Effects of a xylanase on individual bird variation, starch digestion throughout the intestine, and ileal and caecal volatile fatty acid production in chickens fed wheat.

1. The effects of a xylanase on digesta viscosity and starch digestibility throughout the small intestine and volatile fatty acid production in the ileum and caeca were investigated in broilers fed on a low-metabolisable energy wheat diet. 2. The xylanase reduced (P<0.01) duodenal (2.9 vs. 1.7), jejunal (4.6 vs. 2.3) and ileal (14.0 vs. 3.9) digesta viscosities (mPas) and increased AME (P<0.01) of the wheat and starch digestibility (P<0.5) in the jejunum and ileum. Between-bird variability in ME and digestibility of starch was also reduced. 3. Enzyme supplementation reduced (P<0.05) fermentation in the ileum, but increased (P<0.05) it in the caeca. 4. The anti-nutritive effect of soluble non-starch polysaccharides (NSP) is related to their ability to increase digesta viscosity along the gut; this in turn causes changes in gut microflora and efficiency of nutrient utilisation by the chicken. Use of appropriate enzymes is an effective way of dealing with grains with high NSP content in poultry diets.     

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.     

Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology in broilers fed wheat-based diets containing adequate level of phosphorus

1. The aim of the present study was to examine the influence of microbial phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digesta viscosity, digestive tract measurements and gut morphology in broilers fed on wheat-soy diets containing adequate phosphorus (P). The wheat-soy basal diet was formulated to contain 4.5 g/kg non-phytate P and the experimental diets were formulated by supplementing the basal diet with xylanase (1000 xylanase units/kg diet), phytase (500 phytase units/kg diet) or a combination of phytase and xylanase. 2. Supplemental phytase improved the weight gains and feed efficiency by 17.5 and 2.9%, respectively. Corresponding improvements due to the addition of xylanase were 16.5 and 4.9%, respectively. The combination of phytase and xylanase caused no further improvements in broiler performance. 3. Individual additions of xylanase or phytase resulted in numerical improvements in apparent metabolisable energy (AME), but the differences were not significant. The combination of the two enzymes significantly increased AME. Addition of xylanase and the combination of the two enzymes reduced the viscosity of digesta in all sections of the intestine. Phytase supplementation reduced digesta viscosity in the duodenum and ileum, but not in the jejunum. 4. Enzyme supplementation lowered the relative weight and length of the small intestine. Additions of xylanase and phytase reduced the relative weight of the small intestine by 15.5 and 11.4%, respectively, while the corresponding reductions in the relative length of the small intestine were 16.5 and 14.1%, respectively. The combination of phytase and xylanase had no further effects on the relative weight and length of the small intestine compared with the xylanase group. 5. The addition of phytase increased villus height in the duodenum and decreased the number of goblet cells in the jejunum compared with those on the unsupplemented basal diet. Xylanase supplementation tended to increase goblet cell numbers in the duodenum and decreased crypt depth in thejejunum. The combination of phytase and xylanase increased villus height in the ileum and crypt depth in thejejunum and ileum. 6. In summary, the present results showed that the addition of a microbial phytase, produced by solid state fermentation and containing significant activities of beta-glucanase and xylanase, was as effective as xylanase in improving the performance of broiler chickens fed on wheat-based diets containing adequate levels of P. Improved performance with enzyme supplementation was generally associated with reduced digesta viscosity, increased AME, and reduced relative weight and length of small intestine.     

Impact of combined α-galactosidase and xylanase enzymes on growth performance,nutrients digestibility,chyme viscosity,and enzymes activity of broilers fed corn–soybean diets

