The use of NSP enzymes in poultry nutrition: myths and realities

Lignocellulose and probiotic supplementation in broiler chicken diet: effect on growth performance, digestive health, litter quality, and genes expression

Three hundred one-day-old Avian 48 broiler chicks were used to investigate the effect of lignocellulose (LC) and probiotic supplementation in broiler chicken diet on growth performance, digestive health, litter quality, and some gene expression. Experimental treatments consisted of 3 × 2 factorial arrangements with 3 levels of LC without or with probiotics to formulate 6 experimental groups. Groups 1, 2, and 3 were fed on the basal diet with dietary LC inclusion at 0, 0.5, and 1.0%, respectively, while groups 4, 5, and 6 were fed on the previously mentioned design with Bacillus subtilis at 100 gm/ton. The results revealed that Dietary LC inclusion nonsignificantly (P ≥ 0.05) reduced body weight (BW), body weight gain (BWG), and feed intake. Meanwhile, B. subtilis supplementation improved BW and BWG and enhanced the effect of LC on the broilers' weight. The group fed a 0.5% LC and B. subtilis-supplemented diet recorded the best (P ≥ 0.05) BW, BWG, FCR, PER, EEU, and PI. LC and or B. subtilis supplementation improved carcass traits of broiler (higher dressing% with lower abdominal fat% compared with a control group), intestinal health, and absorptive capacity. LC potentiates the effect of B. subtilis supplementation in broilers' diet in modulating intestinal microflora (lowered (P ≥ 0.05) cecal Coliform and increased Lactobacillus counts), the highest Coliform counts were recorded in group fed 0.5 or 1.0% LC plus B. subtilis. LC at 0.5 or 1.0% and or B. subtilis supplementation reduced (P ≥ 0.05) litter moisture% at the 2nd, 4th, and 6th wk compared to the control group. Dietary inclusion of LC and or B. subtilis supplementation significantly (P < 0.001) up-regulated hepatic growth-related genes (growth hormone receptor (GHR) and insulin growth factor1 (IGF-1)) and antioxidant-related genes (superoxide dismutase 1 (SOD1), glutathione peroxidase (GPX1) and uncoupling protein (UCP) and down-regulated (P < 0.001) splenic toll-like receptor 4 (TLRP) gene expression while had no significant effect on splenic interleukin 8 (IL8) and tumor necrosis factor (TNF) with the best-obtained results with 1.0% followed by 0.5% LC with B. subtilis supplementation. We concluded that dietary LC and/or B. subtilis supplementation positively affected the growth performance, feed efficiency, carcass quality, intestinal absorptive capacity and health, litter quality and growth, and antioxidant and immune-related gene expression.

Dietary fibre effects and the interplay with exogenous carbohydrases in poultry nutrition

A comprehensive understanding of the role of dietary fibre in non-ruminant animal production is elusive. Equivocal and conflated definitions of fibre coupled with significant analytical complexity, interact with poorly defined host and microbiome relationships. Dietary fibre is known to influence gut development, feed intake and passage rate, nutrient absorption, microbiome taxonomy and function, gut pH, endogenous nutrient loss, environmental sustainability, animal welfare and more. Whilst significant gaps persist in our understanding of fibre in non-ruminant animal production, there is substantial interest in optimizing the fibre fraction of feed to induce high value phenotypes such as improved welfare, live performance and to reduce the environmental footprint of animal production systems. In order to achieve these aspirational goals, it is important to tackle dietary fibre with the same level of scrutiny as is currently done for other critical nutrient classes such as protein, minerals and vitamins. The chemical, mechanical and nutritional role of fibre must be explored at the level of monomeric sugars, oligosaccharides and polysaccharides of varying molecular weight and decoration, and this must be in parallel to standardisation of analytical tools and definitions for speciation. To further complicate subject, exogenous carbohydrases recognise dietary fibre as a focal substrate and have varying capacity to generate lower molecular weight carbohydrates that interact differentially with the host and the enteric microbiome. This short review article will explore the interactive space between dietary fibre and exogenous carbohydrases and will include their nutritional and health effects with emphasis on functional development of the gut, microbiome modulation and host metabolism.

Dry residue of cassava on slow-growing broiler diets, with or without the addition of carbohydrases

Dry residue of cassava was studied on the digestibility, performance, intestinal measurements, with or without inclusion of carbohydrases, of slow-growing broilers. 160 Label Rouge broiler chickens, 21-d-old, were distributed in a randomized, 2x5 factorial arrangement (male and female x 0, 10, 20, 30 and 40% residue) (metabolism trial). 1,100 male chicks were distributed in a 2x5 factorial arrangement (with/without carbohydrases x 0; 2.5; 5.0; 7.5; and 10.0% residue), with five replicates (performance trial). Increasing residue levels led to increases in energetic values. Feed intake from 1-21-d-old and 1-63-d-old decreased linearly. At 42 d-old, feed intake and weight gain levels exhibited a quadratic response, which predicted a highest value at 3.32% and 4.77%, respectively, for diets without carbohydrases. For 21- and 42-d-old chickens, the inclusion of carbohydrases reduced the weight and length of the small intestine. The energetic values of the diets were positively influenced by the residue and had similar digestibility values for both sexes. Inclusion of up to 10% of residue in slow-growing broiler diets does not impaired performance and intestinal morphology. The addition of carbohydrases reduced the viscosity of the digesta but it was not enough to improve the performance of the birds.

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.

Effects of fermented rapeseed meal on performance, intestinal morphology, the viscosity of intestinal content, phosphorus availability, and egg quality of laying hens

Fermented rapeseed meal has the potential to partial replace soybean meal in feed mixtures for poultry without a negative impact on the health condition and performance of birds. This is due to the fact that the fermentation process can reduce the amount of antinutritional factors, improve the use of nutrients and impart probiotic properties to rapeseed meal. Therefore, this study was undertaken to investigate the effect of fermented rapeseed meal on the performance, egg quality, intestinal morphometry, the viscosity of intestinal content and total phosphorus availability. A total of 108 Lohmann Brown laying hens at 26 wk of age were used in the 90-day study. All hens were randomly divided into 3 treatment groups, with 12 replicates (cages) each, as follows: control group received no rapeseed meal, the URSM group received 3% unfermented rapeseed meal and the FRSM group received 3% fermented rapeseed meal. In the case of performance, egg traits, sensory evaluation of eggs, the viscosity of intestinal content and the availability of total phosphorus, if the distribution was normal, a 1-way analysis of variance was performed. If the distribution was not normal, the Kruskal-Wallis test was performed. In the case of histomorphometric evaluation of the intestine, if the distribution was normal, the Student t test for independent samples was performed. If not, a Mann-Whitney U test was performed. The performed analyses showed that the supplementation of fermented rapeseed meal had no negative effect on the performance of birds and the quality of eggs. Fermented rapeseed meal was also associated with improved histomorphometric parameters of the small intestine compared to the group receiving unfermented rapeseed meal in the feed. Laying hens from FRSM group were characterized by significantly lower viscosity of intestinal content (P < 0.05) compared to URSM group. Phosphorus in FRSM group was significantly more available to the birds (P < 0.05) compared to URSM group. These results suggest that supplementation with fermented rapeseed meal may be beneficial, especially in times of unstable prices of soybean meal and problems with its availability.

