Effects of beta-mannanase in corn-soybean meal diets on laying hen performance

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.

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.

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.

Epiphytic bet-mannanase producing bacterial strains

Dry remains of the herbal species of the plantain (Plantago major), the wormwood (Artemisia vulgaris) and the reed grass (Calamagrostis acutiflora) were used as a natural source for isolation of β- mannanase producing strains. They were isolated by using the carob gum as a single source of carbon and energy. Each chosen plant species was found to be colonized with a single dominant epiphytic group of microorganism, although the plants had been collected in the same location. Bacillus circulans was only found in P. major, Bacillus subtilis on A. vulgaris, whereas Pantoea sp. was found in C. acutiflora. Identification of the taxonomy affiliation of the isolated β-mannanase producers allowed using the formerly proposed primers for PCR cloning of β-mannanase genes previously occurred in the respective bacterial species. This approach let us cloning 330 bp fragment of β-mannanase genes from B. circulans and B. subtilis and 1000 bp fragment of β-mannanase gene from Pantoea sp. Testing the enzymatic activity of the isolated strains by staining the carob gum hydrolysis zones on the plates with Congo Red was carried out. As a result, the maximum activity was found in Pantoea sp.

Effects of multi-enzyme on production performance, egg quality, nutrient digestibility, and excreta noxious gas emission of early phase Hy-line brown hens

The purpose of this study was to investigate the effects of dietary supplementation of non-starch polysaccharide multi-enzyme (NME) in early laying phase of hens on production performance, egg quality, nutrient digestibility, and excreta noxious gas emission. In total, 432 Hy-line brown laying hens at 18 wk of age were used in a 10-wk feeding trail. Hens were randomly assigned to 1 of 3 treatments with 24 replication and 6 hens per replication (1 hen per cage). Dietary treatments were corn-soybean meal-DDGS-based diets supplemented with 0 (based diet, CON), 0.05% (NME1), and 0.1% (NME2) of NME. No significant (P > 0.05) response to increasing NME supplementation was observed for damaged egg rate shown throughout the experiment. Significant (P < 0.05) linear increase was observed for egg production at week 4, 6, and 8; moreover, egg production at week 8 also showed quadratic (P = 0.0344) increase. No significant effects were found on yolk color, eggshell strength, and eggshell thickness during the experiment (P > 0.05) with the increase in NME supplemental levels. Albumin height, haugh unit, and egg color values were linearly (P < 0.05) increased at week 2 and 6 following the increasing NME supplementation, respectively. Additionally, quadratic (P = 0.0013) effect was observed on egg weight at week 6 with the increasing level of NME. Moreover, apparent total tract digestibility of nitrogen and excreta ammonia emission was linearly (P < 0.05) affected increasing NME supplementation. In summary, inclusion of NME containing xylanase, β-glucanase, galactosidase, and galactomannanase activities in corn-soybean meal-DDGS-based diets increased nitrogen digestibility, decreased excreta ammonia emission, and had no negative effects on production performance and egg quality parameters.

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.

The effect of β-mannanase on nutrient utilization and blood parameters in chicks fed diets containing soybean meal and guar gum

The present study was conducted to determine whether the addition of β-mannanase in broiler feed changes hormonal profiles in the blood and broiler performance and nutrient availability. Five hundred and four Cobb male chickens were studied during d 7 to 21. Three corn-soybean meal (SBM) based diets 1) Low SBM (18% SBM); 2) High SBM (31% SBM); and 3) High SBM+GG (31% SBM + Guar Gum (GG) 0.5%) with 3 levels of β-mannanase (0, 200, and 400 ppm) were mixed to produce 9 diets. A factorial design 3 × 3 was performed with JMP pro 13 (SAS, 2017). Analysis of variance and contrast analysis were used to test significance level at P < 0.05. Glucose (190 and 188 mg/dL) was increased with 200 and 400 ppm of β-mannanase, respectively, compared to control (182 mg/dL) in the fasted state (P < 0.037). Glucose was higher in chicks fed with the High SBM and High SBM + GG diets but lower in the fasted re-fed state (P < 0.01). Insulin was higher with 200 and 400 ppm added β-mannanase in the fed state (P < 0.021). Insulin-like growth factor-1 was higher with 400 ppm added to High SBM+GG. β-mannanase improved feed conversion ratio (FCR) 9 points with 400 ppm in High SBM diet (P < 0.01) and 16 and 18 points with 200 and 400 ppm, respectively, added to the High SBM+GG diet (P < 0.01). Viscosity decreased from 19.2 to 7 cps with both enzyme doses in the High SBM + GG diet (P < 0.01). Digestible energy was +152 kcal/kg with 400 ppm β-mannanase in the High SBM diet and +200 kcal/kg with both levels of enzyme in High SBM+GG diet. Digestibility of amino acids was improved from 0.8 to 3.6% with β-mannanase in High SBM+GG diet (P < 0.05). In conclusion, chicks fed with High SBM and High SBM+GG diets with added β-mannanase significantly improved blood glucose and anabolic hormone homeostasis, FCR, digestible energy, and digestible amino acids compared to chicks fed with same diets without β-mannanase.

