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

Early-life environmental effects on birds: epigenetics and microbiome as mechanisms underlying long-lasting phenotypic changes

Although the long-lasting effects of variation in early-life environment have been well documented across organisms, the underlying causal mechanisms are only recently starting to be unraveled. Yet understanding the underlying mechanisms of long-lasting effects can help us predict how organisms will respond to changing environments. Birds offer a great system in which to study developmental plasticity and its underlying mechanisms owing to the production of large external eggs and variation in developmental trajectories, combined with a long tradition of applied, physiological, ecological and evolutionary research. Epigenetic changes (such as DNA methylation) have been suggested to be a key mechanism mediating long-lasting effects of the early-life environment across taxa. More recently, changes in the early-life gut microbiome have been identified as another potential mediator of developmental plasticity. As a first step in understanding whether these mechanisms contribute to developmental plasticity in birds, this Review summarizes how changes in early-life environment (both prenatal and postnatal) influence epigenetic markers and the gut microbiome. The literature shows how both early-life biotic (such as resources and social environment) and abiotic (thermal environment and various anthropogenic stressors) factors modify epigenetic markers and the gut microbiome in birds, yet data concerning many other environmental factors are limited. The causal links of these modifications to lasting phenotypic changes are still scarce, but changes in the hypothalamic-pituitary-adrenal axis have been identified as one putative pathway. This Review identifies several knowledge gaps, including data on the long-term effects, stability of the molecular changes, and lack of diversity in the systems studied, and provides directions for future research.

Unveiling the influence of adaptation time on xylanase and arabinoxylan-oligosaccharide efficacy: a study on nutrient digestibility, viscosity, and scanning electron microscopy in the small and large intestine of growing pigs fed insoluble fiber

The experiment objective was to evaluate the impact of xylanase over time on viscosity and digestibility in growing pigs fed corn-based fiber. Twenty gilts with an initial body weight of 30.6 ± 0.2 kg (n = 5 per dietary treatment) were fitted with t-cannulae in the medial jejunum and terminal ileum, housed individually, and randomly assigned to one of four dietary treatments: low-fiber control (LF) with 10.4% total dietary fiber (TDF), 30% corn bran high-fiber control (HF; 26.4% TDF), HF + 100 mg xylanase/kg (XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (AX). Gilts were limit fed for three 17 d periods (P1, P2, P3); each included 5 d adaptation, 2 d fecal collection, 3 d ileal collection, 3 d jejunal collection, and 4 d related rate of passage study. Data were analyzed as repeated measures using a linear mixed model with surgery date as a random effect, and dietary treatment, period, and their interaction as fixed effects. Jejunal and ileal digesta viscosity did not differ among dietary treatments or periods (P > 0.10). There was a dietary treatment × period interaction for the apparent jejunal digestibility (AJD) of dry matter (DM), gross energy (GE), insoluble dietary fiber (IDF), neutral detergent fiber (NDF), total arabinoxylan (T-AX), total non-starch polysaccharide (T-NSP), and TDF (P≤ 0.05). In P1, LF had the greatest AJD of DM (15.5%), and relative to HF and AX, XY decreased it (9.3%, 10.1 %, and 6.3%, respectively). In P2, the AJD of DM in XY was greater than HF (11.7% vs. 9.1%) but did not differ from AX (10.5%). Relative to HF, in P3, XY increased AJD of DM (11.7 vs 15.3%), and AX decreased it (7.2%). For the AJD of NDF, AX performed intermediately in P1; in P2, relative to HF, XY, and AX increased the AJD of NDF (8.4%, 13.1%, and 11.7%, respectively), and in P3, XY, and LF did not differ (13.6 vs. 14.4%). A similar response was observed for the AJD of IDF and TDF, except for XY having the greatest AJD of IDF, T-AX, T-NSP, and TDF in P3 (P < 0.05). Compared to LF, irrespective of period, HF decreased the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of IDF, TDF, and NDF (P < 0.05). Relative to HF, XY partially mitigated this effect, improving the AID and ATTD of TDF, IDF, and NDF (P < 0.05). Increased corn-based fiber decreased nutrient digestibility, but XY partially mitigated that effect in the small intestine through enhanced fiber digestibility when given sufficient adaptation time.

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.

Ameliorative avian gut environment and bird productivity through the application of safe antibiotics alternatives: a comprehensive review

The avian digestive tract is an important system for converting ingested food into the nutrients their bodies need for maintenance, growth, and reproduction (meat, table eggs, and fertile eggs). Therefore, preserving digestive system integrity is crucial to bird health and productivity. As an alternative to antibiotics, the world has recently turned to the use of natural products to enhance avian development, intestinal health, and production. Therefore, the primary goal of this review is to explain the various characteristics of the avian digestive tract and how to enhance its performance with natural, safe feed additives such as exogenous enzymes, organic acids, photogenic products, amino acids, prebiotics, probiotics, synbiotics, and herbal extracts. In conclusion, the composition of the gut microbiome can be influenced by a number of circumstances, and this has important consequences for the health and productivity of birds. To better understand the connection between pathogens, the variety of therapies available, and the microbiome of the gut, additional research needs to be carried out.

Dietary Fiber Level Improve Growth Performance, Nutrient Digestibility, Immune and Intestinal Morphology of Broilers from Day 22 to 42

There are few systematic studies on the dietary fiber requirements of broilers in the late feeding stage, and there are not enough data to support this hypothesis. This experiment was conducted to examine the effects of dietary fiber level on growth performance, nutrient digestibility, immune function and intestinal morphology of broilers from day 22 to 42. A total of 480 one-day-old Arbor Acres broilers with half male and half female were randomly allocated into four groups, with eight replicates in each group and fifteen chickens in each replicate. The experimental period was 42 days. All broilers were fed a basal diet from 1 to 21 days. During the 22–42 day period, the four experimental groups were fed diets with soybean hulls as the fiber source, and crude fiber (CF) levels were 2%, 5%, 8% and 11%, respectively. The results showed that during the 29–42 day period, the average daily feed intake (ADFI) of broilers was higher in the 5% CF and 8% CF groups (p < 0.05), and during the 29–35 day period, the average daily gain (ADG) of broilers was higher and the ratio of feed and gain (F/G) of broilers was lower in the 5% CF and 8% CF groups (p < 0.05). The digestibility of crude protein (CP), ether extract (EE), CF, acid detergent fiber (ADF) and neutral detergent fiber (NDF) was higher in broilers of the 8% CF group (p < 0.05). The immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) content of the plasma of broilers was higher in the 8% CF group (p < 0.05). The villus height (VH) of the duodenum, jejunum and ileum of broilers was higher, and the crypt depth (CD) was lower in the 8% CF group than that in the 2% CF group (p < 0.05). The ratio of VH and CD (V/C) of the duodenum and jejunum of broilers in the 8% CF group was higher than that in the 2% CF group (p < 0.05). The quadratic regression analysis showed that the optimum dietary CF level was 7–9%. In conclusion, under the conditions of this experiment, a diet of 7–9% CF may promote growth performance by improving the nutrient digestibility, immunity and intestinal morphology of broilers from day 22 to 42.

