Multicarbohydrase Enzymes for Non-ruminants

Dietary multi-enzyme complex improves In Vitro nutrient digestibility and hind gut microbial fermentation of pigs

This study was conducted in two stages to investigate the potential of multi-enzyme supplementation on the nutrient digestibility, growth performance, and gut microbial composition of pigs. In stage 1, effects of multi-enzyme complex (xylanase, α-amylase, β-glucanase, and protease) supplementation on the ileal and total tract dry matter (DM) digestibility of feed-stuffs were investigated with in vitro two-stage and three-stage enzyme incubation methods. A wide range of feed ingredients, namely, corn meal, wheat meal, soybean meal, fish meal, Oriental herbal extract, Italian rye-grass (IRG) and peanut hull were used as substrates. Supplementation of the multi-enzyme complex increased (P < 0.05) the digestibility of the Oriental herbal extract and corn meal. In stage 2, in vivo animal studies were performed to further investigate the effects of the dietary multi-enzyme complex on the nutrient utilization, growth performance, and fecal microbial composition of pigs. A total of 36 weaned pigs were fed corn- and soybean meal-based diets without (control) and with the multi-enzyme complex (treatment) for 6 weeks. Fecal samples were collected from 12 pigs to analyze the microbial communities by using DNA sequencing and bioinformatics tools. Multi-enzyme supplementation had no effect on apparent digestibility of nutrients and growth performance of pigs compared to control. Taxonomic analysis of the fecal samples indicated that the bacteria in both control and treatment samples predominantly belonged to Firmicutes and Bacteroidetes. In addition, the proportion of the phylum Firmicutes was slightly higher in the treatment group. At the genus level, the abundance of Treponema and Barnesiella increased in the treatment group; whereas the numbers ofthe genera including Prevotella, Butyricicoccus, Ruminococcus and Succinivibrio decreased in the treatment group. These results suggest that multi-enzyme supplementation with basal diets have the potential to improve nutrient digestibility and modify microbial communities in the hind-gut of pigs.

UTILIZATION OF AN ENZYME COMPLEX IN DIETS CONTAINING COTTONSEED CAKE FOR GROWING PIGS

Abstract Two experiments were conducted with pigs in the growth phase (30–50 kg). Experiment I consisted of a digestibility trial to determine the nutritional value of cottonseed cake with and without addition of an enzyme complex through the method of total collection of excreta. Twenty barrows were used and housed in metabolic cages to collect the total collection of feces and urine. Four treatments and five replications randomized the experimental design completely. Two reference diets and two test diets were experimental (70% reference diet and 30% cottonseed cake), with and without the addition of an enzyme complex. The evaluated variables were: apparent digestibility coefficient of dry matter, of crude protein, of Gross energy, of phosphorus and the values of digestible dry matter, digestible protein, digestible phosphorus, digestible energy and metabolizable energy of cottonseed cake with and without enzymes. The addition of enzymes increased the levels of digestible protein to 0.302–0.313 kg/kg and digestible energy to 2,538–2,894 kcal/kg. Experiment II was conducted to assess barrow performance when they were fed diets containing increasing levels of cottonseed cake protein (0, 20, 40 and 60%), which replaced protein from soybean meal, with the enzyme complex. The design was a randomized block design consisting of four treatments and five replications. The performance, carcass characteristics and biochemical parameters of the blood were evaluated. These results indicate that the protein from soybean meal can be replaced up to 60% by the cottonseed cake protein with enzyme complex in diets for pigs in the growth phase, without sacrificing performance or carcass characteristics

The effect of enzymes on release of trace elements in feedstuffs based on in vitro digestion model for monogastric livestock

Background

This experiment was conducted to study the effect of different feed enzymes (phytase, xylanase, β-glucanase) on release rate of trace elements (Fe, Cu, Mn and Zn) in 6 commonly used feedstuffs (corn, wheat, barley, soybean meal, wheat bran, wheat middlings) by using an in vitro model, simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.

Results

Phytase raised (P < 0.05) the release rate of Cu and Zn in corn, Cu, Zn and Mn in wheat, Cu in barley, Cu, Zn and Mn in soybean meal, Zn, Fe in wheat bran and Zn, Fe, Mn in wheat middlings. The release rate of various trace elements in feedstuffs was increased after xylanase addition. Compared with the control group, the release rate of soluble Cu in corn, wheat, barley and soybean meal, soluble Zn in corn, wheat and wheat middlings and soluble of Mn in corn, wheat, barley and wheat bran increased (P < 0.05) after xylanase treatment. After the treatment of β-glucanase, the release rate of soluble Cu in corn, wheat and wheat bran, soluble Fe in barley, soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased (P < 0.05) compared with the control group. In each feedstuff, after corresponding enzyme treatment, the contents of phytic acid, xylan and β-glucan were significantly lower than those of the control group (P < 0.05).