A Recombinant Highly Thermostable β-Mannanase (ReTMan26) from Thermophilic Bacillus subtilis (TBS2) Expressed in Pichia pastoris and Its pH and Temperature Stability

A gene encoding a highly thermostable β-mannanase from a thermophilic Bacillus subtilis (TBS2) was successfully expressed in Pichia pastoris. The maximum activity of the recombinant thermostable β-mannanase (ReTMan26) was 5435 U/mL, which was obtained by high-density, fed-batch cultivation after 168-h induction with methanol in a 50-L bioreactor. The protein yield reached 3.29 mg/mL, and the protein had a molecular weight of ~42 kDa. After fermentation, ReTMan26 was purified using a 10-kDa cut-off membrane and Sephadex G-75 column. The pH and temperature optima of purified ReTMan26 were pH 6.0 and 60 °C, respectively, and the enzyme was stable at pH 2.0-8.0 and was active at 20-100 °C. HPLC analysis of the products of locust bean gum hydrolysis showed that the mannan-oligosaccharide content was 62.5%. ReTMan26 retained 58.6% of its maximum activity after treatment at 100 °C for 10 min, which was higher than any other β-mannanase reported up to now, suggesting its potential for industrial applications.

Effects of wheat distillers dried grains with solubles with or without protease and β-mannanase on the performance of turkey hen poults

Expansion in bioethanol production has resulted in distillers dried grains with solubles (DDGS) being readily available as a major protein source in the poultry industry. Two experiments were conducted to investigate effects of wheat DDGS (wDDGS) and enzyme on nutrient digestibility and performance of turkey hen poults (7 to 21 d). Two starter diets (0 or 30% wDDGS) were formulated to meet or exceed the nutrient requirements for Hybrid Converter female turkeys. These diets were then mixed in different proportions to obtain 2 additional wDDGS inclusion levels (10 and 20%). In Experiment 1, 0 and 30% wDDGS diets were each subdivided into 3 portions and supplemented with no enzyme (E-), protease (P+; 0.125 g/kg) or β-mannanase (M+; 0.5 g/kg). A total of 144, 7-day-old poults were randomly distributed in groups of 4 in 6 replicate cages per treatment. There were no significant main effects or interactions on feed intake from 7 to 21 d. However, a positive (P<0.05) effect of 30% wDDGS was shown for weight gain and gain:feed. A significant interaction on nitrogen retention (NR) was found between enzymes and wDDGS level. There were significant main effects and interactions on the AME of the diets. The AME was higher (P<0.05) for 30% compared to 0% wDDGS. Supplementation of P+ decreased (P<0.05) AME for 0% diets as compared to 30% diets and vice versa for M+. In Experiment 2, 7-day-old poults (4 birds per 6 replications per treatment) were fed 4 levels of wDDGS (0, 10, 20, and 30%) with no enzyme. A linear (P<0.01) response was found for gain:feed with 30% wDDGS having a better response. Quadratic (P<0.01) responses were also found for NR and AME; both were highest for 10% wDDGS diets. In summary, no beneficial effects of P+ or M+ were demonstrated in diets containing 30% wDDGS. Wheat DDGS is a valuable energy source and as high as 30% can be incorporated in turkey hen poults (7 to 21 d) diets.

