Non-starch polysaccharide degrading enzymes in poultry diets: influence of ingredients on the selection of activities

Effects of Different Doses of Multienzyme Supplementation on Growth Performance, Duodenal pH and Morphology, and Carcass Traits in Broilers Fed Diets with an Increasing Reduction in Energy

This study evaluated the effects of supplementing different doses of a multienzyme (KZP) consisting of carbohydrases and a protease on growth performance, duodenal pH and morphology, and carcass traits in broilers fed diets with increasing reductions in energy. One thousand two hundred one-day-old broiler chicks were allocated to five dietary treatments with eight replicates of 30 birds each: a positive control diet formulated to meet Arbor Acres' nutritional requirements (PC); a negative control diet reformulated to 80 kcal/kg less than the apparent metabolizable energy (AME) of the PC (NC1); a negative control diet reformulated to 120 kcal/kg less than the AME of the PC (NC2); an NC1 diet supplemented with 300 g/t of KZP (NC1 + KZP300); and an NC2 supplemented with 500 g/t of KZP (NC2 + KZP500). Growth performance was measured throughout the study. At 35 days, 10 birds per treatment were randomly selected and euthanized for a carcass trait evaluation, and samples of the duodenum were collected for morphological examination and pH level determination. The final average body weight and feed conversion ratio were better (p < 0.05) for the broilers in the NC1 + KZP300 group compared to those in NC1, NC2 and NC2 + KZP500 groups and were similar to those of the PC birds (p > 0.05). Birds from the NC1 + KZP500 group showed a better (p < 0.05) final body weight and feed efficiency compared to the NC1 and NC2 groups. The villus height was greater (p < 0.05) for the PC and NC1 + KZP300 groups compared to the rest of the treatments. The crypt depth was longer (p < 0.05) for the NC1 and NC2 groups compared to the NC1 + KZP300 group. The supplementation of KZP to both the NC1 and NC2 diets reduced (p < 0.05) the abdominal fat %. This study demonstrates that supplementing energy-reduced diets with KZP improved performance in broiler chickens.

Impact of Exogenous Xylanase and Phytase, Individually or in Combination, on Performance, Digesta Viscosity and Carcass Characteristics in Broiler Birds Fed Wheat-Based Diets

The current study was conducted to evaluate the effects of stored wheat-based diet (1.5 and 2.5 years stored wheat) with and without the supplementation of xylanase and phytase enzymes in combination or individually on performance parameters, digestibility, digesta viscosity and carcass characteristics of broilers. For this purpose, a total of 640-day-old male broilers were randomly distributed to the 64 pens, and each pen had 10 birds. Two basal isocaloric and isonitrogenous diets contained 1.5 and 2.5 years stored wheat were formulated in this experiment. In the current study, experimental feeds were prepared by supplementing exogenous enzymes in both basal diets with xylanase (500 XU), phytase (500 FTU) alone or in a combination of phytase and xylanase. Performance parameters data represents that both in starter phase and finisher phase, inclusion of exogenous enzymes xylanase and phytase in both basal diets alone or in combination enhance the feed intake, and body weight gain (p < 0.05) and improve the feed conversion ratio in overall phase (p < 0.05). Similarly, supplementation of exogenous xylanase and phytase alone or in combination enhance the nutrient digestibility and reduce the digesta viscosity (p < 0.05). Based on the results of this experiment, it is concluded that supplementation of exogenous xylanase and phytase enzymes alone or in combination in wheat-based diets (stored wheat 1.5 and 2.5 years) enhance and improves the performance of birds.

Critical Factors and Emerging Opportunities in Food Waste Utilization and Treatment Technologies

Globally, approximately one-third of food produced for human consumption is lost or discarded, comprising 1. 3 billion tons annually. Factors contributing to food waste from the food manufacturer to the consumer level are numerous. Events that may result in food waste include, but are not limited to, manufacturing food by-products, improper handling within the supply chain (e.g., cold chain deviations), misunderstood food date labels, over-purchasing, and consumer-level temperature abuse. From the manufacturer to consumer, each node in the food supply requires concerted efforts to divert food waste from entering municipal landfills. Depending on the state of the food waste, it is diverted to various outlets, from food donation for consumption to composting for soil amendment. To better understand the opportunities in the United States to divert food waste from landfills, current and emerging federal policies as well as the causes of food waste generation must be understood. Unfortunately, information on both the composition of food waste in the U.S. and how it impacts critical factors in food waste treatment, especially in food waste composting, is limited. Specifically, this review aims to: (1) discuss and compare critical factors that impact the fate of food waste and (2) examine emerging opportunities to advance the processing and products of food waste.