Conclusions

Results showed that bound trace elements in feedstuffs can be released by feed enzymes. It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes.

The evolution and application of enzymes in the animal feed industry: the role of data interpretation

1. Enzymes have been used commercially for nearly 40 years and save significant costs through sparing of expensive nutrients but the mechanism by which this is achieved is still debated. 2. The research focused on non-starch polysaccharidase (NSPase) enzymes is used as an example of where greater progress could have been made if the details of the work had been described more fully and the analysis of the data generated had been broader in scope and more critical. 3. Lack of standardisation of the details presented in the materials and methods has been identified as a significant barrier to meaningful retrospective analysis and thus limits advances in the understanding of the mode of action of these enzymes. 4. The identity of the enzyme employed and its activity is often lacking, and more importantly the purity is rarely disclosed. Contaminant activities which are neither listed nor assayed could play a significant role in the responses observed. 5. The dose optimum of most enzymes is often considerably higher than that employed in most studies. Thus studies claiming synergy between two 'activities' should ensure that the response is not related to each enzyme simply augmenting the dose of just one activity in the finished feed. This is a common problem, and coupled with the lack of factorial experiments to justify the presence of each enzyme in a multi-enzyme product, it is not surprising that there is still debate as to whether single or multi-enzymes are best suited poultry rations. 6. The three proposed mechanisms for NSPases (viscosity, cell wall and prebiotic) are discussed, and along with their strengths and weaknesses it is suggested that a re-evaluation of each is needed. Viscosity may have to be re-evaluated as being a function not only of the cereal being fed, but of the age of the animal as well. The cell wall theory as described is poorly modelled in vitro and hence the validity of these data is questioned. The prebiotic theory may need significant modification as it appears that the quantities of oligomers produced are insufficient to generate the additional volatile fatty acids (VFA)'s reported. It is likely that all three mechanisms play a role in the responses observed, but the prebiotic mechanism probably plays by far the most important part in low viscosity diets. 7. Future research would be improved if it considered all potential mechanisms when designing a trial. Significant failings are apparent as a result of adherence to tenets in explanation of the results. Most importantly, it should be emphasised that a hypothesis is there to be tested, not defended.

Short-chain arabinoxylans prepared from enzymatically treated wheat grain exert prebiotic effects during the broiler starter period

Carbohydrate-degrading multi-enzyme preparations (MEP) are used to improve broiler performances. Their mode of action is complex and not fully understood. In this study, we compared the effect of water-soluble fractions isolated at the pilot scale from wheat grain incubated with (WE) and without (WC) MEP. The fractions were incorporated in a wheat-based diet (0.1% w/w) to feed Ross PM3 broilers and compared with a non-supplemented control group (NC). The body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) until d 14 were determined. At d 14, ileal and cecal contents and tissue samples were collected from euthanized animals. The intestinal contents were used to measure the short-chain fatty acids (SCFA) concentration using gas chromatography and to determine the abundance and composition of microbiota using 16S sequencing. Villi length of ileal samples was measured, while L-cell and T-cell densities were determined using immuno-histochemistry. The MEP treatment increased the amount of water-soluble arabinoxylans (AX) and reduced their molecular weight while retaining their polymer behavior. The WE fraction significantly (P < 0.05) increased FI by 13.8% and BWG by 14.7% during the first wk post hatch when compared to NC. No significant effect on FCR was recorded during the trial. The WE increased the abundance of Enterococcus durans and Candidatus arthromitus in the ileum and of bacteria within the Lachnospiraceae and Ruminococcaceae families, containing abundant butyrate-producing bacteria, in the ceca. It also increased the concentration of SCFA in the ceca, decreased the T-lymphocyte infiltration in the intestinal mucosa, and increased the glucagon-like-peptide-2 (GLP-2)-producing L-cell density in the ileal epithelium compared with WC and NC. No significant effects were observed on villi length. These results showed that AX present in the WE fraction altered the microbiota composition towards butyrate producers in the ceca. Butyrate may be responsible for the reduction of inflammation, as suggested by the decrease in T-lymphocyte infiltration, which may explain the higher feed intake leading to improved animal growth.

