True Metabolizable Energy Research Articles

Using locally produced millet as a feed ingredient for poultry production in Sub-Saharan Africa

Using locally produced feedstuffs for poultry production in developing countries can greatly lower production costs. Pearl millet is a drought-resistant plant that produces a nutritious grain. Its cultivation in Mali spans thousands of years, but the suitability of the millet grain currently produced in Mali for poultry production is unknown. Therefore, the nutrient composition of 7 different, widely available varieties of pearl millet grown in Mali was assessed before completing experiments in which laying hens or broilers were fed diets containing 0, 14, 28, or 43% whole pearl millet. The 7 varieties of pearl millet grown in different regions of Mali all had protein concentrations that were better than corn and had apparent digestible amino acid coefficients similar to corn. The nitrogen-corrected true metabolizable energy values ranged from 3,395 to 3,738 Kcal/kg on an as-is basis. Egg production and egg weight did not differ between the hens fed the different levels of millet through out a 16-wk experiment. Broilers fed the highest level of pearl millet from 1 to 42 d of age gained less (3.088 versus 2.949 kg) body weight than those fed the control diet. However, body weight gains did not differ between the broilers fed the control diet and the diets containing 14 or 28% whole millet. The results indicate that Malian-grown pearl millet would be an effective feed ingredient for poultry production and that this small seed could be added in whole form into laying hen and broiler diets.

Growth performance, nutrient digestibility, metabolizable energy, and intestinal morphology of growing turkeys fed diet supplemented with arginine

A 8-wk feeding experiment was conducted to investigate the effect of dietary supplementation with Arg on growth performance, nutrient digestibility, metabolizable energy, and intestinal morphology of growing turkeys. A total of one hundred and eighty 56-d-old male grower turkeys were weighed individually and randomly assigned to 1 of 3 dietary treatments with 6 replicate pens and 10 turkeys per pen in a completely randomized design. Dietary treatments consisted of basal diets supplemented with 0, 0.5, and 1.0g Arg/kg. Growth response was measured during the grower (d 56–84) and finisher (d 84–112) phases, while nutrient digestibility, metabolizable energy, and intestinal morphology were measured at d 84 and 112. Arginine supplementation had no effect on growth response during the grower phase. During the finisher phase, feed conversion ratio decreased initially as Arg supplementation increased from 0 to 0.5g/kg, but it increased with the 1.0g Arg/kg (quadratic, P=0.028). At d 84, grower turkeys fed diets supplemented with 1.0g Arg/kg had greater (linear, P<0.001) apparent dry matter, crude protein, and ether extract digestibility. At d 84, greatest apparent metabolizable energy, nitrogen corrected apparent metabolizable energy, and true metabolizable energy values were obtained with grower turkeys fed diet supplemented with 0.5g Arg/kg (quadratic, P<0.001). At d 84, duodenum, and ileum villus height in grower turkeys increased linearly, and quadratically (P<0.001) with increasing Arg supplementation. Dietary supplementation with Arg reduced the apical widths in duodenum (linear, P=0.003; quadratic, P<0.001), jejunum (linear and quadratic, P<0.001), and ileum (linear, P=0.010; quadratic, P=0.004) of grower turkeys. At d 112, jejunum villus height (quadratic, P=0.042), and ileum villus height (linear, P=0.022; quadratic, P=0.042) of finisher turkeys increased, while duodenum apical widths reduced (quadratic, P=0.033) with increasing Arg supplementation. In conclusion, Arg supplementation showed a linear improvement in nutrient digestibility of grower turkeys at d 84, increased nutrient absorption in grower, and finisher turkeys as indicated by increased intestinal villus height at d 84, and 112. Furthermore, dietary supplementation with 0.5g Arg/kg promoted a quadratic improvement in feed conversion ratio of finisher turkeys, and metabolizable energy values of grower turkeys at d 84.