Evaluation of inclusion level of wheat distillers dried grains with solubles with and without protease or β-mannanase on performance and water intake of turkey hens

It is becoming a common practice to use higher levels of wheat distillers dried grains with solubles (wDDGS) in poultry diets. The objective of this study was to determine the effects of level of inclusion of wDDGS with or without enzyme (E-, i.e., wDDGSE-) supplementation on performance and water consumption of turkey hens (0 to 72 d). Two diets (0 or 30% wDDGS) were formulated to meet the nutrient requirements of Hybrid Converter turkeys. Diets (0 or 30% wDDGS; starter, grower, and finisher) were then blended to obtain a different level of inclusion (15%) of wDDGS. The 30% wDDGS diet was divided into 3 fractions and 2 fractions supplemented with either protease (P+, i.e., wDDGSP+; 0.126 g/kg) or β-mannanase (M+, i.e., wDDGSM+; 0.05 g/kg). All 5 diets were fed ad libitum as mash. The 700 0-d turkey hens were randomly allocated into groups of 35 birds per replicate with 4 replicate floor pens per treatment, in a completely randomized design. Water consumption per pen was recorded beginning at 7 d. There was no effect of dietary treatment on feed intake. BW of turkey hens (52 d; grower) was significantly higher for 30% wDDGSP+ as compared to 0% wDDGSE- or 15% wDDGSE- diets; but was not different from 30% wDDGSE- or 30% wDDGSM+ diets. FCR (P < 0.01; 28 to 52 d), and total FCR (P < 0.05; 0 to 72 d) was significantly improved for birds fed 15 or 30% wDDGS regardless of enzyme treatment compared to 0% wDDGSE-. Water intake (WI, in mL per bird per day) tended to be higher (P = 0.08) between 7 and 28 d for 30% wDDGSP+ diets compared to other treatments. Similarly, WI of birds fed 30% wDDGSP+ was higher (P < 0.05; 28 to 52 and 52 to 72 d) and total WI (P = 0.07; 7 to 72 d) tended to be higher than other treatments. This study is the first to report the impact of wDDGS on WI. As high as 30% wDDGS can be substituted in turkey hen diets. No effect of P+ or M+ at the inclusion level tested was found on performance.

Use of Bacillus subtilis isolates from Tua-nao towards nutritional improvement of soya bean hull for monogastric feed application

Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya bean oil extraction. Microbial fermentation was expected to improve SBH qualities before applying to animals, especially monogastric animals. Two bacterial strains, Bacillus subtilis MR10 and TK8 that were isolated from Tua-nao, a traditional fermented soya bean in northern Thailand, were used for fermented soya bean hull (FSBH) production. Both could easily grow at 37°C in SBH as the sole substrate. MR10 produced the highest β-mannanase activity (400 U g(-1) SBH) on day 2, while TK8 produced the highest cellulase activity (14·5 U g(-1) SBH) on day 3. After fermentation, the nutritional quality of SBH was obviously improved by an increase in soluble sugars, soluble proteins, crude protein and crude lipid, and a decrease in the content of raffinose family oligosaccharides. Scavenging activity (%) of SBH against ABTS radical cation was also increased from 14 to 27 and 20% by MR10 and TK8 fermentation, respectively. According to the GRAS property of these both strains and various improvements of nutritional values, the fermented SBH proved to be a potential feed ingredient, especially for the monogastric animals.

SIGNIFICANCE AND IMPACT OF THE STUDY

Normally, soya bean hull has been recognized as only a worthless by-product from soya bean oil production process because of its low utilizable nutrients. Our study introduced an alternative way to utilize this worthless residue using biotechnological knowledge. The nutritional quality of soya bean hull was improved by microbial fermentation. Fermented soya bean hull can be used as a cheap, safe and high-nutrient feed ingredient for livestock production, especially monogastric animals, to promote their growth performances, instead of using antibiotics in some regions of the world.

β-Mannanase production by Aspergillus niger BCC4525 and its efficacy on broiler performance

BACKGROUND

Mannan is a hemicellulose constituent commonly found in plant-derived feed ingredients. The gum-like property of mannan can obstruct digestive enzymes and bile acids, resulting in impaired nutrient utilisation. In this study, β-mannanase production by Aspergillus niger strain BCC4525 was investigated using several agricultural residues under solid state condition. The biochemical properties of the target enzyme and the effects of enzyme supplementation on broiler performance and energy utilisation were assessed.

RESULTS

Among five carbon sources tested, copra meal was found to be the best carbon source for β-mannanase production with the maximum yield of 1837.5 U g(-1) . The crude β-mannanase exhibited maximum activity at 80 °C within a broad range of pH from 2 to 6. In vitro digestibility assay, which simulates the gastrointestinal tract system of broilers, showed that β-mannanase could liberate reducing sugars from corn/soybean diet. Surprisingly, β-mannanase supplementation had no significant effect on broiler feed intake, feed conversion rate or energy utilisation.

CONCLUSION

A high level of β-mannanase was produced by A. niger BCC4525 under solid state condition using copra meal as carbon source. Although the enzyme has the desired properties of an enzyme additive for improving broiler performance, it does not appear to be beneficial.

Cloning, expression, and characterization of β-mannanase from Bacillus subtilis MAFIC-S11 in Pichia pastoris

The β-mannanase gene (1,029 nucleotide) from Bacillus subtilis MAFIC-S11, encoding a polypeptide of 342 amino acids, was cloned and expressed in Pichia pastoris. To increase its expression, the β-mannanase gene was optimized for codon usage (mannS) and fused downstream to a sequence-encoding modified α-factor signal peptide. The expression level was improved by 2-fold. This recombinant enzyme (mannS) showed its highest activity of 24,600 U/mL after 144-h fermentation. The optimal temperature and pH of mannS were 50 °C and 6.0, respectively, and its specific activity was 3,706 U/mg. The kinetic parameters V max and K m were determined as 20,000 U/mg and 8 mg/mL, respectively, representing the highest ever expression level of β-mannanase reported in P. pastoris. In addition, the enzyme exhibited much higher binding activity to chitin, chitosan, Avicel, and mannan. The superior catalytic properties of mannS suggested great potential as an effective additive in animal feed industry.

Overexpression of a fungal β-mannanase from Bispora sp. MEY-1 in maize seeds and enzyme characterization

BACKGROUND

Mannans and heteromannans are widespread in plants cell walls and are well-known as anti-nutritional factors in animal feed. To remove these factors, it is common practice to incorporate endo-β-mannanase into feed for efficient nutrition absorption. The objective of this study was to overexpress a β-mannanase gene directly in maize, the main ingredient of animal feed, to simplify the process of feed production.

METHODOLOGY/PRINCIPAL FINDINGS

The man5A gene encoding an excellent β-mannanase from acidophilic Bispora sp. MEY-1 was selected for heterologous overexpression. Expression of the modified gene (man5As) was driven by the embryo-specific promoter ZM-leg1A, and the transgene was transferred to three generations by backcrossing with commercial inbred Zheng58. Its exogenous integration into the maize embryonic genome and tissue specific expression in seeds were confirmed by PCR and Southern blot and Western blot analysis, respectively. Transgenic plants at BC3 generation showed agronomic traits statistically similar to Zheng58 except for less plant height (154.0 cm vs 158.3 cm). The expression level of MAN5AS reached up to 26,860 units per kilogram of maize seeds. Compared with its counterpart produced in Pichia pastoris, seed-derived MAN5AS had higher temperature optimum (90°C), and remained more β-mannanase activities after pelleting at 80°C, 100°C or 120°C.

CONCLUSION/SIGNIFICANCE

This study shows the genetically stable overexpression of a fungal β-mannanase in maize and offers an effective and economic approach for transgene containment in maize for direct utilization without any purification or supplementation procedures.

Screening and selection of Bacillus spp. for fermented corticate soybean meal production

AIMS

To screen and select the Bacillus spp. from Tua-nao of northern Thailand for fermented corticate soybean meal (FCSBM) production.

METHODS AND RESULTS

After isolation of Bacillus spp. from Tua-nao was carried out, cellulase, hemicellulases (i.e., β-mannanase and xylanase) and phytase production by isolated Bacillus spp. were determined. B. subtilis isolate MR10 showed the highest β-mannanase, xylanase and phytase production at 280, 41 and 16 U g(-1) substrate, respectively, while the highest cellulase production was found in TK8 at 25 U g(-1) substrate. FCSBMs produced by single starter and mixed starter of both isolates showed the better properties than those of corticate soybean meal (CSBM), i.e., higher in soluble sugar, protein and phosphate content, smaller sugar molecules and better digestibility and absorbability than those of CSBM. Moreover, FCSBMs had no toxicity effect on mouse fibroblast cell line (3T3) but had an inhibitory effect on lung cancer cell line (CorL23).

CONCLUSIONS

B. subtilis isolate MR10 and TK8 were selected for FCSBMs production because of their role as nutritional enhancer for CSBM and their safety.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study were useful for FCSBM production process that can be applied as feed ingredient for monogastric animals.

Characterization, gene cloning, and heterologous expression of β-mannanase from a thermophilic Bacillus subtilis

Bacillus subtilis BCC41051 producing a thermostable β-mannanase was isolated from soybean meal-enriched soil and was unexpectedly found to be thermophilic in nature. The extracellular β-mannanase (ManA) produced was hydrophilic, as it was not precipitated even with ammonium sulfate at 80% saturation. The estimated molecular weight of ManA was 38.0 kDa by SDS-PAGE with a pi value of 5.3. Optimal pH and temperature for mannan-hydrolyzing activity was 7.0 and 60°C, respectively. The enzyme was stable over a pH range of 5.0-11.5, and at temperatures of up to 60°C for 30 min, with more than 80% of its activity retained. ManA was strongly inhibited by Hg(2+) (1 mM), but was sensitive to other divalent ions to a lesser degree. The gene of ManA encoded a protein of 362 amino acid residues, with the first 26 residues identified as a signal peptide. High expression of recombinant ManA was achieved in both Escherichia coli BL21 (DE3) (415.18 U/ml) and B. megaterium UNcat (359 U/ml).

Levels of beta-mannan in soybean meal

Beta-mannan, also known as beta-galactomannan, is found in a number of feed ingredients for poultry. Of these, soybean meal (SBM) is by far the most commonly used, being the primary source of protein in poultry feeds in most countries. Although beta-mannan has clearly been shown to be deleterious to poultry and animal performance, a survey of its concentration in SBM has yet to be reported. Thirty-six samples of SBM, identified as either dehulled or nondehulled, were obtained from commercial sources in a number of countries and assayed for beta-mannan content. Results confirmed that all samples of SBM assayed contained at least 1.0% beta-mannan and that concentrations are higher in nondehulled (1.61 +/- 0.20%) than in dehulled samples (1.26 +/- 0.14%).

In vivo measurement of flatulence and nutrient digestibility in dogs fed poultry by-product meal, conventional soybean meal, and low-oligosaccharide low-phytate soybean meal

OBJECTIVE

To determine an optimal window for determining peak flatulence and evaluate the effects of oligosaccharides and supplemental beta-mannanase in soybean meal-based diets on nutrient availability and flatulence.

ANIMALS

6 dogs.

PROCEDURES

Dogs were used in a 2 x 3 factorial arrangement of treatments in a 6 x 6 Latin square experiment to evaluate the digestibility, flatulence, and fecal odor metabolites of low-oligosaccharide low-phytate soybean meal (LLM), conventional soybean meal (SBM), and poultry by-product (PBP) meal diets with or without supplemental beta-mannanase (5 g/kg).

RESULTS

Enzyme supplementation had no effect on total tract dry matter (DM), nitrogen digestibility, or digestible energy; however, differences between protein sources did exist for total tract DM digestibility and digestible energy. The PBP meal had higher DM digestibility and digestible energy (mean, 0.913 and 4,255 cal/g), compared with soy-based diets (mean, 0.870 and 4,049 cal/g). No differences were detected for any treatment regardless of protein source or addition of supplemental enzyme for any flatulence components analyzed. No differences were detected for all fecal odor metabolites regardless of addition of supplemental enzyme; however, differences between protein sources were detected. The PBP meal had lower concentrations of carboxylic acids and esters and higher concentrations of heterocycles, phenols, thio and sulfides, ketones, alcohols, and indoles than LLM and SBM.

CONCLUSIONS AND CLINICAL RELEVANCE

Diets containing < 22.4 g of stachyose/kg and < 2 g of raffinose/kg did not alter digestibility or increase flatulence in dogs.

Effects of beta-mannanase in corn-soy diets on commercial leghorns in second-cycle hens

beta-Mannanase (Hemicell) is a unique enzyme-based feed ingredient that can hydrolyze beta-mannan, an antinutritional fiber in feed. Because soybean meal contains beta-mannan and its derivatives, addition of beta-mannanase may improve soybean-meal utilization. The purpose of this study was to evaluate the effect of beta-mannanase on performance of commercial Leghorns fed corn-soybean meal based diets. In this experiment, 3 diets were formulated. The metabolizable energy content for diet 1 (high-energy diet) was 2,951 kcal/kg, which was 120 kcal/kg higher than diet 2 (low-energy diet supplemented with beta-mannanase) and diet 3 (low-energy diet without beta-mannanase). Hy-Line W-36 hens (n = 720, 98 wk old) were randomly divided into 3 dietary treatments (16 replicates of 15 hens per treatment). The trial lasted for 12 wk. Overall average feed conversion of hens fed the low-energy diet supplemented with beta-mannanase was similar to that of hens fed the high-energy diet, and both were significantly lower than that of hens fed the low-energy diet without beta-mannanase. There were no significant differences in overall average egg production and egg mass among 3 dietary treatments for the 12-wk period. However, the addition of beta-mannanase significantly increased average egg production and egg mass of hens fed the low-energy diet from wk 5 to 8. There were no significant differences in feed intake, egg specific gravity, egg weight, mortality, body weight, and body weight variability among the 3 dietary treatments. beta-Mannanase supplementation improved energy utilization of corn-soybean layer diets and has potential to reduce the cost of practical laying hen diets containing beta-mannan.

A dose-response study with the feed enzyme beta-mannanase in broilers provided with corn-soybean meal based diets in the absence of antibiotic growth promoters

An experiment was designed to assess the effects of graded levels of beta-mannanase on performance and body weight uniformity of male broilers provided with diets based on corn and soybean meal and devoid of antibiotic growth promoters or coccidiostats. Four dietary treatments contained 0, 50, 80, and 110 MU of Hemicell/ ton (where 1 MU = 10(6) enzyme activity units, 100 MU/ton is manufacturer's recommendation). Each treatment contained 15 pens with 40 birds/pen. Individual bird weights were determined on d 0, 21, and 42. From 21 to 42 d of age, feed intake for the 80 MU/ton treatment was significantly greater than the 50 MU/ton treatment. beta-Mannanase inclusion at 80 or 110 MU/ton induced improvements (P < 0.05) in weight gain (3.9 to 4.8%) and feed efficiency (3.5 to 3.8%) over the control, whereas inclusion of 50 MU/ton resulted in no significant benefit. There were no significant differences between 80 or 110 MU/ton. The experiment demonstrated that dietary inclusion of beta-mannanase at approximately 50 MU/ton is not sufficient for maximum response. Inclusion at 80 MU/ ton improved broiler gains and feed conversion and increasing to 110 MU/ton resulted in no significant additional response.

The effect of two different blends of essential oil components on the proliferation of Clostridium perfringens in the intestines of broiler chickens

The effect of 2 different blends of essential oils on Clostridium perfringens (Cp) in the intestine and feces of broiler chickens was tested in 6 field trials for each blend. One hundred parts per million of the blends were mixed in a commercial corn-based diet throughout the entire growing period for experimental flocks. Samples from the jejunum, cecum, cloaca, and feces were taken on d 14, 21, and 30 from experimental and control flocks and tested quantitatively for Cp via blood agar plate, litmus milk medium, and ELISA. Blend A reduced (P < or = 0.05) the average Cp concentration in the feces on all sampling days, in the jejunum and cecum on d 14 and 21, and in the cloaca on d 14. Blend B effected a significant reduction of Cp concentration in the jejunum on d 14 and 30 and in the cloaca on d 14. The percentages of specimens from the control group that tested positive for Cp were 83.3% for feces, 88.0% for jejunum and cloaca, and 82.6% for cecum. Specimens from the feces and 3 sections of the intestine were Cp positive in groups treated with blend A (60.8, 64.6, 47.9, and 70.8%) and with blend B (65.9, 63.6, 63.6, and 72.7%). Our results indicate that specific blends of essential oil components can control Cp colonization and proliferation in the gut of broilers and therefore may be of help to prevent problems with Cp and necrotic enteritis.

