Efficacy of β-mannanase on broiler growth performance and energy utilization in the presence of increasing dietary galactomannan

Potential of guar gum as a leaky gut model in broilers: Digestibility, performance, and microbiota responses

Diet is a major modulator of animal resilience and its three pillars: host's immune response, gut microbiota, and intestinal barrier. In the present study, we endeavour to delineate a challenging condition aimed to degrade these pillars and elucidate its impact on broiler performance and nutrient digestibility. To attain this objective, we opted to use guar gum (GG) as a source of galactomannan. A series of three in vivo experiments were conducted employing conventional or semi-purified diets, supplemented with or without GG during the grower phase (14-28 d). Our findings demonstrate a substantial decline in animal performance metrics such as body weight (reduced by 29%, P < 0.001), feed intake (decreased by 12%, P < 0.001), and feed conversion ratio (up to 58% increase, P < 0.001) in the presence of GG at 2%. The supplementation of a semi-purified diet with incremental doses of GG resulted in a linear reduction (P < 0.001) in the apparent total tract digestibility of dry matter and apparent metabolisable energy. Additionally, a marked reduction in ileal endogenous losses, as well as apparent and standardised digestibility of all amino acids with varying proportions (P < 0.05), was observed. These alterations were accompanied by disrupted gut integrity assessed by fluorescein isothiocyanate-dextran (FITC-d) (P < 0.001) as well as an inflammatory status characterised by elevated levels of acute-phase proteins, namely orosomucoid and serum amyloid A in the sera (P = 0.03), and increased mRNA expression levels of IL-1, IL-6, IL-8, Inos, and K203 genes in the ileum, along with a decrease in IgA levels in the gut lumen (P < 0.05). Microbial ecology and activity were characterised by reduced diversity and richness (Shannon index, P = 0.005) in the presence of GG. Consequently, our results revealed diminished levels of short-chain fatty acids (P = 0.01) and their producer genera, such as Clostridium_XIVa and Blautia, in the gut caeca, coupled with excessive accumulation of lactate (17-fold increase, P < 0.01) in the presence of GG at 2%. In addition to providing a more comprehensive characterisation of the GG supplementation as a leaky gut model, our results substantiate a thorough understanding of the intricate adjustments and interplay between the intestinal barrier, immune response, and microbiota. Furthermore, they underscore the significance of feed components in modulating these dynamics.

Effects of β-mannanase supplementation on productive performance, inflammation, energy metabolism, and cecum microbiota composition of laying hens fed with reduced-energy diets

The objective of this study is to investigate the beneficial effects and underlying mechanism of dietary β-mannanase supplementation on the productive performance of laying hens fed with metabolic energy (ME)-reduced diets. A total of 448 Hy-Line gray laying hens were randomly assigned to seven groups. Each group had 8 replicates with 8 hens. The groups included a control diet (CON) with a ME of 2750 kcal/Kg, diets reduced by 100 kcal/Kg or 200 kcal/Kg ME (ME_100 or ME_200), and diets with 0.15 g/Kg or 0.2 g/Kg β-mannanase (ME_100+β-M_0.15, ME_100+β-M_0.2, ME_200+β-M_0.15, and ME_200+β-M_0.2). The productive performance, egg quality, intestinal morphology, inflammatory response, mRNA expression related to the Nuclear factor kappa B (NF-κB) and AMPK pathway, and cecum microbiome were evaluated in this study. ME-reduced diets negatively impacted the productive performance of laying hens. However, supplementation with β-mannanase improved FCR, decreased ADFI, and restored average egg weight to the level of the CON group. ME-reduced diets increased the levels of interleukin-1β (IL-1β) and IL-6 while decreasing the levels of IL-4 and IL-10 in the jejunum of laying hens. However, dietary β-mannanase supplementation improved jejunum morphology, reduced pro-inflammatory cytokine concentrations, and increased levels of anti-inflammatory factors in laying hens fed with ME-reduced diets. The mRNA levels of IL-6, IFN-γ, TLR4, MyD88, and NF-κB in the jejunum of ME-reduced diets were significantly higher than that in CON, dietary β-mannanase supplementation decreased these genes expression in laying hens fed with ME-reduced diets. Moreover, dietary β-mannanase supplementation also decreased the mRNA levels of AMPKα and AMPKγ, and increased the abundance of mTOR in the jejunum of laying hens fed with ME-reduced diets. Cecum microbiota analysis revealed that dietary β-mannanase increased the abundance of various beneficial bacteria (e.g., g_Pseudoflavonifractor, g_Butyricicoccus, and f_Lactobacillaceae) in laying hens fed with ME-reduced diets. In conclusion, dietary β-mannanase supplementation could improve the productive performance of laying hens fed with a ME-reduced diet by improving intestinal morphology, alleviating intestinal inflammation, changing energy metabolism-related signaling pathways, and increasing cecum-beneficial microbiota.

