Apparent Ileal Digestibility Of Energy Research Articles

Impact of combined xylanase and β-glucanase enzymes on digesta transit time, short-chain fatty acids, and caecal thermal profile of broilers fed corn–soy-based diets

A study was conducted to evaluate the effects of including a xylanase + β-glucanase enzyme product in corn–soy-based diets on performance, caecal short-chain fatty acids and thermal profile, ileal digestibility, and intestinal kinetics of broiler chickens. A total of 744 male day-old chicks were randomly allotted to 24 floor pens and distributed in a 2 × 2 factorial arrangement with low or standard energy level × without or with 100 g of the enzyme per ton of feed. Enzyme supplementation improved bodyweight gain from 1 to 21 d (P < 0.05). An increased caecal concentration of acetic acid was observed when the enzyme was added to the low-energy diet (P < 0.05). The pH of the caecal content was reduced (P < 0.01), and the caecal temperature was increased by low-energy diets (P < 0.05). The apparent ileal digestibility of energy was improved by the enzyme (P < 0.01). The addition of the enzyme increased the mean retention time in the distal ileum (P < 0.05). In summary, the addition of a xylanase + β-glucanase enzyme product in corn-based diets increases the retention time of digesta in the distal ileum and the caecal acetic acid concentration, improves ileal digestibility of energy and performance from 1 to 21 d in broiler chickens fed corn–soy-based diets.

Mathematical prediction of ileal energy and protein digestibility in broilers using multivariate data analysis

A proportional mixture design was used to systematically create a total of 56 diets using ten feed ingredients. Diets differed widely with regards to chemical characteristics and ingredient inclusion levels. Apparent ileal digestibility of energy and protein of the diets were determined in broiler growers fed ad libitum from 21 to 24 d post-hatch. The chemical composition and the in vivo digestibility values were used to establish prediction equations for energy and protein digestibility, using multivariate data analysis. Root mean square error as percentage of the observed means (RMSE%) and residual error were used to evaluate the strength and accuracy of the predictions and to compare predictions based on chemical characteristics with estimates based on table values. The estimates of ileal digestibility of energy from table values were relatively accurate (RMSE% = 5.15) and was comparable to those predicted based on the chemical composition of diets. Estimates of ileal digestibility of protein based on table values were less accurate (RMSE% = 8.21); however, the prediction was improved by multivariate regression (RMSE% = 5.46) based on chemical composition of diets. The best predictors for ileal energy digestibility were starch, crude fiber and phytate contents (P < 0.01) and the best predictors for crude protein digestibility were starch, CF and fat contents (P < 0.05). In conclusion, the ileal digestibility of energy can be accurately predicted using table values; however, the accuracy of prediction of the ileal digestibility of protein can be improved when chemical characteristics of the diet are considered.

The impact of deoxynivalenol, fumonisins, and their combination on performance, nutrient, and energy digestibility in broiler chickens

This study evaluated the effects of the mycotoxins deoxynivalenol (DON), fumonisins (FUM), and their combination on growth performance, nutrient, and energy digestibility in broilers. A total of 960 Cobb-Cobb male broilers were obtained on the day of hatch and placed 10 birds per cage with 8 cages per treatment. The experiment consisted of 12 treatments: control; DON 1.5 mg/kg; DON 5.0 mg/kg; FUM 20.0 mg/kg; DON 1.5 mg/kg + FUM 20.0 mg/kg; and DON 5.0 mg/kg + FUM 20 mg/kg. The remaining dietary treatments were the correlative nitrogen-free diets (NFD) for determining the endogenous nutrients loss. All birds were fed with a corn−soybean meal diet from days 1 to 15, until birds from latter 6 treatments were switched to their correlative NFD diet from days 15 to 21. Feed and BW were weighed by cage on days 8, 15, and 21. On day 21, ileal digesta was collected for digestibility determination. Both DON 1.5 mg/kg + FUM 20 mg/kg and DON 5.0 mg/kg + FUM 20 mg/kg treatments showed reduced feed intake (P ≤ 0.05) from days 8 to 15 and days 15 to 21. However, no significant effects were noted for BW gain or mortality-adjusted feed conversion ratio after adding single or combined mycotoxin on days 8 and 15. At day 21, cumulative BW gain was less (P ≤ 0.05) in birds fed with the mycotoxin combination diets than the control. No significant changes were shown for ileal endogenous amino acids losses. Control treatment had significantly higher (P ≤ 0.05) apparent ileal energy digestibility than the DON 5.0 mg/kg + FUM 20.0 mg/kg treatment (3,126 vs. 2,895 kcal/kg), representing a 5%-unit loss in apparent DM digestibility. No significant difference was found for standardized crude protein and amino acid digestibility. In conclusion, the combination of DON and FUM (DON 1.5 mg/kg + FUM 20 mg/kg or DON 5.0 mg/kg + FUM 20 mg/kg) reduced DM and ileal energy digestibility, which negatively affected BW gain in broilers.

