Amino acid and energy digestibility of conventional corn dried distillers grains with solubles, high protein distillers dried grains, and corn fermented protein, and impacts on turkey poult growth performance and intestinal characteristics

Amino acids (AA) are an expensive nutritional components of poultry diets. Distillers dried grains with solubles (DDGS) is the primary co-product produced by the dry grind bioethanol industry, although new technologies are being implemented to produce high protein distillers dried grains (HP-DDG) and corn fermented protein (CFP), but data on their nutritive value in poultry are lacking. Two experiments (EXP) were conducted to determine the energy and AA digestibility of DDGS, HP-DDG, and CFP in poults in addition to a feeding trial to evaluate increasing dietary levels of HP-DDG and CFP on growth performance and intestinal characteristics. In EXP 1, 6 different DDGS sources were evaluated using poults to determine their nitrogen-corrected apparent metabolizable energy (AMEn) concentrations, and cecectomized roosters were used to determine their standardized ileal (SID) AA digestibility (SID-AA). In EXP 2, AMEn and SID-AA for HP-DDG and CFP were determined in young poults, and a feeding trial was conducted to evaluate growth performance and intestinal morphology and permeability of poults fed diets containing 7.5 and 15% HP-DDG or CFP from 1 to 32 d of age. In EXP 1, the AMEn concentration among the DDGS samples ranged from 2,530 to 3,573 kcal/kg DM but was not different (P = 0.57) among the samples, with an average SID for LYS of 66.6%. In EXP 2, different (P = 0.001) AMEn concentrations for HP-DDG and CFP were observed (3,114 and 3,760 kcal/kg DM, respectively), with the SID for LYS being 66.55 and 77.00% for HP-DDG and CFP, respectively. Including HP-DDG or CFP into the diet at 7.5 and 15% had no effect (P > 0.05) on growth, feed intake, or feed conversion. Neither co-product nor its inclusion rate affected intestinal morphology and permeability (P > 0.05). Overall, DDGS, HP-DDG, and CFP are excellent sources of AMEn and digestible AA, with dietary inclusion rates of up to 15% of HP-DDG or CFP having no impact on growth or intestinal characteristics.

Effect of different levels of whole corn germ on energy values and ileal digestibility in broilers

This study evaluated the effects of broiler age (A) and levels of replacement (L) of control diet (CD) on the utilization of energy and nutrients of whole corn germ. 720 one-day-old broilers (b) were allocated at completely randomized design to six treatments and six replicates, in three assays: pre-starter (1-8 days, 10 b/cage), starter (15-22 days, 6 b/cage), and grower (28-35 days, 4 b/cage) phases. The treatments were: CD and four test diets (L): 100, 150, 200, 250, or 300 g kg-1 of the CD replaced by WCG levels. The data were adjusted to the response surface model. The stationary points for apparent energy metabolizable (AME) and AME corrected for nitrogen balance (AMEn) were: 4173 and 3591 kcal kg-1, respectively, and coefficients of gross energy (AMCGE), crude protein (AMCCP), dry matter (AMCDM), and ether extract (AMCEE) were: 49.3, 40.4, 72.6, and 61.3%, respectively; and Ileal digestibility coefficient of crude protein (IDCCP), dry matter (IDCDM), digestibility crude protein values (DCP), and digestibility dry matter value (DDM) were: 78.0, 57.96, 8.50, and 56.17%, respectively. The EP for AMEn was at 18 days of age, 28 g kg-1 WCG. There was a correlation between A and L on digestibility and metabolisability of nutrient's WCG.

Research Note: Nitrogen-corrected apparent metabolizable energy and standardized ileal amino acid digestibility determination of high-protein dried distiller's grains and corn bran with solubles for broilers