Mannanase improves the growth performance of broilers by alleviating inflammation of the intestinal epithelium and improving intestinal microbiota

This experiment aimed to discuss and reveal the effect and mechanism of mannanase on intestinal inflammation in broilers triggered by a soybean meal diet. In this experiment, 384 Arbor Acres broilers at 1 d old were randomly divided into 3 treatment groups. The broilers were fed a corn-soybean meal basal diet, a low-energy diet (metabolizable energy reduced by 50 kcal/kg), and a low-energy diet supplemented with 100 mg/kg mannanase for 42 d. The low-energy diet increased feed conversion ratio from 0 to 42 d, reduced ileal villus height and villus height-to-crypt depth ratio and upregulated the expression of nuclear factor kappa B (NF-κB) in the ileum (P < 0.05). It also reduced cecal short-chain fatty acids (SCFA), such as acetic acid (P < 0.05). Compared with low-energy diets, the addition of mannanase increased body weight at 42 d, promoted the digestibility of nutrients, and maintained the morphology and integrity of the intestinal epithelium of broilers (P < 0.05). In addition, mannanase upregulated the expression of claudin-1 (CLDN1) and zonula occludens-1 (ZO-1) in the jejunum at 21 d, downregulated the expression of ileal NF-κB, and increased the content of isobutyric acid in the cecum of broilers (P < 0.05). The results for the ileal microbiota showed that a low-energy diet led to a decrease in the relative abundance of Lactobacillus reuteri in the ileum of broilers. The addition of mannanase increased the relative abundance of Lactobacillus-KC45b and Lactobacillus johnsonii in broilers. Furthermore, a low-energy diet reduced the relative abundance of Butyricicoccus in the intestine of broilers and inhibited oxidative phosphorylation and phosphoinositol metabolism. Mannanase increased the relative abundance of Odoribacter, promoted energy metabolism and N-glycan biosynthesis, and increased the activities of GH3 and GH18. It is concluded that mannanase could improve the growth performance of broilers by reducing the expression of NF-κB in the ileum, increasing the production of SCFA in the cecum, suppressing intestinal inflammation, balancing the intestinal microbiota, reducing damage to the intestinal barrier, and improving the efficiency of nutrient utilization to alleviate the adverse effects caused by the decrease in dietary energy level.

Effect of dietary β-mannanase supplementation on broiler performance

This study was conducted to investigate the effect of graded levels of β-mannanase supplementation in broiler diets on growth performance, energy digestibility, and lesion scores in d-old birds fed mash, corn-soybean meal-based diets and raised to 42 d. Five dietary treatments were investigated: 1) positive control diet (PC) containing standard energy; 2) negative control (NC) with 100 kcal/kg diet reduction in AME compared to PC; 3) NC supplemented with 30 U/g β-mannanase (NC + 30 U); 4) NC supplemented with 60 U/g β-mannanase (NC + 60 U); and 5) NC supplemented with 90 U/g β-mannanase (NC + 90 U). Each treatment had 6 replicate pens with 52 chicks per replicate. Data was analyzed using 1-way ANOVA, and means were separated by LSMEANS. Reduction of 100 kcal/kg feed (NC) resulted in an overall body weight gain reduction of 51 g (P < 0.05) and feed conversion loss of approximately 4 points (P < 0.05) compared to PC at 42 d of age. At the same time, supplementing β-mannanase at 60 and 90 U/g improved growth performance parameters compared to NC, while 30 U/g did not result in significant improvements beyond NC; body weight gain was improved (P < 0.05) by 87, and 106 g when β-mannanase was supplemented at 60 and 90 U/g, respectively, compared to NC. This corresponded to an improvement by 6 and 7 points in feed conversion for 60 and 90 U/g supplementation, respectively, compared to NC. Furthermore, AMEn was improved (P < 0.05) by 15, 97, and 116 kcal/kg at 42 d when β-mannanase was added to NC at 30, 60, and 90 U/g, respectively. Digesta viscosity measured at 42 d was decreased (P < 0.05) by β-mannanase supplementation of 60 and 90 U/g, compared to NC, while 42 d lesion scores were improved (P < 0.05) by β-mannanase supplementation compared to NC. Data demonstrated that dietary supplementation of β-mannanase improved growth performance, energy digestibility, and reduced viscosity and lesion scores when supplemented with diets with a reduced energy content of 100 kcal/kg compared to a standard energy diet.

