Effect of wheat cultivar and enzyme addition to broiler chicken diets on nutrient digestibility, performance, and apparent metabolizable energy content

Assessing the Variability of Energy Metabolisability in Barley, Rye, and Wheat Varieties for Broiler Diets

This trial assessed the variability of energy metabolisability in four varieties of barley, rye, and wheat based on changes in energy and nutrient flow estimations in excreta. Twelve diets were created by combining 40% of each cereal variety and 60% of a common mixture, divided into enzyme-supplemented and non-supplemented versions, resulting in 24 experimental diets that included TiO2 and Yb2O3 as indigestible markers. A total of 432 one-day-old broilers were distributed into 72 cages and fed a single diet from day 1 to 15. Experimental runs were conducted from day 16 to 25 using a crossover design. Diets were alternated between enzyme-supplemented and non-supplemented for each cage. Excreta samples were collected on days 20 and 25. Energy metabolisability was highest (p < 0.001) in wheat (83.3%), followed by barley (77.8%) and lowest in rye (70.6%). The variety influenced energy metabolisability in barley and wheat (p < 0.001) at a wider range than predicted by NIR analyses. The variety influenced the increment of energy in response to enzyme supplementation in barley diets (p < 0.05), with varieties having low metabolisability values showing higher responses. TiO2 and Yb2O3 did not differ in estimating nutrient flow. This study quantifies energy variability among and within cereals and identifies potential variation factors.

Interaction of wheat cultivar and enzyme on broiler growth, nutrient utilization, and gut microflora

This study examined the impacts of four wheat cultivars and enzyme supplementation on growth performance, nutrient digestibility, and ileal microbiota composition in broiler chickens. Six hundred forty-eight male broilers (1-day-old, Ross 308) were studied in a completely randomized design factorial 4 × 2 along with control (9 treatments) with 6 replications (12 birds per pen). The Diets consisted of the four varieties of wheat (Sardari, Azar2, Sirvan, and Pishgam) with and without enzyme supplementation, alongside a corn-based control diet. All diets were iso-caloric and iso-nitrogenous. Daily weight gain (DWG) and feed conversion ratio (FCR) were not significantly affected by the dietary treatments. Broilers fed the corn-based diet displayed higher feed intake (FI) than those fed diets containing different wheat cultivars. Enzyme supplementation in wheat-based diets did not impact broiler growth performance. There was an interaction between enzyme and wheat type for protein, fat, calcium, and phosphorus digestibility. Ileal microbiota analysis revealed no significant changes in Lactobacillus and Escherichia coli populations across treatments. Conversely, Enterococcus and Bifidobacteria populations exhibited significant differences, with the Sirvan cultivar diet promoting the highest bacterial counts. It was concluded that different wheat cultivars could affect growth performance, nutrient digestibility, and ileum microbiota, and the beneficial effect of supplemental enzymes was only evident in certain variables and depended on the specific wheat variety.

Feeding dietary non-starch polysaccharides supplemented with xylanase could improve the performance of broilers

The impact of dietary non-starch polysaccharides (NSP) on performance and carcass traits of broilers fed wheat-bran substituted into corn-soybean meal-based diets supplemented with xylanase was investigated. A total of 280 (7-day-old) Ross 308 broilers were randomly allotted to one of five dietary treatments with 8 replicates, 7 chicks per pen. Treatments were; i) CON: Control diet, ii) CON-X (CON + 3,000 U/kg xylanase), iii) L-X: low NSP (2% wheat bran in CON + 3,000 U/kg xylanase), iv) M-X: medium NSP (4% wheat bran in CON + 3,000 U/kg xylanase), v) H-X: higher NSP (8% wheat bran in CON+ 3,000 U/kg xylanase). Birds fed the H-X diet increased (p < 0.05) daily gains, and average daily feed intake and had marginally improved body weights (p = 0.074) on day 35. Relatively, the H-X diet tended to increase the average daily gains (p = 0.053; p = 0.073) of birds during the grower phase (d 24-35) and the entire experimental period (d 8-35), respectively. Moreover, there were no significant differences among treatments in the feed conversion ratio of birds throughout the entire experiment period. Birds fed diets CON-X, L-X, and M-X had improved (p < 0.05) the ileal digestibility of energy on d 24 and 35 compared to those fed the H-X diet. Furthermore, birds fed diet CON-X improved (p < 0.05) N digestibility on d 24. Improved carcass moisture content and lowered crude fat of leg meat (p < 0.05) were noted in birds fed the diet M-X and H-X on d 35, respectively. The intestinal viscosity was reduced (p < 0.05) in xylanase-supplemented treatments CON-X, L-X, M-X, and H-X diets when compared to CON. Our results suggest that supplementing 3,000 U/kg xylanase in a higher NSP (8% wheat bran substituted level) diet could improve the intestinal viscosity and growth performance of broilers.

