Variability in the in vitro degradation of non-starch polysaccharides from wheat by feed enzymes

The effect of different wheat varieties and exogenous xylanase on bird performance and utilization of energy and nutrients

The aims of the present study were to first, determine the xylan fractions of 10 different wheat cultivar samples and their response to treatment by the same commercial xylanase enzyme preparation. Second, use information obtained to select 5 of the wheats for use within a feeding experiment to determine whether the rate of xylan release can be used to predict the feeding value of the wheats when diets have been supplemented with xylanase. Treatment of 10 different wheat varieties by the same enzyme resulted in varying levels of hydrolysis. Soluble xylan content ranged from 7.85 to 14.40 and 3.20 to 5.13 (mg/g) when treated with and without xylanase, respectively. Oligosaccharide content ranged from 0.34 to 1.58 and 0.05 to 0.54 (mg/g) when treated with and without xylanase, respectively. Five of the 10 wheats were then selected based on the determined xylan fractions to use within a feeding experiment. A total of 360 male Ross 308 broilers were randomly allocated to 60 raised floor pens. A soybean meal (SBM) balancer feed was formulated to contain 12.07 MJ/kg apparent metabolizable energy (AME) and 392.9 g/kg crude protein (CP). Five diets were prepared by mixing 630 g/kg of each of the 5 experimental wheats with 370 g/kg of the balancer. Each diet was split into 2, one of which was supplemented with 100 g/MT of Econase XT (223,000 BXU/g), resulting in a total of 10 diets. The birds were fed the diets from 0 to 28 d of age. Wheat cultivar had an effect (P = 0.044) on feed intake (FI), while the addition of xylanase increased (P < 0.05) weight gain (WG) and improved feed conversion ratio (FCR). Various interactions were observed (P < 0.05) between wheat cultivars and xylanase for AME and nutrient utilization. This study suggests that wheats treated with the same xylanase, differ in their susceptibility to release soluble xylan and oligosaccharides, which may partially explain the varying performance and nutrient digestibility responses noted in the literature.

In vitro evaluation of efficacy of nonstarch polysaccharides enzymes on wheat by simulating the avian digestive tract

In this study, the efficacy of different nonstarch polysaccharide (NSP) enzyme sources on wheat ingredients and wheat basal diets in vitro were evaluated by simulating the avian digestive tract. In Exp. 1, pH level was increased from 2.0 to 8.0 by simulating the avian digestive tract. The relative enzyme activities of xylanase A, B, and C and β-glucanase X at pH 3.0-3.5 were higher (P < 0.05) than those at pH 2.0 or 7.0-8.0. The optimal pH levels of 3.5 and 7.0 were screened by simulating the proventriculus and small intestine, respectively to evaluate the efficacy of NSP enzyme on wheat sources. In Exp. 2, wheat 1 contained the highest content of NSP fractions and the lowest digestibility in vitro dry matter (IVDMD) and energy (IVED) in wheat samples. Therefore, wheat 1 was selected for hydrolysis research under different NSP enzyme sources and levels (1,500, 4,500, 13,500, 40,500, 121,500 U xylanase/kg and 250, 500, 1,000, 2,000, 4,000 U β-glucanase/kg) in vitro. The hydrolysis of wheat on the basis of the released reducing sugar content was determined by xylanase sources A > B > C (P < 0.05) and β-glucanase sources of X > Y (P < 0.05). On the basis of the hydrolysis, the optimum dose of xylanase A and β-glucanase X were 40,500 U/kg and 2,000 U/kg, respectively. Subsequently, the completely randomized designs involving 2 NSP enzymes treatments × 2 endogenous digestive enzymes treatments (Exp. 3), as well as 2 wheat basal diets × 2 NSP enzymes treatments (Exp. 4) were used to evaluate the efficacy of NSP enzymes on dietary nutrient digestibility. The addition of NSP enzymes (40,500 U xylanase A/kg and 2,000 U β-glucanase X/kg) increased the IVDMD and IVED of wheat 1 without endogenous enzymes (P < 0.05), while the IVDMD and IVED of wheat 1 with endogenous enzyme were only slightly increased (P > 0.05). The addition of NSP enzymes could increase the IVDMD and IVED of corn-wheat-soybean meal diet (P < 0.05), but had no effect on those of wheat-cottonseed meal rapeseed meal diet (P > 0.05). In conclusion, xylanase and β-glucanase additions could effectively eliminate the adverse effects on wheat and wheat basal diets at the optimal pH levels of 3.5 and 7.0 by simulating the proventriculus and small intestine parts, respectively. The efficacy of NSP enzymes was influenced by the enzyme sources, dietary type, and the interaction of endogenous enzymes.