Determination of True Metabolizable Energy Content of Bobwhite Foods

True metabolizable energy (TME) and nitrogen-corrected true metabolizable energy (TMEn) bioassays were used to determine available energy content of several northern bobwhite (Colinus virginianus) foods. A proximate analysis and trypsin inhibitor (TI) activity were also determined for each food. Corn (Zea mays) was found to contain the highest amount ofTMEn (4.37 kcal/g dry matter) compared with Fayette soybeans (Glycine max; 3.93 kcal/g), Korean lespedeza (Kummerowia stipuki.ceae; 3.73 kcal/g), Marion lespedeza (K. striata; 3.71 kcal/g), tick-trefoil (Desmodium spp.; 3.51 kcal/g), and wild trailing (WI') soybeans (3.24 kcal/g). The higher TMEn value of corn was attributed to its high digestible carbohydrate content and lack of appreciable TI activity.

Lignocellulose Improves Protein and Amino Acid Digestibility in Roosters and Egg Hatchability in Broiler Breeders.

The present work assessed the effect of supplementation of 0.8% dietary Arbocel® RC Fine, a readily available commercial lignocellulose, to poultry feed. In a complete randomized design using 36 individually caged mature dubbed Hy-Line roosters (aged 55 weeks) grouped in 4 treatments with 9 birds per treatment, a digestibility trial was performed to determine apparent and true metabolizable energy values along with digestibility coefficients of protein and amino acid in Arbocel® containing diets. Results showed that 0.8% Arbocel® supplemented diets improved protein digestibility by 6% (P<0.05). Additionally, Arbocel® caused an increase in apparent and true amino acid digestibility in roosters when compared to control diets and controls with 0.8% wheat bran (WB) supplementation. In a second experiment, 26,000 layers and 2,600 roosters aged 33 weeks (Ross 308 broiler breeder strain) were maintained in 6 poultry houses at a commercial breeding farm, with an average of 4330 layers and 433 roosters per house. Performance, egg grade, and hatchability rate were assessed over a post peak period of 6 months. Compared to the control group fed the 0.8% WB diet, the 0.8% lignocellulose dietary supplementation resulted in a decrease (P<0.05) in percent infertility leading to an average increase of 4.07% (P<0.05) in egg hatchability. The Arbocel® fed group had 3.8 more eggs per housed hen compared to control birds. Overall, Arbocel® supplementation at 0.8% resulted in the production of 5.7 more saleable chicks per housed hen during the 6 months trial, a sizeable profit to the farmer.

Chemical composition, true nutrient digestibility, and true metabolizable energy of novel pet food protein sources using the precision-fed cecectomized rooster assay

A wide variety of animal protein-based ingredients is commonly used in the pet food products. The raw ingredients and processing procedures used may greatly affect protein quality. Testing the quality of alternative protein sources is necessary and contributes to the sustainability of pet foods. The objective of this study was to test the chemical composition of 8 protein sources intended for use in dog and cat foods (calamari meal, pork peptone, alligator meal, lamb meal, venison meal, chicken meal, and 2 duck meals), and evaluate their true nutrient digestibility and nitrogen-corrected true ME (TMEn) using the precision-fed cecectomized rooster assay. Calamari meal and pork peptone had lower ash (4.4 and 3.6% of DM, respectively) but greater CP (88.1 and 80.5% of DM, respectively) and either greater or similar GE (5.6 and 5.3 kcal/g of DM, respectively) compared with alligator, lamb, venison, chicken, and duck meals (11.8 to 24.5% ash, 58.7 to 65.9% CP, and 4.6 to 5.3 kcal GE/g). Acid-hydrolyzed fat (AHF) was lower in calamari meal (8.7% of DM) compared with the other proteins tested (15.5-22.1% of DM). True nutrient digestibility was variable among the protein sources (52 to 79% of DM, 60 to 83% of OM, 78 to 92% of AHF, and 70 to 89% of GE) with pork peptone having the highest DM, AHF, and GE digestibility and calamari meal having the highest OM digestibility. True indispensable AA digestibility was highest for calamari meal, with all AA having a digestibility greater than 90%. Except for histidine, all indispensable AA had a digestibility over 85% for pork peptone. In contrast, true indispensable AA digestibility was lowest for lamb meal, with histidine having digestibility less than 70% and the other entire indispensable AA having digestibility between 72 and 88%. The TMEn of calamari meal (4.82 kcal/g DM and 86.9% of GE) was greater ( < 0.05) than the other protein sources. The lamb meal had the lowest TMEn value (3.12 kcal/g DM and 66.9% of GE), with others being intermediate (3.46-4.09 kcal/g DM and 71.2-77.9% of GE). This study demonstrates the considerable variability that exists not only in the chemical composition but also in the true nutrient digestibility among protein sources intended for use in dog and cat foods and justifies further in vivo testing of novel protein sources.