Growth performance, blood lipids, and fat digestibility of broilers fed diets supplemented with bile acid and xylanase

This study aimed to show the effect of bile acid (BA) and xylanase (Xyl) supplementation on the growth, fat digestibility, serum lipid metabolites, and ileal digesta viscosity of broilers. A total of 720 1 d old male broilers were allocated to one of nine treatments with four replicates in each under a factorial design arrangement of three levels of BA (0 %, 0.25 %, and 0.50 %) and three levels of Xyl (0 %, 0.05 %, and 0.10 %) supplementation. The duration of the experiment was 35 d (7-42 d). Growth performance, blood lipids, fat digestibility, and ileal digesta viscosity were determined. The experimental treatments did not affect feed intake (FI) and weight gain (WG). Supplementation of BA or Xyl did not significantly ameliorate the feed conversion rate (FCR) (p < 0.05 ). The addition of BA linearly increased fat digestibility. At 7-21 d of age, the addition of BA or Xyl had a significant (p < 0.05 ) increase in serum cholesterol (Chol) but no significant difference for other serum lipid parameters in broiler chickens fed with Xyl in the starter and grower periods. However, the supplementation of 0.5 % BA at 7-21 d of age significantly increased the Chol and low-density-lipoprotein (LDL) levels. The results of this trial revealed that the supplementation of xylanases had a great effect on the degradation of arabinoxylan from wheat, which led to a relatively greater reduction in ileal digesta viscosity; it was also found that supplementation of BA significantly increased the concentration of serum lipid metabolites, whereas BA and Xyl supplementation linearly increased the fat digestibility of the birds fed wheat and tallow diets.

Effects of protease enzyme supplementation and varying levels of amino acid inclusion on productive performance, egg quality, and amino acid digestibility in laying hens from 30 to 50 weeks of age

An experiment was conducted to evaluate the effects of protease supplementation and reduced digestible amino acid (dAA)/ crude protein (CP) level on productive performance, AA digestibility, and egg quality parameters in Hy-Line W-36 laying hen from 30 to 50 wk of age. A total of 768 hens (12 replicates of 8 hens per treatment) were equally and randomly allocated into 8 experimental diets in a 4 × 2 factorial arrangement of dAA/CP level (100, 95, 90, and 85% of breeder recommendation) and protease (exclusion or inclusion). Protease was added at 60 g/metric ton of feed in the inclusion group. Hens were housed in raised-wire cages with a stocking density of 870 cm²/bird. The adequate (100%) diet was based on corn and soybean meal and formulated based on the digestible (d) Lys and dAAs (dMet, dThr, dTrp, dTSAA, dIle, and dVal) to meet 100% of the current management guide recommendation. Variations in dAA/CP (95, 90, and 85% diets) were accomplished by reducing the 100% dAA by 5, 10, and 15%, respectively. All diets were supplemented with phytase at 500 phytase units (FTU)/kg. Data were analyzed using PROC GLM of SAS 9.4. There was a main effect of dAA/CP level on 85% diet where it had a lower mean hen-day egg production (HDEP, P < 0.01), egg mass (EM, P < 0.01), and higher feed conversion ratio (FCR, P < 0.001). Higher egg weight (P < 0.01) was observed in 95 and 100% dAA/CP level diets. However, Haugh unit (P < 0.01) and albumen height (P < 0.01) were higher in 85 and 90% diets. The inclusion of protease reduced the feed consumption (P = 0.0247), FCR for dozens of eggs (P = 0.0049) from 30 to 49 wk of age without affecting the HDEP or EM. Protease supplementation and dAA/CP level had an effect on the apparent ileal digestibility (AID) of CP (P = 0.019), Lys (P < 0.01), Thr (P < 0.01), Trp (P = 0.017), and Val (P < 0.01). Addition of protease significantly increased egg income (P = 0.033) and return on investment (P = 0.00223) from 30 to 37 wk of age. At 38 to 50 wk of age, dAA/CP level had a significant effect on egg income (P < 0.001), feed cost (P < 0.001), and return on investment (P < 0.001). This experiment indicates that the inclusion of protease in 90 and 95% lower dAA/CP diets could help improve the digestibility of CP, and key amino acids and maintain productive performance of corn and soybean meal-based diets in Hy-Line W-36 laying hen from 30 to 50 wk of age.

Determination of prediction equations for apparent metabolizable energy corrected for nitrogen of corn gluten meal and canola meal in broilers

The objectives of this experiment were to determine the AMEn content of different samples of corn gluten meal (CGM) and canola meal (CM) by a reference diet method and to develop prediction equations based on the chemical composition to estimate the AMEn value of CGM and CM in broilers. A total of 300 one-day-old male broiler chicks were randomly assigned to fifteen treatments (14 experimental diet and 1 reference diet) with 4 replicates of each with 5 birds per replicate. At first, birds were fed a starter diet from 0 to 10 d of age, and then, a grower diet from 11 to 23 d of age. To determine the AMEn content, the test diet consisted of 60% reference diet, 38% each test CGM or CM, and 2% minor ingredients. To adaptation, the broilers were fed experimental diets for 4 d, and then feces were collected on 28 d. The gross energy values and chemical compositions among the CGM and CM from different origins were significantly different. The AMEn values of the CGM samples varied from 3,123 to 3,918 kcal/kg, and for the CM, the range was from 1,578 to 2,109 kcal/kg. At the end of the experiment, data were analyzed with SPSS software, and a regression equation was obtained based on the chemical composition. The best equations were selected based on the standard of prediction and regression adjusted R². The equation, AMEn = 49.196 × CP + 80.87 × EE (SEP 180.99; adjusted R² 0.97), was selected to predict the AMEn value of CGM, and the equation, AMEn = 631.55 × EE + 16.716 × CP (SEP 55.3; adjusted R² 0.94), was selected to predict the AMEn value of CM.

