance and antioxidant capacity in the intestine of on-growing grass carp (Ctenopharyngodon idella)

This study evaluates the effects of dietary mannan oligosaccharides (MOS) supplementation on growth performance and antioxidant capacity, as well as investigates its related signalling molecule mechanism in the intestine of on-growing grass carp (Ctenopharyngodon idella). A total of 540 on-growing grass carp (215.85 ± 0.30 g) were fed six diets containing graded levels of MOS supplementation (0, 200, 400, 600, 800 and 1000 mg kg−1) for 60 days. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila for 14 days. The results showed that (1) appropriate dietary MOS supplementation improved growth performance and enhanced disease resistance (2) appropriate dietary MOS supplementation relieved oxidative damage by decreasing the content of reactive oxygen species (ROS), and oxidative damage biomarker protein carbonyl (PC) and malondialdehyde (MDA). (3) appropriate dietary MOS supplementation enhanced antioxidant capacity by increasing enzyme activities [except manganese superoxide dismutase (MnSOD)] and corresponding gene expression (except MnSOD). (4) appropriate dietary MOS supplementation positively regulated antioxidant function related to MR/PKCδ/Nrf2/Keap1b (not Keap1a in the DI, not PKCα and PKCε in three intestinal segments) signalling pathway. In conclusion, the present study has demonstrated that dietary MOS supplementation could enhance fish intestine antioxidant capacity. Finally, based on the quadratic regression analysis for the percent weight gain (PWG), against enteritis morbidity, and the MDA, PC and ROS contents (in the DI) of on-growing grass carp, the MOS dosage was estimated to be 428.5, 499.1, 536.2, 561.7 and 550.9 mg kg−1 diet, respectively.

Effects of dietary mannan oligosaccharide supplementation on growth performance, antioxidant capacity, non-specific immunity and immune-related gene expression of juvenile hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The present study was conducted to investigate the effects of dietary mannan oligosaccharide (MOS) supplementation on growth performance, antioxidant capacity, non-specific immunity and immune-related gene expression in juvenile hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). A basal diet supplemented with MOS (0, 0.3%, 0.6%, 1.0% and 2.0%) was fed to juvenile hybrid grouper for 9 weeks. Results showed that there were no significant differences in feed intake, hepatosomatic index, spleen index or survival among all groups (P > .05). However, antioxidant analyses showed that hybrid grouper fed with MOS supplementation had significantly enhanced total antioxidant capacity (T-AOC) and superoxide dismutase (SOD). Non-specific immunity evaluation showed that hybrid grouper fed with MOS supplementation had significantly enhanced respiratory burst activity (RB), acid phosphatase activity (ACP) and lysozyme activity (LZM) (P < .05). Moreover, dietary MOS supplementation also enhanced morphological integrity of intestine (muscle thickness, villus length and villus width) (P < .05). Furthermore, in the intestine and liver of juvenile hybrid grouper fed dietary MOS, expression of immune-related genes Interleukin 8 (IL-8), Transforming growth factor β1 (TGF-β1), Target of rapamycin (TOR) and Toll-like receptor 3 (TLR3) was upregulated, whereas Kelch-like-ECH-associated protein 1 (Keap1), IκB kinase α (IKKα) and the apoptosis-related genes (p53 and Caspase-3) were down-regulated. After challenge with Vibrio harveyi, significantly higher post-challenge survival rate was observed in 0.6% MOS supplemented group than the control group (P < .05). These results indicate that dietary MOS supplementation does not improve growth performance or feed utilization of juvenile hybrid grouper; however, it can promote intestinal health and immunological status—by improving intestinal morphological integrity, enhancing antioxidant capacity and non-specific immunity, increasing immune-related gene expression and decreasing apoptosis-related gene expression in the intestine and liver.