Metabolism and digestibility trials were performed on broiler chickens to determine 1) nitrogen-corrected apparent metabolizable energy (AMEn) using total excreta collection and 2) standardized ileal amino acid digestibility (SIAAD) using the ileal digesta collection from high-protein dried distillers' grains (HP-DDG) and corn bran with solubles (CBS). The results of the metabolism trial indicated that AMEn values for HP-DDG and CBS were 3,334 kcal/kg and 2,083 kcal/kg on dry matter (DM) basis, respectively. Concerning the HP-DDG, the digestibility trial resulted in the following SIAAD values and digestible concentrations, respectively: 80.33% and 1.09 for Lys, 85.95% and 1.44 for Met + Cys, 75.58% and 1.24 for Thr, 89.58% and 1.66 for Arg, 84.91% and 1.08 for His, 86.37% and 1.35 for Ile, 90.64% and 4.56 for Leu, 85.76% and 1.80 for Val, and 88.67% and 1.90 for Phe. Concerning the CBS, the following SIAAD values and digestible concentrations were measured, respectively: 79.29% and 0.44 for Lys, 89.57% and 0.31 for Met + Cys, 78.89% and 0.40 for Thr, 92.28% and 0.66 for Arg, 87.48% and 0.36 for His, 93.40% and 0.35 for Ile, 92.27% and 1.01 for Leu, 90.97% and 0.51 for Val, and 88.81% and 0.45 for Phe. The digestibility average of CBS is 88.45% for essential amino acids and 85.21% for nonessential amino acids, whereas the digestibility average of HP-DDG is 85.83% for essential amino acids and 83.83% for nonessential amino acids.

Standardized amino acid digestibility and true metabolizable energy for several increased protein ethanol co-products produced using back-end fractionation systems

Precision-fed rooster trials were conducted to evaluate standardized AA digestibility and TME_n of the increased protein ethanol co-products corn fermented protein (CFP), high protein-distillers dried grains with solubles (HP-DDGS), and reduced fiber high protein-DDGS (RFHP-DDGS) produced using post-fermentation back-end fractionation systems. The TME_n was determined using conventional adult Leghorn roosters, while cecectomized roosters were used to determine standardized AA digestibility. Three to 6 roosters were fasted per treatment for 26 h prior to crop intubation with 27 g of sample and excreta were collected for 48 h post-feeding. Statistical analyses were conducted using a one-way ANOVA for a completely randomized design. Eight samples of CFP were found to contain a mean of 56% CP (DM basis) compared with a mean of 32% for conventional DDGS. The mean TME_n of CFP (3,556 kcal/kg) was greater (P < 0.05) than conventional DDGS1 and 2 (2,767 kcal/kg DM); mean standardized AA digestibility for CFP was similar to conventional DDGS and ranged from 88 to 94%. The mean digestible Lys, Met+Cys, and Thr concentrations for conventional DDGS were 0.79, 1.12, and 0.94%, respectively, whereas those for CFP were 1.74, 2.06, and 1.88%, respectively (DM basis). Two samples of HP-DDGS contained a mean of 51% CP (DM basis), a mean TME_n of 3,325 kcal/kg DM, a mean standardized AA digestibility of 90%, and mean concentrations of digestible Lys, Met+Cys, and Thr, which were 1.53, 1.77, and 1.60%, respectively (DM basis). The mean CP content of 2 RFHP-DDGS was 48% and the mean TME_n was 3,711 kcal/kg DM, which was greater (P < 0.05) than conventional DDGS3 and 4 (2,920 kcal/kg DM). Mean standardized AA digestibility of RFHP-DDGS was 90% and mean digestible Lys, Met+Cys, and Thr concentrations increased from 0.82, 1.01, and 0.95% for conventional DDGS, respectively, to 1.00, 1.59, and 1.44% for RFHP-DDGS, respectively (DM basis). Results indicate these high protein corn ethanol co-products have increased nutritional value for poultry compared with conventional DDGS.

Corn distiller's dried grains with solubles as an alternative ingredient to corn and soybean meal in Pekin duck diets based on its predicted AME and the evaluated standardized ileal digestibility of amino acids