Determination and prediction of standardized ileal amino acid digestibility of wheat in broilers

This experiment evaluated the standard ileal digestibility (SID) of amino acids (AA) in 8 different sources of wheat fed to broilers and established prediction equations based on the chemical properties of wheat. A total of five hundred forty 1-day-old broilers were tested in 2 stages (from d 10 to 13 and from d 25 to 28). On d 13, 324 broilers were randomly assigned to 9 diets (6 replicate cages, 6 broilers per cage); on d 28, 216 broilers were randomly assigned to 9 diets (6 replicate cages, 4 broilers per cage). The 9 experimental diets included 8 test diets and 1 nitrogen-free diet. Titanium dioxide was added as an exogenous indicator at 0.5% of the diet. In 8 wheat samples, the mean values of total amino acids (TAA), dispensable amino acids (DAA), and indispensable amino acids (IAA) were 12.16% (CV 13.70%), 7.97% (CV 15.49%), and 4.20% (CV 11.47%). On d 13, the lowest SID of AA was Lys (86.71%), and the highest was Pro (97.98%). On d 28, the lowest SID of AA was His (81.31%), and the highest was Pro (96.83%). There was an effect of wheat source on the SID of AA except for Trp (P < 0.05); the broiler age had an effect on the SID of AA except for Tyr (P < 0.05); the SID of most AA were higher at d 13 compared to d 28. At d 13, the SID of AA was correlated with CP, NDF, and ST (P < 0.05). At d 28, the SID of AA was correlated with EE, Ash, ADF, and NDF (P < 0.05). The R2 value of stepwise regression equations to predict the SID of AA at d 13 was highest for Leu (R2 = 0.972), lowest for Asp (R2 = 0.785); at d 28 was highest for Gly (R2 = 0.995), lowest for His (R2 = 0.678). In conclusion, this experiment showed that the chemical properties of wheat can be used to establish accurate equations for predicting the SID of AA. This made it more efficient to obtain the SID of AA for wheat.

Validation of a 3-point model for the determination of energy values using the regression method in broiler chickens

Two experiments (Exp.) were conducted to validate a 3-point model for the regression method of determining ME, using canola meal (CM) and wheat as test ingredients (TI). Corn-soybean meal-based test diets (TD) contained 0, 100, 200, or 300 g/kg CM, added at the proportional expense of all energy contributing ingredients for Exp. 1, and 0, 150, 300, or 450 g/kg wheat for Exp. 2. For each Exp., 192 Cobb 500 male broiler chickens were weighed and allotted by BW to 1 of 4 treatments at d 21 post hatching in a randomized complete block design. Growth performance and metabolizability responses were evaluated for linear and quadratic effects using orthogonal contrasts, and ileal digestible energy (IDE), ME, and MEn of TI were determined by regressing the TI-associated energy against the dry matter intake of TI using a generalized linear model. Four data sets were used to determine ME, using all possible 3 and 4-point combinations of TD in each Exp. Increasing TI inclusion elicited linear decreases (P < 0.01) in the digestibility and metabolizability of DM and GE in the 2 studies. The ME of CM obtained from the 4 data sets ranged from 1,731 to 1,992 kcal/kg DM, however, excluding the highest concentration of CM produced the highest estimate of ME, whereas the other 3 sets ranged from 1,731 to 1,793 kcal/kg DM. The ME of wheat from the 4 data sets had a smaller range of 3,041 to 3,106 kcal/kg DM. Excluding the highest concentration of either TI produced higher standard errors for the estimate of ME compared to the other 3 sets (42 and 36% greater SE, respectively). Results for IDE and MEn were similar. These data indicate that there is no difference in the variation of estimates between the 3 and 4-point models, provided that the inclusion of the TI is adequate and both models represent the linearity and variability of responses.

Effect of enzymes by substitution of corn with wheat on growth performance and digestibility of broilers

Substitution of corn with wheat associated with its variable energy content and detrimental effect on broiler performance. In a case of high-cost yellow corn, several feed producers are choosing to replace yellow corn with other ingredients like wheat, barley or sorghum. The predominant Non Starch Polysaccharides (NSP) in wheat are the pentosans (arabinixylans).  Nonstarch polysaccharides create a viscous environment in the gastrointestinal tract of broiler chickens thereby interfering with the digestion and absorption of nutrients. Broilers lack endogenous enzymes to degrade arbino-xylans of wheat. Supplementation of exogenous feed grade enzymes to the cereal based diets improve the performance of broilers. Enzyme supplementation of chicken cereals based diets has resulted in improved starch and nitrogen digestibility as well as improved absorption of starch, amino acids and lipids. Supplemental enzymes such as β-glucanase, xylanase, protease and amylase break the polymeric chains of NSP into smaller pieces, thereby improving their nutritional value. The study concluded that the supplementation of NSP-degrading enzymes in wheat-based diet improve growth performance, ileal viscosity and gastric passage rate in broiler chickens.

nThe effect of partial replacement of milled finisher feed with wheat grains on the production efficiency and meat quality in broiler chickens