Use of feed technology to improve the nutritional value of feed ingredients

Two experiments were conducted to test the hypothesis that reduced particle size of corn will improve the caloric utilisation of corn fed to weanling pigs and to determine effects of pelleting, extrusion and extrusion and pelleting on energy and nutrient digestibility in diets containing low, medium or high levels of fibre. In Experiment 1, 128 pigs were used (initial bodyweight (BW) of 9.41 ± 1.54 kg). Pigs were randomly allotted to four diets in a randomised complete block design. There were four pigs per pen and eight replicate pens per treatment. The corn used was ground to different particle sizes (i.e. 865, 677, 485 or 339 µm). In Experiment 2, three diets were formulated, including a low-fibre diet, a medium-fibre diet-, and a high-fibre diet. Each diet was divided into four batches after mixing and either fed in a meal form without further processing or pelleted, extruded, or extruded and pelleted. In total, 24 growing pigs (initial BW: 26.5 ± 1.5 kg) with a T-cannula installed in the distal ileum were allotted to the diets in a split-plot design, with eight pigs allotted to each level of fibre. Ileal digesta and faecal samples were collected and the apparent ileal digestibility of energy, crude protein and dry matter were calculated as was the metabolisable energy in each diet. Results of Experiment 1 indicated that final BW and average daily gain were not affected by corn particle size. However, average daily feed intake decreased (linear, P &lt; 0.05) as mean particle size decreased from 865 to 677, 485 and 339 µm. Likewise, gain to feed ratio increased (linear, P &lt; 0.05) from 0.65 to 0.66, 0.70 and 0.69 for pigs fed diets containing corn ground to a mean particle size of 865, 677, 485 and 339 µm, respectively. In Experiment 2, results indicated that pelleting, extrusion, or pelleting and extrusion improved (P &lt; 0.05) the apparent ileal digestibility of energy and dry matter, but in most cases, there were no differences among the pelleted, the extruded, and the extruded and pelleted diets. Medium- and high-fibre diets that were extruded had greater metabolisable energy (P &lt; 0.05) than the meal diets. In conclusion, results indicated that gain to feed of pigs fed diets containing corn with the smaller particle size was increased compared with diets containing corn with a greater particle size. In addition, energy utilisation may be improved by pelleting or extrusion or by a combination of the two technologies, but the response seems to be greater for extrusion in diets that are relatively high in fibre.

Effects of dietary coarsely ground corn and litter type on broiler live performance, litter characteristics, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and intestinal morphology

The objectives of this study were to evaluate the effects of the dietary inclusion of 2 coarsely ground corn (CC) levels (0 or 50%) in diets of broilers reared on 2 litter types (new wood shavings or used litter) on live performance, litter characteristics, gastrointestinal tract (GIT) development, apparent ileal digestibility (AID) of energy and nitrogen (N), and intestinal morphology. No interaction effects between CC level and litter type were observed on live performance. No litter effect was observed on live performance. Dietary inclusion of 50% CC increased BW at 35 d (P < 0.01) and improved cumulative feed conversion ratio (FCR) at 35 and 49 d of age (P < 0.01). The 50% CC treatment increased absolute and relative gizzard weight (P < 0.01) and decreased jejunum unit weight (g/cm) (P < 0.01). The new litter treatment (litter N) increased absolute and relative proventriculus weight (P < 0.05) but did not affect gizzard weight. An interaction effect between CC level and litter type was observed for litter N, where the 50% CC treatment reduced litter N regardless of litter type (P < 0.01), but litter N was reduced by new litter only among birds fed 0% CC (P < 0.05). The 50% CC inclusion increased litter pH (P < 0.05) and improved the AID of energy and N by 6.8% (P < 0.01) and 3.5% (P < 0.05), respectively. The 50% CC treatment increased jejunum villi tip width (P < 0.05) and villi surface area (P < 0.01), and decreased the muscularis layer thickness (P < 0.01), whereas new litter increased jejunum villi and ileum villi height (P < 0.05), jejunum villi surface area (P < 0.01), and the ratio of jejunum villi height to crypt depth (P < 0.01). This study showed that birds fed pelleted and screened diets containing 50% CC exhibited improved BW, FCR, and AID of energy and N, in conjunction with altered morphology of the GIT and intestinal mucosa. Litter type affected some GIT traits and functions but did not affect live performance.