Microbial diversity and community composition of fecal microbiota in dual-purpose and egg type ducks

Introduction

Ducks are important agricultural animals, which can be divided into egg and dual-purpose type ducks according to economic use. The gut microbiota of ducks plays an important role in their metabolism, immune regulation, and health maintenance.

Methods

Here, we use 16S rDNA V4 hypervariable amplicon sequencing to investigate the compositions and community structures of fecal microbiota between egg (five breeds, 96 individuals) and dual-purpose type ducks (four breeds, 73 individuals) that were reared under the same conditions.

Results

The alpha diversity of fecal microflora in egg type ducks was significantly higher than that in dual-type ducks. In contrast, there is no significant difference in the fecal microbial community richness between the two groups. MetaStat analysis showed that the abundance of Peptostreptococcaceae, Streptococcaceae, Lactobacillus, Romboutsia, and Campylobacter were significantly different between the two groups. The biomarkers associated with the egg and dual-purpose type ducks were identified using LEfSe analysis and IndVal index. Function prediction of the gut microbiota indicated significant differences between the two groups. The functions of environmental information processing, carbohydrate metabolism, lipid metabolism, xenobiotic biodegradation and metabolism, and metabolism of terpenoids and polyketides were more abundant in egg type ducks. Conversely, the genetic information processing, nucleotide metabolism, biosynthesis of amino acids and secondary metabolites, glycan biosynthesis and metabolism, fatty acid elongation, and insulin resistance were significantly enriched in dual-purpose type ducks.

Discussion

This study explored the structure and diversity of the gut microbiota of ducks from different economic-use groups, and provides a reference for improving duck performance by using related probiotics in production.

Poultry nutrition

Nutrition is the most important environmental factor affecting development, health status, growth performance and profitability of poultry production. Feeds for poultry constitute up to 70–75% of total production costs. Poultry nutrition differs considerably from that of other livestock, which is determined by the specific anatomy of the gastrointestinal tract. Protein, energy, fat, fiber, minerals, vitamins, and water are of basic importance for poultry nutrition and their content in feeds must cover the requirement that differ depending on the bird’s age and species. In general, feed protein must be of good value including the content of essential amino acids. Among them lysine, methionine, cysteine, threonine and tryptophan are the limiting ones. The main ingredient of poultry feeds are cereal grains, i.e. wheat and maize, which predominantly constitute an energy source because their protein content is insufficient for birds. Because of that cereals cannot be the only feed for poultry and must be combined with protein sources such as soybean or rapeseed meal, legume seeds or protein concentrates. Despite birds’ requirement for nutrients and chemical composition of feeds are well known, nutrition must face many problems. One of the most important issues is to find alternatives to antibiotic growth promoters.

Connecting gut microbiomes and short chain fatty acids with the serotonergic system and behavior in Gallus gallus and other avian species

The chicken gastrointestinal tract has a diverse microbial community. There is increasing evidence for how this gut microbiome affects specific molecular pathways and the overall physiology, nervous system and behavior of the chicken host organism due to a growing number of studies investigating conditions such as host diet, antibiotics, probiotics, and germ-free and germ-reduced models. Systems-level investigations have revealed a network of microbiome-related interactions between the gut and state of health and behavior in chickens and other animals. While some microbial symbionts are crucial for maintaining stability and normal host physiology, there can also be dysbiosis, disruptions to nutrient flow, and other outcomes of dysregulation and disease. Likewise, alteration of the gut microbiome is found for chickens exhibiting differences in feather pecking (FP) behavior and this alteration is suspected to be responsible for behavioral change. In chickens and other organisms, serotonin is a chief neuromodulator that links gut microbes to the host brain as microbes modulate the serotonin secreted by the host's own intestinal enterochromaffin cells which can stimulate the central nervous system via the vagus nerve. A substantial part of the serotonergic network is conserved across birds and mammals. Broader investigations of multiple species and subsequent cross-comparisons may help to explore general functionality of this ancient system and its increasingly apparent central role in the gut-brain axis of vertebrates. Dysfunctional behavioral phenotypes from the serotonergic system moreover occur in both birds and mammals with, for example, FP in chickens and depression in humans. Recent studies of the intestine as a major site of serotonin synthesis have been identifying routes by which gut microbial metabolites regulate the chicken serotonergic system. This review in particular highlights the influence of gut microbial metabolite short chain fatty acids (SCFAs) on the serotonergic system. The role of SCFAs in physiological and brain disorders may be considerable because of their ability to cross intestinal as well as the blood-brain barriers, leading to influences on the serotonergic system via binding to receptors and epigenetic modulations. Examinations of these mechanisms may translate into a more general understanding of serotonergic system development within chickens and other avians.

Effect of emulsifier and multicarbohydrase enzyme supplementation on performance and nutrient digestibility in broiler diets containing rapeseed meal

The aim of this study was to determine the effect of emulsifier and multicarbohydrase enzyme supplementation on performance, nutrient utilization, and apparent metabolizable energy-nitrogen (AME_N) value of broiler diets containing rapeseed meal (RSM) as well as their influence on the gut morphological structures, excretion of total and free sialic acid, and cecum concentration of short-chain fatty acids (SCFAs) in broiler chickens. A total of 384 male broiler chicks were assigned to four dietary treatments. The diet of the control treatment (CON) consisted of soybean, maize, and RSM (5% in starter, 7% in grower, 15% in finisher) with soybean and palm oils. The diets used for the experimental treatments were the control diet supplemented with an emulsifier (EMU), enzyme (ENZ), or both (EMU + ENZ). The duodenum (n = 10/treatment) and ileum (n = 10/treatment) digesta samples were assessed to determine nutrient digestibility: crude protein (CP), ether extract (EE), starch, Ca. Throughout the experimental period, EMU + ENZ treatment indicated the lowest total average feed intake and feed conversion ratio, with the highest average weight gain among the studied treatments (P < 0.05). The EMU + ENZ treatment also resulted in higher (P < 0.05): apparent prececal digestibility (APD) of CP, total tract neutral detergent fibre (NDF) degradation, apparent total tract digestibility (ATTD) of EE, villus height to crypt depth ratio (P < 0.1). The highest APD of EE was noted in the EMU treatment (P < 0.05). No significant differences were found in the AME_N values of the diets. A greater jejunum villi surface area was found in groups supplemented by enzyme compared to CON (P < 0.05). The EMU + ENZ treatment presented lower sialic acid excretion in the ileum and concentration of cecum SCFAs compared to the CON treatment (P < 0.05). The obtained results indicate that simultaneous usage of additives had beneficial effect on production parameters, nutrient digestibility, NDF degradation, as well as gut mucosa morphology. Based on the SCFAs concentration results, separate or simultaneous addition of emulsifier or/and enzyme did not provoke excessive fermentation activity of cecal bacteria.

