Effect of dietary supplementation of β-mannanase on growth performance, carcass characteristics, excreta microflora, blood constituents, and nutrient ileal digestibility in broiler chickens

Analysis of the effects of β-mannanase on immune function and intestinal flora in broilers fed the low energy diet based on 16S rRNA sequencing and metagenomic sequencing

As an enzyme, β-mannanase (BM) can be widely used as feed additive to improve the growth performance of animals. This experiment aimed to determine the effect of the addition of BM to low-energy diet on the immune function and intestinal microflora of broiler chickens. In this study, 384 one-day-old Arbor Acres broilers were randomly divided into 3 groups (8 replicates per group): positive control (PC, received a corn-soybean meal basal diet), negative control (NC, received a low-energy diet with Metabolizable Energy (ME) reduced by 50 kcal/kg) and NC + BM group (NC birds + 100 mg/kg BM). All birds were raised for 42 d. The results showed that BM mitigated the damage of immune function in peripheral blood of broilers caused by the decrease of dietary energy level by increasing the Concanavalin A (Con A) index of stimulation (SI) and macrophages phagocytic activity in the peripheral blood of broilers at 42 d (P < 0.05). The analysis of cecum flora showed that the low-energy diet significantly reduced the observed_species index (P < 0.01), Chao1 index and ACE index (P < 0.05), which reduced the abundance and evenness of species in the cecum of broilers at 21 d. It also significantly reduced the relative abundance of Candidatus_Arthromitus and significantly increased the relative abundance of Pseudomonas in the cecum of broilers at 21 d, while also significantly increasing the relative abundance of Monoglobus at 42 d. BM significantly increased the relative abundance of Lachnospiraceae_UCG-001 and Lachnospiraceae_bacterium_615 in the cecum of broilers at 21 d. In addition, BM inhibited microbial Fatty acid degradation by decreasing the activity of glutaryl-CoA dehydrogenase. Collectively, BM could improve intestinal health by enhancing the immune function of broilers, promoting the proliferation of beneficial bacteria and reducing the number of harmful bacteria, regulating intestinal flora, thereby alleviating the adverse effects of lower dietary energy levels.

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.

Effect of an Escherichia coli-derived phytase and a carbohydrase-protease cocktail derived from Bacillus spp. on performance, digestibility, bone mineralization and gut morphology in broilers fed different nutrient density diets

BACKGROUND

Enzyme combinations, particularly phytase (PHY) with various carbohydrases and proteases, are utilized in commercial broiler production to enhance nutrient and energy bioavailability.

OBJECTIVE

A feeding study was undertaken to determine whether the efficiency of an Escherichia coli-derived PHY and a feed enzyme complex (FEC) derived from Bacillus spp. containing carbohydrase and protease as main activities in broiler chickens is dependent on diet quality. A total of 900 male one-day-old broiler chickens (Ross 308) were assigned to a 2 × 3 factorial arrangement of the treatments with 2 different nutrient density diets, standard nutrient diet (SN diet) and a low-nutrient diet (LN diet; -100 kcal/kg for AMEn and -5% for crude protein [CP] and limiting amino acids), and 3 enzyme treatments (control [no enzymes], PHY and PHY + FEC). Each treatment group was composed of 6 replicates of 25 birds each.

RESULTS

The LN diet caused a decrease in performance index, tibia length and diameter, tibia calcium content and jejunal villus surface area (VSA). The interaction effects between diet and enzyme supplementation were observed (p < 0.05) on overall average daily gain (ADG), performance index, tibia ash content and jejunal villus height (VH) and VSA, with the favourable benefits of PHY + FEC treatment being more pronounced in the LN diets. Regardless of dietary nutrient density, supplementation with PHY alone or combined with FEC enhanced (p < 0.05) final body weight, overall ADG and jejunal villus height (VH)/crypt depth, with the highest values observed in the PHY + FEC group. The PHY + FEC treatment also improved (p < 0.05) overall feed conversion ratio, apparent ileal digestibility of dry matter, organic matter, CP, and energy, and tibia phosphorus content compared to the control treatment.

CONCLUSIONS

The results indicate that the simultaneous addition of PHY and FEC to the LN diets improved the growth rate, bone mineralization and gut morphology.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen performance and egg quality

The objective of this study was to assess the impact of β-mannanase and probiotic on the performance, serum biochemistry, gut morphometric traits, and fresh egg quality of laying hens. A total of 120 cages, housing light-weight laying hens (36 weeks old), were randomly assigned to four different treatments. These treatments included a control group fed non-supplemented diets; diets supplemented with 300 g/ton of beta-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotics. The trial spanned a duration of 26 weeks and was divided into three productive phases, each lasting 28 days. The inclusion of β-mannanase resulted in a significant improvement in the laying rate by 11% (p < 0.05) compared to the control treatment. Similarly, the addition of probiotics also enhanced the laying rate by 7% (p < 0.05), as well as the supplementation with combined additives (11.5%). Combined additives showed an increase in egg masses, and additive association improved by 13.9% (p < 0.001) in contrast to the control treatment. Overall, β-mannanase and combined additives used during the supplementation period resulted in improvements in the weight of fresh eggs. These benefits were observed after a period of 14 weeks without supplementation (p < 0.05). Furthermore, significant differences were observed in the serum biochemistry and egg masses of birds that were fed diets containing both additives (β-mannanase + probiotics) compared to the control group. Parameters such as uric acid, total cholesterol, and triglycerides displayed notable variations. The villi height: crypt depth showed differences with combined additives (β-mannanase + probiotics). The β-mannanase improved specific gravity, yolk height, length, and pH, and yolk color traits compared to the control treatment. The use of probiotics helped to improve yolk height, pH, and color score. Besides, combined additives (β-mannanase + probiotics) improve yolk height, length, weight, pH, and better traits in yolk color. Hence, incorporating β-mannanase and probiotics into laying hen diets proves to be a highly effective strategy for enhancing laying rate and overall health status, while simultaneously elevating certain quality attributes of fresh eggs.

