Response of broiler chickens to xylanase and butyrate supplementation

Dietary jack bean (Canavalia ensiformis L.) supplementation enhanced intestinal health by modulating intestinal integrity and immune responses of broiler chickens

This study investigated the influence of supplementing with jack beans on jejunal morphology, cecal short-chain fatty acids production, gene expression both of pro- and anti-inflammatory cytokines and tight junctions. Four treatment groups including 288 Indian River chicks that were one day old were randomized at random. While the treatment groups received jack bean supplementation at levels of 5 %, 10 %, and 15 %, the control group (0 %) was given a basal diet. For 11-35 days, each treatment consisted of 8 pens with 9 birds each. Supplementing with jack beans significantly enhanced butyrate production (P < 0.001), while at 10 % supplementation did not differ from control. Villus height (VH) and the ratio (VH:CD) were significantly (P < 0.001) increased by dietary treatments, while villus width (VW) and crypt depth (CD) were significantly (P < 0.05) decreased. TLR-3, TNF-a, and IL-6 were all significantly (P < 0.001) increased by dietary supplementation. However, at 15 %, TLR-3 and IL-6 were same with control. IL-18 was significantly (P < 0.05) decreased at 15 %. IL-10 decreased significantly (P < 0.001), but at 10 % same with control. At 5 and 10 %, IL-13 increased significantly (P < 0.001), whereas dietary treatments decreased at 15 % compared to control. Although ZO1 decreased significantly (P < 0.001) and OLCN increased significantly (P < 0.001), both ZO1 and OCLN were not significantly different from the control at 15 %. Dietary treatments significantly (P < 0.001) increased CLDN1 but did not differ from the control at 10 %. JAM2 decreased significantly (P < 0.001) with dietary treatments. In conclusion, jack bean supplementation may increase broiler chicken performance and intestinal health due to butyrate production. It may affect intestinal morphology and integrity by upregulating a tight junction protein gene. Jack beans also impacted jejunum immune responses and inflammatory cytokine gene expression.

Growth performance, nutrient digestibility, fecal microbial diversity and volatile fatty acid, and blood biochemical indices of suckling donkeys fed diets supplemented with multienzymes

BACKGROUND

As the foal grows, the amount of breast milk produced by the donkey decreases. In such cases, early supplemental feeding is particularly important to meet the growth needs of the foal. Foals have an incompletely developed gastrointestinal tract with a homogenous microbiota and produce insufficient amounts of digestive enzymes, which limit their ability to digest and utilize forage. Improving the utilization of early supplemental feeds, promoting gastrointestinal tract development, and enriching microbial diversity are the hotspots of rapid growth research in dairy foals. Plant-based feeds usually contain non-starch polysaccharides (NSPs), including cellulose, xylan, mannan, and glucan, which hinder nutrient digestion and absorption. In addition, proteins and starch (both biomolecules) form a composite system mainly through non-covalent interactions. The proteins wrap around the surface of starch granules and act as a physical obstacle, thereby inhibiting water absorption and expansion of starch and decreasing the enzyme's catalytic effect on starch. Glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase added to cereal diets can alleviate the adverse effects of NSPs. The current study determined the effects of adding multienzymes (glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase) to the diet of 2-month-old suckling donkeys on their growth performance, apparent nutrient digestibility, fecal volatile fatty acid (VFA) and pH, fecal bacterial composition, and blood biochemical indices.

RESULTS

On day 120 of the trial, fecal samples were collected from the rectum of donkeys for determining bacterial diversity, VFA content, and pH. Moreover, fresh fecal samples were collected from each donkey on days 110 and 115 to determine apparent digestibility. The multienzymes supplementations did not affect growth performance and apparent nutrient digestibility in the donkeys; however, they tended to increase total height gain (P = 0.0544). At the end of the study, the multienzymes supplementations increased (P < 0.05) the Observed species, ACE, Chao1, and Shannon indices by 10.56%, 10.47%, 10.49%, and 5.01%, respectively. The multienzymes supplementations also increased (P < 0.05) the abundance of Firmicutes, Oscillospiraceae, Lachnospiraceae, Christensenellaceae, Christensenellaceae_R-7_group, and Streptococcus in feces, whereas decreased (P = 0.0086) the abundance of Proteobacteria.

CONCLUSIONS

Multienzymes supplementations added to a basal diet for suckling donkeys can increase fecal microbial diversity and abundance.