Enzyme complex addition in barley or rye broiler diets with two energy levels fed from 1 to 21 days

Two experiments were conducted to evaluate diet digestibility, performance, digestive parameters, and blood parameters when an enzyme complex (EC) was used in barley- and rye-based diets with different energy levels. In the digestibility assay (exp. I), 108 seventeen-day-old Cobb male broilers were distributed in a completely randomized design in 2 × 2 × 2 + 1 factorial arrangement with two feeds (barley or rye), two EC levels (0% and 0.02%), and two energy levels [3025 and 3125 kcal apparent metabolizable energy (AME)·kg−1], plus a control treatment. In exp. II, 1080 one-day-old Cobb male broilers were distributed in a completely randomized design in 2 × 2 × 2 + 1 factorial arrangement with two feeds (barley or rye), two EC levels (0% and 0.02%), and two energy levels (2875 and 2975 kcal AME·kg−1). No interactions were observed for any variables (exp. I and II). Enzyme complex improved the apparent metabolizable coefficient of gross energy (P = 0.0432) of diets. The EC provided greater weight gain (P = 0.0003) and better feed conversion (P = 0.0025). Intestinal viscosity at 21 d was reduced (P < 0.0001) with the addition of the EC. The EC improved nutrient digestibility and performance, but the effects of energy reduction on performance could not be overcome.

Dietary soluble non-starch polysaccharide level and xylanase influence the gastrointestinal environment and nutrient utilisation in laying hens

1. The objective of this study was to examine the influence of dietary soluble non-starch polysaccharide (sNSP) level and xylanase supplementation on productive performance, viscosity and pH along the gastrointestinal tract in laying hens. Excreta moisture content, ileal and caecal microbiota and short chain fatty acid (SCFA) composition and apparent total tract nutrient utilisation was measured.2. Hyline Brown laying hens (n=144) were housed individually at 25 weeks of age and allocated to one of four wheat-based dietary treatments in a 2 × 2 factorial arrangement, consisting of two levels of sNSP (High 13.40 g/kg or Low 11.22 g/kg), with or without xylanase (0 or 12,000 BXU/kg). Birds were fed the dietary treatments for 56 days.3. Increasing dietary sNSP increased jejunum viscosity, degradability of total NSP, total tract flow of insoluble arabinose, and succinic acid concentration in the caeca (P<0.05). Feeding high sNSP decreased excreta moisture content, total tract energy retention and free oligosaccharide, total tract flow of soluble and insoluble galactose and insoluble rhamnose and fucose, and ileal acetic and lactic acid concentrations (P<0.05), and tended to reduce egg production (P=0.058).4. Supplementation with xylanase resulted in reduced jejunum and ileum viscosity, caecal pH, excreta moisture, flow of soluble arabinose and glucose and insoluble arabinose and xylose, caecal concentration of Lactobacillus sp. and isobutyric and succinic acid, and ileal concentration of Bacillus sp. and total anaerobic bacteria (P<0.05). Xylanase application also increased energy retention and insoluble and total NSP degradation, and caecal abundance of Bifidobacteria sp. and valeric acid (P<0.05).6. These results reiterated the ability of xylanase to improve nutrient digestibility and reduce excreta moisture content in laying hens, and highlighted the importance of considering dietary sNSP level in laying hen diets.

Effect of feeding rice gluten meal with and without enzymes on hematobiochemical profile of broiler chickens

Background and Aim

Blood and serological parameters are indicators of the health status of the birds and influenced by the type of feed and their nutrient composition. Scanty researches are available in rice gluten meal (RGM) regarding its effect of feeding with and without enzymes on hematology and serum biochemistry. This study was conducted for in vitro and in vivo investigation regarding feeding RGM without or with different enzymes on hematology and serum biochemistry of broiler chickens. The in vitro study was done to determine chemical composition of RGM used in the biological trial.

Materials and Methods

A biological experiment with 384 broiler chicks was conducted to evaluate the effect of feeding RGM as soybean replacement without or with different enzymes on carcass characteristics in broiler chicken for 42 days. Two levels of RGM were taken (15% and 17.5%). Protease, xylanase, and multienzymes supplementation under different treatments were done.