Xylanase supplementation of pelleted wheat-based diets increases growth efficiency and apparent metabolizable energy and decreases viscosity of intestinal contents in broilers

This study was designed to test graded supplementation of a thermostable xylanase in pelleted, wheat-based diets fed to broiler chickens over a 28-d period. A total of 600 Ross 708 male broilers were allotted to 1 of 5 dietary treatments: positive control (PC), negative control (NC; 125 kcal of AME/kg diet reduction relative to PC), and NC supplemented with 10, 15, or 30 g/ton of xylanase. Wheat-soybean meal-based diets were pelleted and fed in 2 feeding phases (14-d each). Study outcomes included growth performance, AME, and ileal digesta viscosity with 20 battery cages of 6 birds per treatment. Data were analyzed by 1-way ANOVA along with estimation of Pearson correlation coefficients. Whereas no difference between NC and PC was observed for BW gain, NC birds exhibited increased (P < 0.05) feed intake during each feeding phase and overall, which caused improvements (P < 0.05) in feed conversion ratio (FCR) for PC vs. NC birds. The analyzed AME of PC birds was 112 kcal/kg of diet greater (P < 0.05) than for NC birds, though no differences in digesta viscosity were observed. Xylanase supplementation of the NC diet at 15 or 30 g/ton elicited overall improvements (P < 0.05) in BW gain beyond the PC, while the 30 g/ton level equalized feed intake with the PC. Regardless of level, xylanase supplementation improved (P < 0.05) the FCR relative to the NC, thereby equalizing the response with the PC. Similarly, supplementation with any xylanase level increased (P < 0.05) AME over the NC, making all treatments synonymous with the PC. Digesta viscosity of all xylanase-supplemented treatments was decreased relative to both the NC and PC treatments. Overall, this study provided clear evidence that addition of a thermostable xylanase to pelleted wheat-based diets elicited improvements in growth performance of broilers concomitant with a reduction in digesta viscosity and elevation of analyzed dietary AME content.

Novel strategies to improve chicken performance and welfare by unveiling host-microbiota interactions through hologenomics

Fast optimisation of farming practices is essential to meet environmental sustainability challenges. Hologenomics, the joint study of the genomic features of animals and the microbial communities associated with them, opens new avenues to obtain in-depth knowledge on how host-microbiota interactions affect animal performance and welfare, and in doing so, improve the quality and sustainability of animal production. Here, we introduce the animal trials conducted with broiler chickens in the H2020 project HoloFood, and our strategy to implement hologenomic analyses in light of the initial results, which despite yielding negligible effects of tested feed additives, provide relevant information to understand how host genomic features, microbiota development dynamics and host-microbiota interactions shape animal welfare and performance. We report the most relevant results, propose hypotheses to explain the observed patterns, and outline how these questions will be addressed through the generation and analysis of animal-microbiota multi-omic data during the HoloFood project.

The Positive Effects of Exogenous Pancreatin on Growth Performance, Nutrient Digestion and Absorption, and Intestinal Microbiota in Piglets

Pancreatin secretion is dramatically decreased over time after weaning, thus affecting the utilization of nutrients in piglets. Therefore, exogenous pancreatin is expected to alleviate this situation. This experiment was conducted to investigate the effects of exogenous pancreatin on the growth performance, nutrient digestion and absorption, and intestinal microbiota of piglets. One hundred eighty piglets (Duroc × Landrace × Yorkshire, 40 days) were randomly allotted to three treatments (basal diets supplemented with 0, 250, or 500 mg/kg pancreatin) with three replicate pens per treatment and 20 piglets per pen. Compared with the control diet, dietary 500 mg/kg pancreatin significantly increased (p < 0.05) the average daily gain (ADG) and the apparent digestibility of crude protein and crude fat of piglets. Regarding endogenous enzymes, pancrelipase activity in the pancreas, duodenal mucosa, and small intestinal digesta as well as trypsin activity in the jejunal digesta were increased in piglets fed a diet supplemented with 500 mg/kg pancreatin (p < 0.05). Moreover, amylopsin activity was significantly strengthened in the pancreas, duodenal mucosa, and digesta in piglets fed a diet with 500 mg/kg pancreatin (p < 0.05). The mRNA expression of nutrient transporters, including oligopeptide transporter-1 (PepT1), excitatory amino acid transporter-1 (EAAC1), cationic amino acid transporter-1 (CAT1), sodium glucose cotransporter-1 (SGLT1), glucose transporter-2 (GLUT2), and fatty acid transporter-4 (FATP4), in the jejunum significantly increased after dietary supplementation with 500 mg/kg pancreatin (p < 0.05). An increased villus height-to-crypt depth ratio of the ileum was observed in the 500 mg/kg pancreatin-treated group (p < 0.05). The composition of the colonic microbiota modulated by the addition of 500 mg/kg pancreatin was characterized by an increased relative abundance of Lactobacillus (p < 0.05), and the predicted functions revealed that 500 mg/kg pancreatin supplementation enhanced the functional abundance of genetic information processing in colonic microorganisms and environmental information processing. Our findings suggested that the addition of 500 mg/kg pancreatin improved the growth performance of piglets, improved intestinal structure, and modulated the colon microbiota, thereby increasing nutrient digestibility.

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

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

Understanding the Role of Prevotella Genus in the Digestion of Lignocellulose and Other Substrates in Vietnamese Native Goats' Rumen by Metagenomic Deep Sequencing

Simple Summary

Prevotella is an abundant genus which plays an important role for lignocellulose digestion in goat rumen and is significant to the yield and quality of milk and meat in cows. In a previous study, we sequenced bacterial metagenome from Vietnamese native goat rumen to get 8.4 GB clean data and found very diverse genes related to lignocellulose degradation. However, due to the limitation in the metagenomic size, low amount of complete lignocellulase genes, and high bacterial diversity, further analysis was restricted. In this study, metagenomic deep sequencing was used to obtain 48.66 GB of reliable data, thus some lignocellulolytic enzymes were first seen and a picture of bacterial enzymes involved in lignocellulose digestion in the goat rumen was drawn. The loci for galactan-, xylan-, and arabinan-processing in Prevotella were observed for the first time. We confirm that Prevotella plays pivotal role for hemicellulose digestion and significantly participates in starch, cellulose, hemicellulose, and pectin conversion in the goat rumen. A gene coding endoxylanase was expressed in E. coli. The recombinant enzyme was tolerant with some salts, detergents, and had high activity, thus is a good candidate for lignocellulose processing and as an animal feed food additive to effectively improve xylooligosaccharide production.