The study's aim was to assess the production efficiency, evaluate the carcass and meat quality of chickens fed with wheat grains. 200 Ross 308 chickens were divided into 4 groups (5 replicates with 10 birds in each): control (C) and experimental groups, including W50, where the finisher feed was diluted with wheat grain in 50%, W25–25%, and W10–10%. The production efficiency and chemical composition of the feed were analyzed. After 42 d of rearing, 10 birds from each group were selected, and the tissue composition, pH, color, water-holding capacity, drip loss, the chemical composition of meat, and the apparent protein digestibility, bone, and jejunum strength were investigated. It was proved that ground feed had an unfavorable effect on the body weight (BW) in all groups. Wheat decreased the protein level (P < 0.001) and digestibility (P < 0.001). The body weight gain (BWG) in group W50 was lower than in groups C and W10 (P = 0.009), however, this had no effect on the final feed conversion ratio (FCR) (P = 0.146). Finisher feed costs were reduced in groups W50, W25 compared to group C (P < 0.001). The European Production Efficiency Factor and the European Broiler Index in groups W10 and W25 were similar to group C, whereas in W50 they were reduced (P = 0.035; 0.034). No negative effect on carcass traits was shown in groups W10 and W25, however, 50% feed replacement was unbeneficial compared to group C. Pectoral muscles from the experimental groups were characterized by higher lightness (P < 0.001). In group W10 femur bones' strength and in group W25 tibia bones' strength was higher than in group W50 (P = 0.014; 0.006). Jejunum tensile strength was higher in group W25 than in W10 (P = 0.002). The nutritional strategies based on the dilution of the feed with wheat grain could be applied at the level of 10/25%, but 50% had a negative effect.

Apparent metabolizable energy of cereal grains for broiler chickens is influenced by age

The current study was conducted to investigate the influence of broiler age on the AME and AMEn of 4 common cereal grains (wheat, sorghum, barley, and corn). Four experimental diets with the same inclusion (962 g/kg) of each grain were developed and fed to groups of broiler chickens aged 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35, or 36 to 42 d post-hatch. Each diet, in pellet form, was randomly allocated to 6 replicate cages in each age group. Except for the 0 to 7 d age group, the birds were fed a starter (d 0-21) and/or a finisher (d 21-35) diet before the introduction of experimental diets. The number of birds per cage were 10 (d 1-7) and 8 (d 8-42). Excreta were collected over the last 4 d of each age period. The AME and AMEn of the grains were determined by the total excreta collection. Bird age influenced (P < 0.001) the AME and AMEn of all cereal grains. The AMEn of wheat declined quadratically (P < 0.01) with advancing age, from 3,461 kcal/kg in wk 1 to 3,219 kcal/kg in wk 2 and then plateaued. The AMEn of sorghum grain declined linearly (P < 0.001) with advancing age, from 3,762 kcal/kg in wk 1 to 3,614 kcal/kg in wk 2, plateaued to wk 5 and then declined to 3,556 kcal/kg in wk 6. A quadratic (P < 0.001) reduction in the AMEn of barley was observed as birds grew older, with the AMEn decreasing between wk 1 (3,286 kcal/kg) and wk 2 (2,988 kcal/kg), increasing in wk 3 (3,117 kcal/kg) and then plateauing. The AMEn of corn declined quadratically (P < 0.05) with advancing broiler age; the highest AMEn was observed in wk 1 and 5, the lowest AMEn in wk 2, with the other weeks being intermediate. In conclusion, the present results showed that broiler age has a substantial impact on the AME and AMEn of cereal grains and the effect varied depending on the cereal grain. These data suggest that age dependent AME and AMEn values may need to be considered when formulating broiler diets to improve the precision of feed formulation and production efficiency.

Impact of fiber on growth, plasma, gastrointestinal and excreta attributes in broiler chickens and turkey poults fed corn- or wheat-based diets with or without multienzyme supplement

Effects of fiber on growth performance, gizzard attributes, ileal digesta viscosity, plasma uric acid (PUA) and excreta characteristics were investigated in broiler chickens (experiment 1) and turkey poults (experiment 2) fed corn or wheat-based diets with or without multienzyme supplement (MES). Fibrous diets were created by adding 10% corn distillers dried grains with solubles or wheat middlings in corn or wheat-based diets, respectively. The MES had main activities of xylanase and β-glucanase. A total of 960-d old Ross x Ross 708 male chicks and 720-d old male Hybrid toms were allocated to eight grain, fiber and MES combinations to give 6 replicates per combination. In each experiment, birds had free access to feed and water for 28 days. Excreta samples were collected for 3-d prior to the end and on d 28, body weight and feed intake were recorded, birds bled and subsequently necropsied for gastrointestinal samples. There was an interaction (P ≤ 0.036) between grain, fiber and MES in broilers final body weight (FBW) and BW gain (BWG). In this context, high fiber corn diets reduced FBW and BWG and supplementation of MES improved these parameters. Broilers fed corn had a higher (P < 0.05) FBW (1,462 vs. 1,424 g) and BWG (1,416 vs. 1,378 g) than birds fed wheat diets. Broilers fed corn-based diets without fiber diets had a higher ileal viscosity and excreta moisture compared to birds fed wheat-based and high fiber diets. Broilers fed low fiber wheat diets without MES had higher (P < 0.05) PUA concentration compared to birds fed low fiber corn diets without MES. Poults fed wheat diets had a higher (P < 0.05) FBW (1,441 vs. 1,408 g) and BWG (1,376 vs. 1,343 g) than poults fed corn diet. The MES supplementation in corn-based diets rich in fiber increased (P = 0.03) gizzard weight in poults. In conclusion, there were varied growth and physiological responses in broilers and turkey suggesting the need for refining enzyme application for different poultry species.