Supplementation of multi-enzymes alone or combined with inactivated Lactobacillus benefits growth performance and gut microbiota in broilers fed wheat diets

The effects of multi-enzymes mixture supplementation or combination with inactivated Lactobacillus on growth performance, intestinal barrier, and cecal microbiota were investigated in broilers at the age of 15–42 days fed a wheat-based diet. A total of 576 broilers (12 broilers/cage; n = 12) were used and divided into four groups and randomly allotted to four experimental diets throughout grower (15–28 days of age) and finisher (29–42 days of age) phases. Diets consisted of a corn-soybean meal-based diet (BD), a wheat-soybean meal-based diet (WD), and WD supplemented multi-enzymes (WED) or combined with inactivated Lactobacillus (WEPD). The results showed that the average daily gain (ADG) and body weight (BW) were reduced in broilers fed WD diet compared with those fed BD diet during the grower period (P < 0.05). Broilers in the WED or WEPD group had higher ADG and BW during the grower period (P < 0.05) and had a lower feed-to-gain ratio (F/G) compared to broilers in the WD group during the grower and overall periods (P < 0.05). Improved expression of intestinal barrier genes (claudin-1, ZO-1, and mucin-2) was observed in WEPD compared to the BD or WD group (P < 0.05). Compared to the BD group, the WD group decreased the abundance of Oscillospira, norank_f__Erysipelotrichaceae, and Peptococcus, which are related to anti-inflammatory function and BW gain. The WD also increased Bifidobacterium and some short-chain fatty acid (SCFA)-producing bacteria (Anaerotruncus, Blautia, and Oscillibacter), and Barnesiella, which were presumed as “harmful microbes” [false discovery rate (FDR) < 0.05]. WED and WEPD groups, respectively, improved Bilophila and Eubacterium_hallii_group compared with those in the WD group (FDR < 0.05). In addition, the Enterococcus abundance was reduced in the WEPD group compared to the WD group (FDR < 0.05). Higher acetate and total SCFA concentrations were observed (P < 0.05) among broilers who received a WD diet. Compared with the WD group, the WED or WEPD group further increased cecal propionate content (P < 0.05) and tended to improve butyrate concentration. These results suggested that supplemental multi-enzymes alone and combined with inactivated Lactobacillus could improve the growth performance based on the wheat-based diet and offer additional protective effects on the intestinal barrier function of broilers.

Characterization of yeast cell surface displayed Lentinula edodes xylanase and its effects on the hydrolysis of wheat

The current study displayed a xylanase from Lentinula edodes on the surface of Pichia pastoris (sdLeXyn) and investigated its properties and effects on the wheat hydrolysis. Fluorescence microscope results showed that sdLeXyn was successfully anchored and displayed on the surface of P. pastoris X-33 cells. The highest activity of sdLeXyn was obtained at pH 3.0 and 50 °C. The sdLeXyn exhibited anti-high temperature property and showed broad temperature adaptability (>55% of the highest activity at 20-80 °C). The sdLeXyn was very stable at room temperature and could remain functionally stable at 50 °C for 3 h. The K_m value was greater in sdLeXyn than that in free recombinant L. edodes xylanase. The sdLeXyn exhibited well resistance to Mn²⁺, Zn²⁺, Ca²⁺, Na⁺, Cu²⁺, Mg²⁺, K⁺, Ni²⁺ (1 mM and 5 mM) except Cu²⁺, which reduced the sdLeXyn activity by 54.5% at 5 mM dosage. The activity of sdLeXyn was increased by 42.6% by 5 mM Mn²⁺, 5 mM DTT, Trition X-100, and Tween 20 did not affect the activity of sdLeXyn, but SDS and EDTA slightly reduced it by 12.8% and 14.6%, respectively. The sdLeXyn could resist the degradation of pepsin, efficiently hydrolyzed wheat and reduced the viscosity of wheat hydrolysate. Current data indicate that the sdLeXyn has a potential as a feed additive to improve the utilization of wheat in poultry production.