The study aimed to investigate the effects of dietary distillers dried grains with solubles (DDGS) levels on growth performance, carcass characteristic, serum biochemical indexes, meat physical and chemical quality, nutrient utilization, and standardized ileal digestibility of amino acids (SIDAA) in Pekin ducks aged 11 to 42 d based on the evaluation of its SIDAA. A total of 560 eleven-day-old Cherry Valley ducks were randomly allotted to 5 treatments with 7 replicate pens per treatment and 16 ducks per pen based on the average body weight. Six isonitrogenous and isocaloric experimental diets were formulated on a digestible amino acid basis to produce diets containing 0, 5, 10, 15, and 20% DDGS, respectively. With increasing of dietary DDGS levels, a linear and quadratic reduction (P < 0.05) was observed in the body weight (BW) at d 42, average day gain (ADG) and average day feed intake (ADFI) from d 11 to 42, breast meat yield, the moisture and protein content in the breast meat, and dietary DM and EE utilization. Moreover, a linear and quadratic increase (P < 0.05) was observed in the b* value of the breast meat and serum total cholesterol and triglyceride concentrations. Compared with the control group, the group with 10% inclusion of DDGS exhibited no adverse effect on growth performance, carcass characteristics, serum biochemical indexes, meat physical and chemical quality, nutrient utilization, and the SIDAA of the diets (P > 0.05). These results suggested that 10% of corn DDGS can function as an alternative ingredient to corn and soybean meal, and the optimal levels of DDGS in the diets of ducks aged from 11 to 42 d depends more on its quality.

Application of Apparent Metabolizable Energy versus Nitrogen-Corrected Apparent Metabolizable Energy in Poultry Feed Formulations: A Continuing Conundrum

Simple Summary

Despite some limitations, the metabolizable energy system has been extensively used for describing the available energy in ingredients and for formulating complete poultry feeds. Three methods, namely direct, difference (substitution), and regression, or modifications thereof, have been employed to measure the apparent metabolizable energy (AME) of feeds and ingredients for poultry. The AME of feed ingredients are often corrected for zero nitrogen (N) retention to estimate the N-corrected AME (AMEn). Although the need for N-retention corrections has been intensely debated and challenged ever since the advent of the AME system, no definitive conclusion has been reached and the majority of poultry diets today are formulated to meet the requirements for AMEn rather than AME. There is limited information on the effect of zero N-retention correction on the energy value of major protein sources. The aim of this investigation was to understand the consequences of correction to zero N retention to the energy values of samples of several protein sources differing in protein quality. Based on the data presented herein, correcting AME values to zero N retention for modern fast-growing broilers penalizes the energy value of all major protein sources and is of higher magnitude for ingredients with higher protein quality.

Abstract

In the present investigation, N retention, AME, and AMEn data from six energy evaluation assays, involving four protein sources (soybean meal, full-fat soybean, rapeseed meal and maize distiller’s dried grains with solubles [DDGS]), are reported. The correction for zero N retention, reduced the AME value of soybean meal samples from different origins from 9.9 to 17.8% with increasing N retention. The magnitude of AME penalization in full-fat soybean samples, imposed by zero N correction, increased from 1.90 to 9.64% with increasing N retention. The Δ AME (AME minus AMEn) in rapeseed meal samples increased from 0.70 to 1.09 MJ/kg as N-retention increased. In maize DDGS samples, the correction for zero N retention increased the magnitude of AME penalization from 5.44 to 8.21% with increasing N retention. For all protein sources, positive correlations (p < 0.001; r = 0.831 to 0.991) were observed between the N retention and Δ AME. The present data confirms that correcting AME values to zero N retention for modern broilers penalizes the energy value of protein sources and is of higher magnitude for ingredients with higher protein quality. Feed formulation based on uncorrected AME values could benefit least cost broiler feed formulations and merits further investigation.

Effect of feeding corn distillers dried grains with solubles naturally contaminated with deoxynivalenol on growth performance, meat quality, intestinal permeability, and utilization of energy and nutrients in broiler chickens