The effects of phytase and xylanase supplementation on performance and egg quality in laying hens

1. The aim of this study was to evaluate the effects of phytase and xylanase and their interaction on laying hen performance, egg quality, phosphorus (P) digestibility, phytate breakdown, volatile fatty acid (VFA) production and peptide YY concentration. 2. Two hundred and forty hens were allocated to cages at 22 weeks of age based on a 3 × 2 arrangement with phytase (0, 300 or 1500 FTU/kg) and xylanase (0 or 12 000 BXU/kg) as factors. 3. Phytase increased hen-day production (P < 0.05), daily egg mass (P < 0.05) and P digestibility with increasing levels of phytase (P < 0.001). Phytase fed at 1500 FTU/kg reduced IP6 and IP5 and increased myo-inositol concentration in gizzard digesta (P < 0.05). Phytase fed at 300 FTU/kg reduced IP6 in ileal digesta (P < 0.05); however, IP6 and IP5 were further reduced and myo-inositol increased when phytase was added at 1500 FTU/kg (P < 0.05). 4. Xylanase improved feed efficiency when phytase was fed at 300 FTU/kg (P < 0.05). In the absence of phytase, xylanase reduced dry matter and Ca digestibilities (P < 0.05). 5. Neither phytase nor xylanase had an effect on peptide YY or caecal VFA concentrations.

Effects of dietary β-mannanase supplementation on the additivity of true metabolizable energy values for broiler diets

Objective

This experiment was conducted to determine the effects of dietary β-mannanase on the additivity of true metabolizable energy (TME) and nitrogen-corrected true metabolizable energy (TME_n) for broiler diets.

Methods

A total of 144 21-day-old broilers were randomly allotted to 12 dietary treatments with 6 replicates. Five treatments consisted of 5 ingredients of corn, wheat, soybean meal, corn distillers dried grains with solubles, or corn gluten meal. One mixed diet containing 200 g/kg of those 5 ingredients also was prepared. Additional 6 treatments were prepared by mixing 0.5 g/kg dietary β-mannanase with those 5 ingredients and the mixed diet. Based on a precision-fed chicken assay, TME and TME_n values for 5 ingredients and the mixed diet as affected by dietary β-mannanase were determined.

Results

Results indicated that when β-mannanase was not added to the diet, measured TME and TME_n values for the diet did not differ from the predicted values for the diet, which validated the additivity. However, for the diet containing β-mannanase, measured TME_n value was greater (p<0.05) than predicted TME_n value, indicating that the additivity was not validated.

Conclusion

In conclusion, the additivity of energy values for the mixed diet may not be guaranteed if the diet contains β-mannanase.

The effects of xylanase on grower pig performance, concentrations of volatile fatty acids and peptide YY in portal and peripheral blood

Non-starch polysaccharides (NSP) present in wheat and barley can act as anti-nutrients leading to an increase in digesta viscosity and a reduction in nutrient digestibility. Xylanase, an NSP-degrading enzyme, has been shown to increase nutrient digestibility in pigs. The objectives of this study were: (1) to identify the optimum inclusion level of xylanase in grower pig diets by measuring the effect of increasing enzyme levels on growth performance, the concentration of volatile fatty acids (VFA) and peptide YY concentration in portal and peripheral blood of grower pigs and (2) to increase our understanding of the interrelationships between xylanase inclusion, VFA production and peptide YY secretion. A total of 512 grower pigs ((Large White×Landrace)×MAXGRO) were allocated to pens creating 32 replicates of four pigs per pen per treatment. Pigs were allocated to trial weighing 14.2±0.31 kg and remained on trial until ~41.5±3.31 kg. The experiment was a dose response design with four inclusion levels (0, 8000, 16 000 or 32 000 BXU/kg) of xylanase (Econase XT). Diets were cereal-based wheat, barley mix formulated to meet or exceed the nutrient requirements of grower pigs. Body weight and feed intake were recorded to calculate growth performance. Pen faecal samples were collected to estimate DM, organic matter (OM) and crude fibre (CF) apparent total-tract digestibility. At the end of the trial 16 pigs per treatment were euthanised by schedule 1 procedures. Peripheral and portal blood samples were collected for peptide YY and VFA analysis. The addition of xylanase to the diet had no effect on growth performance, DM, OM or CF total-tract digestibility; however, xylanase tended to have a quadratic effect on ileum pH with higher pH values recorded for pigs fed a diet supplemented with 8000 and 16 000 BXU/kg xylanase (P<0.1). Xylanase had no effect on peptide YY levels or VFA concentration. Total VFA concentration was higher in portal compared with peripheral blood (P<0.05). In conclusion, the addition of xylanase had no effect on grower pig performance, nutrient digestibility, VFA concentration or peptide YY concentration when fed up to 32 000 BXU/kg over a 35-day period. Pig performance was good for all treatments throughout the trial suggesting that diet quality was sufficient thus there were no beneficial effects of adding xylanase.