Arabinoxylan source and xylanase specificity influence the production of oligosaccharides with prebiotic potential

Cereal arabinoxylans (AXs) are complex polysaccharides in terms of their pattern of arabinose and ferulic acid substitutions, which influence their properties in structural and nutritional applications. We have evaluated the influence of the molecular structure of three AXs from wheat and rye with distinct substitutions on the activity of β-xylanases from different glycosyl hydrolase families (GH 5_34, 8, 10 and 11). The arabinose and ferulic acid substitutions influence the accessibility of the xylanases, resulting in specific profiles of arabinoxylan-oligosaccharides (AXOS). The GH10 xylanase from Aspergillus aculeatus (AcXyn10A) and GH11 from Thermomyces lanuginosus (TlXyn11) showed the highest activity, producing larger amounts of small oligosaccharides in shorter time. The GH8 xylanase from Bacillus sp. (BXyn8) produced linear xylooligosaccharides and was most restricted by arabinose substitution, whereas GH5_34 from Gonapodya prolifera (GpXyn5_34) required arabinose substitution and produced longer (A)XOS substituted on the reducing end. The complementary substrate specificity of BXyn8 and GpXyn5_34 revealed how arabinoses were distributed along the xylan backbones. This study demonstrates that AX source and xylanase specificity influence the production of oligosaccharides with specific structures, which in turn impacts the growth of specific bacteria (Bacteroides ovatus and Bifidobacterium adolescentis) and the production of beneficial metabolites (short-chain fatty acids).

Distillers dried grains with soluble and enzyme inclusion in the diet effects broilers performance, intestinal health, and microbiota composition

This study tested the effect of distillers dried grains with soluble (DDGS) inclusion in a broiler diet, with or without supplementation of exogenous enzymes, on the microbiota composition, intestinal health, diet digestibility and performance. A total of 288 one-day-old chickens was assigned to 6 treatments (8 replicate of 6 birds each) according to a completely randomized design with a 3 × 2 factorial scheme with 3 DDGS levels (0, 7 and 14%) and 2 inclusions of exogenous enzymes (with or without a multicarbohydrase complex + phytase [MCPC]). The results exhibited that DDGS inclusion up to 14% did not impair broilers performance up to 28 d, however, DDGS-fed animals exhibited significant improvement with the MCPC supplementation. No effects of the enzymes in the ileal digestibility were found at 21 d. DDGS inclusion in the diet affected dry matter and gross energy digestibility. Broilers fed diets with MCPC were found to have less intestinal histological alteration thus better gut health. No effect of DDGS, enzyme or interaction of those were observed for intestinal permeability and in the serum inflammatory biomarker (calprotectin) at 7 and 28 d. The increase of DDGS percentage in the diet reduced the diversity of the ileal microbiota but increased the cecal microbiota diversity. The inclusion of DDGS showed positive effects on microbiota composition due to a reduction of Proteobacteria phylum in the ileum at 28d and a reduction in the presence of Enterococcaceae family in the ileum at 14 and 28d. The inclusion of MCPC complex might promote beneficial changes in the ileal and cecal microbiota due reduce of Proteobacteria, Bacillaceae and Enterobacteriaceae. The supplementation of xylanase, β-glucanase, arabinofuranosidase and phytase to a DDGS diet improves performance and intestinal health allowing the use of these subproduct in the poultry nutrition.

The effect of amylase supplementation on individual variation, growth performance, and starch digestibility in broiler chickens

The objective of this study was to evaluate the variance of starch digestibility in broilers individually fed diets without or with supplemental exogenous amylase. A total of 120 d-of-hatch male chicks were individually reared from 5 to 42 d in metallic cages and fed maize-based basal diets or diets containing 80 kilo-novo-α-amylase units/kg (60 birds or replicates per treatment). Beginning on d 7, feed intake, body weight gain, and feed conversion ratio were recorded; partial excreta collection was conducted every Monday, Wednesday, and Friday until 42 d, when all birds were sacrificed for individual collection of duodenal and ileal digesta. Lower feed intake (4,675 vs. 4,815 g) and feed conversion ratio (1.470 vs. 1.508) were observed in amylase-fed broilers during the overall period (7-43 d; P < 0.01), whereas body weight gain was not affected. Amylase supplementation improved total tract starch (TTS) digestibility (P < 0.05) on each day of excreta collection (except for d 28, where no difference was found), averaging 0.982 vs. 0.973 compared to basal-fed broilers from d 7 to 42. Both apparent ileal starch (AIS) digestibility and apparent metabolizable energy (AME_N) were increased (P <0.05) from 0.968 to 0.976 and from 3,119 to 3,198 kcal/kg, respectively, with enzyme supplementation. Activity of amylase in the duodenum was higher (18.6 vs. 50.1 IU/g of digesta) in supplemented birds. Amylase supplementation led to a reduced coefficient of variation for both TTS (averaged 2.41 vs. 0.92% from 7 to 42 d) and AIS digestibilities (1.96 vs. 1.03%), as well as AME_N (0.49 vs. 0.35%), when compared to the nonsupplemented group, indicating lower individual heterogenity. An age effect was detected for TTS digestibility, as both groups saw an increase during the first weeks (slightly more pronounced in the supplemented group); older birds (d 30 onwards) presented a lower TTS digestibility compared to ages between 7 and 25 d. In conclusion, amylase supplementation in maize diets for broilers can attenuate individual bird variation for starch and energy utilization by increasing amylase activity and enhancing starch digestibility.

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.

Exogenous enzymes, meal size, and meal frequency: effect on ileal and total tract digestibility of carbohydrates, and energy and fiber degradation in growing pigs fed a wheat-barley grain-based high-fiber diet

When conducting a digestibility trial, pigs are usually fed only twice a day with a restricted feed intake which is not representative of the feeding conditions in a commercial farm. This study aimed to determine the effects of meal size and frequency, and exogenous enzymes (xylanase and phytase) on the digestibility of a high-fiber diet using porcine in vivo and in vitro approaches. Pigs (n = 6) were fitted with a T cannula, and each received all treatments using a 6 × 6 Latin square experimental design. The diets were supplemented (Enz) or not with a combination of xylanase and phytase and distributed into three feeding programs: one received two meals per day that met three times the maintenance energy requirement (2M), one received the same quantity of feed in eight meals (8M), and another received an amount that met five times the maintenance energy requirements in eight meals (8M+). For in vitro experiment, the degradability of fiber with or without xylanase supplementation only was determined. Enzyme supplementation increased apparent ileal digestibility (AID) of dry matter, starch, and degradation of insoluble non-starch polysaccharides (I-NSP) in all in vivo treatments (P < 0.05). The 2M compared with 8M increased the AID of starch and total tract digestibility of organic matter and I-NSP (P < 0.05). Enzyme supplementation decreased the content of insoluble arabinoxylan (P < 0.05) and increased arabinoxylan oligosaccharides (P < 0.05) in the in vivo ileal digesta and in vitro incubation. The results of this study confirm degradation by xylanase of the fiber fraction at the ileal level, which resulted in less fermentation of fiber in the large intestine. However, number and size of meals had little influence on feed digestibility. The consequences of shifting fiber fermentation more towards the upper part of the gastrointestinal tract need further investigation. The in vitro model provided a confirmation of the action of xylanase on the degradation of non-starch polysaccharides.