Abstract

Bacteria in rumen play pivotal roles in the digestion of nutrients to support energy for the host. In this study, metagenomic deep sequencing of bacterial metagenome extracted from the goats’ rumen generated 48.66 GB of data with 3,411,867 contigs and 5,367,270 genes. The genes were mainly functionally annotated by Kyoto Encyclopedia of Genes and Genomes (KEGG) Carbohydrate-Active enZYmes (CAZy), and HMMER database, and taxonomically classified by MEGAN. As a result, 65,554 genes encoding for 30 enzymes/proteins related to lignocellulose conversion were exploited, in which nine enzymes were seen for the first time in goat rumen. Prevotella was the most abundant genus, contributing 30% hemicellulases and 36% enzymes/proteins for lignocellulose pretreatment, and supporting 98.8% of feruloyl esterases and 71.7% acetylxylan esterases. In addition, 18 of the 22 most lignocellulose digesting- potential contigs belonged to Prevotella. Besides, Prevotella possessed many genes coding for amylolytic enzymes. One gene encoding for endoxylanase was successfully expressed in E. coli. The recombinant enzyme had high Vmax, was tolerant to some salts and detergents, worked better at pH 5.5–6.5, temperature 40–50 °C, and was capable to be used in practices. Based on these findings, we confirm that Prevotella plays a pivotal role for hemicellulose digestion and significantly participates in starch, cellulose, hemicellulose, and pectin digestion in the goat rumen.

Multi-Omics Characterization of Host-Derived Bacillus spp. Probiotics for Improved Growth Performance in Poultry

Microbial feed ingredients or probiotics have been used widely in the poultry industry to improve production efficiency. Spore-forming Bacillus spp. offer advantages over traditional probiotic strains as Bacillus spores are resilient to high temperature, acidic pH, and desiccation. This results in increased strain viability during manufacturing and feed-pelleting processes, extended product shelf-life, and increased stability within the animal’s gastrointestinal tract. Despite numerous reports on the use of Bacillus spores as feed additives, detailed characterizations of Bacillus probiotic strains are typically not published. Insufficient characterizations can lead to misidentification of probiotic strains in product labels, and the potential application of strains carrying virulence factors, toxins, antibiotic resistance, or toxic metabolites. Hence, it is critical to characterize in detail the genomic and phenotypic properties of these strains to screen out undesirable properties and to tie individual traits to clinical outcomes and possible mechanisms. Here, we report a screening workflow and comprehensive multi-omics characterization of Bacillus spp. for use in broiler chickens. Host-derived Bacillus strains were isolated and screened for desirable probiotic properties. The phenotypic, genomic and metabolomic analyses of three probiotic candidates, two Bacillus amyloliquefaciens (Ba ATCC PTA126784 and ATCC PTA126785), and a Bacillus subtilis (Bs ATCC PTA126786), showed that all three strains had promising probiotic traits and safety profiles. Inclusion of Ba ATCC PTA12684 (Ba-PTA84) in the feed of broiler chickens resulted in improved growth performance, as shown by a significantly improved feed conversion ratio (3.3%), increased of European Broiler Index (6.2%), and increased average daily gain (ADG) (3.5%). Comparison of the cecal microbiomes from Ba PTA84-treated and control animals suggested minimal differences in microbiome structure, indicating that the observed growth promotion presumably was not mediated by modulation of cecal microbiome.

Changes in Growth Performance and Ileal Microbiota Composition by Xylanase Supplementation in Broilers Fed Wheat-Based Diets

Xylanase exerts key roles in improving growth performance and intestinal health of broilers fed wheat-based diets. However, knowledge is limited regarding effects of xylanase supplementation on ileal microbiota in broilers. A total of 128 one-day-old broilers (initial BW 48.03 ± 0.33 g) were selected to investigate effects of xylanase (AT-xynA) on growth performance, ileal morphology, microbiota composition, immune response, antioxidant capacity, and endocrine peptide levels in broilers. Broilers were randomly allotted into two dietary treatments (n = 8), namely, a wheat-soybean basal diet and a basal diet with 4,000 U/kg AT-xynA (XY). On days 7, 14, 21, and 42, broilers were weighted and ileal tissues were sampled. Ileal digesta samples were collected for analyzing microbiota composition on days 21 and 42. The results showed that AT-xynA could improve average daily weight gain and average daily feed intake, and there were interactions between diet and age of broilers (p < 0.05). On days 21 and 42, xylanase supplementation decreased ileal microbiota α-diversity, and the relative abundance of potentially pathogenic microbiota, such as phylum Proteobacteria, family Moraxellaceae and Staphylococcaceae, genus Staphylococcus, Pseudomonas, Streptococcus, and Enterococcus, increased the abundance of Lactobacillus (p < 0.05). Moreover, the reduction in acetate concentration and abundance of short-chain fatty acid-producing bacteria was also observed in broilers from XY group (p < 0.05). AT-xynA increased ileal villus height, glucagon-like peptide-1, and insulin-like growth factor-1 concentrations and decreased interleukin-1β, interleukin-6, tumor necrosis factor-α, and malondialdehyde content in broilers, and these positive effects on intestinal health were greater in young broilers. In conclusion, xylanase supplementation to wheat-based diets could improve ileal intestinal morphology and immune function, and alleviate excess fermentation of bacteria, which may be related to changes of intestinal microbiota. In addition, the positive effects of xylanase on intestinal health were more pronounced in young broilers, thus contributing to subsequent improvement in growth performance of broilers.

Exogenous Enzymes as Zootechnical Additives in Animal Feed: A Review

Enzymes are widely used in the food industry. Their use as a supplement to the raw material for animal feed is a current research topic. Although there are several studies on the application of enzyme additives in the animal feed industry, it is necessary to search for new enzymes, as well as to utilize bioinformatics tools for the design of specific enzymes that work in certain environmental conditions and substrates. This will allow the improvement of the productive parameters in animals, reducing costs and making the processes more efficient. Technological needs have considered these catalysts as essential in many industrial sectors and research is constantly being carried out to optimize their use in those processes. This review describes the enzymes used in animal nutrition, their mode of action, their production and new sources of production as well as studies on different animal models to evaluate their effect on the productive performance intended for the production of animal feed.