Effect of exogenous xylanase, amylase, and protease as single or combined activities on nutrient digestibility and growth performance of broilers fed corn/soy diets

Two trials (a 42-d performance and a 21-d cohort digestibility) were conducted to evaluate the performance and nutrient digestibility of broilers fed corn diets supplemented with exogenous xylanase, amylase, and protease as single or combined activities. A nutritionally adequate, positive control (PC) diet was formulated. The negative control (NC) diet was formulated to be lower in metabolizable energy (∼86 kcal/kg diet) and digestible amino acids (1 to 2%) compared to PC. The other 4 treatments were based on the NC and they were either supplemented with xylanase (X), amylase (A), protease (P), or a combination of X, A, and P (XAP; to provide 2,000 U of X, 200 U of A, and 4,000 U of P/kg diet). All diets were marginal in AvP and Ca and contained a background of phytase (1,000 FTU/kg). In each trial, male broiler (Ross 308) chicks were allocated to the 5 treatments (10 replicates of 20 birds/pen and 9 replicates of 8 birds/cage for the performance and digestibility trials, respectively). In the digestibility trial, ileal digesta was collected on d21 for the determination of nutrient utilization. Data were subjected to one-way ANOVA and means were separated by Tukey's HSD test. Only the XAP improved (P < 0.05) AMEn compared to NC. X, A or XAP improved (P < 0.05) N digestibility and apparent ileal digestible energy (AIDE). Both P and XAP improved N retention. The relative improvement in energy digestibility due to enzyme supplementation was greater at the ileal level than that measured in the excreta. The measured changes on AIDE due to supplemental enzymes were much higher than the sum of calculated contributions from starch, fat, and protein. Supplementation of all enzymes reduced (P < 0.05) ileal flow of soluble rhamnose and mannose relative to NC. In the performance trial, both X and XAP improved (P < 0.05) weight gain (WG) and only XAP improved (P < 0.05) FCR compared to NC during the starter phase (1-21d). Over the entire period (1–42d), WG and FI were not influenced (P > 0.05) by dietary treatments. Both X and XAP had lower (P < 0.05) FCR compared to NC (1.540 and 1.509 vs 1.567, respectively). However, birds fed diet supplemented with XAP had an improved (P < 0.05) FCR compared to birds fed single activities and had similar (P > 0.05) FCR compared to PC. In conclusion, these results suggest a synergistic effect between X, A and P on broiler performance and nutrient digestibility. In the current study, AIDE measurements appeared to overestimate the enzyme response. Calculation of the energy contribution by supplemental enzymes using the improvements in the digestibility of the undigested fraction of starch, fat and protein may be a more accurate measurement for the enzyme response than the absolute response in AIDE.

Xylanase, protease and superdosing phytase interactions in broiler performance, carcass yield and digesta transit time

The interaction of xylanase, protease and superdosing (1,500 FTU/kg) phytase in a 2 × 2 × 2 factorial arrangement was studied in broilers fed sorghum-based diets. A total of 2,800 one-day-old unsexed Ross 308 chicks were housed in 56 pens with 50 birds per pen, with or without inclusion of xylanase, protease and phytase, totaling 8 treatments and 7 replicates per treatment. Body weight (BW) and feed intake (FI) were measured at 21 and 42 days of age, and mortality corrected feed conversion ratio (FCR) was calculated for each period and cumulatively. Tibia ash and carcass yield were determined in 2 birds per replicate at 21 and 42 days of age, respectively. Digesta transit time was determined at 21, 28, 35 and 42 days of age using 5 birds per replicate. Results showed that superdosing phytase increased BW and FI at 42 days of age (P < 0.05) and xylanase improved FCR (P < 0.05). Xylanase and phytase also positively influenced carcass yield and breast weight, respectively. Overall, inclusion of superdosing phytase increased transit time when included in a diet containing xylanase, and no change with protease inclusion. In conclusion, the beneficial effects of xylanase, protease and superdosing phytase in broiler performance were not additive. This limitation is likely not related to the lack of efficacy of any one of the individual enzymes but to a limitation of the bird to respond additively to successive additions of enzymes.