Broiler chicken response to xylanase and fermentable xylooligosaccharide supplementation

A study was conducted to determine the effect of dietary fiber (DF), xylanase (XYL), xylooligosaccharides (XOS), and a combination of XYL and xylooligosaccharides (STBIO) on chicken growth performance, N-corrected apparent metabolizable energy (AMEn), and nutrient availability, characteristics of the gastrointestinal tract (GIT), and cecal content of short-chain fatty acids (SCFA). A 35-day experiment was performed on 1,920 as hatched Ross 308 broiler chicks, reared in 96 pens and fed ad libitum. Experimental diets were split into 2 phases: starter (0-21 d) and finisher (22-35 d). There were 2 basal diets, first contained 54% maize and in the second, 5% of the maize was replaced by wheat bran as DF. The diets were split into 4 batches: one of them was used as a control, and each of the others were supplemented either with XYL or XOS or with the STBIO. Each diet was fed to 12 pens following randomization. The data were analyzed in GenStat (20th edition) by ANOVA using a 2 × 4 factorial design. The addition of STBIO improved feed conversion ratio (FCR) and increased weight gain (WG) from 21 to 35 d and from 0 to 35 d (P < 0.05). The inclusion of DF had a negative effect on N and fat retention coefficients at 35 d as well as AMEn and dry matter retention at 21 and 35 d. At 21 d, neutral detergent fiber (NDF) retention was increased when xylanase and STBIO were added to the diet (P < 0.001) and at d 35 the highest retention was noted when the diet was supplemented with DF and XYL or STBIO (P = 0.001). There was no dietary effect on jejunum histomorphometry (P > 0.05). The addition of DF increased the concentration of cecal SCFA in particular valeric and propionic acid at 35-day-old birds (P < 0.05). It can be concluded that addition of STBIO in diet could provide benefits in terms of fiber degradation, WG, and feed efficiency.

Comparative growth performance, gizzard weight, ceca digesta short chain fatty acids and nutrient utilization in broiler chickens and turkey poults in response to cereal grain type, fiber level, and multienzyme supplement fed from hatch to 28 days of life

Growth performance, gizzard weight, ceca digesta short-chain fatty acids (SCFA), and apparent retention (AR) of components were investigated in broilers and turkeys in response to cereal grain type, fiber level, and multienzyme supplement (MES) fed from hatch to 28 d of life. 480-day-old male broiler chicks and equal number of turkeys were placed separately in metabolism cages (10 birds/cage) and allocated to 8 diets. The species-specific diets were a corn or wheat-based basal diet without (LF) or with 10% corn DDGS or wheat middlings (HF) and fed without or with MES. This effectively created a 2 (grain types) × 2 (fiber levels) × 2 (MES) factorial arrangement of treatments. The diets had TiO2 as an indigestible marker. Body weight, feed intake, and mortalities were recorded to calculate body weight gain (BWG) and feed conversion ratio (FCR). Excreta samples were collected on d 25 to 27 for AR, and all birds were necropsied for gizzard weight and ceca digesta on d 28. The interaction between grain and MES in broilers was such that wheat diets with MES had the lowest (P = 0.005) FCR. In broilers, LF diets had better (P = 0.010) FCR than HF diets. The wheat diets had the highest (P = 0.006) concentration of butyric acid in broilers. Broilers fed HF and corn diets had heavier gizzard than broilers-fed LF and wheat diets. The MES improved (P < 0.05) AMEn in HF, corn, and wheat diets in broilers. The turkeys fed wheat diets had the lowest (P = 0.019) FCR. Turkeys fed HF wheat diets had the heaviest (P < 0.001) gizzard. In turkeys, the MES improved AMEn in HF and LF corn diets, and only in LF wheat diets compared to respective controls. Treatments had no effect on turkeys cecal SCFA. In conclusion, grain type, fiber, and MES did not affect growth in both species. However, species exhibited differing FCR, gizzard, and energy utilization to fiber and MES.

Combined effects of sodium butyrate and xylo-oligosaccharide on growth performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers at early stage