The objective of this experiment was to investigate the effect of feeding corn distillers dried grains with solubles (DDGS) naturally contaminated with deoxynivalenol (DON) on growth performance, meat quality, intestinal permeability, and utilization of energy and nutrients in broiler chickens. Two trials (growth and metabolism trials) were conducted. In the growth trial, a total of four hundred 7-day-old Ross 308 broiler chicks were allotted to 1 of 5 dietary treatments with 8 replicates in a completely randomized design. The diets were formulated to contain 5 inclusion levels of 0, 5, 10, 15, or 20% DON-contaminated DDGS in diets and were fed to birds for 21 d. Results indicated that increasing inclusion levels of DON-contaminated DDGS decreased (linear, P < 0.01) BW gain and feed efficiency of broiler chickens. The relative organ weights of the liver and breast were decreased (linear and quadratic, P < 0.05) by increasing inclusion levels of DON-contaminated DDGS in diets. The transepithelial electrical resistance values as a measure of intestinal permeability were decreased (linear, P < 0.05) by increasing inclusion levels of DON-contaminated DDGS in diets. In the metabolism trial, a total of twenty four 22-day-old Ross 308 broiler chickens were allotted to 1 of 3 dietary treatments consisting of 0, 10, or 20% inclusion of DON-contaminated DDGS in diets. Each treatment had 8 replicates. Increasing inclusion levels of DON-contaminated DDGS in diets decreased (linear and quadratic, P < 0.05) ME_n (AME_n and TME_n) and apparent total tract retention of nitrogen and acid-hydrolyzed ether extract in diets. In conclusion, feeding diets containing more than 10% DON-contaminated DDGS to broiler chickens has negative effects on growth performance, intestinal permeability, and utilization of energy and nutrients in diets. Therefore, it is suggested that if DDGS is contaminated with DON, inclusion level of DDGS should be limited, possibly at less than 5.0% in broiler diets.

Trends in feed evaluation for poultry with emphasis on in vitro techniques

Accurate knowledge of the actual nutritional value of individual feed ingredients and complete diets is critical for efficient and sustainable animal production. For this reason, feed evaluation has always been in the forefront of nutritional research. Feed evaluation for poultry involves several approaches that include chemical analysis, table values, prediction equations, near-infrared reflectance spectroscopy, in vivo data and in vitro digestion techniques. Among these, the use of animals (in vivo) is the most valuable to gain information on nutrient utilization and is more predictive of bird performance. However, in vivo methods are expensive, laborious and time-consuming. It is therefore important to establish in vitro methods that are reliable, rapid and practical to assess the nutritional quality of feed ingredients or complete diets. Accuracy of the technique is crucial, as poor prediction will have a negative impact on bird performance and, increase feed cost and environmental issues. In this review, the relevance and importance of feed evaluation in poultry nutrition will be highlighted and the various approaches to evaluate the feed value of feed ingredients or complete diets will be discussed. Trends in and practical limitations encountered in feed evaluation science, with emphasis on in vitro digestion techniques, will be discussed.

Evaluation of a high-protein DDGS product in broiler chickens: performance, nitrogen-corrected apparent metabolisable energy, and standardised ileal amino acid digestibility

1. New production processes and additional uses for corn co-products have increased the availability of distiller's dried grains with solubles (DDGS) with varying energy and amino acid digestibility, for use in poultry feed. The objective of this study was to determine the performance, N-corrected metabolisable energy (AME_n), and amino acid (AA) digestibility of a 34% CP (as fed) high-protein DDGS (HP-DDGS) included in poultry diets for Cobb 500 broiler chickens.2. A total of 832 Cobb 500 broilers were randomly assigned to four dietary treatments containing 5% conventional DDGS (CV-DDGS) as a control or 10%, 15% and 20% HP-DDGS and fed for 42 d. After the performance trial, 240 birds from the original 832 were selected for a concurrent AME_n and AA digestibility experiment consisting of two AME_n diets and two AA diets.3. Birds fed diets containing 15% and 20% HP DDGS gained less weight than birds fed the CV-DDGS (P < 0.05) but did not differ in feed intake (FI), and therefore had a less efficient FCR than the control (P < 0.05). The AME_n of HP-DDGS was determined to be 11.4 MJ/kg. The standardised ileal amino acid digestibility (SIAAD) of the essential amino acids Lys and Met were determined to be 80.9% and 88.6%, respectively.4. HP-DDGS can be included in broiler diets up to 10% without any negative impact on performance or requiring supplemental Lys and Arg. The results from the AA digestibility study indicated that HP-DDGS could be a good source of digestible Lys.

