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, 5030 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 10 000 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 Contact: jabrijihene@gmail.com