Nutrient Content of Different Wheat and Maize Varieties and Their Impact on Metabolizable Energy Content and Nitrogen Utilization by Broilers

Simple Summary

The current standard for the determination of the energy value of feed is to use regression equations; however, these equations are imprecise and may affect the correct estimation of energy for several reasons. First of all, these equations include the values of some raw components, such as crude protein, ether extracts, and N-free extracts, but not different forms of fiber, which in high concentration reduces the energy value of poultry feed. In addition, in the tables, there are average values for different feeds, which do not take into account differences between varieties of the same species, which, at least in case of grains may be much larger than differences between two different species. Another important aspect is that the concentration of various components, including antinutritional factors, affects their mutual use and thus the energy value of feed. This work was aimed at improving the precision of estimating the energy value of poultry feed by incorporating detergent and dietary fiber as well as additional nutrients such as starch and total sugars separately. In addition, the authors suggest considering the values characteristic of selected grain in the energy calculations rather than the mean values for the species, because it may improve the precision of the result.

Abstract

The study aimed to determine the effect of nutrients of wheat (nine cultivars) and maize (nine cultivars) grain on nitrogen balance and apparent metabolizable energy (AME_N) content for broiler chickens. In vivo digestibility and balance trials were carried out with 90 Ross 308 chickens (2 × 9 groups with 5 birds per group) aged from 42 to 49 days, separately for each cultivar. Considerable variation within each cereal species in fiber and non-fiber carbohydrate fractions and nutrient digestibility of grain were demonstrated. Additionally, regression equations were proposed which allow the estimation of AME_N content of wheat and maize grain varieties based on simple analytical procedures, including cell wall components, starch, and sugars. For practical purposes, these equations seem to be the best solution while reducing time, labor, and cost of analytical procedures.

Dietary Supplementation with Phytase and Protease Improves Growth Performance, Serum Metabolism Status, and Intestinal Digestive Enzyme Activities in Meat Ducks

Two experiments were conducted to investigate the effects of dietary supplementation with protease and phytase on growth performance, serum physiochemical parameters, and activities of digestive enzymes in jejunal digesta of meat ducks. Experiment 1 was carried out to determine the effects of different protease or phytase on growth performance, serum physiochemical parameter, and activities of digestive enzymes in jejunal digesta of meat ducks to select the optimal phytase or protease. According to the hatching age and initial weight, a total of 5040 Cherry Valley ducks (15 days of age) were randomly assigned into six treatments. Treatments included a basal control diet (CON) and 5 basal diets supplemented with different enzyme preparations, which were phytase preparation A (PA, 160 g/t), phytase preparation B (PB, 800 g/t), protease preparation A (PTA, 80 g/t), protease preparation B (PTB, 300 g/t) and protease preparation C (PTC, 200 g/t). The enzyme activities were as follows: Phytase A and B as well as protease A, B, and C were 50,000, 10,000, 250,000, 50,000, and 60,000 U/g, respectively. Each treatment had 7 replicates with 120 meat ducks per replicate. Experiment 1 lasted for 28 days. The results showed that: compared with the CON group, the PA group significantly decreased contents of serum phosphorus and calcium (p < 0.05), and the PTA, PTB, and PTC groups had higher activities of trypsin in jejunal digesta (p < 0.05), and the activity of jejunal chymotrypsin in PTA group was greater (p < 0.05). Experiment 2 was carried out to determine the effects of dietary supplementation with protease and phytase in low-energy and low-protein diet on growth performance, serum physiochemical parameters, and activities of digestive enzymes in jejunal digesta of meat ducks. According to the hatching age and initial weight, a total of 5760 Cherry Valley ducks (15 days of age) were randomly assigned into four treatments on the basis of a trial of 2 × 2 factorial design. Treatments included a basal control diet (PC), basal diet supplemented with enzymes (PCE), low-energy and low-protein diet (LEP), and low-energy and low-protein diet supplemented with enzymes (LEPE), the nutrient levels of energy and CP of basal diet were 2747.2 cal·ME/kg and 16.80%, respectively, and the nutrient levels of energy and CP of low-energy and low-protein diet decreased 45.90 kcal·ME/kg and 0.52% on the basis of basal diet, respectively. According to the results of experiment 1, phytase A and protease A were determined as the optimal enzyme combination of Experiment 2, and additional dosage of which were identical with Experiment 1. Each treatment had 6 replicates with 240 meat ducks per replicate. Experiment 2 lasted for 28 days. The results showed that: compared with PC and LEP groups, PCE and LEPE groups had higher final weight and average daily gain (ADG) (p < 0.05), higher activities of trypsin and chymotrypsin in jejunal digesta (p < 0.05), lower contents of serum calcium and phosphorus as well as higher levels of high-density lipoprotein in the serum (p < 0.05). In conclusion, dietary supplementation with phytase and protease in different energy and protein diets could increase digestive enzymes in jejunal digesta, effect serum physiochemical parameters, improve metabolic status, and increase the growth performance of meat ducks. Meanwhile, with the dietary supplementation with phytase and protease in the lower energy and protein diet, the growth performance could reach to the degree of the higher energy and increased protein diet, but without the addition of phytase and protease.