The influence of xylanase on the fermentability, digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.

Agronomic and In Vitro Quality Evaluation of Dual-Purpose Cereals Clipped at Variable Ages and Their Utilization in Rabbit Feeding

The present study included two experiments; the first one investigated the forage productivity and in vitro quality of a single cut taken at different plant ages (45, 60, and 75 days after sowing—DAS) from four prominent cereal crops, namely, barley, oat, triticale, and ryegrass, grown during two successive winter seasons in Northern Egypt. In addition, the effect of plant age at forage removal on the crop’s regrowth ability and final grain yield was quantified. The second experiment studied the biological in vivo effects of the four crops’ hay cut at the optimum plant age on growth performance, feed utilization, and apparent nutrients’ digestibility of growing rabbits. Despite the progressive increase in the fresh and dry matter yields produced from the four crops with later forage removal and the relatively high quality of the forage removed at 45 DAS, 1st experiment concluded that forage removal at 60 DAS produced a reasonable amount of fresh and dry matter yields with appropriate in vitro quality. Meanwhile, the gain in forage yield, when forage was removed at 60 DAS, was enough to compensate for the consequent reduction in grain yield of the four evaluated crops. The inclusion of variable percentages (0, 10, and 20%) of the four tested crops’ hay, when cut at 60 DAS, in the rabbit’s diet (2nd experiment), resulted in non-significant variations in the rabbit’s final body weight. Meanwhile, regardless of the percentage, the rabbits that were fed on diets including ryegrass hay and barley hay had the highest significant daily weight gain. The best feed conversion ratios were obtained by the rabbits that were fed on diets containing 10 and 20% ryegrass hay as well as 20% triticale hay. The highest dry matter, organic matter, and crude protein digestibility coefficients were obtained by both groups of rabbits that were fed on diets containing 20% ryegrass hay and barley hay. The inclusion of any of the four crops’ hay in the rabbits’ diet resulted in significantly higher digestibility coefficients for all nutrients compared to the control rabbits except for ether extract digestibility. Among the four evaluated crops’ hay, ryegrass hay was found to have an outstanding impact on the productive performance and digestibility of growing rabbits. In growing dual-purpose cereals, it is recommended to cut the crops at 60 DAS to achieve the optimum balance between forage yield and quality on the one hand and final grain yield on the other hand. Moreover, when cut at 60 DAS, the evaluated hay of the four crops was adequate to be included in the rabbits’ diet up to 20% substitution of the commercial fiber sources.

Characterization of a new bifunctional endo-1,4-β-xylanase/esterase found in the rumen metagenome

Metagenomic data mining of the Nellore cattle rumen microbiota identified a new bifunctional enzyme, endo-1,4-β-xylanase/esterase, which was subsequently overexpressed in E. coli BL21 (DE3). This enzyme was stable at pH intervals of 5 to 6.5 and temperatures between 30 and 45 °C, and under the test conditions, it had a V_max of 30.959 ± 2.334 µmol/min/mg, K_m of 3.6 ± 0.6 mM and k_cat of 2.323 ± 175 s^-1. Additionally, the results showed that the enzyme is tolerant to NaCl and organic solvents and therefore is suitable for industrial environments. Xylanases are widely applicable, and the synergistic activity of endo-1,4-β-xylanase/esterase in a single molecule will improve the degradation efficiency of heteroxylans via the creation of xylanase binding sites. Therefore, this new molecule has the potential for use in lignocellulosic biomass processing and as an animal feed food additive and could improve xylooligosaccharide production efficiency.

Impaired Performance of Broiler Chickens Fed Diets Naturally Contaminated with Moderate Levels of Deoxynivalenol

Mycotoxin exposure is common in the poultry industry. Deoxynivalenol (DON) is usually detected at levels below the maximum threshold (5000 ppb), but depending on diet and age, broiler performance can be affected. We evaluated the effects of 900 ppb and 2300 ppb DON on the performance, intestinal morphometry, and lesion scores of broiler chickens. One-day-old male Ross broilers (n = 736) were divided into 4 treatments with 8 replicates each, and a pen containing 23 birds was the experimental unit. The animals were fed diets naturally contaminated with two levels of DON: 900 (Low DON—LD) or 2300 (Moderate DON—MD) ppb, with or without activated charcoal, over 28 days. After this, all birds were fed a marginally DON-contaminated diet without charcoal. During the first 28 days, body weight gain (BWG) and feed conversion ratio (FCR) were significantly impaired when broilers were fed a MD diet without activated charcoal. Even after feeding a marginally contaminated diet from D28–35, birds previously fed the MD diet presented a significantly lower performance. The villus height:crypt depth (VH:CD) ratio was significantly higher in the ileum from 14-day-old broilers fed the MD when compared with the LD diet. At D28, the MD diet caused decreased villus height (VH) and increased crypt depth (CD), affecting VH:CD ratio in both intestinal segments, with higher levels in the jejunum from 28-day-old broilers fed a non-supplemented LD diet. Broiler production was negatively affected by DON, even at moderate levels (2300 ppb).

Immunosecurity: immunomodulants enhance immune responses in chickens

The global population has increased with swift urbanization in developing countries, and it is likely to result in a high demand for animal-derived protein-rich foods. Animal farming has been constantly affected by various stressful conditions, which can be categorized into physical, environmental, nutritional, and biological factors. Such conditions could be exacerbated by banning on the use of antibiotics as a growth promoter together with a pandemic situation including, but not limited to, African swine fever, avian influenza, and foot-and-mouth disease. To alleviate these pervasive tension, various immunomodulants have been suggested as alternatives for antibiotics. Various studies have investigated how stressors (i.e., imbalanced nutrition, dysbiosis, and disease) could negatively affect nutritional physiology in chickens. Importantly, the immune system is critical for host protective activity against pathogens, but at the same time excessive immune responses negatively affect its productivity. Yet, comprehensive review articles addressing the impact of such stress factors on the immune system of chickens are scarce. In this review, we categorize these stressors and their effects on the immune system of chickens and attempt to provide immunomodulants which can be a solution to the aforementioned problems facing the chicken industry.