Nutritional evaluation of 3 types of novel ethanol coproducts

Five 48-h precision-fed rooster assays were conducted with the objective to determine true metabolizable energy (TMEn) using conventional roosters and/or standardized amino acid digestibility using cecectomized roosters for distillers dried grains with solubles (DDGS) produced from human food waste at high solids content (FWDDGS), DDGS produced from 4 corn hybrids with increases in grain protein concentration or the concentrations of several dietary indispensable amino acids, and a coproduct that is produced by a process which separates a high protein and yeast fraction from ethanol stillage (Still Pro, Fluid Quip Process Technologies, Cedar Rapids, IA). These results from the first cecectomized rooster assay indicated that the standardized digestibility values for Lys, Met, Cys, Thr, and Val were 61, 75, 70, 70, and 72%, respectively. Using conventional roosters, the TMEn for the FWDDGS was 3,890 kcal/kg DM. The DDGS produced from the high protein mutant corn hybrid had a higher protein content of 34% compared with 28% protein for DDGS from the control corn hybrid. Using Lys as an example, there was a large difference between the 2 samples; the high protein mutant DDGS contained 1.60% Lys vs 1.05% for the control DDGS. Standardized digestibility of amino acids was generally not different for the mutant DDGS and the control DDGS. Similar results were observed for Lys, Arg, and Trp for the DDGS produced from the second mutant corn hybrid. The Still Pro sample was analyzed to contain 53% protein (DM basis) with 2.22% Lys, 1.05% Met, 0.90% Cys, 2.06% Thr, and 3.08% Val. The standardized digestibility values for these amino acids were 84, 92, 87, 86, and 87%, respectively. The TMEn of the Still Pro sample was determined to be 3,372 kcal/kg DM. In conclusion, the results of this study indicate that the nutritional value of the 3 types of novel ethanol coproducts is equal to or superior to the nutritional values generally reported for conventional DDGS.

Formulation of Broiler Chicken Feeds Using Distillers Dried Grains with Solubles

Distillers dried grains with solubles (DDGS) is a coproduct of corn-based ethanol production that can be a valuable source of energy, digestible amino acids, and available phosphorus in poultry feeds. Dietary incorporation of DDGS reduces the amount of primary ingredients such as corn and soybean meal needed to formulate poultry diets, improving the sustainability of both biofuel and poultry production. The nutritional value of DDGS has been extensively evaluated since it became increasingly available to feed producers in the early 2000s, but evolving methods of ethanol production and coproduct fractionation necessitate its continued characterization. Attempts to relate nutrient utilization of DDGS to its chemical composition have revealed that fiber content is a primary determinant of dietary energy value of DDGS for poultry. Distillers corn oil, which is extracted from thin stillage during production of distillers grains, can also be supplemented into poultry diets as an energy-dense lipid source in place of animal fats or other vegetable-based oils. Poultry feeding practices in the United States are also evolving, including increased adoption of all vegetable-based diets and reduced use of in-feed antimicrobials. Therefore, further characterization of both the nutritional value of DDGS and its impact on gastrointestinal health will support its continued use in poultry diets.

Nutrient composition, digestible and metabolizable energy content, and prediction of energy for animal protein byproducts in finishing pig diets

An industry survey and animal experiment were conducted to evaluate compositional variability and DE and ME content of animal protein byproducts and to generate equations to predict DE and ME content based on chemical analysis. For the 220 samples collected, the greatest concentration of CP was observed in blood meal (BM) and the least in meat and bone meal (MBM) and the greatest concentration of ether extract was in meat meal and the least in BM, with ash content greatest in MBM and least in BM, with Ca and P levels being 36.1 and 16.3% of the ash content, respectively. For the balance experiment, a corn-soybean meal basal diet was used with test diets formulated by mixing 80% of the basal diet with 20% of the animal protein byproduct, except for BM, which was included at 10 and 20% of the test diets. Ten groups of 24 gilts (92.5 ± 7.4 kg final BW) were randomly assigned to the test or basal diet within each group, resulting in 16 replications per animal protein byproduct or basal diet, except for BM determinations (20 replications). Gilts were placed in metabolism crates and offered 2.4 kg daily of their assigned diet for 13 d, with total collection of feces and urine during the last 4 d. Gross energy in the diets, feces, and urine was used to calculate the DE and ME content of each ingredient by the difference procedure, using DE and ME of the basal diet as a covariate among groups of pigs. The DE content of the animal protein byproducts ranged from 5,367 to 2,567 kcal DE/kg DM, and ME ranged from 4,783 to 2,340 kcal ME/kg DM. Using all animal protein byproducts, the best-fit equations were as follows: DE (kcal/kg DM) = -2,468 + (1.26 × GE, kcal/kg DM), with of 0.84, SE = 390, and < 0.01, and ME (kcal/kg DM) = -2,331 + (1.15 × GE, kcal/kg DM), with of 0.86, SE = 327, and < 0.01. The apparent total tract digestibility (ATTD) of Ca and P were also determined using the difference procedure, with the average ATTD of Ca and P for the animal protein byproducts, excluding BM and feather meal, being 27.1 and 39.1%, respectively. These data indicate that DE and ME substantially varied among the animal protein byproducts and sources and that a variety of nutritional components can be used to accurately predict DE and ME for finishing pigs. In addition, it appears that high dietary inclusion rates of animal protein byproducts may result in low ATTD estimates of Ca and P, which may be due to excessive concentrations of total Ca and P affecting digestibility.