Komagataella phaffii as a Platform for Heterologous Expression of Enzymes Used for Industry

In the 1980s, Escherichia coli was the preferred host for heterologous protein expression owing to its capacity for rapid growth in complex media; well-studied genetics; rapid and direct transformation with foreign DNA; and easily scalable fermentation. Despite the relative ease of use of E. coli for achieving the high expression of many recombinant proteins, for some proteins, e.g., membrane proteins or proteins of eukaryotic origin, this approach can be rather ineffective. Another microorganism long-used and popular as an expression system is baker's yeast, Saccharomyces cerevisiae. In spite of a number of obvious advantages of these yeasts as host cells, there are some limitations on their use as expression systems, for example, inefficient secretion, misfolding, hyperglycosylation, and aberrant proteolytic processing of proteins. Over the past decade, nontraditional yeast species have been adapted to the role of alternative hosts for the production of recombinant proteins, e.g., Komagataella phaffii, Yarrowia lipolytica, and Schizosaccharomyces pombe. These yeast species' several physiological characteristics (that are different from those of S. cerevisiae), such as faster growth on cheap carbon sources and higher secretion capacity, make them practical alternative hosts for biotechnological purposes. Currently, the K. phaffii-based expression system is one of the most popular for the production of heterologous proteins. Along with the low secretion of endogenous proteins, K. phaffii efficiently produces and secretes heterologous proteins in high yields, thereby reducing the cost of purifying the latter. This review will discuss practical approaches and technological solutions for the efficient expression of recombinant proteins in K. phaffii, mainly based on the example of enzymes used for the feed industry.

Guar gum as galactomannan source induces dysbiosis and reduces performance in broiler chickens and dietary β-mannanase restores the gut homeostasis

Galactomannans are abundant nonstarch polysaccharides in broiler feed ingredients. In broilers, diets with high levels of galactomannans have been associated with innate immune response stimulation, poor zootechnical performance, nutrient and lipid absorption, and excessive digesta viscosity. However, data about its effects on the gut microbiome are scarce. β-Mannanases are enzymes that can hydrolyze β-mannans, resulting in better nutrient utilization. In the current study, we have evaluated the effect of guar gum, a source of galactomannans, supplemented to broiler diets, either with or without β-mannanase supplementation, on the microbiota composition, in an attempt to describe the potential role of the intestinal microbiota in β-mannanase-induced gut health and performance improvements. One-day-old broiler chickens (n = 756) were randomly divided into 3 treatments: control diet, guar gum-supplemented diet (1.7%), or guar gum-supplemented diet + β-mannanase (Hemicell 330 g/ton). The zootechnical performance, gut morphometry, ileal and cecal microbiome, and short-chain fatty acid concentrations were evaluated at different time points. The guar gum supplementation decreased the zootechnical performance, and the β-mannanase supplementation restored performance to control levels. The mannan-rich diet-induced dysbiosis, with marked effects on the cecal microbiota composition. The guar gum-supplemented diet increased the cecal abundance of the genera Lactobacillus, Roseburia, Clostridium sensu stricto 1, and Escherichia-Shigella, and decreased Intestinimonas, Alistipes, Butyricicoccus, and Faecalibacterium. In general, dietary β-mannanase supplementation restored the main microbial shifts induced by guar gum to levels of the control group. In addition, the β-mannanase supplementation reduced cecal isobutyric, isovaleric, valeric acid, and branched-chain fatty acid concentrations as compared to the guar gum-supplemented diet group, suggesting improved protein digestion and reduced cecal protein fermentation. In conclusion, a galactomannan-rich diet impairs zootechnical performance in broilers and results in a diet-induced dysbiosis. β-Mannanase supplementation restored the gut microbiota composition and zootechnical performance to control levels.