Effects of in Ovo Injection and Inclusion a Blend of Essential Oils and Organic Acids in High NSPs Diets of Broiler Breeders on Performance of Them and Their Offspring

Two factorial completely randomized design trials 2×2 and 2×2×2 were conducted to evaluate the effect of a blend of essential oils and organic acids (Biacid™) in broiler breeder diets at two levels, two dietary non-starch polysaccharides (NSPs) levels and in ovo injection of Biacid™ on their progenies performance, respectively. 240 broiler breeders of Ross 308 strain were fed from the age of week 44^th for 12 weeks in four groups. 120 produced eggs from each group were divided in two groups of 60 eggs for injecting by 0.5 ml of Biacid™ or distilled water. Injection was done during transferring from setter to hatcher in day 18^th of incubation. Twenty-five cockerels from each of 8 treatments were housed into separate pens. Using Biacid™ and high NSPs in broiler breeders' ration affected hatchability, embryo mortality, weight of day old chicks and progenies' carcass yield significantly (p<0.05) whereas in ovo injection of Biacid™ did not show significant effects in this regards (p≥0.05). Offspring's abdominal fat was neither affected by broiler breeders' rations nor in ovo injection of Biacid™ (p≥0.05). Biacid™ and high NSPs content in broiler breeders' ration affected all primary and secondary humoral immune responses of progenies against sheep red blood cells (p<0.05). In ovo injection of Biacid™ increased the primary IgG, primary IgT and secondary IgG responses (p<0.05). The interaction of the effects of Biacid™ and high NSPs in broiler breeders' ration and also in ovo injection of Biacid™ affected progenies' weight gain, feed intake, feed conversion ratio and European production index significantly (p<0.05). It seems that using Biacid™ in broiler breeders' diet can modify the undesirable effects of high NSPs content of breeders' ration on performance of their offspring.

Evaluation of the effect of different wheats and xylanase supplementation on performance, nutrient and energy utilisation in broiler chicks

The aim of this study was to evaluate the performance, nutrient utilisation and energy metabolism of broiler chicks fed 8 different wheat samples, supplemented or not with xylanase. Seven-hundred sixty eight male broilers (1-day-old) were distributed to 16 experimental treatments (6 replicates per treatment). The treatments were in a factorial arrangement with 8 different wheats and 2 levels of xylanase (0 or 16,000 BXU/kg). The predicted apparent metabolisable energy (AME) of the wheat samples ranged from 13.0 to 13.9 MJ/kg and all diets were formulated to contain the same amount of wheat. Body weight gain (BWG) and feed intake (FI) were measured at 21 d, as was jejunal digesta viscosity, and feed conversion ratio (FCR) calculated. On day 24, one representative bird per pen was selected to calculate whole body energetics. At 21 d, 3 chicks per replicate were randomly allocated to metabolism cages for energy and nutrient utilisation determinations, and were continued on the experimental diets until 24-d-old. No interactions were observed for any performance response variables, ileal nutrient utilisation or digesta viscosity. Xylanase improved BWG and reduced FCR and digesta viscosity (P < 0.05). Wheat influenced dry matter (DM) utilisation and xylanase increased ileal digestible energy (P = 0.04). Xylanase also improved (P < 0.05) DM and nitrogen retention. Apparent metabolisable energy and AME corrected for nitrogen (AMEn) were subject to an interaction whereby wheats 2 and 6, which returned the lowest AME and AMEn values, responded to xylanase supplementation and the remainder did not. Net energy for production and the efficiency of energy use for production were not influenced by xylanase, but were affected by wheat (P < 0.05). Despite the significant differences between wheats with regards to their nutrient utilisation and energy metabolism in birds, xylanase removed this variance and resulted in more homogeneous performance.

