Ileal Digestible Energy Research Articles

Evaluation of a thermotolerant xylanase on broiler growth performance and dietary ileal digestible energy value

Two experiments were conducted to evaluate the impact of a thermotolerant xylanase on male broiler performance and dietary ileal digestible energy (IDE). The first experiment consisted of 3 treatment groups with 12 replications per treatment each containing 35 Cobb 500 males for a total of 1,260 broilers placed in floor pens for a 42 d grow-out. The experiment treatments included a corn/soy diet with DDGS control formulated at a low energy level, and the control supplemented with one of 2 concentrations of xylanase (20,000 XU/kg [XYL20] and 40,000 XU/kg [XYL40]). No significant differences in body weight were observed with the inclusion of xylanase when compared to the control diet throughout the experiment. At d 28, the inclusion of XYL20 improved (P < 0.05) mortality corrected feed conversion ratio (FCR) compared to the control diet. Feed conversion ratio was also improved (P < 0.01) at d 42 for birds fed XYL20 when compared to the control. At d 42, inclusion of XYL20 and XYL40 significantly (P < 0.05) increased IDE compared to the control. Experiment 2 consisted of 4 treatment groups with 10 replications per treatment each containing 44 Cobb 500 males for a total of 1,760 broilers placed in floor pens for a 41 d grow-out. The dietary treatments included a positive control (PC) based on a corn/soy diet containing DDGS and phytase, a negative control (NC) diet (PC -150 kcal/kg in AME), NC + xylanase at 10,000 XU/kg (XYL10), and NC + xylanase at 20,000 XU/kg (XYL20). A significant increase (P < 0.05) in BW was observed in broilers fed the inclusion of XYL20 in the NC diet increased (P < 0.05) on d 14. A significant increase in cumulative body weight gain was observed on d 27 and d 41 with xylanase (XYL20) inclusion compared to the NC. These data demonstrate that xylanase inclusion increased energy utilization through improvements in IDE, which improved broiler performance.

257 Standardized ileal digestible amino acids and digestible energy contents in high-protein distiller's dried grains with solubles fed to growing pigs

257 Standardized ileal digestible amino acids and digestible energy contents in high-protein distiller's dried grains with solubles fed to growing pigs

Effects of dietary xylanase supplementation on performance and functional digestive parameters in broilers fed wheat-based diets

This experiment was conducted to evaluate dietary xylanase supplementation in broilers wheat-based diets on performance and functional digestive parameters including ileal digesta viscosity, apparent ileal digestibility, intestinal morphology and microflora, digestive enzyme activities, and excreta odor content. A total of 600 1-day-old Ross 308 male broilers with an initial average BW of 45 ± 0.6 g were randomly allotted into 4 treatments with 10 replicate pens per treatment and 15 broilers in each pen for 35 d. The 4 dietary treatments were wheat-based diets and supplemented with 0, 1,875, 3,750, and 5,625 XU/kg xylanase. Xylanase supplementation improved (linear, P < 0.05) the body weight gain and decreased (linear, P < 0.05) the feed conversion ratio during d 1 to 18 and for the duration of the experiment. Dietary supplementation of xylanase led to a decrease (linear, P < 0.01) in ileal digesta viscosity. The apparent ileal digestibility of dry matter (DM), crude protein (CP), gross energy, and most amino acids (with the exception of Ile, Phe, Asp, Glu, and Pro) were increased (linear, P < 0.05) by xylanase supplementation. Increasing the dietary xylanase levels improved (linear, P < 0.05) the villus height and the ratio of villus height to crypt depth of the duodenum, jejunum, and ileum. In addition, inclusion of xylanase increased (linear, P < 0.05) the Lactobacillus numbers in the ileum and cecum, while decreased the ileal E. coli counts (linear, P < 0.01) and cecal E. coli populations (linear, P < 0.01; quadratic, P < 0.05). There were no significant differences (P > 0.05) in trypsin, amylase, and protease activities of small intestine among dietary treatments. Furthermore, xylanase supplementation reduced excreta NH3 (linear, P < 0.05; quadratic, P < 0.05) and total mercaptan (R.SH) (linear, P < 0.01) concentration. Taken together, dietary xylanase supplementation in broilers wheat-based diets had beneficial effects on growth performance, apparent ileal digestibility of nutrients, intestinal morphology, and microflora balance. Furthermore, the xylanase could reduce the ileal digesta viscosity and excreta odor contents.

