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

F Li,J H Yao,Y J Sun,Y Liu,X J Yang,F F Sun,Y R Liu,G J Li,R Q Yin

doi:10.5713/ajas.2012.12594

Abstract

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.

Highlights

Distillers dried grains with solubles (DDGS) has been commonly used as an ingredient in poultry diets for many decades
Prediction equations Stepwise selection method was used to estimate the Gross energy (GE), chemical composition and color score that contributed to the predictors of true metabolizable energy (TMEn) of 23 DDGS samples (Table 5)
The average concentration of DM, CP, crude fiber (CF) and acid detergent fiber (ADF) of DDGS in the present study are in agreement with the published values (Batal and Dale, 2006; Pedersen et al, 2007; Waldroup et al, 2007), while content of ash and Neutral detergent fiber (NDF) are higher than the results reported by Pedersen (2007), but similar with the results of Stein et al (2006) (n = 10, NDF = 40.1%)

Summary

Introduction

Distillers dried grains with solubles (DDGS) has been commonly used as an ingredient in poultry diets for many decades. Large variability of DDGS composition and poor protein quality may limit its utilization in poultry diets (Cromwell et al, 1993; Fastinger et al, 2006). Many studies were conducted to develop some useful parameters (i.e. color scores or chemical composition) to predict amino acid digestibility and nitrogen-corrected true metabolizable energy (TMEn) of DDGS (Batal and Dale, 2006; Fastinger et al, 2006). Some regression equations have been established to predict energy utilization based on chemical composition for poultry. The color scores included in the model improved the equation for wheat DDGS (Cozannet et al, 2010)

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