Effect of age on the relationship between metabolizable energy and digestible energy for broiler chickens

A total of 960 male Ross 308 chicks (day-old) were used to investigate the effect of age on the relationship between metabolizable energy (ME) and digestible energy (DE) for broiler chickens. Bird growth variables, nitrogen retention (NR), nitrogen digestibility (ND), as well as the relative weight of liver, pancreas, and the gastrointestinal tract were determined. Practical diets that compared 2 cereals (corn and wheat) and exogenous xylanase (0 or 16,000 BXU/kg) were evaluated at 5 ages (7, 14, 21, 28, and 35 D) in a 2 × 2 × 5 factorial arrangement of treatments with 8 replicates per treatment and started with 30 birds per replicate. A randomized block ANOVA analysis of repeated measures was performed, and a 2 × 2 × 5 factorial structure was used to investigate the 2 dietary treatment factors (cereal type and the presence of xylanase) within the 5 bird ages (7, 14, 21, 28, and 35 D), and their interactions. Apparent metabolizable energy (AME) increased linearly from 7 until 28 D of age, but (P < 0.05) decreased at 35 D of age. Digestible energy was high at 7 D of age, then dropped and remained similar (P > 0.05) from 14 to 35 D of age. The AME: DE ratio was lowest (P < 0.05) at 7 D of age but there were no (P > 0.05) differences thereafter. Cereal type and xylanase supplementation did not (P > 0.05) change the ME: DE ratio. The results indicate that determining ME before 14 D of age may give absolute values that are lower than would be obtained with older birds. ME values that are determined on older broiler chickens may overestimate the energy availability of practical feeds used in broiler starter feeds.

Wheat sample affects growth performance and the apparent metabolisable energy value for broiler chickens

1. The aim of this study was to examine chemical composition, quality characteristics, apparent metabolisable energy (AME) and nutrient utilisation of wheat samples currently available to the UK poultry industry and their effect on broiler growth performance. 2. Seventeen current UK wheat samples were used to formulate 17 diets, all of which included 670 g/kg of each wheat sample and 330 g/kg of a balancer feed. Eight hundred 1-day-old male Ross 308 broilers were allocated randomly to 160 raised floor pens. Each diet was replicated eight times, fed ad libitum from 0 to 21d age in a randomised complete block design. Excreta were quantitatively collected during the last 3 days for AME determination. 3. The content of protein, ash and gross energy (GE) ranged from 97 to 143 g/kg DM, 12.8 to 19.6 g/kg DM and 17.81 to 18.24 MJ/kg DM, respectively. The amount of starch and total non-starch polysaccharides (NSP) ranged from 671 to 728 and 80.1 to 98.2 g/kg DM, respectively. The quality characteristics of wheat samples were in the expected range. 4. There were differences (P < 0.05) in AME and N-corrected AME (AMEn) of wheat samples. The AME of the wheat had a maximum range of 1.13 MJ/kg DM between samples. Dry matter retention (DMR) and fat digestibility (FD) were significantly different (P < 0.05) between wheat samples. 5. The daily feed intake (FI) and weight gain (WG) of broilers fed two wheat samples were significantly (P < 0.05) lower as compared to other samples and their low FI and WG were not related to their chemical composition and quality characteristics. 6. The ash content of wheat samples was negatively associated with AMEn (r = - 0.489, P < 0.05). The coefficient of FD was positively related to AMEn (r = 0.552, P < 0.05). 7. Chemical composition and quality characteristics of the wheat did not relate (P > 0.05) to FI and WG of broilers. There was no relationship between growth performance of broilers and AMEn of the wheat samples.

Effects of glucose oxidase on growth performance, gut function, and cecal microbiota of broiler chickens

A study was conducted to study the effects of glucose oxidase (GOD) supplement on the growth performance, gut function, and cecal microbiota in broiler chickens from 1 to 42 d, and further evaluate the use of GOD as an antibiotic substitution. A total of 525 1-d-old healthy Arbor Acres broilers were randomly assigned to five treatments, including control group, antibiotic growth promoters (AGP) supplement group, and three GOD supplement groups, with seven replicates per treatment and 15 birds per replicate. Growth performance, gut function including digestive ability and gut barrier, and cecal microbiota were determined. Compared with the control group, the increased daily body weight gain, improved meat quality, and enhanced digestive ability that indicated from the nutrients apparent digestibility and digestive enzymes were identified in GOD supplement groups, which could have a similar effect with the AGP supplement. The content of secreted immunoglobulin A and the transepithelial electrical resistance were also increased with the GOD supplement, which indicated an enhanced gut barrier. Additionally, 16S rRNA gene of cecal contents was sequenced by high-throughput sequencing. Sequencing data indicated that the Firmicutes phylum, Ruminococcaceae and Rikenellaceae families, Faecalibacterium genus, and F. prausnitzii species were significantly altered. Especially, combined with previous studies, our results indicated that the significantly increased F. prausnitzii, Ruminococcaceae, and Firmicutes could be involved in the effect of GOD on gut function and growth performance of broilers. Our results indicated that dietary GOD supplement could improve the growth performance of broilers in two main ways: by enhancing the digestive function of gut, which concluded from the improved nutrients apparent digestibility and digestive enzyme, and by increasing the abundance of beneficial bacterium, such as F. prausnitzii, Ruminococcaceae, and Firmicutes, which could be further served as an important regulator to improve the growth performance and the gut health.