248 Improvement of ileal digestibility of dry matter and gross energy by commercial carbohydrases is associated with depression of fermentability in an in vitro digestibility determination system

248 Improvement of ileal digestibility of dry matter and gross energy by commercial carbohydrases is associated with depression of fermentability in an in vitro digestibility determination system

Energy values of canola meal, cottonseed meal, bakery meal, and peanut flour meal for broiler chickens determined using the regression method

The energy values of canola meal (CM), cottonseed meal (CSM), bakery meal (BM), and peanut flour meal (PFM) for broiler chickens were determined in 2 experiments with Ross 708 broiler chickens from d 21 to 28 posthatch. The birds were fed a standard broiler starter diet from d 0 to 21 posthatch. In each experiment, 320 birds were grouped by weight into 8 blocks of 5 cages with 8 birds per cage and assigned to 5 diets. Each experiment used a corn-soybean meal reference diet and 4 test diets in which test ingredients partly replaced the energy sources in the reference diet. The test diets in Exp. 1 consisted of 125 g CM, 250 g CM, 100 g CSM, or 200 g CSM/kg. In Exp. 2, the test diets consisted of 200 g BM, 400 g BM, 100 g PFM, or 200 g PFM/kg. The ileal digestible energy (IDE), metabolizable energy (ME), and nitrogen-corrected metabolizable energy (MEn) of all the test ingredients were determined by the regression method. The DM of CM, CSM, BM and PFM were 883, 878, 878, and 964 g/kg, respectively and the respective gross energies (GE) were 4,143, 4,237, 4,060, and 5,783 kcal/kg DM. In Exp. 1, the IDE were 2,132 and 2,197 kcal/kg DM for CM and CSM, respectively. The ME were 2,286 and 2,568 kcal/kg DM for CM and CSM, respectively. The MEn were 1,931 kcal/kg DM for CM and 2,078 kcal/ kg DM for CSM. In Exp. 2, IDE values were 3,412 kcal/kg DM for BM and 4,801 kcal/kg DM for PFM; ME values were 3,176 and 4,601 kcal/kg DM for BM and PFM, respectively, and the MEn values were 3,093 kcal/kg DM for BM and 4,112 kcal/kg DM for PFM. In conclusion, the current study showed that chickens can utilize a considerable amount of energy from these 4 ingredients, and also provided the energy values of CM, CSM, BM and PFM for broiler chickens.

The efficacy of dietary xylanase and phytase in broiler chickens fed expeller-extracted camelina meal