Suitability of Soybean Meal from Insect-Resistant Soybeans for Broiler Chickens.

Benning(M) and Benning(MGH) are near-isogenic lines (NILs) of the soybean cultivar Benning, which contain insect-resistance quantitative trait loci (QTLs) from the soybean accession PI 229358. Benning(M) contains QTL-M, which confers antibiosis and antixenosis. In addition to QTL-M, Benning(MGH) contains QTL-G, which confers antibiosis, and QTL-H, which confers antixenosis. Soybean meal was produced from Benning and the NILs. Nutritional composition, digestible amino acid content, and nitrogen-corrected true metabolizable energy (TMEN) were equivalent among soybean meals. A 21-day broiler feeding trial was carried out to determine if the QTLs affect soybean meal quality. Weight gain and feed-to-gain ratio were evaluated. No biologically significant differences were detected for broilers fed Benning, Benning(M), and Benning(MGH). This demonstrates that soybean meal produced from the insect-resistant NILs is equivalent to soybean meal produced from their non-insect-resistant parent cultivar for broiler weight gain.

Effects of graded fiber level and caecectomy on metabolizable energy value and amino acid digestibility in geese

This study was carried out to evaluate the effects of graded levels of fiber from rice hull and the caecectomy on metabolizable energy (ME) and amino acid digestibility (AAD) in 42 Wuzong geese (21 intact and 21 caecectomized). The experiment was a 3×2 factorial randomized design with 3 fiber levels and 2 treatments of geese (caecectomized and intact). Each of the 3 diets was tube-fed (60 g) to 7 caecectomized and 7 intact adult Wuzong geese that had been fasted for 24 h. Excreta were collected for the next 48 h. The same geese were also fasted for estimation of endogenous losses of amino acids (AA) and energy after short period recovery. AA content and metabolizable energy value were determined in the excreta. In general, significant effects were found for fiber levels on apparent digestibility of Thr, Leu, Pro, Glu, Val, Ala and total AA (P<0.05). Apparent metabolizable energy (AME) and true metabolizable energy (TME) were both significantly influenced by increased fiber levels (P<0.01). Compared with caecectomized geese, markedly increases of AME and TME were found in intact geese (P<0.01 for AME and P<0.05 for TME), but no difference in the AAD were found between intact and caecectomized geese (P>0.05), except for Lys and Try (P<0.05). These observations suggested that dietary fiber level played an important role in digestibility of AAD and ME. Intact geese should be chosen for the nutrient evaluation of feedstuffs in practice, resulting from the significant difference between caecectomized and intact geese.

Chemical composition, amino acid digestibility, and true metabolizable energy of cowpeas as affected by roasting and extrusion processing treatments using the cecectomized rooster assay

SUMMARY Nutritional differences due to variety, source, and effects of heat processing on cowpeas (Vigna unguiculata) were assessed. The precision-fed cecectomized rooster assay was used to determine amino acid digestibility and TME of cowpeas. Mozambican cowpea (nhemba) treatments included either raw or roasted, whereas those (black-eyed beans) sourced from the United States were raw, roasted, or extruded. Crude protein content on a DM basis was similar for raw nhemba (296 g/kg) in comparison to raw black-eyed beans (299 g/kg). Raw nhemba had slightly higher amino acid content (except tryptophan) than raw black-eyed beans. The level of trypsin inhibitors of nhemba was 3 times higher than black-eyed beans (6,700 vs 2,200 TIU/g). Heat treatment generally had no effect on amino acid concentration except for lysine, which was reduced in both beans by heat. Additionally, all heat treatments reduced the concentration of trypsin inhibitors to below 2,000 TIU/g. Amino acid digestibility for the nhemba cowpeas was lower than for the black-eyed cowpeas except for tryptophan. Roasting had no effect on amino acid digestibility in black-eyed beans, but increased digestibility of several amino acids in nhemba cowpeas, and the average increase was 3.4 percentage units. The TMEn of raw nhemba cowpeas was significantly increased (2,806 vs 3,347 kcal/kg DM) by roasting and the TMEn of raw black-eyed cowpeas was significantly increased by extrusion (3,164 vs 3,535 kcal/kilogram DM).