Two experiments were conducted to investigate the effects of a combined α-galactosidase and xylanase preparation on nutrients digestibility and growth performance in broiler chickens. Experiment 1 had 240 broilers allocated to 3 treatments with the dietary supplementation of 0, 300, and 500 g/t of the enzyme combination. Diet and amino acid (AA) digestibility were assessed. Experiment 2 was a 2 × 3 (enzyme × diet) factorial arrangement with 10 replicates of 12 male broilers per replicate. Diets were based on corn–soybean meal (SBM) diet and had 3 nutritional levels (normal, 2% apparent metabolizable energy (AME) and crude protein (CP) reduction, and 4% AME and CP reduction). Each of these diets was fed with or without enzyme supplementation. Growth performance, chyme viscosity, nutrients digestibility, and endogenous enzymes activity were assessed. In experiment 1, enzyme supplementation improved the digestibility of Ca (P = 0.025) and ileal digestibility of total AA, Pro, Alu, Ile, Lys, His, Thr, Glu, Val, Leu, Tyr, and Phe (P < 0.05), and also tended to increase the AME of diets (P < 0.10). In experiment 2, broilers fed the corn–SBM diet with 4% nutrient reduction had better growth performance (P < 0.05), jejunal digesta viscosity at 42 d (P < 0.01), and lower digestibility of gross energy (GE; P < 0.05) when compared with those fed the normal nutrient diet. Enzyme inclusion increased digestibility of CP (P = 0.044), GE (P = 0.009), raffinose (P < 0.001) and stachyose (P < 0.001), improved average daily gain (P = 0.031), and reduced jejunal digesta viscosity at 42 d (P = 0.011). Besides, similar improvements trend in amylase, trypsin, sucrase, and maltase activity with enzyme inclusion were observed as with energy. These data support that the enzyme supplementation increased nutrients and ileal AA digestibility, improved performance and endogenous enzymes activity.     

The effect of graded inclusions of waxy starch hull-less barley and a multi-component exogenous carbohydrase on the growth performance,nutrient digestibility and intestinal morphometry of broiler chickens

ABSTRACT

1. A 21-d experiment was conducted to investigate the effect of graded inclusions of waxy starch hull-less (WSHL) barley and a multi-component exogenous carbohydrase on the growth performance, nutrient digestibility and intestinal morphometry of broiler chickens. Five levels of WSHL barley inclusion (0, 65, 130, 195 and 260 g/kg) in a wheat-based diet, and two levels of enzyme supplementation (0 and 150 g/tonne of feed) were evaluated in a 5 × 2 factorial arrangement of 10 dietary treatments. All diets were equivalent in metabolisable energy and digestible amino acid content. A total of 400, one-d-old male broilers (five cages/treatment; eight birds/cage) were used in the experiment.

2. Regardless of enzyme supplementation, feed intake declined (P < 0.001) with increasing inclusion of WSHL barley. Increasing levels of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.01) increased gain to feed ratio.

3. Birds fed diets with 0 g/kg WSHL barley showed the lowest (P < 0.001 to 0.01) digestibility for all nutrients except starch. Only starch digestibility was improved (P < 0.05) by enzyme supplementation. The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.001). Increasing inclusion of WSHL barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.01). Supplemental enzyme (P < 0.001) reduced digesta viscosity.

4. All levels of WSHL barley inclusion improved digestibility of dry matter, nitrogen and fat, whilst energy utilisation improved at inclusions of 130 g/kg WSHL and above, probably due to lowered digesta viscosity and better development of the gizzard. Gain to feed ratio, starch digestibility, energy utilisation and jejunal digesta viscosity can benefit from carbohydrase supplementation in wheat-based diets, regardless of barley inclusion level.     

Analyses of degradation products from lipid and protein hydrolyses in the small intestine of broiler chickens fed on maize-based diets containing guar gum,or wheat-based diets