A study was conducted to investigate the effects of dietary phytase (PHY) and xylanase (XYL) on growth performance, nutrient utilization, and intestinal characteristics in broilers fed corn-soybean meal-based diets with added expeller-extracted camelina meal (CM). The corn-soybean meal-based diets without or with CM was formulated to contain 2.9 or 2.7 g/kg non phytate phosphorus, respectively. A total of 384 male Ross 708 broilers were allocated to 8 dietary treatments in a randomized complete block design with 6 replicates per treatment, from 7 to 21 d post hatching. The experiment consisted of a 2 × 2 × 2 factorial arrangement of treatments with 2 dietary CM levels (zero or 100 g/kg), 2 dietary levels of XYL (zero or 800 unit/kg), and 2 dietary levels of PHY (zero or 4,000 unit/kg). Chromic oxide was included in the diets as an indigestible marker. Growth was measured throughout the experiment and excreta were collected on d 18 to 21 post hatching for measurement of nutrient and energy retention. On d 21 post hatching, broilers were euthanized by CO2 asphyxiation, ileal digesta was collected for nutrient and energy digestibility measurements, and the left tibia was removed for bone ash measurement. Furthermore, duodenal digesta was collected and a segment of the mid jejunum was excised for viscosity and morphology measurement, respectively. Broilers fed 100 g/kg CM diets showed lower (P < 0.001) BW gain and G:F than those fed zero g/kg CM diets for 7 to 14 d and 7 to 21 d post hatching periods, respectively. Phytase supplementation improved (P < 0.05) all the growth parameters measured regardless of CM addition. Phytase supplementation resulted in an increase (P < 0.05) in jejunum villus height but there was no impact of CM or XYL. Additionally, duodenal digesta viscosity increased (P < 0.001) with added CM. Tibia ash and weight increased (P < 0.001) with PHY supplementation. There was a CM × PHY interaction (P < 0.05) on percentage tibia ash, with greater PHY effect in zero g/kg CM diets compared with 100 g/kg CM diets. Phytase supplementation increased (P < 0.05) ileal DM, N, energy, P, and neutral detergent fiber (NDF) digestibility. In diets with 100 g/kg CM, addition of PHY had a greater effect (CM × PHY; P < 0.05) on ileal P digestibility compared with diet without CM. There was a CM × PHY interaction (P < 0.05) for ileal digestible energy (IDE) in which PHY increased the IDE in birds fed CM supplemented diets. Both ileal digestibility and retentions of DM, N, energy, and IDE, AME, and AMEn were decreased (P < 0.05) by CM supplementation. Retention of ether extract and NDF decreased (P < 0.05) with CM supplementation. Nitrogen retention, AME, and AMEn decreased (CM × XYL; P < 0.05) with XYL supplementation in zero g/kg CM diets. There were CM × XYL interactions (P < 0.01) for P and Ca retentions in which XYL increased retentions in 100 g/kg CM diets. In conclusion, PHY was efficacious at improving P digestibility and retention of birds fed low P corn-soy based diets without or with CM. However, regardless of CM addition, XYL did not improve nutrient utilization and growth performance of broiler chickens. The present data also show that the mechanism underlying the detrimental effects of CM inclusion on nutrient utilization is not mediated through gut morphology and goblet cell density. The data also show that the villus height increase occurring with PHY addition might be a contributor to the improvements in ileal DM, N, and energy digestibility obtained with PHY supplementation.

THESIS-ABSTRACT Supplementation levels of exogenous alpha-amylase in broilers diets.