Implications of uncertainty in true metabolizable energy estimates for estimating wintering waterfowl carrying capacities

Carrying capacity models for wintering waterfowl require estimates of energy availability based on food densities and true metabolizable energy (TME) of various food types. However, because TME values vary widely between studies, estimates of carrying capacity may be less precise than previously acknowledged. We explored how variation in TME values affected estimates of landscape-level energy availability for American black ducks (Anas rubripes), using 4 distinct approaches for assigning TME values to waterfowl food items collected over the winter period in 2011–2012 and 2012–2013: a “best practices” approach, which typically used average TMEs across species, a minimum and maximum reported values approaches, and a coarse-scale “order-average” approach. We found that all 4 approaches yielded significantly different estimates of energy availability across all saltmarsh habitat types. Additionally, we evaluated the potential management implications of variation in TME values by comparing energy supply on 1,223 ha of marsh in Prime Hook National Wildlife Refuge (DE, USA) using all 4 approaches for assigning TME values. We estimated carrying capacity and modeled depletion of energy on this refuge over a hypothetical wintering period. We found that even relatively small variations in TME values produced highly variable estimates of carrying capacity for the refuge. Thus, we recommend that researchers consider the inherent uncertainty in TME values of waterfowl foods, and explicitly include this variation in carrying capacity models. © 2015 The Wildlife Society.

Nutritional properties of dried salmon silage for broiler feeding.

The aim of this study was to evaluate the chemical composition, energy and amino acid profile of dried salmon silage (DSS) for broilers. The DSS was obtained by acid digestion of salmon mortalities and subsequently co-dried with wheat bran in a 70:30 ratio (70 parts silage and 30 parts wheat bran). Samples of DSS were evaluated for chemical composition, gross energy, nitrogen-corrected true metabolizable energy (TMEn ), mineral content, total and digestible amino acids for broilers, and amino acid score. The chemical composition of DSS was (mean ± SD): moisture (12.3 ± 0.8%), crude protein (44.0 ± 1.1%), ether extract (5.0 ± 2.4%), crude fiber (3.3 ± 0.4%) and ash (9.4 ± 0.6%). The gross energy and TMEn for broilers were 4 069 kcal/kg and 2 613 kcal/kg, respectively. The DSS mineral composition showed a high content of calcium (1.01%) and phosphorus (1.08%). The DSS had high levels of digestible methionine (0.74%), lysine (2.27%), and threonine (1.16%), and did not present limiting amino acids for broilers. Nutritional composition of DSS showed high protein content with an amino acid profile considered to be suitable as a protein source for broiler feeding.

Chemical Composition and Nutritive Value of South African Sorghum Varieties as Feed for Broiler Chickens

Sorghum ( Sorghum bicolor (L.) Moench ) is the fifth most important grain crop after wheat, rice, maize and barley. It is cultivated for food and feed in America, Asia, Australia and Africa. Newly developed sorghum varieties should be evaluated for their suitability as food and feed. The physical characteristics and proximate composition, total phenolic content, mineral content, amino acid profile and digestibility, and true metabolizable energy of four sorghum varieties were studied. The condensed tannin sorghum varieties PAN8625 and NS5511 had higher total phenolic content and antioxidant activity than the non-tannin varieties PAN8816 and PAN8906. Crude protein content diverged narrowly across the varieties, ranging from 81.2 to 95.4 g/kg DM. Starch and gross energy contents also differed, though varieties that were used had similar total and individual mineral contents. The threonine, leucine, phenylalanine, valine, proline and alanine contents of PAN8625 and PAN8906 were higher than those of NS5511 and PAN8816, which had similar contents. Amino acid digestibility and metabolizable energy of the tannin varieties were generally lower than those of the non-tannin ones. These results indicate that chemical and nutrient composition of sorghum varieties should be considered when selecting for broiler chicken feeding. Keywords: Amino Acid Profile, Minerals, Tannin Sorghum, Total Phenolics