Short-term effects of lower oil dried distillers grains with solubles in laying hen rations

Extraction of oil from dried distillers grains has become a common practice among US ethanol producers. The valuable oil has been diverted to markets other than poultry feed, leaving new dried distillers grains with solubles (DDGS) products higher in fiber and purportedly lower in ME. This study compared 3 DDGS products with 10.3, 7.3, or 5.2% ether extract, respectively, with a corn-soy control ration in young Bovan laying hens for a feeding period from 20 to 33 wk of age. The DDGS was fed at the rate of 20% of the ration. Lower oil content of DDGS had no effect on short-term egg production parameters: feed intake, egg production, egg weight or mass, and hen weight gain. The diets containing lower fat DDGS (5.2%) did have reduced AME and kilocalories per day intake for laying hens. For each percent reduction in oil from a normal DDGS sample (10.3%) to medium oil (7.3%) DDGS, AME decreased 42.3 kcal/kg of diet. However, total kilocalories per day intake did sustain good egg production during this short trial.

Relationships among dietary fiber components and the digestibility of energy, dietary fiber, and amino acids and energy content of nine corn coproducts fed to growing pigs

An experiment was conducted to determine a best fitting dietary fiber (DF) component to estimate the effect of DF concentration on the digestibility of energy, DF, and AA and energy value of 9 corn coproducts: corn bran (37.0% total nonstarch polysaccharides [NSP]); corn bran with solubles (17.1% NSP); cooked corn distillers dried grains with solubles (DDGS; 20.4% NSP); reduced oil DDGS (25.0% NSP); uncooked DDGS (22.0% NSP); high protein distillers dried grains (21.9% NSP); dehulled, degermed corn (1.1% NSP); corn germ meal (44.4% NSP); and corn gluten meal (4.9% NSP). A total of 20 growing pigs (initial BW: 25.9 ± 2.5 kg) were fitted with a T-cannula in the distal ileum and allotted to 10 dietary treatment groups in a 4-period incomplete block design with 8 observations per treatment. Treatments included a corn-soybean meal-based basal diet and 9 diets obtained by mixing 70% of the basal diet with 30% of the test ingredient. In tested ingredients, 11 DF components were determined: 1) ADF, 2) NDF, 3) total dietary fiber, 4) hemicellulose, 5) total NSP, 6) NSP arabinose, 7) NSP xylose, 8) NSP mannose, 9) NSP glucose, 10) NSP galactose, and 11) arabinoxylan. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of GE, DM, and NDF and the AID of AA of ingredients were measured. A single best fitting DF component was assessed and ranked for each trait, showing that arabinoxylan concentration best explained variance in AID of GE (R(2) = 0.65; cubic, P < 0.01) and DM (R(2) = 0.67; cubic, P < 0.01). The NSP xylose residue best explained variance in ATTD of GE (R(2) = 0.80; cubic, P < 0.01), DM (R(2) = 0.78; cubic, P < 0.01), and NDF (R(2) = 0.63; cubic, P < 0.01); AID of Met (R(2) = 0.40; cubic, P = 0.02), Met + Cys (R(2) = 0.44; cubic, P = 0.04), and Trp (R(2) = 0.11; cubic, P = 0.04); and DE (R(2) = 0.66; linear, P = 0.02) and ME (R(2) = 0.71; cubic, P = 0.01) values. The AID of Lys was not predictable (P > 0.05) from the DF concentration. In conclusion, the arabinoxylan and NSP xylose residue were the DF components that best explained variation due to DF concentration and, with the exception of AID of Lys, can be used to predict the digestibility of energy and DF and the DE and ME values in corn coproducts.