An enzyme complex increases in vitro dry matter digestibility of corn and wheat in pigs

Two experiments were conducted to determine the effects of enzyme complex on in vitro dry matter (DM) digestibility for feed ingredients. The objective of experiment 1 was to screen feed ingredients that can be effective substrates for an enzyme complex, mainly consisted of β-pentosanase, β-glucanase and α-amylase, using in vitro digestibility methods. In experiment 1, the test ingredients were three grain sources (barley, corn and wheat) and six protein supplements (canola meal, copra expellers, cottonseed meal, distillers dried grains with solubles, palm kernel expellers and soybean meal). In vitro ileal and total tract digestibility (IVID and IVTTD, respectively) of DM for test ingredients were determined. In vitro digestibility methods consisted of two- or three-step procedure simulating in vivo digestion in the pig gastrointestinal tracts with or without enzyme complex. As the enzyme complex added, the IVID of DM for corn and wheat increased (p < 0.05) by 5.0 and 2.6 percentage unit, respectively. The IVTTD of DM for corn increased (p < 0.05) by 3.1 percentage unit with enzyme complex addition. As the effect of enzyme complex was the greatest in corn digestibility, corn grains were selected to determine the in vitro digestibility of the fractions (starch, germ, hull and gluten) that maximally respond to the enzyme complex in experiment 2. The IVID of DM for corn starch, germ and hull increased (p < 0.05) by 16.0, 2.8 and 1.2 percentage unit, respectively. The IVTTD of DM for corn starch and hull also increased (p < 0.05) by 8.6 and 0.9 percentage unit, respectively, with enzyme complex addition. In conclusion, the enzyme complex increases in vitro DM digestibility of corn and wheat, and the digestibility increments of corn are mainly attributed to the increased digestibility of corn starch.

Improving efficiency in meat production

Selective breeding and improved nutritional management over the past 20–30 years has resulted in dramatic improvements in growth efficiency for pigs and poultry, particularly lean tissue growth. However, this has been achieved using high-quality feed ingredients, such as wheat and soya that are also used for human consumption and more recently biofuels production. Ruminants on the other hand are less efficient, but are normally fed poorer quality ingredients that cannot be digested by human subjects, such as grass or silage. The challenges therefore are to: (i) maintain the current efficiency of growth of pigs and poultry, but using more ingredients not needed to feed the increasing human population or for the production of biofuels; (ii) improve the efficiency of growth in ruminants; (iii) at the same time produce animal products (meat, milk and eggs) of equal or improved quality. This review will describe the use of: (a) enzyme additives for animal feeds, to improve feed digestibility; (b) known growth promoting agents, such as growth hormone, β-agonists and anabolic steroids, currently banned in the European Union but used in other parts of the world; (c) recent transcriptomic studies into molecular mechanisms for improved growth efficiency via low residual feed intake. In doing so, the use of genetic manipulation in animals will also be discussed.

Does release of encapsulated nutrients have an important role in the efficacy of xylanase in broilers?

The non-starch polysaccharides (NSPs) in cell walls can act as a barrier for digestion of intracellular nutrients. This effect is called "cage effect." Part of the success of fibrolytic enzymes in broiler feed is assumed to be attributed to cage effect reduction. Further, changes in viscosity and potential prebiotic action should also be considered. The aim of this study was to gain insight into the relative importance of the cage effect in xylanase efficacy in broilers. Using a 2×2 factorial design, 24 pens with 30 Ross 308 male chicks were fed corn-soy based diets consisting of normal and freeze-thawed (5 d at -18°C) corn, both with and without xylanase. The freeze-thaw method was used to eliminate the cage effect, whereas a corn-based diet was used to exclude viscosity effects. Body weights (BW), feed intake (FI), and feed conversion ratio (FCR) were determined at d 13, 26, and 39. A balance study was executed at the end of the growing phase. These birds were euthanized at d 34 (non-fasted) to determine the viscosity of digesta, blood metabolites, intestinal morphology, and microbiota composition. During the finisher period, there was a significant interaction between enzyme supplementation and freeze-thawing for FCR, in which FCR was improved by freeze-thawed corn and tended to be improved by normal corn+enzyme compared with the control group. The improvement in performance (finisher period) of freeze-thawed corn and xylanase coincided with increased gut absorption of glucose (based on postprandial plasma concentrations) and increased number of Clostridiumcluster IV in the caecum, and agreed with the higher gut villus height. In addition, xylanase inclusion significantly increased the postprandial plasma glycine and triglycerides concentration, and led to elevated bacterial gene copies of butyryl CoA:acetate CoA-transferase, suggesting a prebiotic effect of xylanase addition through more than just the cage effect reduction. The applied model managed to rule out viscosity by using corn, and it was possible to isolate the cage effect by freeze-thawing the dietary corn.