True metabolizable energy of American black duck foods

ABSTRACTUnderstanding the true metabolizable energy (TME) of foods is critical to estimating the energetic carrying capacity of landscapes for migrating and wintering waterfowl. We estimated gross energy, nutrient composition, and TMEN (TME corrected for zero nitrogen balance) for 7 foods that are commonly found in the diet of American black duck (Anas rubripes) and other waterfowl wintering along the Atlantic Coast. TMEN values ( ± SE) were 3.66 ± 0.12 kcal/g for mummichog (Fundulus heteroclitus), 2.02 ± 0.12 kcal/g for grass shrimp (Palaemonetes intermedius, P. pugio, and P. vulgaris), 1.57 ± 0.11 kcal/g for fiddler crabs (Uca minax, U. pugilator, and U. pugnax), 1.42 ± 0.13 kcal/g for sea lettuce (Ulva lactuca), 1.39 ± 0.12 kcal/g for saltmarsh cordgrass seeds (Spartina alterniflora), 1.10 ± 0.14 kcal/g for widgeon grass vegetation (Ruppia maritima), and 0.77 ± 0.16 kcal/g for saltmarsh snails (Melampus bidentatus). TMEN estimated for foods in this study will assist conservation planners in carrying out bioenergetics modeling along the Atlantic Coast. © 2014 The Wildlife Society.

Use of different statistical approaches in prediction of metabolizable energy of diets for broilers

Energy value of diets has importance for feed producers and farmers. Methods for in vivo determination of metabolisable energy have high accuracy, but they are time and cost consuming. The aim of this study was to investigate the effect of enzymatic digestible organic matter and values of proximate chemical analysis on prediction of the nitrogen corrected true metabolisable energy (TMEn) of diets for broilers. The performance of Artificial Neural Network was compared with the performance of first order polynomial model, as well as with experimental data in order to develop rapid and accurate method for prediction of TMEn content. Analysis of variance and post-hoc Tukey's HSD test at 95% confidence limit have been calculated to show significant differences between different samples. Response Surface Method has been applied for evaluation of TMEn. First order polynomial model showed high coefficients of determination (r2 = 0.859). Artificial Neural Network model also showed high prediction accuracy (r2 = 0.992). Principal Component Analysis was successfully used in prediction of TMEn.

Carcass Characteristics and Meat Quality of Korean Native Ducks and Commercial Meat-type Ducks Raised under Same Feeding and Rearing Conditions.

This study was conducted to compare carcass characteristics and physico-chemical meat quality in two different genotype ducks raised under identical feeding and rearing conditions. A total of ninety 1-d-old Korean native ducks (KND, n = 45) and commercial meat-type ducks (Grimaud, n = 45) were fed same experimental diets during 56 d and 42 d, respectively to obtain similar slaughter weights. The experimental diet for starter period contained 20% crude protein (CP) and 2,900 kcal nitrogen corrected true metabolizable energy (TMEn)/kg of diet and that for grower period contained 17% CP and 3,050 TMEn/kg of diet. Average daily gain and feed efficiency of KND were inferior to those of commercial meat-type ducks (p<0.05). Carcass weight was not different between two genetically different ducks, but carcass yield of KND was significantly higher (p<0.05) than that of commercial meat-type ducks. There were no significant differences in cooking loss and pH of breast meat between two genetically different ducks, but water holding capacity of KND was significantly higher than that of commercial meat-type ducks. The linoleic acid and total polyunsaturated fatty acid of breast meat from KND were significantly higher (p<0.05) than the corresponding part from commercial meat-type ducks. Significant differences were detected in water holding capacity and the content of linoleic acid and polyunsaturated fatty acid, which were significantly higher in KND, whereas growth performance tended to be superior in commercial ducks. At the market weight, the meat from KND was judged to have better qualities with regard to higher water holding capacity and greater content of polyunsaturated fatty acid compare with meat from commercial meat-type duck.