Validation of prediction equations to estimate the energy values of feedstuffs for broilers: performance and carcass yield

The objective was to evaluate the use of prediction equations based on the chemical composition of feedstuffs to estimate the values of apparent metabolisable energy corrected for nitrogen balance (AMEn) of corn and soybean meal for broilers. For performance and carcass characteristics, 1,200 one-d-old birds (male and female) were allotted to a completely randomised factorial 2×8 (two genders and eight experimental diets) with three replicates of each sex with 25 birds. In the metabolism trial, 240 eight-d-old birds were distributed in the same design, but with a split plot in time (age of evaluation) with five, four and three birds per plot, respectively, in stages 8 to 21, 22 to 35, and 36 to 42 d of age. The treatments consisted of the use of six equations systems to predict the AMEn content of feedstuffs, tables of food composition and AMEn values obtained by in vivo assay, totalling eight treatments. Means were compared by Scott-Knott test at 5% probability and a confidence interval of 95% was used to check the fit of the energy values of the diets to the requirements of the birds. As a result of this study, the use of prediction equations resulted in better adjustment to the broiler requirements, resulting in better performance and carcass characteristics compared to the use of tables, however, the use of energy values of feedstuffs obtained by in vivo assay is still the most effective. The best equations were: AMEn = 4,021.8–227.55 Ash (for corn) combined with AMEn = −822.33+69.54 CP-45.26 ADF+90.81 EE (for soybean meal); AMEn = 36.21 CP+85.44 EE+37.26 NFE (nitrogen-free extract) (for corn) combined with AMEn = 37.5 CP+46.39 EE+14.9 NFE (for soybean); and AMEn = 4,164.187+51.006 EE-197.663 Ash-35.689 CF-20.593 NDF (for corn and soybean meal).

Nitrogen-corrected True Metabolizable Energy and Amino Acid Digestibility of Chinese Corn Distillers Dried Grains with Solubles in Adult Cecectomized Roosters

This study was conducted to evaluate chemical composition, nitrogen-corrected true metabolizable energy (TMEn) and true amino acids digestibility of corn distillers dried grains with solubles (DDGS) produced in China. Twenty five sources of corn DDGS was collected from 8 provinces of China. A precision-fed rooster assay was used to determine TMEn and amino acids digestibility with 35 adult cecectomized roosters, in which each DDGS sample was tube fed (30 g). The average content of ash, crude protein, total amino acid, ether extract, crude fiber and neutral detergent fiber were 4.81, 27.91, 22.51, 15.22, 6.35 and 37.58%, respectively. TMEn of DDGS ranged from 1,779 to 3,071 kcal/kg and averaged 2,517 kcal/kg. Coefficient of variation for non-amino acid crude protein, ether extract, crude fiber and TMEn were 55.0, 15.7, 15.9 and 17.1%, respectively. The average true amino acid digestibility was 77.32%. Stepwise regression analysis obtained the following equation: TMEn, kcal/kg = -2,995.6+0.88×gross energy+49.63×a* (BIC = 248.8; RMSE = 190.8; p<0.01). Removing gross energy from the model obtained the following equation: TMEn, kcal/kg = 57.88×ether extracts+87.62×a* (BIC = 254.3, RMSE = 223.5; p<0.01). No correlation was found between color scores and lysine true digestibility (p>0.05). These results suggest that corn DDGS produced in China has a large variation in chemical composition, and gross energy and a* value can be used to generate TMEn predict equation.