Reduced-particle size wheat bran and endoxylanase supplementation in broiler feed affect arabinoxylan hydrolysis and fermentation with broiler age differently

Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre (DF) fraction of the feed to a large extent, increasing the accessibility of DF substrates along the gastrointestinal tract is crucial to benefit from the health stimulating metabolic end-products (e.g. butyric acid) generated upon microbial DF fermentation. Therefore, the present study aimed to evaluate the potential of reduced-particle size wheat bran (RPS-WB) and endoxylanases as feed additives to stimulate arabinoxylan (AX) hydrolysis and fermentation along the hindgut of young broilers. To this end, RPS-WB and endoxylanase supplementation were evaluated in a 2 × 2 factorial design using a total of 256 male 1-d-old chicks (Ross 308). Broilers were assigned to 4 dietary treatments: a basal wheat-based diet with (1) no feed additives (control, CTRL), (2) an endoxylanase (XYL; Econase XT 25 at 0.10 g/kg diet), (3) 1% wheat bran with an average reduced particle size of 297 μm (RPS-WB) and (4) an endoxylanase and 1% RPS-WB (RPS-WB + XYL). Each dietary treatment was replicated 8 times and on d 10 and 28, respectively, 24 and 16 broilers per treatment group were euthanised to analyse AX degradation, short-chain fatty acid production and digesta viscosity in the ileum and caecum. Broilers receiving XYL in their diet showed increased AX solubilisation and fermentation at both d 10 and 28 compared to the CTRL group (P < 0.05). Adding RPS-WB to the diet stimulated wheat AX utilisation by the primary AX degraders in the caecum at 10 d of age compared to the CTRL group, as observed by the high AX digestibility coefficient for the RPS-WB supplemented group at this young age (P < 0.05). At 28 d, RPS-WB supplementation lowered body-weight gains but increased butyric acid concentrations compared to the XYL and CTRL group (P < 0.05). Although no synergistic effect for RPS-WB + XYL broilers was observed for AX hydrolysis and fermentation, these findings suggest that both additives can raise a dual benefit to the broiler as a butyrogenic effect and improved AX fermentation along the ileum and caecum were observed throughout the broiler's life.

Dietary high-protein distiller's dried grains with solubles can fully replace soybean meal in diets for meat quails without affecting growth performance

1. The purpose of this study was to determine the metabolisable energy of high-protein distiller's dried grains with solubles (HP-DDGS) for meat quail (Coturnix coturnix coturnix; Experiment I) and evaluate the effects of dietary levels of HP-DDGS on animal performance, carcass characteristics, meat quality, and organ weights (Experiment II).2. In Experiment 1, 96 meat quail were distributed in a completely randomised design with two treatments (reference or test diet) and six replicates of eight birds. The experimental period consisted of 5 d adaptation, followed by 5 d total excreta collection. The experimental diets consisted of a reference (control) and a test diet formulated with 800 g/kg reference diet and 200 g/kg HP-DDGS.3. In Experiment 2, 612 meat quail were distributed in a completely randomised design fed one of six dietary levels of HP-DDGS (0, 85, 170, 255, 340, or 425 g/kg) as a replacement for soybean meal. At 42 d of age, birds were slaughtered and evaluated for carcass yield, organ weights, and meat quality.4. Apparent metabolisable energy values corrected for nitrogen retention of HP-DDGS were 12.5 and 12.3 MJ/kg for males and females, respectively.5. In the starter phase (1-21 d of age), increasing dietary HP-DDGS levels had a quadratic effect on body weight (BW) (P=0.020) and body weight gain (BWG) (P=0.019). The maximum BW and BWG values were estimated to be achieved with 296.0 and 296.2 g/kg dietary HP-DDGS, respectively. Overall (1-42 d of age), increasing dietary HP-DDGS levels in replacement of soybean meal did not affect animal performance, carcass yield, meat quality or organ weight in meat quail.6. It was concluded that dietary HP-DDGS can fully replace soybean meal in meat quail diets without affecting growth performance, carcass yield, meat quality or organ weight.

Stimbiotic supplementation modulated intestinal inflammatory response and improved boilers performance in an experimentally-induced necrotic enteritis infection model

Background

Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic (STB) supplementation in necrotic enteritis (NE) challenged broilers. In Exp. 1, a total of 120 Arbor Acres (AA) broilers (45.0 ± 0.21 g) were randomly assigned to 6 treatments in a 3 × 2 factorial arrangement. Vaccine treatments included non-challenge (0), × 10 the recommended dose (× 10) or × 20 the recommended dose (× 20) by the manufacturer. Clostridium perfringens (CP) treatments were non-challenge (No) or 3 mL of 2.2 × 10⁷ CFU CP challenge (Yes). In Exp. 2, a total of 72 AA broilers (40.17 ± 0.27 g) were randomly assigned to 6 treatments in a 3 × 2 factorial arrangement. Dietary treatments included non-additive (CON), 100 mg/kg STB (STB) and 100 mg/kg STB on top of a typical commercial blend including an essential oil, probiotics, and enzyme (CB). Challenge treatments included non-NE challenge (No) and NE challenge (Yes) as established in Exp. 1.

Results

In Exp. 1, CP and vaccine challenge decreased (P < 0.05) body weight (BW), body weight gain (BWG) and feed intake (FI), and increased (P < 0.05) the number of broilers with diarrhea and intestinal lesions. The oral administration of × 20 recommended dose of vaccines coupled with 3 mL of 2.2 × 10⁷ CFU CP resulted in (P < 0.01) a significantly increased incidence of wet litter and intestinal lesions. Thus, this treatment was chosen as the challenge model for the successful inducement of NE in Exp. 2. In Exp. 2, the NE challenge negatively affected (P < 0.01) growth performance, ileal morphology, immunoglobulin contents in blood, caecal microbiota in the caecum, footpad dermatitis, intestinal lesion scores, tumour necrosis factor (TNF-α) and endotoxin in the serum compared with the non-NE challenged birds. The supplementation of STB and CB in diets enhanced (P < 0.05) growth performance, intestinal microbiota, and blood profiles by stimulating ileal morphology (VH and VH:CD) and propionate production in the cecum, and there were no differences in measured variables between STB and CB supplemented birds.

Conclusion

Overall, these results indicate that STB supplementation was able to reduce the inflammatory response and improve the performance of NE challenged birds, and the supplementation of STB alone was as effective as a typical commercial blend containing a number of other additives.