Developing a computer-controlled simulated digestion system to predict the concentration of metabolizable energy of feedstuffs for rooster1

Four experiments were conducted to evaluate the effectiveness of a computer-controlled simulated digestion system (CCSDS) for predicting apparent metabolizable energy (AME) and true metabolizable energy (TME) using in vitro digestible energy (IVDE) content of feeds for roosters. In Exp. 1, the repeatability of the IVDE assay was tested in corn, wheat, rapeseed meal, and cottonseed meal with 3 assays of each sample and each with 5 replicates of the same sample. In Exp. 2, the additivity of IVDE concentration in corn, soybean meal, and cottonseed meal was tested by comparing determined IVDE values of the complete diet with values predicted from measurements on individual ingredients. In Exp. 3, linear models to predict AME and TME based on IVDE were developed with 16 calibration samples. In Exp. 4, the accuracy of prediction models was tested by the differences between predicted and determined values for AME or TME of 6 ingredients and 4 diets. In Exp. 1, the mean CV of IVDE was 0.88% (range = 0.20 to 2.14%) for corn, wheat, rapeseed meal, and cottonseed meal. No difference in IVDE was observed between 3 assays of an ingredient, indicating that the IVDE assay is repeatable under these conditions. In Exp. 2, minimal differences (<21 kcal/kg) were observed between determined and calculated IVDE of 3 complete diets formulated with corn, soybean meal, and cottonseed meal, demonstrating that the IVDE values are additive in a complete diet. In Exp. 3, linear relationships between AME and IVDE and between TME and IVDE were observed in 16 calibration samples: AME = 1.062 × IVDE - 530 (R(2) = 0.97, residual standard deviation [RSD] = 146 kcal/kg, P < 0.001) and TME = 1.050 × IVDE - 16 (R(2) = 0.97, RSD = 148 kcal/kg, P < 0.001). Differences of less than 100 kcal/kg were observed between determined and predicted values in 10 and 9 of the 16 calibration samples for AME and TME, respectively. In Exp. 4, differences of less than 100 kcal/kg between determined and predicted values were observed in 3 and 4 of the 6 ingredient samples for AME and TME, respectively, and all 4 diets showed the differences of less than 25 kcal/kg between determined and predicted AME or TME. Our results indicate that the CCSDS is repeatable and additive. This system accurately predicted AME or TME on 17 of the 26 samples and may be a promising method to predict the energetic values of feed for poultry.

Determination of Energy Value of Corn with Different Methods for Japanese Quails (Coturnix Coturnix Japonica)

The present study was conducted to investigate two different method of energy determination on energy content of corn in Japanese quail. The experiment was carried out at 120 mature male quails with 134± 4 g mean live weight were assigned in a completely randomized design to three treatments: 1-The total collection of excreta method (TC), 2-External marker (Cr2o3) Method and 3-The last group for determination of endogenous losses. A reference diet (RD) was then formulated to supply the birds' nutritional requirements. Feedstuffs (corn) replaced RD at 40%. Five replications and eight quails per experimental unit were used. The experimental period was twelve days, seven days for adaptation to experimental cages and five days for the collection of excreta. Values of Apparent Metabolizable Energy (AME) and True Metabolizable Energy (TME) were calculated on the basis of analysis of result. Feed intake (FI) was measured during the experiment daily by difference between allocated feed and orts. Based on feed intake and dry matter records, dry matter consumption (DMC) was calculated. Excretion of DM was calculated based on excreta weight and DM of excreta in each replicate. Dry matter digestibility coefficient was measured by means of DM intake and DM excretion. There was no significant difference (P>0.05) between TC and CrO method in energy values of corn. The means of apparent metabolizable energy (AME) of the corn with TC and CrO method was 2881.58 and 2985.25 Kcal/kg, respectively. Feedstuff metabolizable energy estimation using the external marker method with the use of chromium oxide (Cr2o3) was similar to that obtained using total excreta collection method, demonstrating that total excreta collection can be replaced by chromium oxide (Cr2o3) marker methods in Japanese quail. The difference observed in the metabolizable energy values of corn among this study and NRC recommendation suggested that Japanese quail can used energy content of corn less efficiently than chickens.