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

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

Effects of thermo-resistant non-starch polysaccharide degrading multi-enzyme on growth performance, meat quality, relative weights of body organs and blood profile in broiler chickens

This research was conducted to study the performance and carcass parameters of broiler chickens fed diets supplemented with heat-treated non-starch polysaccharide degrading enzyme. A total of 432 one-day old Ross 308 broiler chickens were allocated to five treatments: (i) CON (basal diet), (ii) E1: CON + 0.05% multi-enzyme, (iii) E2: CON + 0.1% multi-enzyme, (iv) E3: CON + 0.05% thermo-resistant multi-enzyme and (v) E4: CON + 0.1% thermo-resistant multi-enzyme, each treatment consisted of six replications and 12 chickens in each replication. The chickens were housed in three floor battery cages during 28-day experimental period. On days 1-7, gain in body weight (BWG) improved by feeding the diets supplemented with thermo-resistant multi-enzyme. On days 7-21 and 1-28, chickens fed the diets containing thermo-resistant multi-enzyme showed improved (p < 0.05) BWG and feed conversion ratio (FCR) compared to CON group. Supplementing the diets with multi-enzyme or thermo-resistant multi-enzyme affected the percentage of drip loss on d 1 (p < 0.05). Drip loss percentage on days 3 and 5 and also meat colour were not affected significantly. Supplementing the diets with multi-enzyme or thermo-resistant multi-enzyme did not affect the relative weights of organs but compared to CON group, relative weight of breast muscle increased and abdominal fat decreased (p < 0.05). Among measured blood constituents, chickens fed supplemented diets with thermo-resistant multi-enzyme showed higher (p < 0.05) IgG. Counts of red and white blood cells and lymphocyte percentage were not affected. In conclusion, the results demonstrated that supplementing pelleted diets with thermo-resistant multi-enzyme improved performance of broiler chickens.

Effects of an enzyme complex on in vitro dry matter digestibility of feed ingredients for pigs

Feed ingredients of plant origin are commonly used in swine diets. However, the major components of plant cell walls, non-starch polysaccharides (NSPs), reduce nutrient digestibility. To improve the efficiency of feed utilization, exogenous enzyme products that degrade NSPs have been widely used in commercial animal feeds. Nonetheless, the effects of exogenous enzyme addition to swine diets on nutrient digestibility have not been determined. To this end, in vitro approaches may be used. The objective of this study was to determine the effects of an enzyme complex (EC) containing xylanase, protease, and phytase on the in vitro dry matter (DM) digestibility of nine feed ingredients including cereal grain energy sources (corn, wheat, and barley) and protein sources (soybean meal, rapeseed meal, palm kernel meal, cottonseed meal, copra meal, and distillers dried grains with solubles). Both in vitro ileal and total tract digestibility (IVID and IVTTD, respectively) of DM were determined for the nine test ingredients, with or without EC addition. The EC addition increased the IVID of DM in copra meal (p = 0.047) and tended to increase the IVID of DM in corn, wheat, barley, palm kernel meal, cottonseed meal, and DDGS (p < 0.10). On the other hand, no significant effect was observed in soybean meal and rapeseed meal. The IVTTD of DM in the test ingredients was not affected by the addition of EC, except for cottonseed meal (52.1 vs. 50.6%, p = 0.053). In conclusion, the effects of EC addition on in vitro DM digestibility may vary, depending on the test ingredient and method used.

Growth performance and endogenous losses of broilers fed wheat-based diets with and without essential oils and xylanase supplementation

An experiment was conducted to compare the effect of a supplementary mixture of essential oils, with and without exogenous xylanase, on performance, carcass composition, dietary nitrogen (N)-corrected apparent metabolizable energy (AMEn), dry matter retention (DMR), N retention (NR), fat digestibility (FD) coefficients, and endogenous mucin losses (measured as sialic acid, SA) when fed to broiler chickens. Three hundred male Ross 308 broilers in total were reared in floor pens from 0 to 21 d of age. Birds were fed 1 of 3 wheat-based diets: basal diet (215 g/kg CP, 12.12 MJ/kg AME) with either no additive (control diet; C) or 100 g/tonne of a standardized combination of 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin (diet XT); or a combination of XT and commercial xylanase enzyme at a rate of 100 g of XT and 2,000 units (U) of xylanase/kg (diet XYL), respectively. Each diet was randomly allocated to 10 pens with 10 birds. Feeding XT and XYL diets improved birds' growth performance (P<0.05). Birds fed XT and XYL diets had an improved caloric conversion ratio (P<0.05) and consumed 1.3 MJ less AMEn per kilogram of growth compared to birds fed the control diet only. Feeding XT improved only the dietary FD coefficient (P<0.05) compared to control-fed birds, but the dietary FD coefficient did not differ for XYL diet (P>0.05). Birds fed XYL diet excreted 35% less endogenous mucin compared to control-fed birds (P<0.05). Birds fed XT alone gained more carcass protein than the control-fed birds (P<0.05) but did not differ from the birds fed XYL diet (P>0.05). There was no indication of a negative interaction between dietary essential oils and xylanase.