1. Three maize diets containing graded levels (0, 0.1, 0.3%) of guar gum and two wheat diets differing in their in vitro viscosities were fed to male broiler chickens (7 to 23 d) for measurements of growth performance and analyses of degradation products from lipid and protein hydrolyses in the small intestine of broiler chickens. Analyses of degradation products were conducted to define which step (hydrolysis or absorption) was most involved in the negative effects of the digesta viscosity on lipid and protein digestibilities. The experiment was also carried out to examine whether effects of wheats could be explained in terms of intestinal viscosity alone. 2. The intestinal viscosities with wheat diets were within the range of those observed with the three maize diets. The correlations between in vivo and in vitro viscosities were higher with real than with potential applied viscosity of diets, both in jejunum and ileum. 3. The mean gain:food ratio observed with wheat diets was lower (P<0.05) than with maize diets despite lower (P<0.05) mean intestinal viscosities in birds given the wheat than given the maize diets. This shows that factors different from intestinal viscosity were also involved in the negative effects of wheats. 4. Distributions of nitrogen compounds in digesta were characterised by low proportions of compounds with high molecular weight (>12,000). For all classes of nitrogen compounds, the contents measured in digesta dry matter did not differ between chickens fed with or without guar gum. 5. Distributions of lipid classes in both jejunum and ileum were characterised by a large proportion of free fatty acids (FFA) and very few triglycerides (TG). In the ileum, FFA and TG contents were both positively correlated with supernatant viscosity, but the slope for FFA content was 35 times higher than for TG. In these relationships, there was no difference between maize and wheat diets. 6. It is concluded that absorption was the main step involved in the lipid digestibility reduction due to intestinal viscosity. For proteins, the most important step (hydrolysis or absorption) involved in decreased digestibility due to intestinal viscosity was not clearly identified.     

木薯型日粮添加复合酶对肉鸡生长性能、组织器官重量及养分消化的影响

文章旨在评估日粮用木薯粉替代玉米同时补充外源复合酶对肉鸡生长性能、组织器官重量及养分表观消化率的影响。试验选择平均初始体重（44.15±0.76）g的肉鸡576只,随机分为4组,每组4个重复,每个重复36只。试验日粮采用2×2因子设计,即2种原料（玉米和木薯）和酶添加量（0和100?mg/kg复合酶）,其中T1组和T2组分别饲喂玉米、木薯型日粮,T3和T4组分别在T1和T2基础日粮中添加100?mg/kg复合酶,试验为期3周。结果：玉米型日粮组肉鸡末重较木薯型日粮组显著提高6.65%（P＜0.05）,但料重比显著降低2.10%（P＜0.05）。无论日粮类型如何,添加复合酶较未添加组肉鸡料重比显著降低2.10%（P＜0.05）。日粮类型及复合酶对肉鸡平均日增重和料重比的影响具有显著交互作用（P＜0.05）。与T2组相比,T3组肉鸡脾脏相对重量显著提高50%（P＜0.05）。无论日粮是玉米型还是木薯型,补充100?mg/kg复合酶较未补充组淀粉表观消化系数显著提高5.59%（P＜0.05）。结论：在本研究条件下,日粮中添加50%木薯粉完全替代玉米同时补充100?mg/kg复合酶可以改善肉鸡饲料效率,提高淀粉表观消化率。 [关键词]木薯|复合酶|肉鸡|生长性能|养分消化     

Effect of enzyme addition to wheat-, barley- and rye-based diets on nutrient digestibility and performance of laying hens

1. Laying hen performance, egg quality, intestinal viscosity and nutrient apparent digestibility were evaluated with respect to the main cereal used in the diet and dosage rate of a fungal beta-glucanase/xylanase enzyme complex. 2. Twelve diets were arranged factorially, with three soluble fibre cereals (SFC); 500 g/kg of wheat or barley or 350 g/kg of rye, and 4 enzyme concentrations (0, 250, 1250 and 2500 mg/kg). An additional control diet based on maize was also included. 3. The use of SFC in the diet instead of maize did not affect egg production or food efficiency, but hens fed on SFC diets exhibited a higher incidence of dirty eggs than hens fed on the maize diet (8-6 vs 4.6%; P<0.01). 4. Laying hens fed on enzyme-supplemented diets produced more eggs (2.1%; P<0.05) and had better food efficiency per dozen eggs (2.5%; P<005) than hens fed on non-supplemented diets. An excess of enzymes in the diet (10 times the recommended dose) did not produce any deleterious effect on laying hen productivity. 5. Enzyme supplementation (ES) reduced intestinal viscosity (P<0.001) and the incidence of dirty eggs (P<0.01). The reduction in viscosity was more pronounced in barley than in wheat or rye diets (P<0.05). 6. Apparent nutrient digestibility in SFC diets was higher with ES, including dry matter (3.1%; P=0.08), fat (4.4%; P<0.001), non-starch polysaccharides (83.3%; P<0.01) and AMEn (2.5%, P<0.01). 7. It is concluded that substitution of maize by SFC is facilitated by ES, especially with respect to egg production, food conversion efficiency and egg shell cleanliness. An excess of enzymes did not produce any deleterious effect on nutrient digestibility or performance of laying hens.     