Effect of dietary β-mannanase supplementation on growth performance, digestibility, and gene expression levels of Cyprinus carpio (Linnaeus) fingerlings fed a plant protein-rich diet

The aim of this study was to assess possible beneficial effects of dietary β-mannanase supplementation on the nutrient digestibility, growth performance, digestive and metabolic enzyme activity, and immune response of common carp (Cyprinus carpio) fed plant protein-rich diets. An experiment was conducted in triplicate, and a total of 225 fingerlings of common carp with an average body weight of 13.17 ± 0.12 g were stocked in 15 fiberglass tanks (15 fish/tank). Five dietary treatments (control 35% crude protein, plant-rich basal diet without supplement and four diets supplemented with β-mannanase from two sources (commercially available and locally isolated), each at two dosage levels (500 and 1,000 U/kg diet) were prepared and fed to respective groups of fish, twice a day (8:00 AM and 4:00 PM) at 4 % body weight. During the trial, changes in the level of DO and temperature ranged from 5.5 to 6.1 mg L-1 and 21.5 to 23.5°C, respectively. At the end of the feeding experiment, all fish in each tank were weighed and counted to determine growth parameters, while for the study of other indices, nine samples/treatment group were selected. The results of the study indicated a positive effect of both sources and dosage levels of β-mannanase supplementation on all studied indices, that is, significantly improved (P < 0.05), growth performance (%weight gain, specific growth rate), survival %, hematological indices (RBC, Hb, HCT, and MCHC), immunological indices (lysozyme activity, WBC, respiratory burst activity, and phagocytic activity), improved apparent digestibility of nutrients (crude protein, crude fat, and carbohydrates), and digestible energy. Furthermore, higher activity (P < 0.05) of the digestive enzymes (cellulase, lipase, and protease) and upregulation of MyoD gene in muscle and TNF-α gene in liver, intestine, and muscle were also observed, while the activity of serum AST (serum aspartate aminotransferase) and ALT (alanine transaminase) as compared to control group was significantly decreased (P < 0.05). Based on the results, β-mannanase supplementation (500 U/kg) could be recommended for obtaining better carp production when low-cost plant protein-rich diets are used.

Energy values evaluation and improvement of soybean meal in broiler chickens through supplemental mutienzyme

This study measured the metabolizable energy of soybean meal (SBM) and evaluated effects of soybean meal specific enzymes supplementation in corn-soybean diets on growth performance, intestinal digestion properties and energy values of 28-day-old broilers. A total of 336 one-day-old male AA broiler chickens were distributed to 7 groups in a completely random design. The birds were given 7 diets containing 6 diets with different combined soybean meals and a fasting treatment, 8 replicates per treatment and 6 birds per replicate (Trial 1). A total of 672 one-day-old male AA broiler chickens were randomly allocated to 7 dietary treatments including a control diet and 6 diets supplemented with 300 mg/kg α-galactosidase, 200 mg/kg β-mannanase, and 300 mg/kg protease individually or in combination (Trial 2). Apparent metabolizable energy (AME) of broilers was measured from d 25 to 27 in both trial 1 and trial 2. The results showed that AME values of combined soybean meals averaged 2,894 kcal/kg. Dietary β-mannanase and protease supplementation increased body weight gain (P < 0.05) during d 0 to 14, whereas did not affect the growth performance (P > 0.05) during d 14 to 28. Addition of β-mannanase in combination with other enzymes significantly increased lipase and trypsin content (P < 0.05) in ileum. In addition, dietary β-mannanase and protease supplementation individually or in combination enhanced trypsin enzyme content in jejunum (P < 0.05). The β-mannanase enzyme enhanced villus height and villus height to crypt depth ratio (P < 0.05) of ileum compared with control diet. Moreover, supplementation of enzyme except for protease enhanced raffinose and stachyose degradation ratio (P < 0.05). Dietary β-mannanase supplementation individually or in combination enhanced AME and AMEn values (P < 0.05). This study demonstrated that dietary enzyme supplementation especially β-mannanase improved intestinal digestion properties and contributed to high energy values.