This study aimed to evaluate the individual and combined effects of chemically protected sodium butyrate (CSB) and xylo-oligosaccharide (XOS) on performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers. A total of 280 one-day-old Arbor Acres broilers were randomly distributed into 5 treatments: basal diet (CON), basal diet supplemented with 100 mg/kg aureomycin and 8 mg/kg enramycin (ABX), 1000 mg/kg CSB (CSB), 100 mg/kg XOS (XOS), and mixture of 1000 mg/kg CSB and 100 mg/kg XOS (MIX), respectively. On d 21, ABX, CSB, and MIX decreased feed conversion ratio compared with CON (CON: ABX: CSB: MIX = 1.29: 1.22: 1.22: 1.22), whereas body weight of CSB and MIX was increased by 6.00% and 7.93%, and average daily gain was increased by 6.62% and 8.67% at 1-21 d, respectively (P < 0.05). The main effect analysis showed that both CSB and XOS treatments increased ileal villus height and villus height to crypt depth ratio (VCR) (P < 0.05). Moreover, broilers in ABX showed lower 21.39% ileal crypt depth and higher 31.43% VCR than those in CON (P < 0.05). Dietary CSB and XOS were added individually or collectively increased total antioxidant capacity and superoxide dismutase, and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β, whereas decreased malondialdehyde, and proinflammatory cytokines IL-6 and tumor necrosis factor-α content in serum (P < 0.05). Meanwhile, MIX showed the best effect of antioxidant and anti-inflammatory capacity among the 5 groups (P < 0.05). There was an interaction between CSB and XOS treatments on increasing cecal acetic acid, propionic acid, butyric acid and total short-chain fatty acid (SCFA) (P < 0.05), and the one-way ANOVA showed that propionic acid in CSB was 1.54 times that of CON, whereas butyric acid and total SCFAs in XOS were 1.22 times and 1.28 times that of CON, respectively (P < 0.05). Furthermore, dietary combination of CSB and XOS changed phyla Firmicutes and Bacteroidota, and increased genera Romboutsia and Bacteroides (P < 0.05). In conclusion, dietary CSB and XOS improved growth performance of broilers, and the combined addition of them had the best effect on anti-inflammatory and antioxidant capacity, and intestinal homeostasis of broilers in current study, indicating that it may be a potential natural alternative to antibiotics.

Butyrate's role in human health and the current progress towards its clinical application to treat gastrointestinal disease

Butyrate is a key energy source for colonocytes and is produced by the gut microbiota through fermentation of dietary fiber. Butyrate is a histone deacetylase inhibitor and also signals through three G-protein coupled receptors. It is clear that butyrate has an important role in gastrointestinal health and that butyrate levels can impact both host and microbial functions that are intimately coupled with each other. Maintaining optimal butyrate levels improves gastrointestinal health in animal models by supporting colonocyte function, decreasing inflammation, maintaining the gut barrier, and promoting a healthy microbiome. Butyrate has also shown protective actions in the context of intestinal diseases such as inflammatory bowel disease, graft-versus-host disease of the gastrointestinal tract, and colon cancer, whereas lower levels of butyrate and/or the microbes which are responsible for producing this metabolite are associated with disease and poorer health outcomes. However, clinical efforts to increase butyrate levels in humans and reverse these negative outcomes have generated mixed results. This article discusses our current understanding of the molecular mechanisms of butyrate action with a focus on the gastrointestinal system, the links between host and microbial factors, and the efforts that are currently underway to apply the knowledge gained from the bench to bedside.

Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

This review paper discussed the nutritional and functional roles of phytase and xylanase enhancing the intestinal and growth of nursery pigs and broiler chickens. There are different feed enzymes that are currently supplemented to feeds for nursery pigs and broiler chickens. Phytase and xylanase have been extensively studied showing consistent results especially related to enhancement of nutrient digestibility and growth performance of nursery pigs and broiler chickens. Findings from recent studies raise the hypothesis that phytase and xylanase could play functional roles beyond increasing nutrient digestibility, but also enhancing the intestinal health and positively modulating the intestinal microbiota of nursery pigs and broiler chickens. In conclusion, the supplementation of phytase and xylanase for nursery pigs and broiler chickens reaffirmed the benefits related to enhancement of nutrient digestibility and growth performance, whilst also playing functional roles benefiting the intestinal microbiota and reducing the intestinal oxidative damages. As a result, it could contribute to a reduction in the feed costs by allowing the use of a wider range of feedstuffs without compromising the optimal performance of the animals, as well as the environmental concerns associated with a poor hydrolysis of antinutritional factors present in the diets for swine and poultry.

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.

The influence of nutrition on intestinal disease with emphasis on coccidiosis

Ever since the poultry industry began to intensify early last century, coccidiosis has been a significant problem with which it has had to contend. Losses due to mortality and morbidity can be significant and before the advent of control agents there were several practices, some of which were nutritional, which were implemented to limit these losses. The development of coccidiostats reduced these problems considerably and as a result some of the more extreme intervention measures were no longer necessary. Modern day interpretation of what may have been happening with some of these early interventions provide interesting insights into what may be possible today should cocciodiostats be removed. More recent research has also indicated that the diet has a significant influence on the ability of poultry to resist and resolve an infection through direct and indirect effects on the pathogen, the immune system and on the litter. This paper reviews the role of dietary ingredients and nutrients on the pathogen to establish and the host to resist such an infection. There is clearly no panacea, but the combination of a few practices may reduce the overall challenge experienced by the poultry producer.