This study aimed to evaluate the supplementation levels of an exogenous alpha-amylase in broilers diets and compare two indicators in determining the diets energy. The experiment was divided into two parallel evaluations, being one of performance and the other of metabolism. In performance assay, 1,700 one-day-old Cobb-500 male chicks were used. The animals were distributed in 50 experimental plots and evaluated five treatments with ten replicates in a completely randomized design (CRD). The treatments were: a positive control (PC), a negative control (NC) and three alpha-amylase supplementation levels 200, 400 and 600 g/t, and the NC was formulated with 50 and 90 kcal of energy reduction in relation to the PC to the phases from 1 to 21 days and from 22 to 42 days, respectively. In the metabolism assay were used 240 animals, 150 birds for stage from 14 to 21 days and 90 birds to stage from 35 to 42 days of age and the treatments were the same as the performance assay, with six replicates per treatment in CRD. All diets of metabolism test contained the digestibility indicators Lipe® (eucalyptus purified lignin) and chromic oxide (Cr2O3), in concentrations of 0.05 and 1.0%, respectively. In the period from 1 to 21 days old, no significant differences were observed in weight gain (WG) (P > 0.05), however, feed intake (FI) was found higher by using 200 ppm of enzyme (P < 0.05) and better feed conversion (FC) with the PC (P < 0.05). From 22 to 42 days, no significant differences were observed on the WG (P > 0.05), but were observed lower FI and better FC to PC treatment (P < 0.05). In the period from 1 to 42 days of age, significant differences were also not observed on the WG (P > 0.05), but there was lower FI and better FC for the PC treatment (P < 0.05). The AMEn (apparent metabolizable energy corrected for nitrogen balance), determined using the total collection, reaffirmed the values ​​calculated for the PC and NC with intermediate data obtained from the enzyme use (200, 400 and 600 ppm). Comparing the total collection using Lipe® and Cr2O3, a correlation was observed only for the PC results, that were always higher, and for the NC results, that were lower for the three methodologies. For IDE (ileal digestible energy), determined by Cr2O3, significant differences were observed (P < 0.05) and it presented higher values in the PC treatment and lower values in the NC. In IDE determining by Lipe®, significant was observed (P < 0.05), showing higher value in the PC treatment. It is concluded that in the metabolism assessments, exogenous alpha-amylase tested was effective in increasing the metabolizable energy (ME), however, not enough to be equivalent to the ME of PC treatment, a result that was better expressed in the total collection, AMEn by Lipe® and IDE by Lipe® methodologies. The performance results reflect the superiority of PC treatment, pointing enzyme limitation to supply the energy deficit practiced in this work.

Standardized ileal digestible amino acids and digestible energy contents in high-protein distiller’s dried grains with solubles fed to growing pigs

Standardized ileal digestible amino acids and digestible energy contents in high-protein distiller’s dried grains with solubles fed to growing pigs

Apparent total tract digestibility and ileal digestibility of dry matter, nitrogen, energy and amino acids in conventional, Bacillus subtilis-fermented and enzyme-treated soybean meal fed to weanling pigs

Apparent total tract digestibility and ileal digestibility of dry matter, nitrogen, energy and amino acids in conventional, Bacillus subtilis-fermented and enzyme-treated soybean meal fed to weanling pigs

Effects of feed intake and dietary nutrient density on apparent ileal and total tract digestibility of nutrients and gross energy for growing pigs.

The present study was conducted to investigate the effects of feed intake (FI) and dietary nutrient concentration on the determination of apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and GE for growing pigs. A total of 48 growing pigs (40.7 ± 1.3 kg initial BW) were surgically fitted with simple T-cannulas at the distal ileum and assigned to 6 treatment groups in a 2 × 3 factorial arrangement of 2 diets (a low-nutrient-density [LND] diet or a normal-nutrient-density [NND] diet) and 3 FI levels (3, 4 or 5% of BW per day). The experimental period consisted of a 5-d adjustment period: 2 d of feces collection (on d 6 and 7), and 2 d of ileal digesta collection on (d 8 and 9). Chromic oxide was used as an indigestible marker to calculate AID of AA and AID and ATTD of CP, ether extract (EE), ash, ADF, NDF, total carbohydrates (CHO), and GE. The AID of CP ( < 0.05), EE ( < 0.1), ash ( < 0.05), and GE ( < 0.1); the ATTD of ash ( < 0.1); and the hindgut disappearance of CP ( < 0.05), ash ( < 0.1), and most AA were affected by the interaction of dietary nutrient density and FI level. The AID of CP and the AID and ATTD of DM, EE, CHO, and GE linearly decreased for pigs fed a NND diet as FI increased ( < 0.05). Furthermore, the AID of CHO ( < 0.1) and NDF ( < 0.05), the ATTD of DM ( < 0.1), and the hindgut disappearance of CHO and NDF ( < 0.1) were influenced by FI. When pigs were fed the NND diet, the AID of most AA decreased (linear, < 0.05) with increasing FI. However, there were no linear or quadratic effects of FI levels on the AID, ATTD, and the hindgut disappearance of DM, CP, EE, CHO, NDF, ADF, and GE and the AID of most AA for pigs fed the LND diet. In summary, the AID and ATTD of nutrients and GE response of growing pigs to FI levels are dependent on dietary nutrients density. The AID and ATTD of nutrients and GE decreased for pigs fed the NND diet as FI increased.