Interactions between the concentration of non-starch polysaccharides in wheat and the addition of an enzyme mixture in a broiler digestibility and performance trial

Two broiler trials were designed to investigate the relationship between the concentration of non-starch polysaccharides (NSP) in wheat and 1) its nutritional value for broilers and 2) the efficacy of exogenous enzymes. In a balance trial, diets were formulated with 3 wheat cultivars (Rustic and Viscount—medium NSP, Centenaire—high NSP) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 144 male Ross 308 broiler chickens housed in digestibility cages. Total tract nutrient digestibilities and AME_n were measured from 18 to 22 d of age. In a performance trial, diets were formulated with wheat (medium NSP diet) or with wheat mixed with rye and barley (high NSP diet) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 960 male Ross 308 broilers housed in pens and broiler performance during starter, grower and finisher periods was measured.

In the balance trial, wheat cultivar did not affect nutrient digestibility or AME_n. Enzyme addition caused a significant increase in nutrient digestibilities and AME_n for the diet formulated with the high NSP wheat Centenaire only. In the performance trial, feeding the high NSP diet resulted in a higher feed conversion ratio and lower final body weight compared to the medium NSP diet. The largest improvements by enzyme addition were observed in the high NSP diet.

In conclusion, the study was not able to show a consistent relationship between the NSP concentration of wheat and its nutritional value, but did demonstrate that the effect of an enzyme mixture on nutrient digestibility or broiler performance depends upon the NSP concentration in the diet.

In vitro assessment of the starch digestibility of western Canadian wheat market classes and cultivars

The objective of the study was to measure the effect of wheat market class and cultivar on starch digestibility using an in vitro model that mimics the chicken digestive tract and relate it to grain characteristics. The study evaluated 18 wheat cultivars from eight western Canadian wheat classes and, each cultivar was replicated four times. Samples were subjected to gastric and small intestine (SI) digestion phases and each sample was assayed in triplicate; glucose release was measured in SI phase. Starch granule distribution, amylose, total starch, crude protein (CP), ash, and non-starch polysaccharides (NSP) were analyzed in all wheat samples. Small intestinal phase times of 15, 60, and 120 min were chosen to approximate digestion in the terminal duodenum, jejunum, and ileum. Starch digestibility of wheat classes ranged as follows: 15 min — 33.1% to 49.1%, 60 min — 80.2% to 93.3%, and 120 min — 92.4% to 97.6%. Starch digestibility positively correlated with CP, ash, NSP, and proportion of large granules, whereas it negatively correlated with total starch, and proportion of small and medium granules. In conclusion, market class and cultivar of western Canadian wheat affects both rate and extent of starch digestibility and it is related to various grain characteristics.

Superior Growth Rates in Broilers Fed Wheat with Low In Vitro Feed-Xylanase Inhibition

Grain-batch variation in xylanase-inhibitor levels may account for variations in the efficacy of feed xylanase supplementation. This would make inhibition an important quality parameter in the routine analysis of feedstuffs. Two analytical procedures for testing feedstuffs against specific xylanases were researched: the high-throughput viscosity-pressure assay (ViPr) and the extraction-free remazol-brilliant-blue-beechwood-xylan (RBBX) assay. Thirty-two wheat cultivars were analyzed for inhibition of a commercial xylanase, Ronozyme WX. Four cultivars were selected for a feeding experiment in which the growth of 1440 broilers from ages 7-33 days was monitored. The treatments resulted up to 7 % difference (day 14) in broiler weight . The cultivar choice had an effect throughout the experiment ( p < 0.05). The performance ranking of the treatments corresponded better to xylanase inhibition than to crude-protein content or nonstarch-polysaccharide content. Wheat-grain xylanase-inhibitor content is therefore a highly relevant quality parameter when broiler diets are supplemented with feed xylanase.

Combined effect of using near-infrared spectroscopy for nutritional evaluation of feed ingredients and non-starch polysaccharide carbohydrase complex on performance of broiler chickens

This study was carried out to evaluate the combined effect of using near-infrared spectroscopy (NIRS) for nutritional evaluation of feed ingredients and the addition of non-starch polysaccharide carbohydrase complex (NSP enzymes) on the growth performance of broilers fed diets produced with low-quality wheat and soybean meal. A 2 × 2 trial design was performed, with seven replicates of 40 male Ross 308 broilers per treatment, evaluating the effect of the addition of NSP enzymes and the ingredients' nutritional matrix based on table values or NIRS values. Diets without added enzymes were formulated to reach nutritional requirements, whereas diets with enzymes were reformulated, reducing the apparent metabolizable energy (AME) by 85 kcal/kg. In the overall period (days 0-35), broilers fed diets formulated using NIRS values had higher (P < 0.001) average daily gain (+11.3%) and daily feed intake (+7.2%), and a lower (P < 0.001) feed conversion ratio (-5.3%) compared to those fed diets formulated using table values. When formulating diets for broilers with low-quality feed ingredients, performance can be improved by considering NIRS values and by the addition of NSP enzymes, even with a reduction of AME. These nutritional approaches are efficient in improving broilers' performances by themselves and even more so when they are combined.

DETERMINAÇÃO DA COMPOSIÇÃO QUÍMICA E DOS VALORES DE ENERGIA METABOLIZÁVEL DE ALGUNS ALIMENTOS PROTEICOS PARA FRANGOS DE CORTE

Resumo Foi realizado um experimento, utilizando-se o método tradicional de coleta total de excretas, com o objetivo de determinar os valores de energia metabolizável aparente, energia metabolizável aparente corrigida pelo balanço de nitrogênio e composição química de seis alimentos: soja integral desativada com casca, soja integral desativada sem casca, concentrado proteico de soja, farelo de soja extrusada semi-integral, farelo de soja e glúten de trigo. Foram utilizados 252 pintos de corte da linhagem comercial Cobb 500, com 14 dias de idade, distribuídos em delineamento inteiramente casualizado, com sete tratamentos (seis rações testes e uma ração referência), seis repetições e seis aves por unidade experimental. Os cinco dias iniciais foram destinados à adaptação das aves às rações experimentais e os cinco dias finais à coleta total das excretas, realizada duas vezes ao dia. Os valores de energia metabolizável aparente corrigida pelo balanço de nitrogênio na matéria natural determinados em frangos de corte no período de 14 a 24 dias de idade foram os seguintes: soja integral desativada com casca: 2797 kcal/kg; soja integral desativada sem casca: 3012 kcal/kg; concentrado proteico de soja: 2554 kcal/kg; farelo de soja extrusada semi-integral: 2467 kcal/kg; farelo de soja: 2221 kcal/kg; glúten de trigo: 3813 kcal/kg.

In vitro gastrointestinal digestion study of two wheat cultivars and evaluation of xylanase supplementation

BACKGROUND

The filamentous fungus Talaromyces versatilis is known to improve the metabolizable energy of wheat-based poultry diets thanks to its ability to produce a pool of CAZymes and particularly endo-β(1,4)-xylanases. In order to appreciate their in vivo mode of action, the supplementation effect of two of its xylanases, XynD and XynB from families GH10 and GH11 respectively, have been evaluated on two different wheat cultivars Caphorn and Isengrain, which were chosen amongst 6 varieties for their difference in non starch polysaccharides content and arabinoxylan composition.

RESULTS

Polysaccharides digestion was followed during 6 h along the digestive tract using the TNO gastrointestinal model-1, to mimic monogastric metabolism. Polysaccharide degradation appeared to occur mainly at the jejunal level and was higher with Isengrain than with Caphorn. For both cultivars, XynD and XynB supplementation increased notably the amount of reducing end sugars into the jejuno-ileal dialysates, which has been confirmed by a valuable increase of the soluble glucose into the jejunal dialysates.

CONCLUSIONS

The amounts of arabinose and xylose into the dialysates and ileal deliveries increased consequently mainly for Caphorn, suggesting that XynD and XynB supplementation in wheat-based diet could alleviate the anti-nutritional effects of arabinoxylans by limiting the physical entrapment of starch and could increase the available metabolizable energy.

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 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.

Review: Prediction of variation in energetic value of wheat for poultry

Yegani, M. and Korver, D. R. 2012. Review: Prediction of variation in energetic value of wheat for poultry. Can. J. Anim. Sci. 92: 261–273. Variations in physical and chemical characteristics of wheat can significantly influence the energy availability of this feed ingredient for poultry. These variations can result in inefficiencies in the form of over- or under-formulation of the diets at commercial feed mills or on poultry farms. Therefore, having a clear understanding of the variations is of paramount importance in the formulation of poultry diets as they can have negative consequences for production performance of birds. There are a large number of factors that can contribute to variations in energy availability of wheat for poultry. This review is intended to briefly discuss these factors and also practical approaches that can be used to predict these variations. These approaches include measuring physico-chemical characteristics, in vivo digestibility trials, in vitro digestibility techniques, and near infrared reflectance spectroscopy (NIRS). There are limitations associated with physico-chemical and in vivo measurements. However, in vitro digestibility techniques are simple and fast and can provide data for database development and ongoing calibrations of NIRS systems. Near infrared reflectance spectroscopy has enormous potential to predict variations in wheat apparent metabolizable energy, leading to more accurate diet formulation.

Treatment of APMP pulping effluent based on aerobic fermentation with Aspergillus niger and post-coagulation/flocculation

A novel two-stage biological/flocculation process was developed for treating the pulping effluent from the alkaline peroxide mechanical pulping (APMP) process. In the first biological stage, the aerobic fermentation by using Aspergillus niger can decrease the chemical oxygen demand (COD) by about 60% while producing about 7 g/l of solid biomass. In the second stage (post-coagulation/flocculation), the residual COD, turbidity and color, can be further decreased by using alum and polyacrylamide (PAM). The overall removal efficiencies of COD, color and turbidity from the APMP pulping effluent by the above two-stage biological-coagulation/flocculation process were 93%, 92% and 99%, respectively, under the conditions studied.