Review of glucose oxidase as a feed additive: production, engineering, applications, growth-promoting mechanisms, and outlook

The regulation and prohibition of antibiotics used as growth promoters (AGP) in the feed field are increasing because they cause antimicrobial resistance and drug residue issues and threaten community health. Recently, glucose oxidase (GOx) has attracted increasing interest in the feed industry as an alternative to antibiotics. GOx specifically catalyzes the production of gluconic acid (GA) and hydrogen peroxide (H₂O₂) by consuming molecular oxygen, and plays an important role in relieving oxidative stress, preserving health, and promoting animal growth. To expand the application of GOx in the feed field, considerable efforts have been made to mine new genetic resources. Efforts have also been made to heterologously overexpress relevant genes to reduce production costs and to engineer proteins by modifying enzyme properties, both of which are bottleneck problems that limit industrial feed applications. Herein, the: different sources, diverse biochemical properties, distinct structural features, and various strategies of GOx engineering and heterologous overexpression are summarized. The mechanism through which GOx promotes growth in animal production, including the improvement of antioxidant capacity, maintenance of intestinal microbiota homeostasis, and enhancement of gut function, are also systematically addressed. Finally, a new perspective is provided for the future development of GOx applications in the feed field.

Tolerability and SCFA production after resistant starch supplementation in humans: a systematic review of randomized controlled studies

BACKGROUND

Resistant starches (RSs) have been advocated as a dietary supplement to address microbiota dysbiosis. They are postulated to act through the production of SCFAs. Their clinical tolerability and effect on SCFA production has not been systematically evaluated.

OBJECTIVES

We conducted a systematic review of RS supplementation as an intervention in adults (healthy individuals and persons with medical conditions) participating in randomized controlled trials. The primary outcome was tolerability of RS supplementation, the secondary outcome was SCFA production.

METHODS

MEDLINE, Embase, and the Cochrane Central Register were searched. Articles were screened, and data extracted, independently and in duplicate.

RESULTS

A total of 39 trials met eligibility criteria, including a total of 2263 patients. Twenty-seven (69%) studies evaluated the impact of RS supplementation in healthy subjects whereas 12 (31%) studies included individuals with an underlying medical condition (e.g., obesity, prediabetes). Type 2 RS was most frequently investigated (29 studies). Of 12 studies performed in subjects with health conditions, 11 reported on tolerability. All studies showed that RS supplementation was tolerated; 9 of these studies used type 2 RS with doses of 20-40 g/d for >4 wk. Of 27 studies performed in healthy subjects, 20 reported on tolerability. In 14 studies, RS supplementation was tolerated, and the majority used type 2 RS with a dose between 20 and 40 g/d. Twenty-one (78%) studies reporting SCFAs used type 2 RS with a dose of 20-40 g/d for 1-4 wk. In 16 of 23 studies (70%), SCFA production was increased, in 7 studies there was no change in SCFA concentration before and after RS supplementation, and in 1 study SCFA concentration decreased.

CONCLUSIONS

Available evidence suggests that RS supplementation is tolerated in both healthy subjects and in those with an underlying medical condition. In addition, SCFA production was increased in most of the studies.

Chemically Protected Sodium Butyrate Improves Growth Performance and Early Development and Function of Small Intestine in Broilers as One Effective Substitute for Antibiotics

The purpose of this study was to investigate the effects of chemically protected sodium butyrate (CSB) on growth performance and the early development and function of small intestine in broilers as one potential substitute for antibiotics. A total of 192 one-day-old Arbor Acres male broilers were randomly assigned into three dietary treatment groups (eight replicates per treatment): the control (CON) diet; ANT diet, CON diet supplemented with the antibiotics (enramycin, 8 mg/kg and aureomycin, 100 mg/kg); CSB diet, CON diet supplemented with 1000 mg/kg CSB, respectively. The results showed that dietary CSB and antibiotics addition significantly improved the growth performance of broilers by increasing the body weight gain (BWG) and feed conversion ratio (FCR) during different stages (p < 0.05). On day 21, the supplement of CSB in diet improved the structure of small intestine (duodenum, jejunum, and ileum) in broilers by increasing the ratio of villus height to crypt depth (VH/CD) (p < 0.05) and enhanced the butyric acid (BA) (p < 0.05) and total short chain fatty acids (SCFA) concentrations of small intestine (jejunum and ileum) compared with the CON and ANT diets. Besides that, the superoxide dismutase (SOD), total antioxidant capacity (TAC) and TAC to malondialdehyde (TAC/MDA) ratio of the ileal and jejunal mucosa were significantly higher (p < 0.05) in the CSB and ANT than in the CON. In addition, the supplement of CSB in diet markedly significantly enhanced α-amylase, lipase, and trypsin activities of the ileum (p < 0.05) as compared to the ANT diet. 16S rRNA gene sequencing indicated that CSB markedly increased the microbiota diversity of ileum in broilers at 21 days of age as compared to CON and ANT (p < 0.05). Furthermore, we found that Firmicutes was the predominant phyla and Lactobacillus was the major genus in the ileum of broilers. Compared with the ANT diet, the supplement of CSB in diet increased the relative abundance of some genera microbiota (e.g., Candidatus_Arthromitus, Romboutsia) by decreasing the relative abundance of Lactobacillus. Moreover, Akkermansia in the CSB was the highest in comparison to that in the CON and ANT. In addition, Kitasatospora that belongs to the phylum Actinobacteriota was only found in ileum of broilers fed the ANT diet. In summary, the supplement of 1000 mg/kg CSB in the diet improved the growth performance by promoting early development and function of the small intestine, which is associated with the regulation of intestinal flora and reestablishment of micro-ecological balance in broilers. Thus, CSB has great potential value as one of effective substitutes for in-feed antibiotics in the broiler industry.