Responses of Combined Non-starch Polysaccharide Enzymes and Protease on Growth Performance, Meat Quality, and Nutrient Digestibility of Yellow-Feathered Broilers Fed With Diets With Different Crude Protein Levels

The aim of this study was to investigate the responses of non-starch polysaccharide (NSP) enzymes and protease combination on growth performance, meat quality, and nutrients digestibility of yellow-feathered broilers fed with corn-soybean meal basal diets with normal and subnormal crude protein (CP) levels. The experimental design was completely randomized with a 2 × 2 factorial arrangement of treatments, including six replicates of 20 birds per pen. Two basal diets were formulated with normal CP level as positive control (PC) and subnormal CP level without extra essential amino acid (AA) supplementation as negative control (NC). The basal diets were supplemented without or with NSP enzymes and protease. Broilers fed with the NC diet had lower (P < 0.05) final body weight (BW), average daily weight gain (ADG) on days 1–21, 22–56 and 1–56 and higher (P < 0.05) feed-to-gain ratio (F/G) on day 22–56 than those fed with PC diet. The broilers fed with the NC diet had higher (P < 0.05) L^* and b^* values in thigh muscle, crypt depth in the duodenum, and dry matter (DM) digestibility as well as lower (P < 0.05) villus height, musculature thicknesses, and villus height: crypt depth in the duodenum than those fed with the PC diet. Dietary NSP enzymes and protease combination increased (P < 0.05) the ADG and F/G of the broilers on days 1–56, and pH values in breast and thigh muscles as well as the digestibility of DM, gross energy (GE), CP and most AAs of the broilers on day 56. Compared with the PC diet, the combination of NSP enzymes and protease exhibited greater (P < 0.05) improvements in the digestibility of DM, CP, and some AAs (Asp, Ile, and Leu) in the broilers fed with the NC diet. In conclusion, reducing CP diet without essential AA supplementation impaired the growth performance and meat color of the thigh muscles of the broilers. The combination of NSP enzymes and protease effectively improved the growth performance, meat quality, and nutritional values of the broilers. In terms of the digestibility of DM, CP, and some AAs, the magnitude of response to the addition of NSP enzymes and protease was greater in the low nutritional-quality diet with a subnormal CP level.

Comparing a single dose of xylanase to a double dose or cocktail of non-starch polysaccharide-degrading enzymes in broiler chicken diets

This study compared supplementation with a single dose of xylanase to a double dose of xylanase or a non-starch polysaccharide (NSP) degrading enzyme cocktail (NSP-ase cocktail) on productive performance, nutrient utilisation and the gastrointestinal environment in broilers fed commercial diets. Cobb 500 broilers (n=1,080) were fed 12 dietary treatments; four Australian commercial diets (based on wheat-barley, wheat-maize, wheat-sorghum or wheat only) with three different enzyme treatments (single dose of xylanase (16,000 BXU/kg), double dose of xylanase (32,000 BXU/kg) or NSP-ase cocktail (xylanase, β-glucanase, cellulase, pectinase, mannanase, galactanase, arabinofuranosidase). There were 108 pens, nine replicates per dietary treatment, with 10 birds per pen. Performance (total pen body weight, feed intake and feed conversion ratio corrected for mortality) was determined at d 0-35. On d 35, one male and one female were weighed individually and used to determine breast meat, thigh and drumstick weight, dry matter (DM) contents from the gizzard, jejunum and ileum, ileal protein, energy, starch and dry matter digestibility, ileal viscosity and xylo-oligosaccharide (XOS) concentration, caecal microbiota and short chain fatty acid (SCFA) composition. The double dose of xylanase and NSP-ase cocktail had no effect on bird performance, meat yield, ileal viscosity, ileal starch, energy or DM digestibility or digesta DM content. The double xylanase dose and NSP-ase cocktail increased protein digestibility in birds fed the wheat-sorghum based diet (P=0.041) and increased caecal concentration of butyric acid in birds fed the wheat-maize based diet (P=0.040), and propionic, valeric and lactic acid and Bifidobacteria and Enterobacteria spp. in birds fed the wheat-based diet (P<0.05). The double xylanase dose increased XOS production, particularly in birds fed the wheat-barley based diets (P<0.05). The lack of performance effects observed when feeding the double xylanase dose or NSP-ase cocktail suggested that the current recommended xylanase dose (16,000 BXU/kg) is sufficient.

Effects of micronized bamboo powder on growth performance, serum biochemical indexes, cecal chyme microflora and metabolism of broilers aged 1-22 days

Adding insoluble fiber to diet of broilers has been reported to improve intestinal health and promote growth performance. Bamboo powder is a cheap raw material with rich insoluble fiber. This study aims to explore the effects of feeding micronized bamboo powder (MBP) on growth performance, serum biochemical indexes, intestinal microflora, and metabolism of broilers. A total of 1440 1-day-old slow-growing Ephedra chickens were randomly divided into three groups considering gender and body weight: (1) Group D: feeding with basal diet without antibiotics; (2) Group E: feeding with basal diet supplemented with 5% rice bran (RB); (3) Group F: feeding with basal diet supplemented with 1% MBP. Each group involved 8 replicates feeding for 22 days, with 60 chickens per replicate. Various indexes were detected. For the growth performance, the weight gain and feed consumption ratio (G: F) of Group F supplemented with MBP is 0.57 ± 0.04, which is significantly higher than that of E group supplemented with RB (0.52 ± 0.01, P < 0.05). For the serum biochemical indexes, the glutathione peroxidase activity in Group F is significantly higher than that of Group D, while the malondialdehyde content is significantly lower than that of Group D and Group E (P < 0.05 for all). The fresh cecal chyme is taken for determination. In Group F, the α diversity index Faith_pd is significantly lower in Group F than that of Group D. The microorganism species in cecal chyme of Group F and Group E are also different. The metabolic pathways of Group F, mainly in fatty acid metabolism, amino acid metabolism and intestinal immune IgA production, were different from those of Group D and Group E. Adding 1% MBP to broiler diet can enhance the anti-oxidant capacity, improve chyme microflora, regulate the metabolism pathways responsible for intestinal fatty acids, amino acids, and immunity.

Non-starch polysaccharide degradation in the gastrointestinal tract of broiler chickens fed commercial-type diets supplemented with either a single dose of xylanase, a double dose of xylanase or a cocktail of non-starch polysaccharide-degrading enzymes

The aim of this study was to examine non-starch polysaccharide (NSP) degradation in the gastrointestinal tract of chickens fed a range of commercial-type diets supplemented with a commercial dose of xylanase, a double dose of xylanase or a cocktail of NSP – degrading enzymes. Cobb 500 broilers (n = 1,080) were fed 12 dietary treatments; 4 diets with differing primary grain sources (barley, corn, sorghum, and wheat) and three different enzyme treatments (commercial recommended dose of xylanase (16,000 BXU/kg), a double dose of xylanase (32,000 BXU/kg) or an NSP-degrading enzyme cocktail (xylanase, β-glucanase, cellulase, pectinase, mannanase, galactanase, and arabinofuranosidase at recommended commercial levels). There were 108 pens, approximately 10 birds per pen, 9 replicates per dietary treatment. The diets were fed as 3 phases, starter (d 0–12), grower (d 12–23), and finisher (d 23–35). On bird age d 12, 23, and 35, performance (total pen body weight, feed intake, and feed conversion ratio corrected for mortality [cFCR]), litter and excreta dry matter content, and ileal and total tract soluble and insoluble NSP degradability and free oligosaccharide digestibility was determined. On d 35, the quantity of NSP in the gizzard, jejunum, ileum and excreta was determined. Results from this study showed that the double xylanase dose and NSP-ase cocktail had positive impacts on starter phase performance in birds fed the corn- and wheat-based diets. In the grower phase in birds fed the barley-based diet, these enzyme treatments improved cFCR and increased litter dry matter content. The NSP-ase cocktail had a negative impact on finisher phase cFCR in birds fed the sorghum-based diet. The double xylanase dose induced a positive impact on NSP degradability and free oligosaccharide digestibility. In conclusion, there appears to be advantages to feeding broilers a double xylanase dose, but lack of consistency when using an NSP-ase cocktail containing many enzymes.

Interaction between xylanase and a proton pump inhibitor on broiler chicken performance and gut function

Three hundred thirty-six Ross 308 male broiler chicks were used in a 21-d study to explore performance and gut function when treated with a proton pump inhibitor (PPI; 0 or 89 mg/kg) in a 2 × 2 factorial arrangement with a xylanase (Xyl; 0 or 0.1 g/kg) to determine if the beneficial activity of arabinoxylan (AX) depolymerisation, through arabinoxylo-oligosaccharides (AXOS) production, starts in the upper gastrointestinal tract. Treatment with the PPI started from d 14, and by d 21 animal performance had deteriorated (P < 0.001). An interaction was observed between PPI and Xyl for feed conversion ratio (FCR) (P < 0.05), whereby the combination reduced the negative effect of PPI on FCR. Application of PPI raised digesta pH in the gizzard and caecum (P < 0.05), increased protein concentrations in the lower gut (P < 0.05) and reduced intake of digestible nutrients (P < 0.05). Caecal concentrations of indole, p-cresol, ammonia and the ratio of total volatile fatty acid (VFA) to butyric acid were increased with PPI (P < 0.05), indicating enhanced protein fermentation. Xylanase activity in the digesta were greatest in the caeca, especially when Xyl was supplemented (P < 0.001). The concentration of total soluble AX was greater in the gizzard and ileal digesta with Xyl supplementation (P < 0.05), supporting the depolymerisation action of xylanase even under acidic conditions. These data suggest xylanase may function in the gizzard even though pH is not optimal for activity and emphasises the importance of chlorohydric acid secretions in ensuring overall optimum gut function. AX depolymerisation benefits animal performance although it is still unknown how the AXOS produced with xylanase supplementation in the upper gastrointestinal tract influence the microbial populations and overall gut functionality.

Performance and egg qualities of laying japanese quails fed yam peel meal based diets with enzymes complex+yeast supplementation

A 10-week experiment was conducted to evaluate the combined effect of enzyme complex + yeast (Maxigrain®, MXG®) supplementation of sun-dried yam peel meal (YPM) based diet of laying Japanese quails (Coturnix coturnix japonica) on performance and egg quality. A total of 240, seven-weeks old quails were distributed in a completely randomize design with four dietary treatments and five replicates of 12 quails each. Diet 1 served as the control diet without YPM while diet 2, 3, and 4 contained 25, 50, and 75% YPM with MXG® supplementation (1g per kg), respectively. MXG® supplementation in YPM diets improved (p < 0.05) egg mass and feed conversion per egg. Increasing levels of YPM with MXG® supplementation did not show any effect (p > 0.05) on internal and external egg quality attributes except for eggshell weight and thickness which was higher (p < 0.05) in quails fed 75% YPM diet. It was concluded, therefore, that the utilization of YPM as an alternative dietary ingredient with MXG® supplementation can be tolerated in the diets of laying Japanese quails up to 75% inclusion level without any negative effect on productive and egg quality performance.

Potential Replacements for Antibiotic Growth Promoters in Poultry: Interactions at the Gut Level and Their Impact on Host Immunity

The chicken gastrointestinal tract (GIT) has a complex, biodiverse microbial community of ~ 9 million bacterial genes plus archaea and fungi that links the host diet to its health. This microbial population contributes to host physiology through metabolite signaling while also providing local and systemic nutrients to multiple organ systems. In a homeostatic state, the host-microbial interaction is symbiotic; however, physiological issues are associated with dysregulated microbiota. Manipulating the microbiota is a therapeutic option, and the concept of adding beneficial bacteria to the intestine has led to probiotic and prebiotic development. The gut microbiome is readily changeable by diet, antibiotics, pathogenic infections, and host- and environmental-dependent events. The intestine performs key roles of nutrient absorption, tolerance of beneficial microbiota, yet responding to undesirable microbes or microbial products and preventing translocation to sterile body compartments. During homeostasis, the immune system is actively preventing or modulating the response to known or innocuous antigens. Manipulating the microbiota through nutrition, modulating host immunity, preventing pathogen colonization, or improving intestinal barrier function has led to novel methods to prevent disease, but also resulted in improved body weight, feed conversion, and carcass yield in poultry. This review highlights the importance of adding different feed additives to the diets of poultry in order to manipulate and enhance health and productivity of flocks.

Feed endoxylanase type and dose affect arabinoxylan hydrolysis and fermentation in ageing broilers

Despite the general use of endoxylanases in poultry feed to improve broiler performance, the abundance of different endoxylanase products and the variable response to their application in the field prevent a clear understanding of endoxylanase functionality in vivo. To gain insight into this functionality, we investigated the impact of endoxylanase type (Belfeed from Bacillus subtilis versus Econase XT from Nonomuraea flexuosa) and dose (10, 100, 1,000 mg/kg) in combination with broiler age on arabinoxylan (AX) hydrolysis and fermentation in broilers (Ross 308) fed a wheat-soy based diet. In a digestibility trial and a performance trial, a total of 1,057 one-day-old chicks received the control diet or 1 of the 6 endoxylanase supplemented wheat-soy based diets with, respectively, 5 replicate cages and 8 replicate pens per dietary treatment per trial. The AX content and structure, the AX digestibility values and the short-chain fatty acids produced were analysed at the level of the ileum, caeca and excreta at d 11 and 36. Endoxylanase supplementation resulted in a more extensive solubilisation of wheat AX and a reduction in the intestinal viscosity compared to the control (P < 0.05). A high endoxylanase dose was, however, required to obtain increased hydrolysis of the dietary AX along the gastrointestinal tract against the control (P < 0.001). Depending on the type of endoxylanase, a pool of AX with distinct physicochemical properties was created. The B. subtilis endoxylanase created a large pool of soluble AX in the ileum, thereby increasing ileal viscosity compared to broilers fed an endoxylanase from N. flexuosa (P < 0.001). The N. flexuosa endoxylanase mainly triggered caecal AX fermentation in young broilers, by delivering easily fermentable AX substrates with a low degree of polymerisation (P = 0.03). The effects were particularly present in young broilers (d 11). From this study, it is clear that the type and dose of endoxylanase added to wheat-soy based diets determine the nature of AX substrates formed. These, in turn, affect the intestinal viscosity and the interplay between the dietary AX compounds and microbiota, hence dictating AX digestion at young broiler ages and performance outcomes towards slaughter age.

Evaluation of xylanase and a fermentable xylo-oligosaccharide on performance and ileal digestibility of broiler chickens fed energy and amino acid deficient diets

The objective of this study was to evaluate the effect of a product consisting of a combination of xylanase and xylo-oligosaccharide (STBIO) on performance and ileal digestibility of broiler chickens fed energy and amino acid (AA) deficient diets. Day-old male Ross 308 broiler chicks were randomly allocated to 8 pens per treatment, with 25 chicks per pen. Treatments based on wheat-corn-soybean meal diets were arranged in a 3 × 2 factorial design: a positive control that met or exceeded nutrient recommendations (PC), a negative control diet with a 50 kcal/kg apparent metabolizable energy (AME) reduction (NC1) and NC1 with a 3% reduction in AA content (NC2), each with or without supplementation of 100 g/t of the STBIO. Body weight gain (BWG), feed intake, feed conversion ratio corrected for mortality (FCR) and the European production efficiency factor (EPEF) were recorded from 0 to 42 d. On d 42, ileal samples were collected to determine dry matter (DM), organic matter (OM), ash, protein and energy digestibility. A significant interaction was observed for BWG and feed intake (P < 0.001). The energy and AA reduction reduced (P < 0.05) BWG when compared to the PC. The effect of STBIO on BWG was greater in NC1 (+451 g/bird) than in NC2 (+314 g/bird) or PC (+176 g/bird) diets (P < 0.05), and that in NC2 with STBIO was equal to that in PC without STBIO, and that in NC1 with STBIO was equal to that in PC with STBIO. No interactions were observed on the EPEF or FCR; however, STBIO improved EPEF (P < 0.001) and FCR (P < 0.001) irrespective of the energy reduction or AA density. The intake of digestible DM, OM, ash and energy for the finisher period was increased with STBIO supplementation (P < 0.01). A significant interaction was observed for the intake of digestible protein. NC1 and NC2 reduced the intake of digestible protein; however, when STBIO was supplemented, it was improved in both diets to similar levels to the PC. The stimbiotic supplementation improved performance of broiler chickens fed all diets, particularly those deficient in AME and AA.

Effect of different levels of bioplex manganese along with probiotics and multi-enzymes on performance and immune system indices of broilers

To investigate the effect of different levels of bioplex manganese along with probiotics and multi‐enzymes on the performance and immune system of broilers, 640 one‐day‐old male chicks of the Ross 308 strain were reared and the data analysed in a 4 × 2 × 2 factorial experiment with four levels of bioplex manganese (0, 60, 72 and 84 mg per kg of diet), two levels of Parsilact probiotic (0 and 200 mg per kg of diet) and two levels of Combo multi‐enzyme (0 and 1,000 mg per kg of diet) in a completely randomized design with 16 experimental treatments, 4 replicates and 10 chickens per replicate during a period of 42 days. The results showed that the performance of the broiler chickens in the diets containing 72 and 84 mg bioplex manganese along with probiotics and multi‐enzymes had the greatest difference compared to the control (p < .05). Compared to the control with 0 mg/kg manganese; the bursa of Fabricius weight was greater in chickens fed diets containing additional manganese (p < .05). The concentration of antibodies produced against Newcastle disease virus, as well as the concentrations of IgG, IgM and total immunoglobulins produced against SRBC, were highest in the group fed a diet containing 84 mg manganese along with probiotics and multi‐enzymes (p < .05). The results show combining additional manganese with probiotics and multi‐enzymes in chicken diets leads to better performance as well as a stronger immune system of chickens.

The results show combining additional manganese with probiotics and multi‐enzymes in chicken diets leads to better performance as well as a stronger immune system of chickens.

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.

Effects of Dietary Fiber on Nutrients Utilization and Gut Health of Poultry: A Review of Challenges and Opportunities

Simple Summary

The inclusion of agricultural co-products has been increased to utilize the nutrients in these products available at low cost, but inherently, it adds a high dietary fiber content in the poultry diets. The use of exogenous feed enzymes along with advancements in feed milling, feed formulation, and processing of these non-conventional ingredients to improve their digestibility and utilization have played an emphatic role in boosting their use globally. Despite such developments, the presence of a high level of dietary fibers (DF) acting in an anti-nutritive manner still poses challenges in poultry feeding. Various isolated forms of fiber or feed enzymes to break DF into fermentable substrates are being used extensively to provide potential prebiotics to support beneficial gut microbiota or probiotics to improve the gut health of poultry raised without antibiotic growth promoters (AGP). This review reports and discusses the existing challenges in feeding high-DF feed ingredients to poultry and the opportunities that are available to improve the nutritive value of such non-conventional feed ingredients by adopting various technologies.

Abstract

Many fibrous ingredients incorporated in poultry feed to reduce production costs have low digestibility and cause poor growth in poultry. However, all plant-based fibers are not equal, and thus exert variable physiological effects on the birds, including but not limited to, digestibility, growth performance, and microbial fermentation. Several types of fibers, especially oligosaccharides, when supplemented in poultry diets in isolated form, exhibit prebiotic effects by enhancing beneficial gut microbiota, modulating gut immunity, boosting intestinal mucosal health, and increasing the production of short-chain fatty acids (SCFA) in the gut. Recently, poultry producers are also facing the challenge of limiting the use of antibiotic growth promoters (AGP) in poultry feed. In addition to other alternatives in use, exogenous non-starch polysaccharides digesting enzymes (NSPase) and prebiotics are being used to provide substrates to support the gut microbiome. We also conducted a meta-analysis of different studies conducted in similar experimental conditions to evaluate the variability and conclusiveness in effects of NSPase on growth performance of broilers fed fibrous ingredients. This review presents a holistic approach in discussing the existing challenges of incorporating high-fiber ingredients in poultry feed, as well as strategies to fully utilize the potential of such ingredients in improving feed efficiency and gut health of poultry.

Emulsifier and Xylanase Can Modulate the Gut Microbiota Activity of Broiler Chickens

Simple Summary

Modern broiler nutrition, due to widely accepted goals of sustainable production, is concerned with the improvement of nutrient utilization. To achieve this, in our study, we used feed additives that improve the value of feed components. Due to the significant amounts of non-starch polysaccharides (which are not digested under broiler intestinal tract conditions and negatively affect broilers performance) in popular feed components like wheat, enzymes are needed. Furthermore, the use of emulsifiers to improve fat digestion is necessary, as young birds do not secrete sufficient enzyme and bile salts. Previous studies have shown that an additional increase in carbohydrate digestibility can be obtained by using an emulsifier containing xylanase in the feed. Presumably, the increase in carbohydrate digestibility occurred after adding the emulsifier. In our study, we aimed to investigate the effect of xylanase, emulsifier, and a combination of both in wheat diets with high level of tallow on the gastrointestinal tract microbiota activity of 480 one-day-old male ROSS 308 broiler chickens. The simultaneous usage of both additives in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Abstract

In this study, we aimed to investigate the effect of xylanase (XYL), emulsifier (EMU), and a combination of both (XYL + EMU) in wheat diet with a high level of tallow on gastrointestinal tract microbiota activity, excretion of sialic acids, and selected gut segments morphology of 480 one-day-old male ROSS 308 broiler chickens. The activities of bacterial enzymes in the ileal digesta were lower in experimental groups compared to the control (CON) group. Enzyme activity in the cecum was significantly higher than in the ileum. The additives did not affect the excretion of sialic acid. The number of duodenum goblet cells on the villi decreased in all of the experimental groups (p < 0.05). The simultaneous use of XYL + EMU deepened the ileum crypts (p < 0.05). The total short-chain fatty acid (SCFA) concentration in the cecal digesta was higher in experimental groups. The abundance of Bifidobacterium, Lactobacillus, and Escherichia coli did not change among experimental groups. The relative abundance of Clostridium was significantly (p < 0.05) lower in groups with emulsifier addition. In conclusion, the simultaneous usage of EMU and XYL in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Carbohydrase Complexes Rich in Xylanases and Arabinofuranosidases Affect the Autofluorescence Signal and Liberate Phenolic Acids from the Cell Wall Matrix in Wheat, Maize, and Rice Bran: An In Vitro Digestion Study

The high fiber content of cereal coproducts used in animal feed reduces the digestibility and nutrient availability. Therefore, the aim of this study was to elucidate the ability of two carbohydrase complexes to degrade the cell wall of wheat, maize, and rice during in vitro digestion. One complex was rich in cell-wall-degrading enzymes (NSPase 1), and the other was similar but additionally enriched with xylanases and arabinofuranosidases (NSPase 2). Degradation of arabinoxylan, the main cereal cell wall polysaccharide, was followed directly by gas-liquid chromatography (GLC) and indirectly through phenolic acid liberation as quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effect was additionally visualized using a unique multispectral autofluorescence approach. Wheat fractions, in particular aleurone, were susceptible to degradation as judged from the redistribution of arabinoxylan (25% reduction in insoluble arabinoxylan), whereas the highest relative liberation of ferulic acid was observed in rice bran (6%). All cereal fractions, except for maize, had a higher release of ferulic acid with NSPase 2 than NSPase 1 (38% in rice and wheat bran, 30% in wheat whole grain, and 28% in wheat aleurone). Thus, the carbohydrase complexes were able to degrade important cell wall components during in vitro digestion but apparently through different mechanisms in wheat, maize, and rice.

Arabinoxylan-oligosaccharides kick-start arabinoxylan digestion in the aging broiler

While arabinoxylans (AX), an important dietary fiber fraction of wheat-based broiler diets, are known for exerting antinutritional effects in the gastrointestinal (GI) tract of broilers, the prebiotic potential of arabinoxylan-oligosaccharides (AXOS) is also well-documented. However, inconsistent performance responses as well as the effectiveness of low amounts of AXOS used in diets of previously conducted experiments put into question the classical prebiotic route being the sole mode of action of AXOS. The objective of this study was to investigate the effects of dietary AXOS addition on the rate of AX digestion in the gastrointestinal tract of broilers as a function of broiler age to gain more insight into the mode of action of these oligosaccharides. A feeding trial was performed on 480 one-day-old chicks (Ross 308) receiving a wheat-based diet supplemented with or without 0.50% AXOS, containing no endoxylanases. Digesta samples from ileum and caeca and fecal samples were analyzed for AX content, AX digestibility, intestinal viscosity, and microbial AX-degrading enzyme activities at 6 different ages (day 5, 10, 15, 21, 28, 35). Chicks fed from hatching with 0.50% AXOS demonstrated a higher ileal viscosity (P < 0.05). Also higher levels of AX solubilization and fermentation compared to control birds at 10 D were observed. This was noted by the higher total tract AX digestibility of water-extractable AX (WE-AX) and total AX (TOT-AX) at this age (P < 0.05). Although no significant difference in AX-degrading enzyme activities was observed among the dietary treatments, AXOS supplementation in young broilers was shown to stimulate or "kick-start" dietary AX digestion, thereby speeding up the development of a fiber-fermenting microbiome in the young broiler. This stimulation effect of AXOS could enable greater functional value to be extracted from dietary fiber in broiler feeds.

Influence of Different Time and Frequency of Multienzyme Application on the Efficiency of Broiler Chicken Rearing and Some Selected Metabolic Indicators

Simple Summary

Enzymes are a useful, valuable and economic tool to improve feed utilization and thus animal performance. Costs of enzymes supplementation and time and application frequency of enzymes have received little attention other than dose and type of enzymes. This study showed that multienzymes offered intermittently during both early and late growth periods up to market age of broilers enhanced productive performance and economic profits and can substitute the daily administration with a considerable lowering of the supplementation cost.

Abstract

This study looks at the influence of time and/or frequency of multienzymes application on productivity, carcass characteristics, metabolic profile, and red blood cell characteristics of broiler chickens. Two hundred and eighty, one-day-old Arbor Acres broiler male chicks were randomly distributed into seven treatment groups. Each group consisted of eight replicates of five unsexed birds. The same basal diet was fed in a crumble form to all experimental groups: group one was the unsupplemented control that did not receive multienzymes supplementation. Additionally, multienzymes in water were supplemented in six groups in a factorial arrangement, including three times of application (starter time only which included days 1–21 of age, grower time only which included days 22–37 of age, and starter and grower time which included days 1–37 of age) and two application frequencies (continuously or intermittently). In the continuous application, the multienzymes were added to water over 24 h in a day, while in the intermittent frequency multienzymes were added to water for one day followed by a day off according to the time of application. Regardless of time and frequency of application, enzymes supplementation significantly increased growth rate, feed intake, European Production Index (EPI), protein digestibility, serum albumin, and high-density lipoprotein (HDL). Intermittent multienzymes application during days 1–21 of age or days 22–37 of age resulted in significantly greater growth, better feed conversion rate (FCR), and higher EPI of broilers during the whole rearing period than those under continuous multienzymes during different growth periods. Besides, intermittent multienzymes addition during days 1–37 of age improved FCR of broiler chicks compared to constant application. The intermittent addition of multienzymes during days 1–21 of age or 22–37 days of age and days 1–37 of age caused a significant increase in dry matter (DM) digestibility than the continuous application. The intermittent addition of multienzymes during days 1–21 of age significantly increased the digestibility of crude protein (CP), ether extract (EE), and crude fiber (CF) compared to continuous application. A similar trend was shown in the digestibility of CP and EE due to intermittent use during days 22–37 of age. Intermittent enzymes addition significantly increased high density lipoprotein (HDL) of groups receiving enzymes during days 22–37 of age compared to continuous application of enzymes. In conclusion, the use of multienzymes intermittently during days 1–21 of age and 22–37 days of age significantly increased growth, improved FCR, and raised EPI. Intermittent use can replace continuous multienzyme applications which can save 68.6% of the cost, even though further research is need from the cost-saving edge.

Impact of Multienzymes Dose Supplemented Continuously Or Intermittently in Drinking Water on Growth Performance, Nutrient Digestibility, and Blood Constituents of Broiler Chickens

The aim of this work was to study the continuous or intermittent impact of a multienzyme supplement on growth performance, nutrient digestibility, and blood metabolites of broilers, and to evaluate production index of dietary supplementation. A total of 315 unsexed day-old Arbor Acres broiler chicks were randomly distributed to seven treatments groups, keeping initial body weights similar, in 35-floor pens (replicates) of nine chicks per replicate (pen) and five experimental units per treatment. All experimental groups were fed the same basal diet and administered seven multienzyme treatments: the 1st group (control) did not receive any enzyme supplementation; the 2nd, 3rd, and 4th groups were administered multienzymes at 0.5, 1.0, and 1.5 mL/L drinking water, respectively. Each enzyme supplemented-group was divided into two subgroups, with additives being applied either continuously (24 h/day) or intermittently (12 h/day) from 1 to 35 days old. Regardless of administration method, multienzyme supplements at 1.0 mL/L water along with a corn-soybean meal diet increased the body weight gain (BWG) by 7.8% compared to 0.5 mL/L water during days 1-21 of age. In addition, 1.5 mL/L water significantly improved BWG by 5.1% of broilers compared to 0.5 mL/L water during days 1-35 of age. Enzyme supplementation at 1.5 mL/L water significantly enhanced feed conversion ratio (FCR) by 4.3% during days 1-21 of age, and FCR by 5.2% and European production index (EPI) by 10.4% during days 1-35 of age compared to the group on 0.5 mL/L water. For the whole period, there were improvements of beneficial consideration in BWG (4.0%), FCR (4.0%), and European production index (8.2%) due to continuous multienzyme supplementation at 0.5 mL/L water compared to the same dose added intermittently. A similar trend was observed due to intermittent multienzymes at 1 mL/L drinking water that resulted in increased BWG by (6.4%) and improved FCR by (6.7%) and EPI by (12.7%). Intermittent administration significantly increased feed intake of broilers during 22-35 days of age compared to continuous supplementation. Multienzymes at different doses did not significantly affect the digestibility of nutrients, blood serum biochemical constituent, inner body organs, and markers of functions of liver and renal organs. In conclusion, the highest BWG and the best FCR and EPI for the whole period were from broilers given continuous 1 and 1.5 mL/L drinking water or intermittent multienzyme supplementation at 1.5 mL/L drinking water. Furthermore, intermittent supplementation of enzymes at 1 mL/L drinking water and continuous supplementation at 0.5 mL/L drinking water can be investigated in further experiments as a tool to improve broiler growth performance and economic traits and to decrease the cost of enzyme application.