The effects of xylanase supplementation on growth, digestion, circulating hormone and metabolite levels, immunity and gut microflora in cockerels fed on wheat-based diets

1. The xylanase product used in this study was derived from a genetically modified isolate of Aspergillus niger. Two trials were conducted to investigate the effects of xylanase supplementation on growth, digestion, circulating hormone and metabolite levels, immune parameters and composition of the gut microflora in cockerels fed on wheat-based diets. 2. The experimental diets consisted of a wheat-based control diet supplemented with 0 or 0.1% enzyme preparation. The diets were fed between 7 and 21 d of age. 3. Enzyme supplementation improved growth and feed conversion efficiency. The addition of enzyme to wheat-based diet increased the apparent total digestibility of dry matter (DM), crude protein and fat. 4. Enzyme supplementation reduced the relative weight of digestive organs to a certain extent, but there was no significant difference. Enzyme supplementation reduced digesta viscosity in the jejunum. There was no significant difference between the two experimental groups in counts of lactobacillus and coliform bacteria in the caeca. 5. Enzyme supplementation increased the concentration of blood thyroxine (T(4)), insulin-like growth factor I (IGF-I) and insulin, reduced the concentrations of blood uric acid, but had no significant effect on the concentrations of blood glucose and triiodothyronine (T(3)). 6. Enzyme supplementation increased the relative weight of spleen of cockerels, serum antibody titres to Newcastle disease virus (NDV), lymphocyte proliferation in response to phytohaemagglutinin (PHA) and the natural killer (NK) cell activity. 7. It is concluded that supplementation with an enzyme preparation (xylanase), which hydrolyses non-starch polysaccharides can improve growth in cockerels fed on wheat-based diets. This improvement is achieved through enzyme effects on digestion, absorption, metabolism and immunity of cockerels.     

Influence of inclusion level of barley in wheat-based diets and supplementation of carbohydrase on growth performance,nutrient utilisation and gut morphometry in broiler starters

ABSTRACT

1. The influence of barley inclusion level and supplementation of a multi-component non-starch polysaccharide degrading enzyme on performance and nutrient utilisation in broilers was investigated. Normal-starch hulled barley was evaluated with five levels of inclusion (0, 141, 283, 424 and 565 g/kg) in a wheat-based diet and two levels of enzyme supplementation (0 and 150 g/tonne of feed; a 5 × 2 factorial arrangement of 10 dietary treatments). All diets were equivalent in metabolisable energy and digestible amino acid contents. A total of 400, one-d old male broilers (five cages/treatment; eight birds/cage) were used in the experiment.

2. Regardless of enzyme supplementation, weight gain (WG) increased up to 283 g/kg of barley and was reduced afterwards (P < 0.01). Increasing levels of barley resulted in greater (P < 0.001) gain per feed (G/F). Enzyme addition increased WG (P < 0.05) and G/F (P < 0.001) at each barley inclusion level.

3. Birds fed diets with 0 and 565 g/kg barley showed the lowest and highest (P < 0.001to 0.05) digestibility for all nutrients measured, respectively. Digestibility of all nutrients was improved by enzyme supplementation at each barley inclusion level (P < 0.05). The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of barley (P < 0.001) and supplemental enzyme (P < 0.01). Increasing inclusion of barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.001). Supplemental enzyme (P < 0.001) reduced digesta viscosity.

4. The optimum inclusion level of barley, with respect to growth performance, was 283 g/kg of diet. Increasing barley inclusion improved nutrient and energy utilisation, possibly through lowered digesta viscosity and better function of the gizzard. Feed efficiency and nutrient and energy utilisation can benefit from carbohydrase supplementation in barley-based diets, regardless of barley inclusion level.     