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.

Effects of Bacillus subtilis, butyrate, mannan-oligosaccharide, and naked oat (ß-glucans) on growth performance, serum parameters, and gut health of broiler chickens

Four nonantibiotic alternative growth promoters for broiler chickens were evaluated. Ross 308 chicks were fed a control diet (mainly corn and soybean meal) or a diet supplemented with a probiotic (Bacillus subtilis Gallipro DSM 17299), encapsulated butyric acid (Novyrate C), mannan-oligosaccharide (Actigen MOS) or formulated with 20% naked oat (starter diet) and 30% naked oat (grower and finisher). The study was carried out as a complete random blocked design with 10 pens for each diet, 45 birds per pen. Compared to the control, the naked oat diet improved the average daily gain by 16% during the starter phase (up to d 10). The probiotic did so during the grower phase as did butyric acid in the finisher phase (up to d 34). For the experiment overall, the probiotic decreased average daily gain slightly. The best improvement in feed conversion ratio was obtained in the butyrate group (5%). No significant treatment effect on crop pH or on mortality was observed. The naked oat diet gave a slightly lower cecum pH on d 34. The MOS supplement decreased jejunal mass on d 34 and increased villus length (34%) and villus height/crypt depth ratio (32%) measured on d 10. Naked oat, butyric acid and MOS diets all reduced serum endotoxin levels. The probiotic increased serum C-reactive protein. All noncontrol diets reduced serum malondialdehyde. The naked oat diet reduced d 34 litter pH by about 0.3. Some effects of the proposed non-antibiotic growth promoters have been observed and could contribute to livestock performance. Their exact modes of action remained to be defined.

Development of the in vitro Cecal Chicken ALIMEntary tRact mOdel-2 to Study Microbiota Composition and Function

The digestive system of the chicken plays an important role in metabolism, immunity, and chicken health and production performance. The chicken ceca harbor a diverse microbial community and play a crucial role in the microbial fermentation and production of energy-rich short-chain fatty acids (SCFA). For humans, dogs, and piglets in vitro digestive system models have been developed and are used to study the microbiota composition and metabolism after intervention studies. For chickens, most research on the cecal microbiota has been performed in in vivo experiments or in static in vitro models that may not accurately resemble the in vivo situations. This paper introduces an optimized digestive system model that simulates the conditions in the ceca of the chicken, i.e., the Chicken ALIMEntary tRact mOdel-2 (CALIMERO-2). The system is based on the well-validated TNO in vitro model of the colon-2 (TIM-2) and is the first dynamic in vitro digestion model for chickens species. To validate this model, the pH, temperature, and different types of microbial feeding were compared and analyzed, to best mimic the conditions in the chicken ceca. The bacterial composition, as well as the metabolite production at 72 h, showed no significant difference between the different microbial feedings. Moreover, we compared the CALIMERO-2 digestive samples to the original inoculum and found some significant shifts in bacterial composition after the fermentation started. Over time the bacterial diversity increased and became more similar to the original inoculum. We can conclude that CALIMERO-2 is reproducible and can be used as a digestive system model for the chicken ceca, in which the microbial composition and activity can be maintained and shows similar results to the in vivo cecum. CALIMERO-2 can be used to study effects on composition and activity of the chicken cecum microbiota in response to in-feed interventions.