Effect of dietary coarsely ground corn on broiler live performance, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and digesta particle size distribution and retention time

Dietary structural material has been reported to improve broiler live performance and gastrointestinal tract (GIT) function. In this 50 d cage study, the effects of coarsely ground corn (CC) inclusion on broiler live performance, GIT development, apparent ileal digestibility (AID) of energy and nitrogen (N), and digesta particle size distribution and retention time were investigated. This study included 3 CC inclusions (0, 25, and 50% fine corn [FC] replaced by CC), with 6 replicate cages of 10 birds per treatment. The feed conversion ratio (FCR) at 35 and 42 d was improved (P < 0.01) as the dietary inclusion of CC increased without effect on feed intake. The 50% CC diet increased absolute and relative gizzard weight at 42 d of age as compared to diets with 0 and 25% CC (P < 0.01). Dietary CC increased absolute proventriculus weight at 28 d of age (P < 0.05). A numerically lower gizzard digesta pH (P < 0.08) was observed at 28 d but not 42 d of age, and there was no difference in proventriculus, jejunum, or ileum digesta pH at 28 or 42 d of age. The 25 and 50% CC treatments increased the digesta retention time at 30 and 45 d of age (P < 0.05 and P < 0.01, respectively). The 25 and 50% CC treatments improved AID of energy by 7.1 and 8.2%, respectively, when compared with the 0% CC treatment, and they improved AID of N by 12.2 and 12.4%, respectively (P < 0.01). The digesta particles in the jejunum exhibited a similar distribution, with a dgw (geometric mean diameter by mass) of 218, 204, and 181 μm when 0, 25, of 50% CC diets were consumed, respectively. In conclusion, birds fed pelleted and screened diets that contained 25 and 50% CC exhibited increased BW, improved FCR, and increased AID of energy and N, which was probably due to enhanced gizzard development and greater digesta retention time.

Effect of xylanase supplementation of diets containing wheat distiller's dried grains with solubles on energy, amino acid and phosphorus digestibility and growth performance of grower-finisher pigs

Wheat-based diets with or without wheat distiller's dried grains with solubles (DDGS) were tested with or without supplementary xylanase (4000 U kg-1 feed) in a 2 × 2 factorial arrangement. In eight ileal-cannulated barrows, xylanase improved the apparent ileal digestibility of energy and threonine in wheat (P &lt; 0.05), but not in wheat DDGS diets (P &gt; 0.10). Xylanase did not affect total tract digestibility of energy or P (P &gt; 0.10). In 72 grower-finisher pigs, xylanase did not increase growth performance of pigs fed either wheat or wheat DDGS (P &gt; 0.10). The differential response of supplementary xylanase to wheat versus wheat DDGS diets indicates that the arabinoxylans in wheat DDGS did not match the specific xylanase activity. Key words: Distiller's dried grains with solubles, digestibility, energy, pig, xylanase

Apparent Ileal Digestibility of Energy, Nitrogen, and Amino Acids of Soybean Meals of Different Origin in Broilers

The coefficient of apparent ileal digestibility (CAID) of DM, gross energy (GE), N, and amino acids (AA) of 6 soybean meal (SBM) samples were compared in 21-d-old broilers. In addition, the digestibility of DM and N of diets that contained these SBM were tested in vitro. Four of the SBM were of South American origin, had a CP content varying from 45.2 to 47.2% and a trypsin inhibitor activity (TIA) varying from 4.1 to 6.5 mg/g, and were collected from local traders. The other 2 SBM were from US origin; one was a branded product with 48.6% CP and 1.8 mg of TIA/g and the other was obtained from soybeans of US origin that were dehulled and processed in Spain (50.6% CP and 2.4 mg of TIA/g). The experimental design was completely randomized with 6 diets and 6 replicates per treatment. Chicks were fed a commercial diet from 1 to 16 d of age and then their respective experimental diets for 5 d. The diets were based on sucrose and corn starch, with the SBM tested as the only source of protein. At 21 d of age, digesta was collected from the distal ileum and the CAID of nutrients was determined using celite as an indigestible marker. Diets that included the 2 SBM with the greatest CP content had greater CAID of DM (P <or= 0.001), GE (P <or= 0.001), N (P <or= 0.01), and S AA (P <or= 0.001) than the other diets. The regression coefficient (R(2)) between in vitro and in vivo CAID was 0.76 for DM and 0.68 for N (P <or= 0.05). We conclude that DM, GE, N, and AA digestibility varies among SBM samples with the greater values for those samples with the greater CP and lesser TIA. Also, the in vitro test can be used to predict ileal digestibility of DM and N of SBM in broilers.