Results

The RGM feeding and enzyme supplementation or their interaction revealed no significant (p>0.05) effects on the hematological parameters and serological parameters of broiler chickens except the significant (p<0.05) effect of enzyme supplementation on serum albumin and triglyceride values. The higher albumin values were observed in xylanase and protease supplemented birds and lower triglyceride values were observed in xylanase supplemented birds.

Conclusion

Thus, it may be concluded that RGM feeding at 15% or 17.5% inclusion level with or without enzymes had no adverse effect on hematobiochemical profile of broiler chickens.

Assessment of a Potential Role of Dickeya dadantii DSM 18020 as a Pectinase Producer for Utilization in Poultry Diets Based on in silico Analyses

Currently, the poultry industry has been faced with consumer pressure to utilize only vegetable feedstuffs in poultry diets, eliminate antibiotics from poultry production, and rear poultry in free range systems. To maintain current production standards, the industry must determine ways to enhance nutrient uptake and utilization further. One possible solution is the supplementation of pectinase, an enzyme that degrades pectin within the cell walls of plants, in poultry diets. Therefore, the objective of the current study was to determine the potential role of a pectinase producer, Dickeya dadantii DSM 18020, as a commercially utilized pectinase producer in poultry diets against other known pectinase producers, in silico. In the current study, whole genomes of Dickeya dadantii DSM 18020 (Dd18020), D. dadantii 3937 (Dd3937), D. solani IPO 2222 (Ds2222), Bacillus halodurans C-125 (BhC125), and B. subtilis subsp. subtilis str. 168 (Bs168) were compared using bioinformatic approaches to compare the chromosomal genome size, GC content, protein coding genes (CDS), total genes, average protein length (a.a.) and determine the predicted metabolic pathways, predicted pectin degrading enzymes, and pectin-degradation pathways across pectinase producers. Due to insufficient information surrounding the genome of Dd18020 (lack of annotation), the genome of Dd3937, a 99% identical genome to Dd18020, was utilized to compare pectinase-associated enzymes and pathways. The results from the current study demonstrated that Dd3937 possessed the most significant proportion of pathways presented and the highest number of pathways related to degradation, assimilation, and utilization of pectin. Also, Dd18020 exhibited a high number of pectinase-related enzymes. Both Dd3937 and Dd2222 shared the pectin degradation I pathway via the EC 3.1.1.11, EC 3.2.1.82, and EC 4.2.2.- enzymes, but did not share this pathway with either Bacillus species. In conclusion, Dd18020 demonstrated the genetic potential to produce multiple pectinase enzymes that could be beneficial to the degradation of pectin in poultry diets. However, for Dd18020 to become a commercially viable enzyme producer for the poultry industry, further research quantifying the pectinase production in vitro and determining the stability of the produced pectinases during feed manufacturing are necessary.

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.

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.

Formulating poultry diets based on their indigestible components

Since it started as an organized economic activity, poultry production has been undergoing an evolution toward the optimization of its feed formulation features. Notably, advances in the knowledge of birds' nutrient requirements have allowed recommendations that are increasingly closer to the needs of the birds. Over time, availability of nutrients and energy has been incorporated into those recommendations, especially to compensate for the variability in the digestibility of nutrients originating from variable feed ingredient sources. Instead of using the total energy and nutrient content, current tables of nutrient recommendations provide an estimate of the digestible fractions of the nutrients in ingredients. For instance, nonphytate P is preferred instead of total P to account for the unavailable phytate P, and digestible amino acids to account for the differences in digestibility of amino acids in different ingredients, whereas energy is usually expressed as a proportion that has been digested and metabolized (AME). With the increasing interest in the use of exogenous enzymes in poultry feeds, special attention is directed to the feed substrates such that an added enzyme can match it, forming an enzyme-substrate complex that will be followed by a chemical reaction within the gastrointestinal tract. As a consequence of a degradation reaction, nutrients released can be absorbed and metabolized. In general, nutritional data banks used in linear feed formulation software have limited data on the proportions of fractions of ingredients that are indigestible. Therefore, estimations of the presence of many substrates in the feeds, and therefore the benefits of adding exogenous enzymes, are frequently limited because of the scarcity of adequate information. The objective of this review paper is to provide insights into the use of expanded nutrient databanks to include all the molecules considered potentially indigestible for poultry such that the inclusion of exogenous enzymes allows the estimation of the values of the product originated by their hydrolysis.