Biological Function of Short-Chain Fatty Acids and Its Regulation on Intestinal Health of Poultry

Short-chain fatty acids (SCFAs) are metabolites generated by bacterial fermentation of dietary fiber (DF) in the hindgut. SCFAs are mainly composed of acetate, propionate and butyrate. Many studies have shown that SCFAs play a significant role in the regulation of intestinal health in poultry. SCFAs are primarily absorbed from the intestine and used by enterocytes as a key substrate for energy production. SCFAs can also inhibit the invasion and colonization of pathogens by lowering the intestinal pH. Additionally, butyrate inhibits the expression of nitric oxide synthase (NOS), which encodes inducible nitric oxide synthase (iNOS) in intestinal cells via the PPAR-γ pathway. This pathway causes significant reduction of iNOS and nitrate, and inhibits the proliferation of Enterobacteriaceae to maintain overall intestinal homeostasis. SCFAs can enhance the immune response by stimulating cytokine production (e.g. TNF-α, IL-2, IL-6, and IL-10) in the immune cells of the host. Similarly, it has been established that SCFAs promote the differentiation of T cells into T regulatory cells (Tregs) and expansion by binding to receptors, such as Toll-like receptors (TLR) and G protein-coupled receptors (GPRs), on immune cells. SCFAs have been shown to repair intestinal mucosa and alleviate intestinal inflammation by activating GPRs, inhibiting histone deacetylases (HDACs), and downregulating the expression of pro-inflammatory factor genes. Butyrate improves tight-junction-dependent intestinal barrier function by promoting tight junction (TJ) assembly. In recent years, the demand for banning antibiotics has increased in poultry production. Therefore, it is extremely important to maintain the intestinal health and sustainable production of poultry. Taking nutrition strategies is important to regulate SCFA production by supplementing dietary fiber and prebiotics, SCFA-producing bacteria (SPB), and additives in poultry diet. However, excessive SCFAs will lead to the enteritis in poultry production. There may be an optimal level and proportion of SCFAs in poultry intestine, which benefits to gut health of poultry. This review summarizes the biological functions of SCFAs and their role in gut health, as well as nutritional strategies to regulate SCFA production in the poultry gut.

Qualitative and quantitative profiles of jejunal oligosaccharides and cecal short-chain fatty acids in broiler chickens receiving different dietary levels of fiber, protein and exogenous enzymes

BACKGROUND

Dietary supplemental carbohydrases are able to degrade non-starch polysaccharides and generate oligosaccharides in the gastrointestinal tract. This study was conducted to investigate the influence of dietary fiber and protein levels on growth performance, nutrient utilization, digesta oligosaccharides profile and cecal short-chain fatty acid (SCFA) profile in broilers receiving diets supplemented with xylanase or protease individually or in combination.

RESULTS

Enzyme supplementation had no effect on growth performance. There was significant (P < 0.05) fiber × protein × xylanase interaction for ileal nitrogen digestibility and significant (P < 0.01) protein × xylanase × protease interaction for nitrogen-corrected apparent metabolizable energy. Birds fed high-fiber diets had higher (P < 0.05) jejunal oligosaccharides and cecal SCFA concentrations. Xylanase and protease combination produced the greatest pentose (Pent) levels in low fiber-adequate protein diets but lowest levels in highfiber-low protein diets. There was significant (P < 0.05) fiber × xylanase × protease interaction explained by the digesta concentrations of (Pent)₃ , (Pent)₄ and (Pent)₅ being greatest (P < 0.5) in protease-only supplemented high-fiber diets but lowest in protease-only supplemented low-fiber diets.

CONCLUSION

These results suggest that, of all the factors investigated, dietary fiber level had the greatest effect on modulating digesta concentration of oligosaccharides and cecal SCFA. Evidence points to the fact that there is considerable capacity for generating pentose oligosaccharides in the digestive tract of broilers receiving diets rich in fibrous feedstuffs, and that this may have a beneficial effect on microbial profile in the digestive tract. © 2021 Society of Chemical Industry.

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.

Dietary stevioside supplementation increases feed intake by altering the hypothalamic transcriptome profile and gut microbiota in broiler chickens

BACKGROUND

Stevioside (STE) is a widely used sweetener. Despite the fact that chickens are insensitive to sweetness, dietary STE supplementation could increase the feed intake of broiler chickens. Stevioside might regulate the feeding behavior through functional mechanisms other than its high-potency sweetness. The present study was aimed to elucidate the potential sweetness-independent mechanism of an STE-induced orexigenic effect using the broiler chicken and considering the hypothalamic transcriptome profile and gut microbiome.

RESULTS

The analysis of RNA-Seq identified 398 differently expressed genes (160 up-regulated and 238 down-regulated) in the hypothalamus of the STE-supplemented group compared with the control group. Cluster analysis revealed several appetite-related genes were differentially expressed, including NPY, NPY5R, TSHB, NMU, TPH2, and DDC. The analysis of 16S rRNA sequencing data also indicated that dietary STE supplementation increased the relative abundance of Lactobacillales, Bacilli, Lactobacillus, and Lactobacillaceae. Meanwhile, the proportion of Ruminococcaceae, Lachnospiraceae, Clostridia, and Clostridiales was decreased after dietary supplementation with STE.

