1. Use of Exogenous Fibrolytic Enzymes
TERRA day – May 20th 2016
Use of Exogenous Fibrolytic Enzymes
to improve the utilization of straws 
By ruminants
J. Jabri1,2, K. Abid2, H. Yaich2, Y. Beckers3, A. Malek2, J. Rekhis2, M. Kamoun2
1 Biology department, Faculty of sciences of tunis, University Campus El Manar, 2092 El Manar, Tunisia
2 Animal Nutrition Service, National School of Veterinary Medicine Sidi Thabet, 2020 Ariana, Tunisia
3 Precision Livestock and Nutrition Unit, AgroBioChem,, Ulg, Passage des Déportés, 2, Gembloux, Belgium
INTRODUCTION
Livestock production in many developing countries is constrained by poor nutrition because animal feeds are in short supply and what is available is often of poor quality. Cereal crops (maize, rice, wheat, sorghum etc) straw and stover are the main source of feed for ruminant animals especially during the dry season and/or winter although it is well recognized that these straws and stover have poor nutritional value because of their low energy and nitrogen and high fiber content.
Main objective: to improve the efficiency of using locally available feed resources like agricultural by-products (straws…) to improve livestock productivity by using the exogenous enzymes as feed additives.
Programme of Works
In vitro screening of commercial fibrolytic enzymes to identify the best level of enzymes for further evaluation in animal trials including : mode of action of the enzyme, optimal level of application, the most cost effective application method.
Materials and methods
Différents types of straws (cereals, leguminous..), sunflower stalks : natural and chemically treated.
Two cannulated cows
Fibrolytic Enzymes : Cellulase PLUS (Dyadic) , Xylanases Plus (Dyadic)
Enzymes levels: 0; 1; 2; 5; 10; 20; 30 µl/ g MS
Enzymes combinations :
100% cellulase
100 % xylanase
50 % cellulase – 50 % xylanase
75 % cellulase – 25% xylanase
25% cellulase – 75% xylanase
Cellulase (Dyadic Plus)
Xylanase (Dyadic Plus)
Activity
Cellulase
30 000 à 36 000 UI/g
Xylanase
34,000 to 41,000 UI/g
ß-glucanase
7 500 à  000 UI/g
Beta-Glucanase
12,000 to 15,000 UI/g
45,000 to 55,000 UI/g
FEEDING THE FUTURE
In vivo evaluation of the best level of fibrolytic enzymes
Materials and methods
20 lambs, divided in 4 groups, replicated 4×4 Latin square design
diets:
1- cereal straw
2- cereal straw treated with fibrolytic enzymes
3- cereal straw treated chemically
4- cereal straw treated chemically and fibrolytic enzymes
Evaluation parameters
Ruminal fermentation
Volatile Fatty Acids
Methane production
Nutrient intake
Diet digestibility
Animal performance and production
Acknowledgements
IAEA/ TERRA/ AgroBioChem/
Precision Livestock and Nutrition Unit/ENMV sidi thabet
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