Effect of a by-product of solid state fermentation (Synergen™) on broiler performance

The trial was conducted to evaluate the effect of a by-product of solid state fermentation (Synergen™ (SGN), Alltech Inc, Nicholasville KY, USA) on broiler performance and health. One thousand two hundred and eighty male Ross 308 broilers were used in a 42 day pen trial. The trial was designed as a 2 × 2 factorial, with two diet specifications (standard and reformulated) plus or minus SGN (0 and 200 g/t, SGN replaced with commercial enzyme Ronozyme™ at 150 g/t) to give four dietary treatments in total in a corn-soy based diet formulated to commercial standards. Birds fed the reduced energy diets had significantly lower cumulative feed intakes at 42 d (P < 0.01) compared to those on the full specification standard diet. There were no significant differences in broiler body weight due to treatments at any age. Significant improvements (P < 0.05) in FCR, primarily due to SGN inclusion in the feed, were observed for all weekly reported data. There were no significant differences in either mortality or EPEF for any of the treatment diets. The present study indicates that SGN, a by-product of solid state fermentation (SSF) can improve feed conversion of broilers fed a corn-soy diet.

Effects of a mono-component endo-xylanase supplementation on the nutritive value of wheat-based broiler diets

1. Two trials were conducted to evaluate the effects of a mono-component thermostable endo-1,4-β-xylanase derived from Thermomyces lanuginosus on the nutritive value of wheat-based broiler diets. In a 5-week growth trial, the efficacy of xylanase supplementation at 0, 100, 150, 200, 400 and 4000 FXU/kg diet was evaluated. A short-term balance trial was carried out according to a 4 × 2 factorial arrangement of treatments, involving 4 wheat cultivars and endo-xylanase at 0 or 200 FXU/kg. 2. In the growth trial, enzyme supplementation from 0 to 400 FXU/kg reduced feed intake and improved feed conversion linearly. Digesta viscosity was significantly reduced by all enzyme inclusion levels by 49·6-56·9%, in a quadratic manner. 3. In the balance trial, xylanase supplementation resulted in a significant improvement of protein, lipid and dry matter apparent digestibility coefficients of diets, accompanied by improved dietary AME(N) values. There was a significant wheat × enzyme interaction on AME(N) and lipid digestibility. There was a significant effect of wheat cultivar on dry matter digestibility.

Dietary roles of non-starch polysaccharides in human nutrition: a review

Nonstarch polysaccharides (NSPs) occur naturally in many foods. The physiochemical and biological properties of these compounds correspond to dietary fiber. Nonstarch polysaccharides show various physiological effects in the small and large intestine and therefore have important health implications for humans. The remarkable properties of dietary NSPs are water dispersibility, viscosity effect, bulk, and fermentibility into short chain fatty acids (SCFAs). These features may lead to diminished risk of serious diet related diseases which are major problems in Western countries and are emerging in developing countries with greater affluence. These conditions include coronary heart disease, colo-rectal cancer, inflammatory bowel disease, breast cancer, tumor formation, mineral related abnormalities, and disordered laxation. Insoluble NSPs (cellulose and hemicellulose) are effective laxatives whereas soluble NSPs (especially mixed-link β-glucans) lower plasma cholesterol levels and help to normalize blood glucose and insulin levels, making these kinds of polysaccharides a part of dietary plans to treat cardiovascular diseases and Type 2 diabetes. Moreover, a major proportion of dietary NSPs escapes the small intestine nearly intact, and is fermented into SCFAs by commensal microflora present in the colon and cecum and promotes normal laxation. Short chain fatty acids have a number of health promoting effects and are particularly effective in promoting large bowel function. Certain NSPs through their fermented products may promote the growth of specific beneficial colonic bacteria which offer a prebiotic effect. Various modes of action of NSPs as therapeutic agent have been proposed in the present review. In addition, NSPs based films and coatings for packaging and wrapping are of commercial interest because they are compatible with several types of food products. However, much of the physiological and nutritional impact of NSPs and the mechanism involved is not fully understood and even the recommendation on the dose of different dietary NSPs intake among different age groups needs to be studied.