CONCLUSION

Dietary STE supplementation promoted feed intake through the regulation of the hypothalamic neuroactive ligand-receptor interaction pathway and the alteration of intestinal microbiota composition. This study provides valuable information about the sweetness-independent mechanism of the STE-induced orexigenic effect using the broiler chicken (which is insensitive to sweetness) as the animal model. © 2020 Society of Chemical Industry.

Sodium butyrate in post-hatch feed for broiler chicks

ABSTRACT This study was designed to determine adequate levels for sodium butyrate inclusion in pre-hatching and pre-starter feed in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. Newly-hatched chicks were allotted in a completely randomized design, with five treatments, each comprising five replicates of ten birds each. Five dietetic levels of sodium butyrate (control, 0.050, 0.075, 0.100 and 0.200%) were used in the pre-starter feed offered to the chicks in the transporting box and during the pre-starter phase. Performance, yolk sac retraction, plasma glucose concentration, weight and histomorphometry of the small intestine were evaluated after 24 hours of feed access and at 7 days of age. A metabolic trial was performed when the chicks were seven to ten days of age. Supplementation of 0.1% sodium butyrate increased the development of broiler chicks’ intestinal villi at seven days of age but was not able to improve performance in the pre-starter phase. Supplementation with sodium butyrate in a diet offered in the transportation box does not improve broiler performance in the pre-starter phase. Supplementation of up to 0.16% is recommended, in order to improve the metabolizability of the ether extract for broilers at seven days of age.

The effects of exogenous xylanase supplementation on the in vivo generation of xylooligosaccharides and monosaccharides in broilers fed a wheat-based diet

1. This study quantified xylanase-induced changes in soluble monosaccharides, xylooligosaccharides (XOS) and volatile fatty acid (VFA) contents of the different sections of the gastrointestinal tract (GIT) and whether these were related to altered bird performance. 2. An in vitro digestion of the wheat-based diet was carried out with the xylanase (Econase XT at 16,000BXU/kg diet) to compare the in vitro and in vivo generation of these XOS and monosaccharides. For the in vivo study, 80 male Ross 508 b roiler chicks were split into two groups fed a wheat-based diet with or without Econase XT (16,000BXU/kg diet) for 21 days. 3. There were no effects of Econase XT inclusion on growth performance characteristics, likely a result of the high-quality wheat diet, the corresponding high performance of the control group (FCR average of 1.45 in controls) and the relatively young age of the birds (from four to 26 days of age). 4. Econase XT supplementation increased the xylotetraose (X₄) content in the colon (P = 0.046, enzyme x GIT section interaction) and the xylose contents in the colon and caeca (P < 0.001, enzyme x GIT section interaction). 5. The trend for increased acetate production in the caeca of Econase XT treated birds (P = 0.062) suggested that the XOS generated were subsequently fermented in the caeca, potentially impacting upon the types of microbiota present. 6. The present study suggested that wheat arabinoxylan degradation was enhanced by xylanase supplementation, which may have increased the production of beneficial volatile fatty acids (VFA) in the caeca, and thereby potentially modulated the caecal microbiome, but without affecting bird performance at this early age.

Effect of dietary supplementation of xylanase in a wheat-based diet containing canola meal on growth performance, nutrient digestibility, organ weight, and short-chain fatty acid concentration in digesta when fed to weaned pigs