Effects of nonantibiotic growth promoter combinations on growth performance, nutrient utilization, digestive enzymes, intestinal morphology, and cecal microflora of broilers

Given the ban on antibiotic growth promoters, the effects of nonantibiotic alternative growth promoter combinations (NAGPCs) on the growth performance, nutrient utilization, digestive enzyme activity, intestinal morphology, and cecal microflora of broilers were evaluated. All birds were fed pellets of two basal diets-starter (0-21 d) and grower (22-42 d)-with either enramycin (ENR) or NAGPC supplemented. 1) control + ENR; 2) control diet (CON, basal diet); 3) control + mannose oligosaccharide (MOS) + mannanase (MAN) + sodium butyrate (SB) (MMS); 4) control + MOS + MAN + Bacillus subtilis (BS) (MMB); 5) control + MOS + fruit oligosaccharide (FOS) + SB (MFS); 6) control + FOS + BS (MFB); 7) control + MOS + FOS + MAN (MFM); 8) control + MOS + BS + phytase (PT) (MBP). ENR, MOS, FOS, SB, MAN, PT, and BS were added at 100, 2,000, 9,000, 1,500, 300, 37, and 500 mg/kg, respectively. The experiment used a completely random block design with six replicates per group: 2400 Ross 308 broilers in the starter phase and 768 in the grower phase. All NAGPCs significantly improved body weight gain (P < 0.01), utilization of dry matter, organic matter, and crude protein (P < 0.05), villus height and villus height/crypt depth in the jejunum and ileum (P < 0.01), and decreased the feed conversion ratio (P < 0.01) at d 21 and 42. MMS, MMB, MFB, and MFM duodenum trypsin, lipase, and amylase activities increased significantly (P < 0.05) at d 21 and 42. On d 21 and 42, MMS, MMB, and MBP increased the abundance of Firmicutes and Bacteroides whereas MMB, MFB, and MBP decreased the abundance of Proteobacteria, compared to ENR and CON. Overall, the NAGPCs were found to have some beneficial effects and may be used as effective antibiotic replacements in broilers.

Significance of single β-mannanase supplementation on performance and energy utilization in broiler chickens, laying hens, turkeys, sows, and nursery-finish pigs: a meta-analysis and systematic review

This review will give a brief description of β-mannans, abundance in feedstuffs, utility of supplemental feed β-mannanase, and subsequent animal responses. Soybean products and co-products of processing palm, coconut, and guar seeds are the major sources of β-mannans in poultry and livestock feed. β-Mannans are linear polymers of mannose residues linked by β-1,4 glycosidic bonds and their ingestion elicit undesirable and metabolically costly responses. Web of Science was searched to retrieve published studies for meta-analyses of the impact of supplemental β-mannanase on performance and digestibility in pigs and poultry. The mean difference (MD) between β-mannanase and control on average daily gain (g/d) was +0.23 (P = 0.013; 95% CI of 0.05; 0.41), +10.8 g/d (P = 0.0005; 95% CI of 6.6; 15.0 g/d), and +20.68 (P < 0.000; 95% CI of 17.15; 24.20 g/d) for broiler chickens, nursery pigs, and grow-finish pigs, respectively. The MD on β-mannanase improvement on feed conversion (FCR) was -0.02 (P < 0.0001) with 95% CI (-0.03; -0.02) suggesting a 2-to-3-point FCR improvement in broiler chickens. β-Mannanase improvement on gain to feed (G:F) was +13.8 g/kg (P = 0.027; 2.1; 25.4 g/kg) and +8.77 g/kg (6.32; 11.23 g/kg) in nursery and grow-finish pigs, respectively. β-Mannanase improved apparent metabolizable energy by 47 kcal/kg (P = 0.0004) with 95% CI (28.8; 65.7 kcal/kg) in broiler chickens. The improvement of gross energy digestibility in pigs was 1.08% unit with 95% CI (0.90; 1.26) translating to the release of between 30.6 and 42.8 kcal/kg of digestible energy. Although data were limited, β-mannanase improved egg production in laying hens linked to improved energy metabolism in laying hens linked to improved energy metabolism but had no impact on egg quality. Turkeys may be more adversely affected by β-mannans because of the high protein/amino acids requirements necessitating higher dietary inclusion of soybean meal. However, growth performance and feed efficiency responses of turkeys fed diets supplemented with β-mannanase were variable. In summary, β-mannanase supplementation improved performance linked to energy and nutrient utilization. However, the magnitude of response was variable within and between species indicating further application refinement is warranted to achieve consistent efficacy, and improved understanding of the functional contribution of β-mannans hydrolysis products.