Effect of food enzymes on utilisation of lupin carbohydrates by broilers

1. The effects of 3 commercial enzyme products on the nutritive value of 2 lupin species were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSPs) along the digestive tract. Enzyme A contained primarily cellulase, beta-glucanase and xylanase activities, enzyme B primarily hemicellulase, pentosanase and xylanase activities, and enzyme C primarily hemicellulase, pectinase and beta-glucanase activities. 2. The enzymes were added to semi-purified diets based on sorghum and casein containing 35% whole seed lupins (Lupinus angustifolius cv Gungurru or Lupinus albus cv Kiev mutant). Control diets contained no lupins. 3. Food conversion ratio (FCR), excreta moisture content and apparent metabolisable energy (AME) were affected by lupin species but not by enzyme supplementation. 4. In diets with L. angustifolius, enzyme C significantly increased digesta viscosity and increased the concentration of soluble NSPs in all sections of the intestine. 5. Digestibility of protein and NSPs in the ileum and microbial fermentation in the ileum and caeca were not affected by adding enzymes to diets containing L. angustifolius. 6. Enzyme addition to diets with L. albus did not affect digesta viscosity nor concentration of soluble NSPs but caused a significantly (P<0.05) reduced concentration of insoluble NSP in the ileum. 7. Enzyme addition to L. albus significantly (P<0.05) increased NSP digestibility in the ileum but had no effects on protein digestibility and fermentation in the ileum and caeca.     

米曲霉发酵粗酶制剂对肉鸡生产性能和食糜黏度的影响

选择健康、体重一致的1日龄商品代AA肉鸡960只随机分为4组,每组8个重复,每个重复30只,研究分别在玉米-豆粕型日粮和玉米-小麦-豆粕型日粮中添加粗酶制剂对肉鸡生产性能和食糜黏度的影响。结果表明,添加粗酶制剂显著降低了肉鸡的料重比(P<0.05),有提高肉鸡1~42日龄日增重和出栏体重的趋势(P<0.10);在玉米-小麦-豆粕型日粮中添加粗酶制剂可以显著降低肉鸡食糜的黏度(P<0.05)。结果揭示,添加粗酶制剂可以降低肉鸡肠道内食糜的黏度,改善肉鸡的生产性能。     

Effects of oregano essential oil with or without feed enzymes on growth performance,digestive enzyme,nutrient digestibility,lipid metabolism and immune response of broilers fed on wheat–soybean meal diets

1.?The study was conducted to determine the effects of dietary supplementation of enzyme and oregano essential oil at two levels, alone or together, on performance, digestive enzyme, nutrient digestibility, lipid metabolism and immune response of broilers fed on wheat–soybean meal based diets.

2.?The following dietary treatments were used from d 0 to 21. Diet 1 (control, CONT): a commercial diet containing no enzyme or oregano essential oil, diet 2 (ENZY): supplemented with enzyme, diet 3 (EO250): supplemented with essential oil at 250 mg/kg feed, diet 4 (EO500): supplemented with essential oil at 500 mg/kg feed, diet 5 (ENZY + EO250): supplemented with enzyme and essential oil at 250 mg/kg, and diet 6 (ENZY + EO500): supplemented with enzyme and essential oil at 500 mg/kg.

3.?Birds fed on diets containing ENZY, EO250 and ENZY + EO250 had significantly higher weight gain than those given CONT diet from d 0 to 7. No significant effects on feed intake, feed conversion ratio, mortality, organ weights except for jejunum weight and intestinal lengths was found with either enzyme or essential oil, alone or in combination, over the 21-d growth period. The supplementation of essential oil together with enzyme decreased jejunum weight compared with essential oil alone.

4.?Supplementation with enzyme significantly decreased viscosity and increased dry matter of digesta, but did not alter pH of digesta. There was no effect of essential oil alone at either concentration on viscosity, dry matter or pH of digesta. A significant decrease in viscosity of digesta appeared when essential oil was used with together enzyme.

5.?The supplementation of essential oil at both levels with or without enzyme significantly increased chymotrypsin activity in the digestive system, and improved crude protein digestibility.