Effect of dietary β-Mannanase addition on performance, pododermatitis, and intestinal morphology as well as digesta Clostridium perfringens in broiler chickens: a pilot study

This preliminary study was conducted to evaluate the effects of β-mannanase in diets of broilers on performance, pododermatitis, intestinal morphology, and digesta Clostridium perfringens counts. A total of 264 broilers (Ross 308) were randomly allotted to four treatments. A wheat-soybean based diet (CO) was supplemented with either 0.15 g xylanase/kg (XY), 0.15 g xylanase/kg + 110 mL β-mannanase/ton (MA1) or 0.15 g xylanase/kg + 220 mL β-mannanase/ton (MA2). At the end of the experiment, only significant differences in body weight were noted between groups fed MA1 and MA2 diets (2501 g vs 2641 g, respectively). Birds fed MA1 had significantly the lowest pododermatitis scores (2.26) compared to other groups. Ileal villus height measurements revealed that birds fed CO and MA2 diets had significantly higher values (1614 and 1651 µm, respectively) than those fed the MA1 diet (1489 µm). The positive percent of Clostridium perfringens in intestinal digesta at d 36 was significantly the highest in the XY group. Overall, although not improving performance, supplementing the diet with β-mannanase (110 mL/ton) contributed positively to foot pad health.

Productive Performance and Cecum Microbiota Analysis of Broiler Chickens Supplemented with β-Mannanases and Bacteriophages—A Pilot Study

Simple Summary

For several years, antibiotic growth promoters (AGPs) have been used in poultry production; however, with the recent ban on the use of AGPs, several alternatives have been evaluated. In the present work, we evaluated the use of β-mannanases and bacteriophages as an alternative to AGPs. This study demonstrates that supplementation with β-mannanases, bacteriophages, or a mix of these two does not affect the productive performance in broilers fed corn–soybean meal. The mixture of β-mannanases and bacteriophages promoted the abundance of beneficial microorganisms in the cecum. These preliminary results suggest that β-mannanases and bacteriophages have potential as alternatives to AGPs in poultry production.

Abstract

This study was conducted to evaluate the productive performance, intestinal health, and description of the cecum microbiota in broilers supplemented with β-mannanases (MNs) and bacteriophages (BPs). Six hundred one-day-old broilers were divided into four groups and fed one of the following diets: CON—corn–soybean meal + 10 ppm enramycin (ENR); MN: CON + 500 ppm MN; BP: CON + 500 ppm BP; MN + BP: BP + 500 ppm MN. The BP and MN factors showed similar performances to ENR. MN improved the concentration of IgA in the jejunum at 35 days of age. The morphometric index (IM) of the thymus increased by adding MN, while BP increased the liver and thymus IM. The histological analysis showed that BP and MN improved the intestinal morphology. MN + BP showed a tendency to decrease the abundance of Proteobacteria and increase the abundance of Bacteroidetes, indicating better microbiota function. In conclusion, our results demonstrate that the combination of MN + BP has potential in poultry nutrition; however, we highly recommend further experiments to confirm this hypothesis.

Effects of dietary protein, energy and β-mannanase on laying performance, egg quality, and ileal amino acid digestibility in laying hens

