n
Emma Teirlynck; Evelyne Delezie; Leo O. Fiems; Sam De Campeneere; Johan L. De
Boever; Luc Maertens
Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit, Scheldeweg
68, B-9090 Melle, Belgium
Corresponding author: Emma.Teirlynck@ilvo.vlaanderen.be
ABSTRACT
Because of its high protein content, ‘dried distillers grains with solubles’ (DDGS) is a potential alternative for the traditional protein sources in livestock feeds. In Europe mainly wheat based DDGS is produced. In order to determine the maximum inclusion level of a wheat based DDGS in broiler diets, a multi-level experiment was designed during which the effect on nitrogen-corrected metabolizable energy (AME n
) and dietary fat digestibility was studied. A wheat/corn/triticale (70/20/10) based DDGS was introduced in a basal broiler growth diet at 0, 6, 12, 18 and 24%, respectively. Chromic oxide was used as inert marker.
Each diet was fed to 6 groups of 4 broilers. After 6 days of adaptation, the 4 day balance trial was executed between 18 and 22 days of age. Through analysis of nutrients and chromic oxide in diets and feces, the digestibility of the diets was determined. Dietary AME n amounted to 3219, 3207, 3170, 3067 and 2923 kcal/kg fresh weight (FW) at an inclusion of 0,
6, 12, 18 and 24% DDGS, respectively. Statistical analysis showed a significant decrease of the dietary AME n
with increasing amounts of DDGS. However, dietary fat digestibility was not depressed with increasing inclusion level and amounted to 72, 75, 75, 73 and 70%, respectively.
KEYWORDS: broilers, wheat DDGS, multi-level experiment, nutritional value.
INTRODUCTION
There is a rising interest in alternative fuels, since the fossil fuel sources are limited. One of these alternative fuels is bio-ethanol by processing grain into ethanol. During the production process only the starch of the original materials is converted into ethanol, leaving 2 intermediate products: wet distillers grains and solubles. When both of these fractions are added and dried DDGS is obtained.
Due to the high protein content of DDGS, it could be used as an alternative for the traditional protein source in livestock feed, namely soybean meal. However, DDGS should be validated before it can be used on a larger scale in livestock production. Corn based DDGS, mostly used in the US, has already been studied for use in broiler diets (Lumpkins et al.
, 2004;
Bregendahl, 2008; Adeola and Zhai, 2012). In Europe and Canada however, bio-ethanol production mostly relies on other grains such as wheat, barley, triticale,… leading to another type of DDGS.
The objective of the present trial was to determine the effect of the inclusion level of wheat based DDGS on the dietary AME n
and fat digestibility value of broiler diets.

MATERIALS AND METHODS
A multi-level experiment was designed to assess the effects of graded levels of DDGS in a broiler growth diet on the nitrogen-corrected metabolizable energy (AME n
) and the dietary fat digestibility. Animal procedures were approved by the ILVO Ethical Committee for Animal
Experiments.
A basal wheat-soybean meal broiler growth diet was formulated to which 0.4% chromic oxide was added as an index marker. The four experimental diets were obtained by substituting part of this basal diet by graded levels of a wheat/corn/triticale (70/20/10) based DDGS, respectively 6, 12, 18 and 24 %. The nutrient composition of the basal diet and the wheat
DDGS are shown in Table 1.
Table 1. Nutrient composition of the basal diet and wheat DDGS.
Nutrients Basal diet DDGS
Dry Matter (DM) 89.46
Gross Energy (kcal/kg FW) 4136
Crude Protein (% FW) 19.9
89.61
4425
31.2
Fat (% FW) 8.3 8.2
Ash (% FW) 5.7 5.7
Each treatment consisted of six replicates of four male Ross 308 broilers. The animals were housed in the digestibility cages at 12 days of age. An adaptation period of 6 days was followed by a 4 day period during which the balance trial was executed. Through analysis of dry matter, fat, gross energy and chromic oxide in both the feed and the feces, AME n
and fat digestibility of the five diets were determined. The balance trial was carried out according to the EU-reference method (Bourdillon et al.
, 1990).
Data were analysed using a nonparametric test (Kruskal-Wallis). When this test was significant, Dunn’s test on mean ranks was performed.
RESULTS
The AME n
amounted to 3219 ± 99, 3207 ± 37, 3170 ± 50, 3067 ± 45 and 2923 ± 172 kcal/kg
FW respectively for the five dietary treatments containing 0, 6, 12, 18 and 24 % DDGS
(Figure 1).
Statistical analysis showed a significant decrease of the AME n
with increasing amounts of DDGS (P<0.001). A drop of the dietary AME n
was determined at an inclusion level of 18% and 24% (0.05<P<0.001 and P<0.001, respectively; Dunn’s test on mean ranks).
Regression analysis shows this is a non-linear decrease.
The fat digestibility was 71.8 ± 3.6, 75.5 ± 2.2, 74.9 ± 2.6, 72.5 ± 2.5 and 69.9 ± 6.2% respectively (Figure 2). In contrast with the AME n
value, no significant impact of the inclusion level of DDGS on the dietary fat digestibility could be demonstrated (P=0.153).

Figure 1. AME n
(kcal/kg) of the diets.
3400
3300
3200
3100
3000
2900
2800
2700
0 6 12
% DDGS in the diet
Figure 2. Fat digestibility (%) of the diets.
80
75
70
65
60
55
50
100
95
90
85
0 6 12
% DDGS in diet
18
18
24
24
CONCLUSION
The AME n
value of wheat based DDGS depends on the inclusion level of DDGS in the diet.
A significant drop of the dietary AME n
was determined at an inclusion level of 18% and 24%.
The dietary fat digestibility on the other hand, was not affected by the inclusion level of wheat
DDGS.
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BREGENDAHL, K . (2008) Use of distillers coproducts in diets fed to poultry, in:
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