Effect of dietary xylanase on energy, amino acid and mineral metabolism, and egg production and quality in laying hens

1. The aim was to examine the effect of dietary xylanase on the availability of nutrients for laying hens when fed on wheat-rye-soy-based diets. The basal diet was formulated to contain 11.03 MJ/kg apparent metabolisable energy (AME), and the experimental diets were formulated by supplementing the basal diet with four different activities of xylanase (400, 800, 1200 and 1600 xylanase units (XU)/kg). 2. The AME and nitrogen metabolisability coefficients of xylanase-supplemented diets were 1.2% and 7.1%, respectively, greater than in the control diet. 3. Supplementary xylanase significantly improved the coefficients of metabolisability of indispensable, dispensable and total amino acids by 8.2%, 6.9% and 7.8%, respectively, and led to a significantly linear response of total amino acid metabolisability coefficient to xylanase. There was a range of effects within the indispensable amino acids with xylanase supplementation (1600 XU/kg) significantly improving the metabolisability of threonine by 4.9%, but having no have effect on lysine. The response of total amino acid retention to added xylanase was a significant quadratic function and suggests that 800 XU/kg is the optimum supplementary dosage. 4. Supplementary xylanase significantly improved sulphur metabolisability in a linear fashion to a maximum of 2.3% higher than that of the control diet. In terms of daily retention, most of the minerals responded in a quadratic manner to dietary xylanase, as the suggested optimal supplementary level was between 800 and 1200 XU/kg. 5. The yolk colour of the birds receiving 1200 and 1600 XU/kg was 0.33 and 0.28 units (Roche score); these were 4.1% and 3.5%, respectively, darker than the yolk of the birds given the control diet. 6. Birds receiving xylanase had a significantly higher weight gain than those fed on the unsupplemented diet. Feed intake, the number of eggs per hen per d, dirty and cracked eggs, and feed conversion ratio for egg production were not affected by xylanase. These data suggest that use of a xylanase may improve the metabolisability of many nutrients, but that such effects may not always benefit production parameters.

Intestinal function and gut microflora of broiler chickens as influenced by cereal grains and microbial enzyme supplementation

A study was conducted to investigate the effect of the key cereal grains and a microbial enzyme supplement on broiler chicken performance, gut microflora and intestinal function. Ingestion of the barley-based diet was associated with low 28-day body weight, decreased feed intake and high FCR. The supplemental enzyme increased feed intake and weight gain of the chickens on a wheat-based diet. The pH of the gizzard and caecal contents varied with the grain type. Enzyme supplementation reduced ileal viscosity, particularly in birds that received the diet based on wheat. The birds on the barley-based diet had lower ileal digestibility of dry matter, protein and energy than those given maize and sorghum-based diets. The ileal digestibility of starch was increased by enzyme supplementation. Enzyme supplementation increased the number of total anaerobic bacteria in the gizzard of birds fed on sorghum and increased lactobacilli in the gizzard of those fed both sorghum and wheat. The birds fed the sorghum-based diet had the lowest counts of caecal total anaerobic bacteria and lactobacilli. Jejunal villus height and villus:crypt ratio of birds fed the barley-based diet were the lowest when compared with those fed the other diets. Enzyme application induced an increase in villus height and villus:crypt ratio of birds on wheat, crypt depth on barley and a reduction in crypt depth of chickens on the sorghum-based diets. The highest activity of maltase and the lowest activity of sucrase were observed in tissue from birds fed on maize and sorghum-based diets respectively. The differences in the performance of broilers on cereal grains could be explained by changes in intestinal morphology, enzyme activities and gut microflora as well as nutrient digestibility. The improved performance by supplemental enzyme in wheat-fed chickens was associated with beneficial changes in intestinal morphology and digesta viscosity.

An effective combination of carbohydrases that enables reduction of dietary protein in broilers: importance of hemicellulase

After observing the effects of purified cellulase (C), hemicellulase (H), pectinase (P), and their combinations on the in vitro digestibility of a corn-soybean meal broiler diet, we examined the associations between pectin breakdown and the digestibilities of CP and DM by using free galacturonic acid (GA) as an index of pectin breakdown. There was no significant effect of the single enzymes except for H. However, the enzyme combinations H + P, C + H, and C + H + P significantly increased CP and DM digestibilities, whereas the combination of C + P was not effective. Because H has activities of both H and P, these enzymes were considered to be important in stimulating digestion. Furthermore, when the enzymes increased CP and DM digestibilities, GA concentration was significantly higher, and clear correlations between CP and DM digestibilities and GA concentration were observed, whereas correlations between the digestibilities and concentration of glucose or xylose + mannose as indices of cellulose and hemicellulose breakdown, respectively, were not significant. From these observations, we hypothesized that a mixture of enzymes could increase the protein digestibility of broiler feed. Thus, in the in vivo experiment, low-protein (19% CP) diets made mainly of corn and soybean meal with or without mixed enzymes were prepared and given to broiler chicks. The birds given the diet containing mixed enzymes showed significantly higher BW gain, with higher CP and DM digestibilities than the birds given the diet without the mixed enzymes. Moreover, the growth rate was same as that of the birds given the normal (21% CP) diet. The results indicate that the mixed enzyme preparation can effectively degrade indigestible cell constituents and thus enable the protein of the broiler feed to become more digestible. Furthermore, the results indicate the importance of H as a rate-limiting factor of cell wall breakdown.