β-mannan is a nonstarch polysaccharide found in hulled and dehulled soybeans that can survive drying-toasting phase of processing soybeans and have antinutritive effects in poultry. β-mannanase is an active enzyme (endohydrolase) that can hydrolyze β-mannan to reduce its antinutritional effects. Two experiments were conducted to evaluate the effects of β-mannanase supplementation in low energy/protein diets on egg production, egg quality, and apparent ileal digestibility of the dry matter (DM), crude protein (CP), and amino acids in 21-week-old Single Comb White Leghorn hens (Hy-Line W-36). A total of 192 hens (8 replicates of 6 hens per treatment) for a production study (Exp. 1) and a total of 64 hens (8 replicates of 2 hens per treatment) for a digestibility study (Exp. 2) were randomly allocated to 4 experimental treatments in a 2 × 2 factorial arrangement. Four dietary treatments were control (CS) based on corn and 44% CP soybean meal (ME: 2,850 kcal/kg CP: 18.5%) and CS-low energy/protein (CSL) (ME: 2,750 kcal/kg CP: 17.5%), with or without 0.05% β-mannanase enzyme. Hens were fed the experimental diets for 14 d for the digestibility study and 8 wk for the production study. Hen-day egg production (HDEP), weekly feed intake, FCR, and biweekly egg quality parameters were measured. Significant interaction on feed intake (P < 0.01) was observed between energy/protein and enzyme. At 3, 6 and 8 wk, the feed intake and FCR of CSL with enzyme were significantly lower than those of CSL without enzymes. The main effects indicated that birds fed diets without inclusion of β-mannanase had higher feed intake than those fed diets with enzymes at 4, 7, and 8 wk. The inclusion of β-mannanase significantly increased (P < 0.05) HDEP at 2, 3, 5, and 7 wk. However, there was no significant effect of nutrient density or enzyme supplementation on egg quality parameters. The digestibility study showed that the inclusion of β-mannanase significantly improved (P < 0.01) apparent ileal digestibility of lysine, histidine and tryptophan in the diet. The results of these experiments indicate that supplementation of β-mannanase could reduce the feed intake and FCR and improve HDEP and apparent ileal digestibility of key amino acids in corn/soy diets fed to laying hens.

Guar gum-derived galactomannan induces inflammatory responses and increased energy expenditure in the intestine

Guar gum-derived galactomannan (GGGM) has been widely used in the food industry for a long time and its adverse impacts have been scarcely reported. Galactomannan is considered to have a structure similar to the surface components of certain pathogens, and the present study was thus conducted to investigate if oral administration of GGGM could cause physiological effects that were hypothesized to be related to intestinal inflammatory responses. The results showed that oral administration of GGGM resulted in compromises on growth performance, an increase of the relative weight of spleen and epididymal fat, and an elevation of the α1-acid glycoprotein content in both serum and livers of mice. With regard to energy metabolism-related indices, the activities of intestinal lactic dehydrogenase and succinic dehydrogenase were all increased by the GGGM treatment in both in vivo and in vitro experiments, the latter of which also showed an elevation in the consumption of reducing sugar by intestinal epithelial cells along with a reduced viability of these cells in response to the GGGM treatment. Notably, the GGGM treatment triggered intestinal inflammatory responses that were evidenced by the increased expression of intestinal inflammatory cytokines such as TNF-α and IL-6 both in vivo and in vitro, which were at least partially responsible for the increased energy expenditure in the intestine and the retardation of growth. The results of this study could expand our knowledge of GGGM administration and provide integrated insights into the consumption of GGGM-containing foods.

Applications of Microbial β-Mannanases

Mannans are main components of hemicellulosic fraction of softwoods and they are present widely in plant tissues. β-mannanases are the major mannan-degrading enzymes and are produced by different plants, animals, actinomycetes, fungi, and bacteria. These enzymes can function under conditions of wide range of pH and temperature. Applications of β-mannanases have therefore, been found in different industries such as animal feed, food, biorefinery, textile, detergent, and paper and pulp. This review summarizes the most recent studies reported on potential applications of β-mannanases and bioengineering of β-mannanases to modify and optimize their key catalytic properties to cater to growing demands of commercial sectors.

Inclusion of dietary β-mannanase improves performance and ileal digestibility and reduces ileal digesta viscosity of broilers fed corn-soybean meal based diet

This study was aimed to evaluate the influence of dietary β-mannanase inclusion on growth performance, apparent ileal digestibility, digesta viscosity, blood metabolites and excreta noxious gas emissions in broilers fed corn-soybean meal based diet. A total of 600 conventional healthy 1-d-old ROSS 308 broilers with body weight 45 ± 0.50 g (mean ± SD) were randomly assigned to 4 dietary treatments with 10 replicates cages, with 15 broilers in each and fed basal diet supplemented to corn-SBM based diets with 0, 2400, 4800, and 7200 MNU β-mannanase/kg for 35 d feeding trial period. Significant results were observed on improved average daily gain and reduced feed conversion ratio during trial period and also reduced ileal digesta viscosity and improved apparent ileal digestibility of dry matter, nitrogen and energy. However, no significant effects were found on blood urea nitrogen and creatinine, excreta noxious gas emissions. In conclusion, the inclusion of dietary β-mannanase had potential to improve daily gain and feed efficiency and apparent ileal digestibility while decreasing digesta viscosity of broiler.