Role of Dietary Fiber in Poultry Nutrition

Simple Summary

Dietary fiber is an inherent compound found in common vegetables that are fed to broiler chickens. Fiber has the ability to scape digestion and absorption in the small intestine, which makes it able to affect the way other nutrients are absorbed and metabolized in the gastrointestinal tract. The functionality attributed to fiber varies based on chemical and physical structure, and most of the time, it is hard to make a clear differentiation among attributes due to the complexity of carbohydrates found in common feedstuffs. Data on the effect of dietary fiber have been gaining importance due to the use of grains for ethanol production and the search for feed alternatives that could help in sustainable and cost-effective broiler production. Therefore, it is paramount to integrate the current knowledge on the nutritional and physiological attributes of dietary fiber in poultry diets to be able to make correct use of fibrous feedstuffs.

Abstract

Dietary fiber (DF) is an intrinsic component in plant feedstuffs that has been associated with physiological, structural, and functional changes in the gastrointestinal tract. DF is composed of non-starch polysaccharides (NSP), oligosaccharides, and lignin that scape digestion and enzymatic hydrolysis. In general terms, fiber can be classified as insoluble or soluble based on their solubility in water. Both fiber types have direct nutritional implications in broiler diets. Inclusion of insoluble DF in broiler diets modulates intestinal morphology, digestive organ development, nutrient absorption, growth performance, and intestinal microbiota. Soluble DF is thought to increase intestinal viscosity and is associated with negative changes in intestinal microflora and reduction in nutrient absorption. Nevertheless, there is a group of soluble fibers, integrated by oligosaccharides, that function as prebiotics positively modulating intestinal microbiota. Due to the changes in chemical structure and subsequent variation in functionality, it is a difficult task to assign clear attributes to DF as a whole. Therefore, the following review paper compiles data from research conducted using DF and tries to unify such information into practical decisions to be considered when using DF as a functional nutrient in poultry nutrition.

Effects of graded levels of exogenous xylanase in corn-soy diets with two amino acid density and fat levels postpellet in broiler chickens: live performance, energy utilization, digestibility, and carcass characteristics

This experiment evaluated the interactive effects among xylanase (XL; 0, 8,000, 16,000, and 32,000 BXU/kg), amino acid density (AA; high and low 10% difference), and additional fat (AF; 0 or +1.17%) applied postpellet in corn-soybean meal diets with dried distillers grains with solubles on performance, energy utilization, digestibility, and carcass traits in Ross 708 male broilers. A completely randomized block (pen location) design with 16 treatments arranged factorially (4 XL levels, 2 AA, and 2 AF) was analyzed using mixed models. No significant interactions or main effects were observed for feed intake at 49 d (P > 0.05) but chicks were heavier when consuming diets containing 0 or 8,000 BXU/kg (P = 0.015), high AA (P < 0.001), and 1.17% AF (P < 0.001). Feed efficiency did not vary with XL supplementation (P > 0.05) but was improved in broilers fed the higher AA and AF diet (P = 0.015 for AA × AF). AME, GE, and CP digestibility were assessed at days 17 and 42. There were multiple interactions observed at day 17 with a significant three-way showing that AME and CP digestibility improved when increasing the XL and AF levels in the high AA fed birds compared with the low-density diets. At day 42, XL and AF significantly affected AMEn, GE, or CP digestibility; however, there was a significant interaction between XL and AF. Diets supplemented with 1.17% AF improved AMEn significantly in broilers fed the highest XL level. Breast yield was not affected by treatments, but wing yield decreased with high AA density when diets contained 16,000 BXU/kg without differences for the other diets (P = 0.04 for XL × AA). Effects of XL, AA, and AF interactions on performance and cut-up-part yields have to be considered until day 42 for most of the variables studied. However, at 49 d of age, the dietary AA density and AF did not markedly influence the response to XL in maize-based diets.

Xylanase supplementation in corn-based swine diets: a review with emphasis on potential mechanisms of action

Corn is a common energy source in pig diets globally; when financially warranted, industrial corn coproducts, such as corn distiller's dried grains with solubles (DDGS), are also employed. The energy provided by corn stems largely from starch, with some contribution from protein, fat, and non-starch polysaccharides (NSP). When corn DDGS are used in the diet, it will reduce starch within the diet; increase dietary protein, fat, and NSP levels; and alter the source profile of dietary energy. Arabinoxylans (AXs) comprise the majority of NSP in corn and its coproducts. One strategy to mitigate the antinutritive effects of NSP and improve its contribution to energy is by including carbohydrases within the diet. Xylanase is a carbohydrase that targets the β-1,4-glycosidic bonds of AX, releasing a mixture of smaller polysaccharides, oligosaccharides, and pentoses that could potentially be used by the pig. Xylanase is consistently effective in poultry production and moderately consistent in wheat-based swine diets, but its efficacy in corn-based swine diets is quite variable. Xylanase has been shown to improve the digestibility of various components of swine-based diets, but this seldom translates into an improvement in growth performance. Indeed, a review of xylanase literature conducted herein suggests that xylanase improves the digestibility of dietary fiber at least 50% of the time in pigs fed corn-based diets, but only 33% and 26% of the time was there an increase in average daily gain or feed efficiency, respectively. Intriguingly, there has been an abundance of reports proposing xylanase alters intestinal barrier integrity, inflammatory responses, oxidative status, and other health markers in the pig. Notably, xylanase has shown to reduce mortality in both high and low health commercial herds. These inconsistencies in performance metrics, and unexpected health benefits, warrant a greater understanding of the in vivo mechanism(s) of action (MOA) of xylanase. While the MOA of xylanase has been postulated considerably in the literature and widely studied in in vitro settings, in wheat-based diets, and in poultry, there is a dearth of understanding of the in vivo MOA in pigs fed corn-based diets. The purpose of this review is to explore the role of xylanase in corn-based swine diets, discuss responses observed when supplemented in diets containing corn-based fiber, suggest potential MOA of xylanase, and identify critical research gaps.

Xylanase increased the energetic contribution of fiber and improved the oxidative status, gut barrier integrity, and growth performance of growing pigs fed insoluble corn-based fiber