Determination of the ileal amino acid and energy digestibilities of corn distillers dried grains with solubles using grower-finisher pigs1,2,3

An experiment evaluated the ileal apparent and standardized AA and apparent energy digestibilities in grower-finisher pigs of 5 sources of distillers dried grains with solubles (DDGS) from corn. The 5 DDGS sources were analyzed for AA, GE, NDF, ADF, and color score. Diets were formulated to contain 15% CP from the test DDGS sources (approximately 60% of the diet). A low-protein (5% casein) diet was used to estimate basal endogenous AA losses. The experiment was conducted in 2 replicates of a 6 x 6 Latin Square design, with 6 treatments and six 1-wk periods. The experiment used 12 crossbred barrows [(Yorkshire x Landrace) x Duroc], averaging 28 kg of BW and 60 d of age, and surgically fitted with a T-cannula in the distal ileum. After a 10-d recovery period, treatment diets were fed in meal form, initially at 0.09 kg . BW(0.75). Feed intake was equalized between pigs within each period and increased for each subsequent period. Periods included 5 d of diet acclimation followed by two 12-h ileal digesta collections, one on d 6 and one on d 7. Apparent and standardized digestibility of AA was calculated using chromic oxide (0.4%) as an indigestible marker. The results demonstrated that apparent and standardized lysine digestibilities ranged from 24.6 to 52.3% and 38.2 to 61.5%, respectively. Average apparent essential AA digestibility was lower (P < 0.05) in sources 1 and 5, the 2 sources that were darkest in color. Apparent and standardized digestibility of the averaged nonessential AA were lower (P < 0.05) in source 5 than in all other sources. Source 5, the darkest colored DDGS, had a 10% lower (P < 0.05) average apparent and standardized essential AA digestibility and was more than 15% lower (P < 0.05) in lysine digestibility than the 3 lightest colored sources. Apparent ileal energy digestibility did not differ among the 5 sources. Lysine content and digestibility seemed to be reduced to a greater extent by the darker colored DDGS than the other essential AA, suggesting that the Maillard reaction reduced total lysine content and lowered its digestibility. These results, therefore, imply that darker colored DDGS sources may have lower (P < 0.05) analyzed lysine contents, as well as lower (P < 0.05) lysine and essential AA digestibilities, than lighter colored DDGS sources.

Effects of supplementing diets containing hulless barley varieties having different levels of non-starch polysaccharides with β-glucanase and xylanase on the physiological status of the gastrointestinal tract and nutrient digestibility of weaned pigs

Pigs ( n=78), weaned at 21 days, were used for determining the effects of β-glucanase and xylanase inclusion, in feeds containing hulless barley, on performance and nutrient utilization in different parts of the gastrointestinal tract (GIT). The hulless barley varieties, Buck and Falcon, having high and low concentrations of β-glucan and xylose, respectively were used with or without β-glucanase (600 units/kg diet) and xylanase (745 units/kg diet) inclusions. Diets were provided for ad libitum consumption and blood samples were taken from the jugular vein. Weight gain and feed consumption were recorded on days 5, 10 and 15. Six pigs per treatment were euthanised on days 0, 5, 10 and 15, and digestive tracts were rapidly removed and divided by ligature into the stomach, three equal parts (proximal, medial and distal) of the small intestine, caecum and colon. The digesta from each section were analyzed for viscosity, energy, non-starch polysaccharide (NSP) and amino acids. Enzyme inclusion improved growth performance particularly for Buck. Enzyme treatment decreased ( P<0.05) the viscosity in the distal part of the small intestine for pigs at days 5 and 10. Enzyme treatment also reduced ( P<0.05) the plasma urea nitrogen concentration at day 10 and increased the apparent ileal digestibility of energy and some amino acids. These results suggest that NSP degrading enzymes are of benefit to early-weaned pigs fed diets based on hulless barley with high β-glucan content.