Effect of Different Levels of Multienzymes on Immune Response, Blood Hematology and Biochemistry, Antioxidants Status and Organs Histology of Broiler Chicks Fed Standard and Low-Density Diets

This study was executed to investigate the effect of supplementing three multienzyme levels (0, 0. 1, and 0.2%) with two types of diet [standard diet (SD) vs. low-density diet (LDD)] on immune response, blood hematology and biochemistry, antioxidant status, and organ histology of broilers during 1–38 days of age. A total of 216 unsexed 1-day-old Arbor Acres broiler chicks were randomly distributed, on a factorial design (2 × 3), to six treatments each with six replicates. There were six chicks per replicate. Results showed that LDD significantly decreased body weight gain (BWG) of broilers, but did not affect the European Production Efficiency Index (EPEI). Addition of multienzymes at both levels (0.1 and 0.2%) significantly increased BWG and improved EPEI, compared to the control diet. Alanine aminotransferase (ALT), aspirate aminotransferase (AST), malondialdehyde (MDA), lymphocyte, lymphocyte transformation test (LTT), and phagocyte activity (PA) were significantly higher for LDD than the SD, but eosinophil was lower. Supplementation of multienzymes significantly decreased ALT, AST, and MDA, compared to the control group, but increased packed cell volume (PCV), hemoglobin (Hgb), lymphocytes, and monocytes. Immune organs, such as spleen, thymus, and the bursa of Fabricius were significantly increased with multienzyme supplementation. It could be concluded that multienzyme supplementation at either 0.1 or 0.2% to SD or LDD improved EPEI and immune status of broiler chicks.

Age-related arabinoxylan hydrolysis and fermentation in the gastrointestinal tract of broilers fed wheat-based diets

Endoxylanases are frequently used in cereal-based broiler feeds to improve the nutritional quality of the feed. It is hypothesized that the age of broilers and the age-related development of their intestinal microbiota influence the efficacy of these enzymes. Hence, the objective of this study was to identify possible age-related changes in arabinoxylan (AX) digestion in the different parts of the gastrointestinal (GI) tract of broilers. A feeding trial was performed with 240 1-day-old chicks (Ross 308) receiving a wheat-based feed containing no supplemented endoxylanase. Digesta samples from every section of the GI tract were collected at 5, 10, 15, 21, 28, and 35 d of age and analyzed for AX content, AX digestibility, intestinal viscosity, and microbial endoxylanase and arabinofuranosidase activities. In the first 2 wk, the microbiota were able to solubilize a part of the water-unextractable arabinoxylan (WU-AX), thereby increasing intestinal viscosity and water-extractable arabinoxylan (WE-AX) concentrations in the GI tract. In these young birds, WU-AX and WE-AX with low arabinose to xylose ratios were able to enter the caeca but were not yet extensively fermented by the caecal microbiota as indicated by the high caecal AX concentrations at 5 and 10 d (P < 0.01). Establishment of a more mature microbial community at 3 wk of age resulted in a further increase in both the solubilization of WU-AX and fermentation of WE-AX at the ileum and caecum (P < 0.10). Furthermore, the increase in AX degrading enzyme activities with age denotes the high AX degrading capacity of the caecal microbiota. Finally, a total tract AX digestion of 24% was achieved at slaughter age (day 35). Our results clearly indicate that the capacity of intestinal microbiota to degrade AX in the hindgut increases as the broiler ages. This suggests that the benefits of endoxylanase supplementation of broiler feeds depend on the interaction of the intestinal microbiota and AX present in the GI tract at specific broiler ages.

Response of broiler chickens to xylanase and butyrate supplementation

A 2 × 2 factorial experiment was used to evaluate the effect of xylanase and sodium butyrate supplementation on performance, intestinal fermentation, histology, and morphometry in broiler chickens. A total of 384 Ross 308 broiler chicks (1-day-old) were allocated to 4 experimental treatments: CTR (control diet), XYL (CTR diet with 16,000 BXU/kg of xylanase), BUT (CTR diet with 1 kg/t sodium butyrate), and XYL+BUT (CTR diet plus xylanase and sodium butyrate). Each treatment had 8 replicates of 12 animals. Starter and grower diets, based on wheat and soybean meal, and water were available ad libitum. Body weight gain and feed intake were measured from 0 to 42 D, and feed conversion ratio corrected for mortality (FCR) was calculated. The profile of short-chain fatty acids in the duodenum, jejunum, ileum, and ceca digesta on days 21 and 42 was analyzed in addition to the relative weights of the different portions of the gastrointestinal tract (GIT). The villus height (VH), crypt depth (CD), and villus to crypt (VH: CD) ratio from the ileal tissue on day 42 were also evaluated. Statistical comparisons were performed using a 2-way ANOVA. Xylanase supplementation improved 42-D FCR by 5 points (P = 0.006), while butyrate did not affect 42-D FCR. On day 21, birds fed butyrate had heavier total GIT (P = 0.024), duodenum (P < 0.001), and jejunum (P = 0.025). Xylanase did not influence the relative weights in any intestinal section except the crop which was smaller in xylanase supplemented birds. At day 42, the VH: CD ratio was increased with sodium butyrate (P = 0.005). Supplementation of broiler diets with xylanase improved performance but had little effect on intestinal measures, whereas sodium butyrate influenced many of the intestinal indices with no consequence on animal performance.

An update on carbohydrases: growth performance and intestinal health of poultry

Poultry is an imperative domesticated livestock species that provides high quality protein and micronutrients as meat and eggs. In poultry production, feed is the single major input constituting 70-75% of total production cost. Feed mainly consists of cereal grains, those provide energy to the birds. However, these grains contain different levels of anti-nutritional factors such as non-starch polysaccharides (NSP). These NSP are indigestible by poultry birds due to the lack of vital endogenous enzymes (carbohydrases) thus increase intestinal viscosity which slower the migration and absorption of nutrients. Consequently, these NSP may also increase the chances for infection by inducing competition within gut microbiota for digestible nutrients. This affects bird's health and increases the production cost. Therefore, there is a need to find efficient and effective solutions for these problems. Carbohydrases supplementation have an important role in poultry diets with high NSP contents. Feed enzymes are being used from years to enhance growth performance and digestibility but have limited activity for selective ingredients. New generation carbohydrases with a board range of activity and stability help to degrade the complex substrates and improve growth performance of poultry. Present review summarizes the updated literature on the use of carbohydrases to improve bird's performance and intestinal health.