Comparison of Two Different In Vivo Models and an In Vitro Model for Caloric Determination of Four Novel Fiber Ingredients

The objective of this study was to compare two in vivo methods using pigs and roosters and an in vitro method for determining the caloric value of four fiber sources [i.e., two resistant starches (RS 60 and RS 75), soluble corn fiber (SCF 70), and pullulan]. Metabolizable energy (ME) in pigs and true metabolizable energy (TMEn) in roosters were determined by using 72 barrows and 24 roosters, respectively. A two-step in vitro procedure was used to quantify monosaccharides released. Results of the two in vivo experiments corresponded well with RS 75 having the least caloric value (7.55 MJ/kg in pigs; 6.19 MJ/kg in roosters) and pullulan having the greatest caloric value (12.21 MJ/kg in pigs; 13.94 MJ/kg in roosters). The caloric values for all the fiber ingredients were less (P < 0.05) than in MD both in pigs and in roosters. Despite some limitations, results of the in vitro procedure corresponded well with the in vivo experiments where the concentration of glucose hydrolyzed from RS 60, RS 75, and SCF 70, but not pullulan, was less (P < 0.05) than the concentration of glucose hydrolyzed from MD. However, the greatest accuracy was obtained in the in vivo experiments.

Predicting the metabolizable energy content of corn for ducks: a comparison of support vector regression with other methods

Support vector regression (SVR) is used in this study to develop models to estimate apparent metabolizable energy (AME), AME corrected for nitrogen (AMEn), true metabolizable energy (TME), and TME corrected for nitrogen (TMEn) contents of corn fed to ducks based on its chemical composition. Performance of the SVR models was assessed by comparing their results with those of artificial neural network (ANN) and multiple linear regression (MLR) models. The input variables to estimate metabolizable energy content (MJ kg-1) of corn were crude protein, ether extract, crude fibre, and ash (g kg-1). Goodness of fit of the models was examined using R2, mean square error, and bias. Based on these indices, the predictive performance of the SVR, ANN, and MLR models was acceptable. Comparison of models indicated that performance of SVR (in terms of R2) on the full data set (0.937 for AME, 0.954 for AMEn, 0.860 for TME, and 0.937 for TMEn) was better than that of ANN (0.907 for AME, 0.922 for AMEn, 0.744 for TME, and 0.920 for TMEn) and MLR (0.887 for AME, 0.903 for AMEn, 0.704 for TME, and 0.902 for TMEn). Similar findings were observed with the calibration and testing data sets. These results suggest SVR models are a promising tool for modelling the relationship between chemical composition and metabolizable energy of feedstuffs for poultry. Although from the present results the application of SVR models seems encouraging, the use of such models in other areas of animal nutrition needs to be evaluated.

Interannual Consistency of Gross Energy in Red Oak Acorns

Abstract Red oak Quercus spp., Subgenus Erythrobalanus acorns are forage for mallards Anas platyrhyncos, wood ducks Aix sponsa, and other wildlife that use bottomland hardwood forests in the southeastern United States. However, annual variation in true metabolizable energy from acorns would affect carrying-capacity estimates of bottomland hardwood forests for wintering ducks. Because gross energy and true metabolizable energy are strongly positively correlated and gross energy is easier to measure than true metabolizable energy, we used gross energy as a surrogate for true metabolizable energy. We measured gross energy of six species of red oak acorns in autumns 2008 and 2009. Within species, mean gross energy of these acorns varied less than 2% between years. The small interannual variation in gross energy of red oak acorns found in this study would have negligible effect on estimates of carrying capacity of bottomland hardwood forests for wintering ducks and other wildlife.

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

BackgroundThis 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.MethodsTwenty-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.ResultsResults 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).ConclusionsThis 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.