This study was designed to determine the effect of dietary supplementation of xylanase on growth performance, nutrient digestibility, organ weight, digesta pH, and concentration of short-chain fatty acids (SCFA) of weaned pigs fed wheat-canola meal (CM) diets over a 35-d period. A total of 144 piglets (72 barrows and 72 gilts) weaned at 18 ± 2 d of age, with initial body weight (BW) of 6.2 ± 0.7 kg, received one of eight dietary treatments based on randomized complete block design. BW and feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Treatments consisted of a control wheat-soybean meal-based diet and wheat-regular (RCM), dehulled (DCM), or coarse CM (CCM) without and with 16,000 BXU/kg xylanase (Econase XT). All diets contained 500 FTU/kg of phytase (Quantum Blue 5G) and titanium dioxide (0.3%). Apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF), crude protein (CP), phosphorous (P), calcium (Ca), dry matter, and diet were determined. On day 35, one pig per pen was euthanized to evaluate the main factors of protein, xylanase supplementation, and sex on organ weight, ileal and colon digesta pH, and colon digesta concentrations of SCFA. The main factors did not affect growth performance. Xylanase supplementation improved nutrient digestibilities in all diets and increased ileal and colonic digesta pH without affecting the growth performance of weaned pigs fed wheat and CM-based diets. A protein-xylanase effect (P < 0.05) resulted in increasing the ATTD of NDF from 28% to 32% and from 29% to 37% for RCM and DCM, respectively. The ATTD of CP was greater (P < 0.05) with xylanase supplementation (75% vs. 70%). Xylanase supplementation increased ATTD of P and Ca. A three-way interaction (P < 0.05) for protein-xylanase-gender for colon pH, acetic, and propionic acid in the colon digesta of pigs indicated that, in addition to the protein source, piglet sex could have influenced how xylanase works. Xylanase supplementation increased (P < 0.05) the weight of the liver and spleen and tended (P < 0.10) to increase the size of the kidney. In conclusion, dietary supplementation of xylanase increased nutrient digestibility and digesta pH but did not influence the growth performance of weaned pigs fed wheat and CM-based diets over a 35-d period.

Short-chain fatty acids and ceca microbiota profiles in broilers and turkeys in response to diets supplemented with phytase at varying concentrations, with or without xylanase

Two independent studies were performed, each with a 3 × 2 factorial arrangement to compare the response in broilers and turkeys to phytase and xylanase supplementation on cecal fermentation and microbial populations. For both studies, 960 Ross 308 and 960 BUT 10 (1-day-old) were allocated to 1 of 6 experimental treatments: (1) control diet, containing the standard dose (100 g/ton) of phytase (STD-Xyl); (2) the control diet with 100 g/ton of xylanase (STD + Xyl); (3) the control diet supplemented on top with 2 fold the standard dose of phytase (200 g/ton), also referred as superdosing (SD-Xyl); (4) the superdosed diet with 100 g/ton of xylanase (SD + Xyl); (5) the control diet supplemented with 5-fold the standard dose of phytase (500 g/ton), also referred as megadosing (MD-Xyl); and (6) the megadosed diet with 100 g/ton of xylanase (MD + Xyl). Each treatment had 8 replicates of 20 animals. Broiler and turkey diets, based on wheat, soybean meal, rapeseed, and barley, and water were available ad libitum. On day 28, the cecal contents from 5 birds per pen were collected. The profile of short-chain fatty acids (SCFA) and microbiome structure (by % guanidine and cytosine [G + C] method) were analyzed. Selected % G + C fractions were used for 16S rDNA sequencing for the identification of bacteria. No treatment effects were noted on SCFA concentrations in either broilers or turkeys. Broilers fed MD diets had greater proportions of unclassified Clostridiales, Mollicutes (RF9) and Faecalibacterium. Xylanase supplementation in broilers resulted in lower proportions of Lactobacillus but increased Mollicutes (RF9), unclassified Ruminococcus, unclassified Clostridiales, and Bifidobacterium. The microbiome in turkeys was unaffected by phytase supplementation, but xylanase supplementation increased the proportions of Lachnospiraceae (Incertae sedis), Lactobacillus, and Bifidobacterium. Supplementation of turkey diets with increasing doses of phytase did not affect the cecal microbiota in contrast to what was observed in broilers. In contrast, xylanase supplementation in both species led to significant changes in the microbial populations, suggesting a positive influence through the provision of oligosaccharides.

Effect of Sodium Butyrate on Intestinal Health of Poultry – A Review

Health of the intestine is one of the main reasons that affects the bird’s performance, and thus the economic yield in the poultry sector. Various studies have examined how to improve the intestinal health using dietary supplements, including organic acids such as sodium butyrate (SB). The efficacy of the dietary supplementation in poultry is often assessed using an important parameter such as intestinal integrity, which is often assessed as a measure of high villus height and the ratio of villus height to crypt depth, or count of goblet cell numbers. In broilers, the villus length and width were increased by the addition of dietary SB. Since, at day 21 and 42, the villus length was increased by 55 and 27%, and 39 and 18% for birds fed 0.5 and 1 g/kg, respectively, compared with the control diet. Furthermore, SB plays an important role in development of poultry intestinal epithelium. It can be employed by the intestinal epithelial cells as an energy source to stimulate their differentiation and proliferation, and to improve intestinal barrier function. SB is effective against acid intolerant species such as Salmonella, Clostridium perfringens and E. coli. In addition, use of butyric acid at 0.6% reduced the pH of gastrointestinal segments. For this, SB could be a potential alternative in maintaining the health of gastrointestinal tract and improving the productive performance of poultry. This review refers to the expanding horizons in the research on SB supplementation in poultry health and nutrition.