6.?The higher concentration of essential oil with and without enzyme significantly increased serum total cholesterol concentrations. No significant effect on immune response was found with either enzyme or essential oil, alone or together.

7.?Enzymes and essential oil had different modes of actions. The supplementation of enzyme with essential oil in diets is likely more effective in view of performance, nutrient digestibility, enzyme activities and immune system.     

Effects of diet acidification and xylanase supplementation on performance, nutrient digestibility, duodenal histology and gut microflora of broilers fed wheat based diet

1. The objective of this experiment was to study the influences of xylanase and citric acid on the performance, nutrient digestibility, digesta viscosity, duodenal histology, and gut microflora of broilers fed on a wheat based diet.

2. The experiment was carried out as a 2?×?3 factorial arrangement with two concentrations of xylanase (0 and 200?mg/kg) and three concentrations of citric acid (0, 20 and 40?g/kg). A total of 408 one-day-old chickens with similar body weight were distributed into 24 pens with 17 birds/pen. Each dietary treatment was given to 4 replicate pens from 0 to 24?d of age. To determine the apparent nutrient digestibility, chromic oxide (3?g/kg) was added to the diets as an indigestible marker.

3. Xylanase significantly increased body weight gain at 24?d of age by 1·4% and improved gain-to-feed (G:F) by 3·6%. The inclusion of 40?g/kg citric acid decreased feed intake and body weight gain by 15·4% and 11·8%, respectively. The inclusion of 20?g/kg of citric acid decreased feed intake, but it did not affect body weight gain of broilers at 24?d of age. The inclusion of 20 and 40?g/kg citric acid improved G:F by 3·8 and 4·3% respectively. Xylanase significantly decreased the viscosity of digesta and improved retention of DM, CP, and energy.

4. Xylanase and citric acid did not have any effect on the histo-morphology of the duodenum and intestinal microbial population.

5. In conclusion, citric acid at 20?g/kg decreased feed intake, did not have a negative effect on body weight gain, and improved G:F. Xylanase decreased digesta viscosity, increased nutrient retention and consequently improved performance of broilers fed on a wheat based diet.     

Effects of feed enzymes on nutritive value of soyabean meal fed to broilers

1. The effects of two enzyme products on the nutritive value of soyabean meal (SBM) were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSP) along the digestive tract. Enzyme A was a commercially available product containing mainly hemicellulase, pectinase, beta-glucanase and some protease activities and Enzyme B was an experimental product with mainly beta-galactanase activity. 2. Enzymes were added at the recommended dosage (normal) and at 5 times the recommended dosage (high) to a semi-purified diet based on maize with SBM as the sole protein source. 3. The enzymes had no effect on digesta viscosity in the jejunum or ileum. 4. Enzyme A at the high dosage significantly (P<0.05) improved AMEN, reduced excreta moisture content and improved ileal protein digestibility. The addition of the same enzyme at the recommended dosage had no effect on any of the above parameters. 5. Analysis of the monosaccharide composition revealed that Enzyme A tended to reduce the amounts of rhamnose and galactose in the soluble and insoluble NSP fractions in thejejunal and ileal digesta. The reduction was significant (P<0.05) when the same enzyme was added at the high dosage. 6. Enzyme B significantly (P<0.05) improved AMEN of the diet but not the growth or the feed conversion ratio (FCR) of the birds. Enzyme B at the high dosage significantly reduced (P<0.05) ileal protein digestibility. 7. Enzyme B significantly (P<0.05) increased the amount of free sugars in thejejunum and reduced (P<0.05) the concentration of soluble NSP in the ileum. 8. Analysis of the monosaccharide composition in the jejunal and ileal digesta showed that this enzyme was highly effective in releasing galactose from both the soluble and insoluble NSP fractions. 9. It is concluded that glycanases with galactanase and pectinase activities supplemented at appropriate dosages can improve the digestibility of the NSP in SBM and increase the metabolisable energy content of the diet containing high levels of SBM. 10. Furthermore, the addition of Enzyme B at the high dosage significantly (P<0.05) reduced protein digestibility without any measurable reduction in growth performance.     