The experimental objective was to investigate the impact of xylanase on the bioavailability of energy, oxidative status, and gut function of growing pigs fed a diet high in insoluble fiber and given a longer adaptation time than typically reported. Three replicates of 20 gilts with an initial body weight (BW) of 25.43 ± 0.88 kg were blocked by BW, individually housed, and randomly assigned to one of four dietary treatments: a low-fiber control (LF) with 7.5% neutral detergent fiber (NDF), a 30% corn bran without solubles high-fiber control (HF; 21.9% NDF), HF + 100 mg/kg xylanase (HF + XY; Econase XT 25P), and HF + 50 mg/kg arabinoxylan-oligosaccharide (HF + AX). Gilts were fed ad libitum for 36 d across two dietary phases. Pigs and feeders were weighed on days 0, 14, 27, and 36. On day 36, pigs were housed in metabolism crates for a 10-d period, limit fed (80% of average ad libitum intake), and feces and urine were collected the last 72 h to determine the digestible energy (DE) and metabolizable energy (ME). On day 46, serum and ileal and colonic tissue were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment, time, and treatment × time as fixed effects. There was a significant treatment × time interaction for BW, average daily gain (ADG), and gain to feed (G:F; P < 0.001). By design, BW at day 0 did not differ; at day 14, pigs fed LF were 3.5% heavier, and pigs fed HF + XY, when compared with HF, were 4% and 4.2% heavier at days 27 and 36, respectively (P < 0.001). From day 14 to 27 and day 27 to 36, when compared with HF, HF + XY improved ADG by 12.4% and 10.7% and G:F by 13.8% and 8.8%, respectively (P < 0.05). Compared with LF, HF decreased DE and ME by 0.51 and 0.42 Mcal/kg, respectively, but xylanase partially mitigated that effect by increasing DE and ME by 0.15 and 0.12 Mcal/kg, over HF, respectively (P < 0.05). Pigs fed HF + XY had increased total antioxidant capacity in the serum and ileum (P < 0.05) and tended to have less circulating malondialdehyde (P = 0.098). Pigs fed LF had increased ileal villus height, and HF + XY and HF + AX had shallower intestinal crypts (P < 0.001). Pigs fed HF + XY had increased ileal messenger ribonucleic acid abundance of claudin 4 and occludin (P < 0.05). Xylanase, but not AX, improved the growth performance of pigs fed insoluble corn-based fiber. This was likely a result of the observed increase in ME, improved antioxidant capacity, and enhanced gut barrier integrity, but it may require increased adaptation time to elicit this response.

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.

Are the energy matrix values of the different feed additives in broiler chicken diets could be summed?

BACKGROUND

The aim of this study is to investigate whether the energy matrix values of the nonstarch polysaccharide- (NSP-) degrading enzymes, bioemulsifier (LYSOFORTE®), guanidinoacetic acid (CreAMINO®), or their combinations could be summed. The effects of these additives on the growth performance, carcass traits, and economic value of the broiler chicken diets were evaluated. A total of 525-one-day-old Ross chicks with an initial body weight of 42.96 ± 0.87 g were haphazardly allocated into seven groups with five replicates. The seven experimental treatments are as follows: (1) basal diet with no additives (breeder recommendation), which is the control group, (2) basal diet minus 100 kcal/kg supplemented with 0.02% NSP-degrading enzymes (NSP), (3) basal diet minus 50 kcal/kg supplemented with 0.025% emulsifier (LYSOFORTE®), (4) basal diet minus 50 kcal/kg supplemented with 0.06% guanidinoacetic acid (CreAMINO®), (5) basal diet minus 150 kcal/kg supplemented with a mixture of NSP and LYSOFORTE® (NSPL), (6) basal diet minus 100 kcal/kg supplemented with a mixture of NSP and CreAMINO® (NSPC), and (7) basal diet minus 200 kcal/kg supplemented with a mixture of NSP, LYSO, and CreAMINO® (NSPLC). The experiment lasted for 35 days.

RESULTS

It was found that the final body weight, body weight gain, and relative growth rate were significantly higher in birds fed diets supplemented with NSPL, NSPC, CreAMINO, and LYSO with the reduced energy matrix value. The overall feed conversion ratio was significantly improved due to the supplementation of NSPC, CreAMINO, NSPL, and LYSO with the reduced energy matrix value compared to the control group. Moreover, no significant effect on the carcass criteria was observed by the different treatments. As a result of the dietary supplementation with NSPL, NSPC, CreAMINO®, and LYSO with the reduced energy matrix value, the net profit, total return, economic efficiency, and performance index were increased and the cost of feed per kg of body weight gain was decreased.

CONCLUSION

The energy matrix value of NSPL, NSPC, CreAMINO®, and LYSOFORTE could be established in the diets of broiler chickens to improve the growth performance and economic efficiency.

Titration of supplemental Bacillus subtilis subsp. subtilis American Type Culture Collection PTA-125135 to broiler chickens fed diets of 2 different metabolizable energy concentrations

Bacillus subtilis subsp. subtilis American Type Culture Collection deposit number PTA-125135 has recently been studied by our laboratory as a potential probiotic strain for avian species. The objective of the present study was to evaluate growth performance and feed efficiency in broiler chickens in response to a dose titration of the Bacillus strain in feed. In addition to a nonsupplemented control, Bacillus spores were supplemented into broiler chicken diets at 4 levels, which were 8.1 × 10⁴, 1.6 × 10⁵, 2.4 × 10⁵, and 3.2 × 10⁵ CFU per g of feed. The titration was applied to two different dietary regimes of standard or low metabolizable energy (ME), which differed in ME by 22, 56, and 110 kcal/kg in starter, grower, and finisher dietary phases, respectively. All diets contained 249 g per metric ton of a previously patented synbiotic feed additive. Performance data were collected at day 14, 26, and 40 of age, and the effects of Bacillus and ME treatments were evaluated by factorial ANOVA. Treatment group means were further examined for significant (P < 0.05) pairwise differences among treatments and for significant (P < 0.05) linear and quadratic effects. At day 14 of age, significant linear effects for decreased feed conversion ratio (FCR) with higher CFU of Bacillus supplementation were observed within the standard ME diet. At day 26, a linear trend was observed for increased mortality with increased dose within the standard ME diet only. Bacillus supplementation at day 26 also significantly affected FCR and mortality-adjusted FCR, where supplementation with 3.2 × 10⁵ CFU per g feed produced lower FCR and mortality-adjusted FCR than supplementation with 1.6 × 10⁵ CFU per g feed. We conclude from linear effects related to feed efficiency observed at day 14 and from the significant separation of Bacillus treatment means within the titrated range of supplementation at day 26 that further evaluation for effects on performance should be made of doses at 2.4 × 10⁵, 3.2 × 10⁵, and greater CFU per g in feed.

Effects of Dietary Inclusion of Bilberry and Walnut Leaves Powder on the Digestive Performances and Health of Tetra SL Laying Hens

Simple Summary

In poultry, diet composition influences growth performance, egg production, as well as digestion. In this study, the effects of dietary additives obtained from bilberry and walnut leaves powder on the digestive performances of Tetra SL hens were evaluated by histologic and morphometric analyses of the intestinal mucosa as well as by the enzymatic activity measurements of alpha-amylase, invertase, maltase, and trypsin correlated with cecum microbiota.

