Knowledge of amino acid (AA) digestibility of feed ingredients is necessary to feed broilers with properly balanced compound diets. For this reason, more attention has recently been given to the determination of AA digestibility of ingredients, recognizing that it may vary greatly depending upon the feed ingredient. The effects of the inclusion of a mono-component serine protease (Ronozyme® ProAct) on standardized ileal amino acid digestibility (SIAAD) of diets containing wheat by-products (wheat DDGS (WDDGS) and wheat middlings (WM)) were evaluated in broilers. - Improvement of SIAAD in the presence of protease is not the same for all AA and varies from one ingredient to another one. The effects of added protease are dependent on feed composition and on intrinsic digestibility of AA (COWIESON and ROOS (2014)). -™ Factors such as type and quality of the ingredients, industrial processing and the presence of anti-nutritional substances such as tannins, phytates, trypsin inhibitors in plant species modulate the digestibility in poultry feed and thus the effectiveness of exogenous protease.™ -The physiological state of animals (growth or maintenance), feed consumption or the nutritional feed quality could also influence the digestibility values.

1. CONCLUSION
In this study, protease supplementation was effective in improving the
standardized ileal digestibility of almost all the amino acids in wheat
middlings.
Improvement of SIAAD in the presence of protease is not the same for all AA and varies from one ingredient to another one. The
effects of added protease are dependent on feed composition and on intrinsic digestibility of AA (COWIESON and ROOS (2014)).
Factors such as type and quality of the ingredients, industrial processing and the presence of anti-nutritional substances such as
tannins, phytates, trypsin inhibitors in plant species modulate the digestibility in poultry feed and thus the effectiveness of
exogenous protease.
The physiological state of animals (growth or maintenance), feed consumption or the nutritional feed quality could also influence
the digestibility values.
MATERIALS & METHODS
Animals: 6 x 8 male broilers (Ross PM3) / treatment
Diets:
Diet 1 was Nitrogen-free diet (NFD) to be used for estimating endogenous nitrogen and amino acids losses
Diets 2 and 3 were experimental diets in which wheat by product DDGS and wheat middlings was the only
source of dietary protein included at 94.5 %
Diets 5 and 6 were the same as diets 2 and 3, with the protease Ronozyme® ProAct added at 15000 PROT/kg
Feeding: mash, ad libitum
Duration: day 20 to day 24 of bird age
Parameters: standardized ileal amino acid digestibility (SIAAD) calculated using the formula given by LEMME et al.(2004)
Statistical analysis: ANOVA followed by Newman-Keuls test (p<0.05)
Effects of protease supplementation on the standardized
ileal amino acid digestibility in two wheat by-products in
broiler chickens
R. Aureli1, P.Guggenbuhl1 and J. Broz2
1Research Centre for Animal Nutrition and Health, DSM Nutritional Products France, Saint Louis, France,
2DSM Nutritional Products Ltd, Basel, Switzerland
OBJECTIVE
Knowledge of amino acid (AA) digestibility of feed ingredients is necessary to feed broilers with
properly balanced compound diets. For this reason, more attention has recently been given to the
determination of AA digestibility of ingredients, recognizing that it may vary greatly depending
upon the feed ingredient. The effects of the inclusion of a mono-component serine protease
(Ronozyme® ProAct) on standardized ileal amino acid digestibility (SIAAD) of diets containing wheat
by-products (wheat DDGS (WDDGS) and wheat middlings (WM)) were evaluated in broilers.
OBJECTIVE
Knowledge of amino acid (AA) digestibility of feed ingredients is necessary to feed broilers with
properly balanced compound diets. For this reason, more attention has recently been given to the
determination of AA digestibility of ingredients, recognizing that it may vary greatly depending
upon the feed ingredient. The effects of the inclusion of a mono-component serine protease
(Ronozyme® ProAct) on standardized ileal amino acid digestibility (SIAAD) of diets containing wheat
by-products (wheat DDGS (WDDGS) and wheat middlings (WM)) were evaluated in broilers.
RESULTS & DISCUSSION
20th European Symposium on Poultry Nutrition ,24–27 August 2015 , Prague
SIAAD (%)
Enzyme1
- + - +
WM p= SEM WDDGS p= SEM
EAAs2
Arg 81.5 82.2 0.684 0.27 72.1 72.9 0.516 0.24
His 74.9 80.9 0.007 0.35 88.0 87.3 0.197 0.16
Ile 77.5 79.9 0.293 0.32 67.8 65.8 0.239 0.28
Leu 81.3 82.4 0.449 0.26 78.1 78.8 0.490 0.21
Lys 80.2 78.1 0.292 0.31 73.0 74.5 0.409 0.28
Met 83.4 83.4 0.945 0.24 74.2 75.2 0.490 0.25
Phe 81.4 83.5 0.142 0.26 83.3 83.4 0.990 0.19
Thr 68.9 71.3 0.272 0.31 65.4 68.6 0.115 0.31
Val 78.2 78.9 0.743 0.30 70.0 72.6 0.175 0.30
NEAAs3
Ala 74.8 76.4 0.358 0.28 67.6 65.5 0.178 0.27
Asp 73.5 76.0 0.177 0.29 47.7 42.7 0.053 0.36
Cys 75.2 74.8 0.809 0.28 67.9 68.7 0.707 0.31
Glu 88.7 89.6 0.314 0.21 85.0 83.7 0.129 0.20
Gly 85.6 90.3 0.058 0.35 60.4 52.7 0.068 0.45
Pro 86.2 86.9 0.410 0.20 84.4 84.5 0.869 0.19
Ser 76.8 75.8 0.752 0.38 72.7 72.7 0.990 0.23
Tyr 79.2 80.7 0.278 0.31 79.6 79.8 0.898 0.26
1 - No added enzyme, + Added enzyme (Ronozyme® ProAct at 15000 PROT/kg); 2EAAs: essential amino acids; 3NEAAs: non-essential amino acids
Figure 1: Efficacy of protease in improving SIAAD in broiler chickens fed
experimental diets for wheat middlings and wheat DDGS
References
COWIESON A.J, ROOS F. F., 2014: Bioefficacy of a mono-component protease in the diets of pigs and poultry: a meta-analysis of effect on ileal amino acid
digestibility. J.Appl Ani.Nut. 2, 1-8
LEMME, A., V. RAVINDRAN, W. L. BRYDEN, 2004: Ileal digestibilityof amino acidin feed ingredients for broilers. World’s Poult. Sci. J.60, 423-437
Table 1: Ileal standardized ileal digestibility coefficients (%) of amino acids (SIAAD) for
broilers fed experimental diets