0987 Evaluation of ileal energy digestibility of diets based on different grain species fed to growing pigs

0987 Evaluation of ileal energy digestibility of diets based on different grain species fed to growing pigs

Energy and phosphorus values of sunflower meal and rice bran for broiler chickens using the regression method

The energy and phosphorus values of sunflower meal (SFM) and rice bran (RB) were determined in 2 experiments with Ross 708 broiler chickens from 15 to 22 d of age. In Exp.1, the diets consisted of a corn-soybean meal reference diet (RD) and 4 test diets (TD). The TD consisted of SFM and RB that partly replaced the energy sources in the RD at 100 or 200g/kg and 75 or 150g/kg, respectively, such that the equal ratios were maintained for all energy containing ingredients across all experimental diets. In Exp.2, a cornstarch-soybean meal diet was the RD and TD consisting of SFM and RB that partly replaced cornstarch in the RD at 100 or 200g/kg and 60 or 120g/kg, respectively. Addition of SFM and RB to the RD in Exp.1 linearly decreased (P <0.01) the digestibility coefficients of DM, energy, ileal digestible energy (IDE), metabolizability coefficients of DM, nitrogen (N), energy, N correct energy, metabolize energy (ME), and nitrogen-corrected ME. Except for RB, the increased levels of the test ingredients in RD did affect the metabolizability coefficients of N. The IDE values (kcal/kg DM) were 1,953 for SFM and 2,498 for RB; ME values (kcal/kg DM) were 1,893 for SFM and 2,683 for RB; and MEn values (kcal/kg DM) were 1,614 for SFM and 2,476 for RB. In Exp.2, there was a linear relationship between phosphorus (P) intake and ileal P output for diets with increased levels of SFM and RB. In addition, there was a linear relationship between P intake and P digestibility and retention for diets with increased levels of SFM. There were a quadratic effect (P <0.01) and a tendency of quadratic effect (P = 0.07) for P digestible and total tract P retained, respectively, in the RB diets. The P digestibility and total tract P retention from regression analyses for SFM were 46% and 38%, respectively.

Energy and nutrient utilization of broiler chickens fed corn-soybean meal and corn-based diets supplemented with xylanase

A study was conducted to evaluate the effects of increased levels of a β-xylanase on energy and nutrient utilization of broiler chickens fed corn-soy diets. A total of 480 slow feathering Cobb × Cobb 500 male broilers were randomly distributed to 10 treatments having 8 replicates of 6 birds each. Birds were fed a common starter diet to d 14 post hatch (3,050 kcal/kg AMEn, 21.7% CP, 1.05% Ca, and 0.53% nPP). The experimental diets were provided afterwards until 25 d. Two experimental diets, a conventional corn/soy-based basal diet (CS) and the basal diet in which 40% of the diet was displaced by corn (CN), were fed as-is or supplemented with 50, 100, 150, or 200 fungal β-xylanase units (FXU)/kg. Dietary treatments were distributed factorially as a 2 × 5 arrangement. Samples of feed, excreta, and ileal digesta were analyzed for determination of ileal digestible energy (IDE), metabolizable energy, and total tract retention of protein and lipid. No interactions between diet and xylanase were observed. The CS diets had higher (P < 0.05) energy utilization and nutrient digestibility when compared to the CN diets. AMEn and IDE were improved (P < 0.05) by 192 and 145 kcal/kg, respectively, when diets were supplemented with 100 FXU/kg xylanase. The xylanase added to the CN diet led to quadratic increases (P < 0.05) in IDE (Y = - 0.014x(2) + 2.570x + 3,155; r(2) = 0.60) and in AMEn (Y = - 0.016x(2) + 3.982x + 3,155; r(2) = 0.68). Crude protein digestibility and AMEn were linearly increased (P < 0.05) when xylanase was added to the CN diet. In conclusion, energy utilization and digestibility of crude protein and dry matter increased with xylanase supplementation in corn/soy-based diets. When xylanase was tested in the CS diet, 92 and 124 FXU/kg maximized the energy release effect; however, the maximum energy response in the CN diet or corn was not achieved until 200 FXU/kg.