Improving the digestibility of cereal fractions of wheat, maize, and rice by a carbohydrase complex rich in xylanases and arabinofuranosidases: an in vitro digestion study

BACKGROUND

Cereal co-products rich in dietary fibres are increasingly used in animal feed. The high fibre content decreases the digestibility and reduces the nutrient and energy availability, resulting in lower nutritive value. Therefore, this study investigated the ability of two carbohydrase complexes to solubilize cell-wall polysaccharides, in particular arabinoxylan (AX), from different cereal fractions of wheat, maize, and rice using an in vitro digestion model of the pig gastric and small intestinal digestive system. The first complex (NSPase 1) was rich in cell-wall-degrading enzymes, whereas the second complex (NSPase 2) was additionally enriched with xylanases and arabinofuranosidases. The extent of solubilization of insoluble cell-wall polysaccharides after in vitro digestion was evaluated with gas-liquid chromatography and an enzymatic fingerprint of the AX oligosaccharides was obtained with high-performance anion-exchange chromatography with pulsed amperometric detection.

RESULTS

The addition of carbohydrase increased the digestibility of dry matter and solubilized AX in particular, with the greatest effect in wheat fractions and less effect in maize and rice fractions. The solubilization of AX (expressed as xylose release) ranged from 6% to 41%, and there was an increased effect when enriching with xylanases and arabinofuranosidases in wheat aleurone and bran of 19% and 14% respectively. The enzymatic fingerprint of AX oligosaccharides revealed several non-final hydrolysis products of the enzymes applied, indicating that the hydrolysis of AX was not completed during in vitro digestion.

CONCLUSION

These results indicate that the addition of a carbohydrase complex can introduce structural alterations under in vitro digestion conditions, and that enrichment with additional xylanases and arabinofuranosidases can boost this effect in wheat, maize, and rice. © 2020 Society of Chemical Industry.

The effect of carbohydrases or prebiotic oligosaccharides on growth performance, nutrient utilisation and development of small intestine and immune organs in broilers fed nutrient-adequate diets based on either wheat or barley

BACKGROUND

Non-starch polysaccharides are large complex molecules and are found in cereal grains. This study was conducted to investigate the effect of carbohydrase enzymes or prebiotic oligosaccharides on growth performance, nutrient utilisation and weight of organs associated with the immune system in broilers fed wheat- or barley-based diets.

RESULTS

In wheat-based diets, feed intake was lower (P < 0.05) following xylo-oligosaccharide supplementation, whereas in barley-based diets feed intake was greater (P < 0.05) following β-glucanase supplementation. Gross energy digestibility was improved (P < 0.01) when either level of xylanase was added to wheat diets. Ileal digestible energy was greater (P < 0.01) in wheat diets including an additive compared with the control diet. In wheat diets, bursa weight was lower (P < 0.05) following xylo-oligosaccharide supplementation compared with the control treatment.