Energy utilization and growth performance of chickens fed novel wheat inbred lines selected for different pentosan levels with and without xylanase supplementation

Different F5 recombinant inbred lines from the cross Yumai 34×Ukrainka were grown in replicated trials on a single site in one harvest year at Rothamsted Research. A total of 10 samples from those lines were harvested and used in a broiler experiment. Twenty nutritionally complete meal-form diets that had 630 g/kg of wheat with different amounts of pentosan, with and without exogenous xylanase supplementation, were used to compare broiler growth performance and determine apparent metabolizable energy corrected for N retention (AMEn). We examined the relationship between the nutritive value of the wheat samples and their chemical compositions and results of quality tests. The amounts of total and water soluble pentosans in wheat samples ranged from 36.7 to 48.0 g/kg DM, and 6.7 to 11.6 g/kg DM, respectively. The mean crude oil and protein contents of the wheat samples were 10.5 and 143.9 g/kg DM, respectively. The average determined value for the kinematic viscosity was 0.0018 mPa.s, and 2.1 mPa.s for the dynamic viscosity. The AMEn of the wheat-based diets had a maximum range of 0.47 MJ/kg DM within the ten wheat samples that were tested. Xylanase supplementation improved (P<0.05) dietary AMEn, dry matter, and fat digestibility coefficients. There was a positive (P<0.05) relationship between in vitro kinematic viscosity of the wheat samples and the total pentosan content. There was a negative relationship between the total pentosan content in the wheat and broiler growth performance. An increase by 10 g of pentosan per kg of wheat reduced (P<0.001) daily feed intake and weight gain by 2.9 g and 3.5 g, respectively. The study shows that the feeding quality of wheat samples can be predicted by their total pentosan content. Supplementary xylanase improved energy and nutrient availability of all wheat samples that was independent of differences in pentosan content.

Effects of exogenous xylanase on performance, nutrient digestibility, volatile fatty acid production and digestive tract thermal profiles of broilers fed on wheat- or maize-based diet

1. A previous experiment reported that caecal temperature was negatively correlated with d 49 feed conversion ratio (FCR). This increased temperature in the caeca may indicate a prebiotic effect. An experiment was designed to investigate whether caecal temperature was affected in diets based on maize and whether other portions of the tract were affected. 2. A total of 25 Ross 308-d-old male broilers were allocated to each of 8 replicate pens per treatment. Treatments followed a 2 × 3 factorial design: two diets based on wheat or maize and three levels of enzyme addition, 0, 16 000 or 32 000 BXU/kg. Growth performance was assessed between d 1 and 49. Digestibility measurements were taken at d 28 and 49. On d 49, the excised small and large intestine of each bird was thermally imaged, weighed and volatile fatty acids (VFA) measured. 3. On d 28 and d 49, birds on the maize diets had higher feed intake and weight gain than those offered wheat diets. Additionally, on d 28, birds that received the maize diet had lower FCR than those offered the wheat diet. Enzyme improved FCR at d 49, independently of cereal. On d 28, enzyme improved the coefficient of apparent ileal DM digestibility and the coefficient of apparent ileal nitrogen digestibility. Enzyme only improved apparent ileal digestible energy in wheat-based diets (interactive term). On d 49, all digestibility parameters were improved by enzyme. Enzyme increased gizzard weight in maize-fed birds and the caeca of those fed wheat were heavier. The higher enzyme dose decreased duodenal temperature. In summary of VFA data, wheat-based diets produced more total VFAs and the total amount also increased with enzyme. 4. It appears from this study that there is equal potential in both wheat and maize diets for xylanase to improve performance of broilers probably through different mechanisms.