Investigation of the effect of coccidial vaccine challenge on apparent and standardized ileal amino acid digestibility in grower and finisher broilers and its evaluation in 21-day-old broilers

The effect of coccidial vaccine challenge (CVC, Coccivac(®)B; challenged, CHA; or unchallenged, NCH) on ileal endogenous amino acid (IEAA) losses and standardized ileal AA digestibility (SIAAD) in 21- and 42-day-old broilers fed a corn-soybean meal-dried distillers' grains with solubles-poultry by-product meal-based diet (Expt.1) and the effect of supplemental AA in ameliorating the effect of CVC (Expt.2) were evaluated. Expt.1 was designed as a 2 (d 21 or 42) x 2 (NCH or CHA) factorial arrangement of treatments with 8 replicates in a complete randomized design. The CVC birds were gavaged with 12 x coccidial vaccine on d 15 and 36 and were sampled on 6 d post challenge. SIAAD was determined by correcting apparent ileal AA digestibility for IEAA losses. Feed intake (FI) and BW gain were higher (P ≤ 0.05) in 21-day-old NCH birds compared to the 21-day-old CHA birds while 42-day-old birds had higher FI and BW gain than 21-day-old NCH and CHA birds. Ileal endogenous nitrogen loss was higher (P ≤ 0.05) in 42-day-old CHA birds compared to 42-day-old NCH birds. Apparent ileal AA digestibility in 21-day-old CHA birds was lower (P ≤ 0.05) than for 21-day-old NCH and 42-day-old NCH and CHA birds. SIAAD in 21-day-old CHA birds was lower (indispensable AA = 15.2 and dispensable AA = 17.8%-unit; P ≤ 0.05) than for 21-day-old NCH and 42-day-old NCH and CHA birds. Apparent ileal digestibility and total tract utilization of DM, N, and energy were not different between d 21 NCH and d 42 NCH and CHA birds but higher (P ≤ 0.05) than for d 21 CHA birds. Supplemental AA restored feed efficiency, but not BW gain, to that of the positive control (0.715vs. 0.737). Results from Expt.1 showed that CVC significantly influenced ileal AA digestibility in 21- but not in 42-day-old birds. Expt.2 showed that consideration of SIAAD in feed formulation may benefit feed efficiency.

Age-related energy values of bakery meal for broiler chickens determined using the regression method

A study was conducted to determine the ileal digestible energy (IDE), ME, and MEn contents of bakery meal using the regression method and to evaluate whether the energy values are age-dependent in broiler chickens from zero to 21 d post hatching. Seven hundred and eighty male Ross 708 chicks were fed 3 experimental diets in which bakery meal was incorporated into a corn-soybean meal-based reference diet at zero, 100, or 200 g/kg by replacing the energy-yielding ingredients. A 3 × 3 factorial arrangement of 3 ages (1, 2, or 3 wk) and 3 dietary bakery meal levels were used. Birds were fed the same experimental diets in these 3 evaluated ages. Birds were grouped by weight into 10 replicates per treatment in a randomized complete block design. Apparent ileal digestibility and total tract retention of DM, N, and energy were calculated. Expression of mucin (MUC2), sodium-dependent phosphate transporter (NaPi-IIb), solute carrier family 7 (cationic amino acid transporter, Y+ system, SLC7A2), glucose (GLUT2), and sodium-glucose linked transporter (SGLT1) genes were measured at each age in the jejunum by real-time PCR. Addition of bakery meal to the reference diet resulted in a linear decrease in retention of DM, N, and energy, and a quadratic reduction (P < 0.05) in N retention and ME. There was a linear increase in DM, N, and energy as birds’ ages increased from 1 to 3 wk. Dietary bakery meal did not affect jejunal gene expression. Expression of genes encoding MUC2, NaPi-IIb, and SLC7A2 linearly increased (P < 0.05) with age. Regression-derived MEn of bakery meal linearly increased (P < 0.05) as the age of birds increased, with values of 2,710, 2,820, and 2,923 kcal/kg DM for 1, 2, and 3 wk, respectively. Based on these results, utilization of energy and nitrogen in the basal diet decreased when bakery meal was included and increased with age of broiler chickens.