Beneficial Effect of β-Mannanase Feed Enzyme on Performance of Chicks Challenged with Eimeria sp. and Clostridium perfringens

Two experiments were conducted to determine the effect of a beta-mannanase feed enzyme on the performance of broiler chicks subject to a necrotic enteritis disease challenge model involving oral inoculation of Eimeria sp. and Clostridium pefringens. Beta-mannanase is known to improve productive performance when added to poultry and swine diets. In both experiments, disease challenge in the absence of feed additives demonstrated significant reductions in performance as measured by weight gain, feed conversion, and the incidence of coccidial lesion scores. Significant mortality was also observed in challenged groups in Experiment 1. The disease challenge model was therefore judged as highly effective. Additions of a commonly used antibiotic, bacitracin methylene disalicilate (BMD), and coccidiostat, salinomycin, were highly effective in partially counteracting negative effects of the disease challenge. In both experiments, addition of beta-mannanase significantly improved performance and reduced lesion scores in disease-challenged groups. The degree of improvement was somewhat less than that afforded by a combination of BMD and salinomycin in Experiment 1 but was not different from that afforded by BMD alone in Experiment 2. We conclude that the beta-mannanase enzyme can play a role in circumstances where the use of antibiotics is not desired.

Effect of mannan-endo-1,4-beta-mannosidase on the growth performance of turkeys fed diets containing 44 and 48% crude protein soybean meal

Soybean meal (SBM) contains heat-resistant mannans. Domesticated turkeys are sensitive to mannans because of the high inclusion rate of SBM in their diets, causing increased chyme viscosity, wet droppings, and reduced feed conversion. Three experiments of similar design were conducted to determine the effect of mannan-endo-1,4-f'-mannosidase supplementation of corn-SBM diets on market turkeys. Experiment 1 was conducted at North Carolina State University using Nicholas hens raised from 1 to 98 d of age. Experiments 2 and 3 were conducted at PARC Institute Inc. using Large White turkey toms raised from 1 to 126 d of age. In each experiment, birds were randomly assigned to litter floor pens. Each pen was assigned to one of four experimental treatments in 2 x 2 factorial arrangement of two basal diets containing 44% CP and 48% CP SBM (SBM-44 and SBM-48, respectively) with or without 100 million units (MU) Hemicell/tonne (1 MU = 106 enzyme activity U). Birds fed SBM-44 had lower final BW (14.9 vs. 14.56 kg 18 wk BW / tom; 7.66 vs. 7.46 kg 14 wk BW/hen, P < 0.05) and higher final cumulative feed/gain than those fed the SBM-48. Hemicell supplementation generally improved performance of all birds, with a greater response in birds fed SBM-44. Hemicell improved BW and feed/gain by 1% (P = 0.779) and 3% (P = 0.377) in hens and 2.5% (P = 0.0016) and 4% (P = 0.0001) in toms, respectively. The results of these experiments indicate that some of the adverse effects of antinutritional factors of SBM of on turkey growth performance can be alleviated by dietary mannan-endo-1,4-beta-mannosidase supplementation.

Recovery of a marker strain of Salmonella typhimurium in litter and aerosols from isolation rooms containing infected chickens

Screening of poultry flocks for foodborne pathogen Salmonella contamination is critical for Salmonella control in preharvest stages of poultry production. In this study, two sampling methods (litter and air filter) were compared for detection of S. typhimurium from experimentally infected chicks some of which had received either a probiotic competitive exclusion culture or transfer of cecal contents from salmonellae-free adult birds. At 4, 9, and 11 days after inoculation, S. typhimurium samples were enumerated by selective plating. For both types of sampling, the control birds yielded the greatest levels of environmental contamination followed by the samples from the probiotic inoculated birds with the birds receiving the cecal transfer culture having the lowest levels of contamination. Although the two sampling methods responded in a similar fashion, detection sensitivity needs to be increased for air filter sampling.