Supplementation of Avizyme 1502 to corn-soybean meal-wheat diets fed to turkey tom poults: the first fifty-six days of age

A study was designed to determine the effects of enzyme supplementation on poults fed commercially based diets that included corn, soybean meal, and ground wheat with meat and bone meal (0 to 21 d) or Pro-Pak (22 to 56 d). Day-old turkey poults (n = 3,850) were divided into 35 pens and fed 1 of 5 dietary treatments for 56 d. Treatments were a positive control, a negative control (corn matrix adjustment of 140 kcal), and negative control diets supplemented with Avizyme 1502 at 250, 500, or 750 g/tonne. Feed intake, live weight gain, feed conversion ratio, and mortality were measured for the periods 0 to 21 d, 21 to 42 d, and 42 to 56 d, as well as for the cumulative 0 to 56 d. The 0- to 21-d period was further divided into subperiods (0 to 4 d, 4 to 8 d, 8 to 12 d, 12 to 16 d, 16 to 21 d) to evaluate early nutritional development. Ileal contents along with duodenal, jejunal, and ileal sections (n = 7/treatment) were sampled to determine apparent digestibility and morphology. In most instances, production response differences between the positive and negative controls were not significant, making definitive interpretation of enzyme addition difficult. Energy and protein ileal digestibilities of the negative control diets were lower than those of the positive control diet at 4, 8, 12, 16, and 42 d. Enzyme supplementation significantly improved energy and protein beyond that of the PC diet on d 42. Villus height and crypt depth did not respond to dietary treatment, although there was a significant interaction of age by treatment on jejunal villus height. The similarity between the controls, as well as the high inclusion of CuSO(4), may be responsible for the low response with enzyme inclusion.

Nutritive values of corn, soybean meal, canola meal, and peas for broiler chickens as affected by a multicarbohydrase preparation of cell wall degrading enzymes

The effect of a new multicarbohydrase supplement of cell wall degrading activities on the nutritive value of corn, soybean meal (SBM), canola meal (CM), and peas for broiler chickens was investigated. Four isoenergetic and isonitrogenous corn (69% corn), SBM (30% SBM, 59% corn), CM (30% CM, 54% corn), and pea (30% peas, 52% corn) diets, without or with enzyme supplementation, were formulated to meet NRC specifications for broiler chickens (except for AME and CP, which were at 95 and 92% of NRC requirements, respectively). The enzyme supplement supplied 1,000 U of xylanase, 400 U of glucanase, 1,000 U of pectinase, 120 U of cellulase, 280 U of mannanase, and 180 U of galactanase per kilogram of diet. Each diet was fed in a mash form to 9 replicate pens of 5 broilers from 5 to 18 d. When compared with the control treatment, enzyme addition to the corn diet improved (P < 0.05) feed-to-gain ratio, whereas the performance of birds fed the other 3 diets was not affected. An increase (P < 0.05) in total tract nonstarch polysaccharides (NSP) digestibility, ileal starch digestibility, and AMEn was observed in birds fed the enzyme-supplemented corn diet. An improvement (P < 0.05) in total tract NSP digestibility, ileal protein digestibility, and AMEn content with enzyme supplementation was observed for the SBM diet. However, nutrient digestibilities and AMEn of CM and pea diets were not affected (P > 0.05) by enzyme addition even though the NSP digestibilities increased significantly (P < 0.05). A significant increase (P < 0.05) in water-soluble NSP and a decrease (P < 0.05) in water-insoluble NSP concentration of ileal digesta was noted for birds fed all 4 enzyme-supplemented diets. It would appear from this study that the nutrient utilization of corn-SBM diet by broilers could be enhanced by using an appropriate multicarbohydrase enzyme supplement. The nutrient encapsulating effect of cell wall polysaccharides in SBM, CM, and peas may not be the only factor responsible for incomplete nutrient utilization. The improvement in feed efficiency and starch availability in birds fed corn diet likely resulted from the cell wall degrading activity of the enzyme supplement.