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

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

Energy and nutrient utilisation of broilers fed soybean meal from two different Brazilian production areas with an exogenous protease

A study was conducted to evaluate the effects of an exogenous protease added to diets having soybean meal (SBM) from two geographic areas in Brazil (South or North). Evaluation was conducted on energy utilisation and nutrient digestibility using 224 slow feathering Cobb×Cobb 500 male broilers. Birds were fed a common starter diet to d 15. Semi-purified experimental diets containing 555g/kg SBM and 408g/kg maize starch plus minerals and vitamins were provided afterwards until 24 d. Diets had 0.1g/kg phytase and 10g/kg Celite (indigestible marker). Birds were randomly distributed in a 2×2 factorial arrangement of the two SBM with or without protease supplementations (0 or 15,000 protease units/kg) from 17 to 24 d. Excreta were collected from 21 to 23 d and ileal content was collected from all birds. Samples of feed, excreta, and ileal content were analysed for determination of total tract retention and ileal apparent digestibility. No interactions between SBM and protease were observed. Broilers fed semi-purified diets formulated with South SBM had lower (P<0.05) ileal digestibility of crude protein and also from most amino acids (AA) when compared with birds fed North SBM. Ileal digestible energy was increased (P<0.01) by 0.51MJ/kg when birds were fed the diet supplemented with protease. Indispensable and dispensable AA digestibility also increased (P<0.05) with protease supplementation. Ileal digestibility coefficients of Met, Lys, Thr and Val were increased (P<0.05) by 3.1%, 3.1%, 4.8%, and 3.3%, respectively when birds were fed the diet supplemented with protease. Results from this experiment show that utilisation of energy and AA from SBM depends on its origin, but protease supplementation improved their utilisation regardless of the SBM source.

Interactive effects of dietary protein concentration and aflatoxin B1 on performance, nutrient digestibility, and gut health in broiler chicks

A 20-day trial was conducted to determine the impact of aflatoxin B1 (AFB1) and dietary protein concentration on performance, nutrient digestibility, and gut health in broiler chicks. The 6 dietary treatments were arranged in a 2 × 3 factorial with 3 crude protein (CP) concentrations (16, 22, and 26%) with or without 1.5 mg/kg AFB1. Each diet was fed to 6 replicate cages (6 chicks per cage) from zero to 20 d of age. Endogenous N and amino acid loss were estimated from birds fed a N-free diet with or without 1.5 mg/kg AFB1. A significant interaction between AFB1 and CP concentration was observed for growth performance, where reduction of BW gain, feed intake, gain:feed ratio, and breast muscle weight by AFB1 were most profound in birds fed the 16%-CP diet, and were completely eliminated when birds were fed the 26%-CP diet (AFB1 by CP interaction; P ≤ 0.023). Similarly, AFB1 reduced serum albumin, total protein, and globulin concentrations in birds fed 16 and 22% CP diets, but not in those fed the 26%-CP (AFB1 by CP interaction; P ≤ 0.071). Gut permeability was increased in birds fed AFB1-contamiated diets as measured by serum lactulose/rhamnose ratio (main effect; P = 0.04). Additionally, AFB1 tended to increase endogenous N loss (P = 0.09), and significantly reduced apparent ileal digestible energy and standardized ileal N and amino acid digestibility in birds fed the 16%-CP diet, while birds fed higher dietary CP were not affected (AFB1 by CP interaction; P ≤ 0.01). Further, AFB1 increased the translation initiation factor 4E-binding protein (4EBP1), claudin1, and multiple jejunal amino acid transporters expression (main effect; P ≤ 0.04). Results from this study indicate that a 1.5 mg AFB1/kg diet significantly impairs growth, major serum biochemistry measures, gut barrier, endogenous loss, and energy and amino acid digestibility. Aflatoxicosis can be augmented by low dietary CP, while higher dietary CP completely eliminated the impairment of performance, serum proteins, and nutrient digestibility from aflatoxicosis in zero to 20 d broiler chicks.