CONCLUSIONS

The current study showed that supplemented carbohydrases or prebiotic oligosaccharides could alter the development of immune organs or small intestine without any significant effect on growth performance in broilers receiving nutrient-adequate diets. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Interactions between the concentration of non-starch polysaccharides in wheat and the addition of an enzyme mixture in a broiler digestibility and performance trial

Two broiler trials were designed to investigate the relationship between the concentration of non-starch polysaccharides (NSP) in wheat and 1) its nutritional value for broilers and 2) the efficacy of exogenous enzymes. In a balance trial, diets were formulated with 3 wheat cultivars (Rustic and Viscount—medium NSP, Centenaire—high NSP) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 144 male Ross 308 broiler chickens housed in digestibility cages. Total tract nutrient digestibilities and AME_n were measured from 18 to 22 d of age. In a performance trial, diets were formulated with wheat (medium NSP diet) or with wheat mixed with rye and barley (high NSP diet) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 960 male Ross 308 broilers housed in pens and broiler performance during starter, grower and finisher periods was measured.

In the balance trial, wheat cultivar did not affect nutrient digestibility or AME_n. Enzyme addition caused a significant increase in nutrient digestibilities and AME_n for the diet formulated with the high NSP wheat Centenaire only. In the performance trial, feeding the high NSP diet resulted in a higher feed conversion ratio and lower final body weight compared to the medium NSP diet. The largest improvements by enzyme addition were observed in the high NSP diet.

In conclusion, the study was not able to show a consistent relationship between the NSP concentration of wheat and its nutritional value, but did demonstrate that the effect of an enzyme mixture on nutrient digestibility or broiler performance depends upon the NSP concentration in the diet.

Variation in levels of non-starch polysaccharides and endogenous endo-1,4-β-xylanases affects the nutritive value of wheat for poultry

1. Endo-1,4-β-xylanase is known to improve the nutritive value of wheat-based diets for poultry by degrading dietary arabinoxylans. However, broilers' response to supplementation of wheat-based diets with exogenous endo-1,4-β-xylanase is not always observed. 2. In this study, 108 different wheat lots were analysed for levels of extract viscosity as well as for endogenous endo-1,4-β-xylanase activity, and the impact of these two variables in animal performance was tested. 3. Results revealed that endogenous endo-1,4-β-xylanase activity and extract viscosity content varied widely among different wheat lots. Thus, a trial was conducted to evaluate the efficacy of exogenous enzyme supplementation in broiler diets using wheats with different levels of extract viscosity and endogenous endo-1,4-β-xylanase activity. 4. The data revealed that exogenous enzyme supplementation was only effective when the wheat present in the diet had high levels of extract viscosity (14.8 cP) with low endogenous endo-1,4-β-xylanase activity (347.0 U/kg). Nevertheless, it is apparent that exogenous microbial xylanases reduce digesta extract viscosity and feed conversion ratio independently of the endogenous properties presented by different wheat lots. 5. The data suggest that extract viscosity and/or endogenous endo-1,4-β-xylanase activity affect the response to enzyme supplementation by poultry fed on wheat-based diets.

The effect of dietary faba bean and non-starch polysaccharide degrading enzymes on the growth performance and gut physiology of young turkeys

The aim of this study was to investigate the effect of dietary replacement of soya bean meal (SBM) with faba bean (FB) and a blend of non-starch polysaccharide (NSP) degrading enzymes on the gastrointestinal function, growth performance and welfare of young turkeys (1 to 56 days of age). An experiment with a 2×2 factorial design was performed to compare the efficacy of four diets: a SBM-based diet and a diet containing FB, with and without enzyme supplementation (C, FB, CE and FBE, respectively). In comparison with groups C, higher dry matter content and lower viscosity of the small intestinal digesta were noted in groups FB. The content of short-chain fatty acids (SCFAs) in the small intestinal digesta was higher in groups FB, but SCFA concentrations in the caecal digesta were comparable in groups C and FB. In comparison with control groups, similar BW gains, higher feed conversion ratio (FCR), higher dry matter content of excreta and milder symptoms of footpad dermatitis (FPD) were noted in groups FB. Enzyme supplementation increased the concentrations of acetate, butyrate and total SCFAs, but it did not increase the SCFA pool in the caecal digesta. The enzymatic preparation significantly improved FCR, reduced excreta hydration and the severity of FPD in turkeys. It can be concluded that in comparison with the SBM-based diet, the diet containing 30% of FB enables to achieve comparable BW gains accompanied by lower feed efficiency during the first 8 weeks of rearing. Non-starch polysaccharide-degrading enzymes can be used to improve the nutritional value of diets for young turkeys, but more desirable results of enzyme supplementation were noted in the SBM-based diet than in the FB-based diet.

Combined effect of using near-infrared spectroscopy for nutritional evaluation of feed ingredients and non-starch polysaccharide carbohydrase complex on performance of broiler chickens

This study was carried out to evaluate the combined effect of using near-infrared spectroscopy (NIRS) for nutritional evaluation of feed ingredients and the addition of non-starch polysaccharide carbohydrase complex (NSP enzymes) on the growth performance of broilers fed diets produced with low-quality wheat and soybean meal. A 2 × 2 trial design was performed, with seven replicates of 40 male Ross 308 broilers per treatment, evaluating the effect of the addition of NSP enzymes and the ingredients' nutritional matrix based on table values or NIRS values. Diets without added enzymes were formulated to reach nutritional requirements, whereas diets with enzymes were reformulated, reducing the apparent metabolizable energy (AME) by 85 kcal/kg. In the overall period (days 0-35), broilers fed diets formulated using NIRS values had higher (P < 0.001) average daily gain (+11.3%) and daily feed intake (+7.2%), and a lower (P < 0.001) feed conversion ratio (-5.3%) compared to those fed diets formulated using table values. When formulating diets for broilers with low-quality feed ingredients, performance can be improved by considering NIRS values and by the addition of NSP enzymes, even with a reduction of AME. These nutritional approaches are efficient in improving broilers' performances by themselves and even more so when they are combined.

Impact of combined β-glucanase and xylanase enzymes on growth performance, nutrients utilization and gut microbiota in broiler chickens fed corn or wheat-based diets

The effects of a xylanase and β-glucanase (XB) blend (2,500 U of xylanase and 250 U of β-glucanase per kg of complete feed) on growth performance, nutrients utilization and digesta microbiota in broiler chickens were investigated. A total of 140 day-old male Ross 308 broiler chicks were randomly assigned to 7 replicate cages and fed experimental diets. Diets were based on either corn or wheat without or with supplemental XB. Performance was monitored weekly and excreta were collected from d 17 to 20 for nutrients digestibility and AMEn measurements. On d 21, jejunal contents were collected for viscosity determination whereas ileal and cecal contents were obtained for microbial analysis by Illumina sequencing. Microbial data were analyzed using QIIME and PLS-DA whilst other data were analyzed using SAS. Birds fed wheat diets had higher (P < 0.001) BWG (3.4%) than birds fed corn-based diet whilst birds fed XB had better BWG (4%) and FCR (7%) than birds fed non-XB diets. Birds fed wheat diet had higher (P < 0.001) NDF (46.5%) and less (P = 0.01) CP (-5.4%) digestibility compared to birds fed corn-based diet. XB reduced (P < 0.001) jejunal digesta viscosity to a greater extent in wheat diet (-31%) than in corn-based diet (-10%). Birds fed wheat-based diet with XB had higher (3.5%) starch digestibility than birds fed this diet without XB. Janthinobacterium was associated with non-XB corn-based diet, whereas Ruminococcus, Lachnospiraceae, Lactobacillaceae, Peptostreptococcaceae, Clostridiales, Acidovorax and Blautia were associated with XB corn-based diet in the ileum. A relatively similar microbiome clustering was observed in wheat-based treatments in the cecum. There were no significant (P ≥ 0.05) correlations between selected ileal or cecal bacterial taxa and AMEn. Diet impacted growth performance but XB was efficacious across diet types, implying that degradation of dietary fibrous components by feed enzymes may stimulate performance in young birds. Data provided significant insight on ileal and cecal microbial profile associated with the dietary types and XB; however their functional roles require further investigations.