Abstract

The purpose of this study was to examine the effects of dietary inclusion of two additives at the final concentration of 0.5% bilberry (E1) and 1% walnut (E2) leaves powder in the basal diet on digestive health of hens. A total number of 90 Tetra SL hens were divided into two experimental groups (E1 and E2) and one control group (C) consisting of 30 hens each. After four weeks, 10 hens of each group were sacrificed and tissue samples and intestinal content were taken from the duodenum, jejunum, and cecum in order to perform histological, enzymatic, and microbiota analyses. In groups E1 and E2, the histological analysis showed a significant increase of villus height, resulting probably in increased absorption of nutrients in duodenum and jejunum. A decrease in the specific activity of alpha-amylase and trypsin in E1 and E2 for both duodenum and jejunum compared to the control one was also recorded. In addition, the maltase and invertase specific activity in duodenum increased, a tendency that was kept for maltase but not for invertase in jejunum. The cecal microbiota of E1 and E2 individuals was characterized by an increase of Firmicutes and Lactobacilli and a decrease of Enterobacteriaceae. In conclusion, our results indicate that bilberry and walnut leaves additives in feed may improve the health status of the poultry gastrointestinal tract.

The Effect of Whey on Performance, Gut Health and Bone Morphology Parameters in Broiler Chicks

Whey is a highly nutritious byproduct of the cheese industry that can be used effectively in the animal feed industry. However, the use of whey in poultry diets is limited by its high lactose and mineral contents. The objective of the present study was to evaluate the effect of different concentrations of whey in poultry diets on the performance, intestinal microbiota and physico-chemical parameters of the intestinal ecosystem, as well as on the bone morphology and its strength in broiler chicks. One hundred and twenty-eight, day-old, male broiler chicks were randomly allocated into four treatment groups of 32 chicks each. The treatment groups were: group A, which served as negative control and groups B, C and D, supplemented with 1, 2 and 5% of dietary whey, respectively. Performance of the groups was evaluated throughout the experiment. Following necropsies, the gastrointestinal tract from each bird was removed, divided into its anatomical parts and intestinal samples were taken for microbiological analysis and for pH and viscosity measurement as well. Tibiotarsus was also collected for morphometric analysis and strength evaluation. The statistical analysis of the experimental data revealed that the dietary supplementation of 1 and 2% of whey improved significantly (p ≤ 0.05) the body weight, while the addition of 5% of whey reduced significantly (p ≤ 0.05) the body weight. Furthermore, the addition of 1, 2 and 5% of dietary whey increased significantly (p ≤ 0.05) the pH of jejunum digesta and reduced significantly (p ≤ 0.05) the pH of caecum digesta compared to the control group. The addition of 1 and 2% of whey reduced significantly (p ≤ 0.05) the viscosity in the jejunum and ileum digesta, compared to the addition of 5% of whey which reduced significantly (p ≤ 0.05) the viscosity in jejunum digesta but increased significantly (p ≤ 0.05) the viscosity in ileum digesta. Moreover, the addition of 1, 2 and 5% of dietary whey increased significantly (p ≤ 0.05) the caecal counts of Lactobacillus spp. and Lactococcus lactis, while the addition of 5% of whey reduced significantly (p ≤ 0.05) the tibiotarsus length. It can be concluded that the addition of low quantities of whey up to 2% promoted the performance and gut health of birds, while the addition of higher quantities of whey at the level of 5% had a detrimental effect on the performance and tibiotarsus length.

Identification and functional characterization of a β-glucosidase from Bacillus tequelensis BD69 expressed in bacterial and yeast heterologous systems

Background

The identification and characterization of novel β-glucosidase genes has attracted considerable attention because of their valuable use in a variety of industrial applications, ranging from biofuel production to improved digestibility of animal feed. We previously isolated a fiber-degrading strain of Bacillus tequelensis from buffalo dung samples, and the goal of the current work was to identify β-glucosidase genes in this strain. We describe the cloning and expression of a new β-glucosidase gene (Bteqβgluc) from Bacillus tequelensis strain BD69 in bacterial and yeast hosts. The recombinant Bteqβgluc were used to characterize specificity and activity parameters, and candidate active residues involved in hydrolysis of different substrates were identified through molecular docking.

Methods

The full length Bteqβgluc gene was cloned and expressed in Escherichia coli and Pichia pastoris cultures. Recombinant Bteqβgluc proteins were purified by immobilized metal affinity or anion exchange chromatography and used in β-glucosidase activity assays measuring hydrolysis of ρ-nitrophenyl-β-D-glucopyranoside (pNPG). Activity parameters were determined by testing relative β-glucosidase activity after incubation under different temperature and pH conditions. Candidate active residues in Bteqβgluc were identified using molecular operating environment (MOE) software.

Results

The cloned Bteqβgluc gene belongs to glycoside hydrolase (GH) family 4 and encoded a 54.35 kDa protein. Specific activity of the recombinant β-glucosidase was higher when expressed in P. pastoris (1,462.25 U/mg) than in E. coli (1,445.09 U/mg) hosts using same amount of enzyme. Optimum activity was detected at pH 5 and 50 °C. The activation energy (E _a) was 44.18 and 45.29 kJ/mol for Bteqβgluc produced by P. pastoris and E. coli, respectively. Results from other kinetic parameter determinations, including pK _a for the ionizable groups in the active site, Gibbs free energy of activation (ΔG ^‡), entropy of activation (ΔS ^‡), Michaelis constant (K _m) and maximum reaction velocity (V _max) for pNPG hydrolysis support unique kinetics and functional characteristics that may be of interest for industrial applications. Molecular docking analysis identified Glu, Asn, Phe, Tyr, Thr and Gln residues as important in protein-ligand catalytic interactions.

Importance of banana flour and its effect on growth performance of broiler

The main objective of this work was to study the effects of banana flour as energy sources on broiler performance. Seventy-five broilers were randomly distributed into five groups each with 15 broilers (n = 15 broilers/group). The broilers were grouped to maize-soybean meal diet as control, T1 : (5% of banana flour), T2 : (10% of banana flour), T3 : (15% of banana flour), and T4 : (20% of banana flour). The parameters analyzed in this research were body weight, daily weight gain, and daily feed intake at days 0, 10, 20, 30, and 40. The results showed no significant effects on body weight during the time of assessment, showing healthy values (>1,400 g) in all treatments (p > .05). Daily Weight gain was affected significantly during the days of assessment (p < .05). In all treatments and at different days of assessment, T3 showed the highest daily weight gain at day 10 (37.56 ± 4.52 g) compared to the other experimental treatments. Regarding daily feed intake, significant differences were observed at day 10 in the control and treatments T1 , T2 , T3 , and T4 compared to days 20, 30, and 40 (p < .05), being the highest value for T1 (35.14 ± 2.77).