Performance and nutrient digestibility in growing pigs fed wheat dried distillers’ grain with solubles‐containing diets supplemented with phytase and multi‐carbohydrase

Effect of supplementing wheat dried distillers’ grain with solubles (DDGS)‐containing diet with enzymes on nutrient utilization by growing pigs was evaluated in two experiments. In Experiment 1, 60 pigs weighing ~30 kg were fed five diets that included a corn‐based diet (Control), Control with 10% wheat DDGS (DDGS‐PC), DDGS‐PC without inorganic P source (DDGS‐NC), and DDGS‐NC plus phytase alone or with multi‐carbohydrase for 4 weeks to determine average daily gain (ADG), average daily feed intake (ADFI) and gain‐to‐feed ratio (G:F). In Experiment 2, 30 barrows weighing 22 kg were fed five diets fed in Experiment 1 to determine nutrient digestibility and retention. Pigs fed DDGS‐PC and Control diets had similar ADG and G:F. The ADG and G:F for DDGS‐PC diet were higher (P < 0.05) than those for DDGS‐NC diet. Phytase improved (P < 0.05) ADG, G:F, total tract P digestibility and P retention by 6.6, 8.7, 86.0 and 85.5%, respectively. Addition of multi‐carbohydrase to phytase‐supplemented diet did not affected growth performance, but reduced (P < 0.05) P retention. In conclusion, inclusion of 10% wheat DDGS in growing pig diet may not affect growth performance of growing pigs. Phytase supplementation to wheat DDGS‐containing diet can eliminate the need for inorganic P supplement in pig diets.     

Effect of exogenous enzymes in maize-based diets varying in nutrient density for young broilers: growth performance and digestibility of energy, minerals and amino acids

1. A total of 192 male broilers (Cobb 500) were used in a growth and digestibility assay, involving a 2 x 2 factorial arrangement of treatments, to assess the effects of an enzyme cocktail of xylanase, amylase and protease in maize-based diets. 2. The following two diets were formulated: a positive control diet containing adequate nutrient concentrations for broiler starters as per breeder recommendations and a negative control diet to contain approximately 0.63 MJ/kg apparent metabolisable energy (AME) and 3% amino acids less than the positive control. 3. A further two dietary treatments were developed by supplementing each control diet with an enzyme product containing xylanase, amylase and protease. 4. Birds fed on the negative control diet had poorer weight gain and feed efficiency than those given the positive control diet. There was no effect of diet or enzyme on feed intake. The digestibility of nitrogen, calcium, phosphorus and most amino acids were unaffected by dietary nutrient density. 5. Supplementation of both the positive and negative control diets with the enzyme improved weight gain and feed efficiency compared with the unsupplemented diets. In the case of the negative control, supplemental enzyme improved performance to that of the unsupplemented positive control diet. There was no interaction between diet and enzyme for either weight gain or FCR, suggesting similar beneficial responses regardless of the nutrient density of the diet. 6. In both diets, enzyme supplementation improved AME by an average of 3% (0.35 MJ/kg DM) and nitrogen retention by an average of 11.7% (26 g/kg DM intake vs 29 g/kg DM intake). There was no interaction between diet and enzyme for AME or nitrogen retention. 7. Ileal digestibilities of calcium and phosphorus were not influenced by supplemental enzyme, whereas the digestibility of nitrogen and most amino acids was improved by enzyme addition compared with the unsupplemented control diets. There was no interaction between diet and enzyme for the ileal digestibility of nitrogen and amino acids. 8. These data demonstrate that it is possible to improve the nutritional value of a maize/soy-based diet for broiler starters through the use of exogenous enzymes. The nutrient density of the diet does not appear markedly to influence the response to enzyme, offering flexibility in the use of enzymes for maize-based diets. 9. It is concluded that the energy and amino acid values of maize-based diets for broilers can be enhanced by supplementation with an enzyme cocktail of xylanase, amylase and protease, offering potential economic benefits to producers.     

Effects of cysteamine supplementation on the intestinal expression of amino acid and peptide transporters and intestinal health in finishing pigs

This study aimed to evaluate the effects of cysteamine supplementation on the expression of jejunal amino acid and peptide transporters and intestinal health in finishing pigs. Sixty barrows were allocated into two experimental diets consisting of a basal control diet supplemented with 0 or 142 mg/kg cysteamine. After 41 days, 10 pigs per treatment were slaughtered. The results showed that cysteamine supplementation increased the apparent digestibility of crude protein (CP) (P < 0.05) and the trypsin activity in jejunal digesta (P < 0.01). Cysteamine supplementation also increased the messenger RNA abundance of SLC7A7, SLC7A9 and SLC15A1, occludin, claudin‐1 and zonula occludens protein‐1 (P < 0.001) in the jejunum mucosa. Increased glutathione content (P < 0.01) and glutathione peroxidase activity (P < 0.05) and decreased malondialdehyde content (P < 0.01) were observed in pigs receiving cysteamine. Additionally, cysteamine supplementation increased the concentrations of secretory immunoglobulin A (IgA) (P < 0.05), IgM (P < 0.001) and IgG (P < 0.001) in the jejunal mucosa. It is concluded that cysteamine supplementation could influence protein digestion and absorption via increasing trypsin activity, enhancing the digestibility of CP, and promoting the expression of jejunal amino acid and peptide transporters. Moreover, cysteamine improved intestinal integrity, antioxidant capacity and immune function in the jejunum, which were beneficial for intestinal health.     

Growth performance and carcase quality in broiler chickens fed on bacterial protein grown on natural gas

1. The effects of increasing concentrations (0, 40, 80 or 120 g/kg) of bacterial protein meal (BPM) and bacterial protein autolysate (BPA) grown on natural gas on growth performance and carcase quality in broiler chickens were examined. 2. Adding BPM to diets reduced feed intake and improved gain: feed from 0 to 21 d and overall to 35 d, but did not significantly affect weight gain compared to the soybean meal based control diet. 3. Increasing concentrations of BPA significantly reduced growth rate, feed intake, gain: feed, carcase weight and dressing percentage, but significantly increased carcase dry matter, fat and energy content. 4. Adding BPM to diets had no effect on viscosity of diets and jejunal digesta, and minor effects on litter quality, whereas BPA increased the viscosity of diets and jejunal digesta, improved litter quality at 21 d, but decreased litter quality at 32 d. 5. To conclude, broiler chickens performed better on a BPM product with intact proteins than on an autolysate with ruptured cell walls and a high content of free amino acids and low molecular-weight peptides.     

Synergistic effect of cellulase and hemicellulase on nutrient utilization and performance in broilers fed a corn–soybean meal diet

In the present study, the synergistic effect of dietary cellulase and hemicellulase on the nutrient utilization, performance and digesta (content of jejunum) viscosity in broilers fed a corn–soybean meal diet were studied. The treatment groups included a control, cellulase (0.33 U/g feed), hemicellulase (2 U/g feed) and mixed enzyme (cellulase (0.33 U/g feed) + hemicellulase (2 U/g feed)) group. The enzymes were mixed with the basal diet (21.1% crude protein, 3000 kcal/kg metabolizable energy) and fed to male broiler chickens (Cobb strain) for 12 days from 15 days of age. Feed and water were offered ad libitum. Chicks were raised under 25°C in wire‐bottomed cages during the entire experimental period. We found that broilers given enzymes grew faster, and that the mixed enzyme was most effective. Feed intake remained the same for all of the treatment groups. Carcass weight was increased by mixed enzyme significantly, but not by cellulase and hemicellulase. The enzymes, but not mixed enzyme, decreased abdominal fat and were significant in the case of cellulase. Enzymes did not affect muscle weight and nitrogen‐retention, but metabolizable energy content of the diet was improved by the mixed enzyme. Ash‐retention was increased by hemicellulase and mixed enzyme. Digesta viscosity was significantly decreased by cellulase, but not by hemicellulase and the mixed enzyme. The results indicate that the combination of cellulase and hemicellulase has a synergistic effect on the performance of broilers fed a corn–soybean meal diet.