Validation of prediction equations for apparent metabolizable energy of corn distillers dried grains with solubles in broiler chicks

An experiment consisting of 3 nearly identical trials was conducted to determine the AMEn content of distillers dried grains with solubles (DDGS) to validate 4 previously published prediction equations for AMEn of corn DDGS in broilers. In addition, prior research data were used to generate a best-fit equation for AMEn based on proximate analysis. Fifteen samples of DDGS ranging in ether extract (EE) from 4.98 to 14.29% (DM basis) were collected from various dry-grind ethanol plants and were subsequently fed to broiler chicks to determine AMEn content. A corn-soybean meal control diet was formulated to contain 15% dextrose and test diets were created by mixing the control diet with 15% DDGS at the expense of dextrose. In each trial, male Ross × Ross 708 chicks were housed in grower battery cages and received a common starter diet until the experimental period. Each cage was randomly assigned to 1 of the dietary treatments (trial 1 and trial 2: control + 6 test diets, 13 replicates per diet; trial 3: control + 3 test diets, 12 replicates per diet). Experimental diets were fed over a 6-d acclimation period, followed by a 48-h total excreta collection period. On a DM basis, AMEn of the 15 DDGS samples ranged from 1,975 to 3,634 kcal/kg. Analyses were conducted to determine gross energy, CP, EE, DM, starch, total dietary fiber, neutral detergent fiber, crude fiber (CF), acid detergent fiber, and ash content of the DDGS samples. All results were reported on a DM basis. Application of the 4 equations to the validation data resulted in root mean square error (RMSE) values of 335, 381, 488, and 502 kcal/kg, respectively. Least absolute shrinkage and selection operator technique was applied to proximate analysis data for 30 corn coproducts adapted from prior research and resulted in the following best-fit equation: [AMEn (kcal/kg) = 3,673 - (121.35 × CF) + (51.29 × EE) - (121.08 × ash); P < 0.01; R(2) = 0.70; R(2) adj = 0.67; RMSE = 270 kcal/kg]. The RMSE values obtained through validation were not consistent with the expectation of predictive performance based on internal measures of fit for each equation. These results indicated that validation is necessary to quantify the expected error associated with practical application of each individual prediction equation to external data.

Apparent metabolizable energy and prediction equations for reduced-oil corn distillers dried grains with solubles in broiler chicks from 10 to 18 days of age

An experiment consisting of 2 identically designed trials was conducted to determine the nutrient composition and AMEn content of distillers dried grains with solubles (DDGS) to develop prediction equations for AMEn in broilers. Fifteen samples of DDGS ranging in ether extract (EE) from 3.15 to 13.23% (DM basis) were collected from various dry-grind ethanol plants and were subsequently fed to broiler chicks to determine AMEn content. A corn-soybean meal control diet was formulated to contain 15% dextrose, and test diets were created by mixing the control diet with 15% DDGS at the expense of dextrose. In each trial, 672 male Ross × Ross 708 chicks were housed in grower battery cages with 7 birds per cage (0.06 m(2)/bird) and received a common starter diet until 10 d of age. Each cage was randomly assigned to 1 of 16 dietary treatments, with 6 replicate pens per treatment. Experimental diets were fed over a 6-d acclimation period from 10 to 16 d of age, followed by a 48-h total excreta collection period. Gross energy (GE) and CP of the experimental diets and excreta were determined to calculate AMEn for each DDGS sample. On a DM basis, AMEn of the 15 DDGS samples ranged from 1,869 to 2,824 kcal/kg. Analyses were conducted to determine the GE, CP, EE, DM, starch, total dietary fiber (TDF), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash content of the DDGS samples. Stepwise regression resulted in the following best-fit equation for AMEn (DM basis) based on the adjusted coefficient of determination (R(2)adj), SE, and prediction error sum of squares (PRESS): AMEn, kcal/kg = -12,282 + (2.60 × GE) + (89.75 × CP) + (125.80 × starch) - (40.67 × TDF; R(2)adj = 0.86; SE = 98.76; PRESS = 199,819; P ≤ 0.001). These results indicated that the composition of DDGS with variable EE content may be used to predict AMEn in broiler chicks.

The correlationship between the metabolizable energy content, chemical composition and color score in different sources of corn DDGS

Background

This study was conducted to evaluate the apparent metabolizable energy (AME) and true metabolizable energy (TME) contents in 30 sources of corn distillers dried grains with solubles (DDGS) in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score.

Methods

Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy (ME) contents, measured for color score and chemical composition (crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber), to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed (50 g) to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses.

Results

Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content (-0.64, P < 0.01) and between ME and yellowness score (0.39, P < 0.05) of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R² = 0.70). The best-fit regression equation for TME content of DDGS was TME = 7.92283 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R² = 0.70).

Conclusions

This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content.