Determination of ileal digestible and apparent metabolizable energy contents of expeller-extracted and solvent-extracted canola meals for broiler chickens by the regression method.

The present study was conducted to determine ileal digestible energy (IDE), metabolizable energy (ME), and nitrogen-corrected ME (MEn) contents of expeller- (EECM) and solvent-extracted canola meal (SECM) for broiler chickens using the regression method. Dietary treatments consisted of a corn–soybean meal reference diet and four assay diets prepared by supplementing the reference diet with each of canola meals (EECM or SECM) at 100 or 200 g/kg, respectively, to partly replace the energy yielding sources in the reference diet. Birds received a standard starter diet from day 0 to 14 and the assay diets from day 14 to 21. On day 14, a total of 240 birds were grouped into eight blocks by body weight and randomly allocated to five dietary treatments in each block with six birds per cage in a randomized complete block design. Excreta samples were collected from day 18 to 20 and ileal digesta were collected on day 21. The IDE, ME, and MEn (kcal/kg DM) of EECM or SECM were derived from the regression of EECM- or SECM-associated IDE, ME and MEn intake (Y, kcal) against the intake of EECM or SECM (X, kg DM), respectively. Regression equations of IDE, ME and MEn for the EECM-substituted diet were Y = −21.2 + 3035X (r2 = 0.946), Y = −1.0 + 2807X (r2 = 0.884) and Y = −2.0 + 2679X (r2 = 0.902), respectively. The respective equations for the SECM diet were Y = 20.7 + 2881X (r2 = 0.962), Y = 27.2 + 2077X (r2 = 0.875) and Y = 24.7 + 2013X (r2 = 0.901). The slope for IDE did not differ between the EECM and SECM whereas the slopes for ME and MEn were greater (P < 0.05) for the EECM than for the SECM. These results indicate that the EECM might be a superior energy source for broiler chickens compared with the SECM when both canola meals are used to reduce the cost of feeding.

Influence of partial replacement of ground wheat with whole wheat and exogenous enzyme supplementation on growth performance, nutrient digestibility and energy utilization in young broilers.

This study investigated the influence of pre-pelleting inclusion of whole wheat (WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility (CAID) and apparent metabolizable energy (AME) in broilers fed wheat-based pelleted diets. A 2×3 factorial arrangement of treatments was used with two methods of wheat inclusion [622g/kg ground wheat (GW) and 250g/kg WW replaced GW (wt/wt) pre-pelleting (PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one-day-old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p<0.05) weight than those fed GW diets. There was no effect (p>0.05) of WW inclusion on feed intake (FI). Phytase alone increased (p<0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p<0.05) the gain-to-feed ratio (G:F). Feeding xylanase plus phytase and phytase-added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p<0.05) relative gizzard weights than those fed GW diets. There was no effect (p>0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p<0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p<0.05) AME values than GW diets. Combination of xylanase and phytase increased (p<0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre-pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive.