Phụ phẩm từ sắn là nguồn thức ăn tiềm năng trong chăn nuôi bò ở cộng hoà dân chủ nhân dân lào

HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHANTHAVONG VONGSAMPHANH CASSAVA BY-PRODUCT AS POTENTIAL FEED SOURCE FOR YELLOW CATTLE IN LAO PDR DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES HUE, 2019 HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHANTHAVONG VONGSAMPHANH CASSAVA BY-PRODUCT AS POTENTIAL FEED SOURCE FOR YELLOW CATTLE IN LAO PDR SPECIALIZATION: ANIMAL SCIENCES CODE: 9620105 DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES SUPERVISOR 1: ASSOCIATE PROFESSOR DR NGUYEN XUAN BA SUPERVISOR 2: DR DINH VAN DUNG HUE, 2019 GUARANTEE I hereby declare that this dissertation is the result of my work and that is has not been presented previously as a dissertation at this university or elsewhere To declare that all sources to be acknowledged and all to be listed in the reference Hue University, 2019 Phanthavong Vongsamphanh, PhD student ACKNOWLEDGEMENTS I would like to express my sincere gratitude and appreciation to my major advisor, Associate Professor Dr Nguyen Xuan Ba, Faculty of Animal Science and Veterinary Medicine, Hue University of Agriculture and Forestry, Hue University, Hue City, Vietnam for his invaluable advice, encouragement and generous sharing of knowledge both scientifically and actually, which has enabled me to complete this thesis I would like also deeply grateful to my co-advisors, Dr Dinh Van Dung, Faculty of Animal Science and Veterinary Medicine, Hue University of Agriculture and Forestry, Hue University, Hue City, Vietnam for his kind not only served as my coadvisor, but has been a friend, encouraging me to explore and experience to the limit He has provided so many valuable services beyond just advising, teaching, mentoring and continuous support in many ways to broaden my perspectives and made this thesis the final product of my research I would like to express my sincere thanks to Professor Dr T R Preston from Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria (CIPAV), Carrera 25 No 6-62 Cali, Colombia for his advice, suggestions and guided in my experiment from the beginning and made correction as needed, include revision of English in the manuscript His encouragement, criticism, excellent technical assistance guided not only my study but also invaluable suggestions for me in the future My research and education would not have been possible without Dr Viengsakoun Napasirth from Faculty of Agriculture, National University of Lao and the Faculty of Agriculture and Forest Resource, Souphanouvong University and my friend there’s Mr Sangkhom Inthapanya and Mr Phonevilay Silivong for their provided valuable help in the laboratory I also would like to thanks to Mr Khamla and Mr Vakili Vongxay, owners of the Sukanya and Natthanasouck farms where the experiments were carried out, for providing access to cattle, feed resources and infrastructure.The Tropical Feed Resources Research and Development Center (TROFEC) of Khon Kaen University, Thailand is acknowledged for support in collection of rumen samples and VFA analysis Thanks to Department of Livestock and Fisheries, National Agriculture and Forestry Research Institute, Ministry of Agriculture and Forestry for facilities supported and permission for me to study I wish to express my sincere appreciation to all those people whose names not appear here-in who helped me to complete this thesis I would like to give big thanks to my family for their understanding and moral support during the study, especially my wife for her encouragement and inspiration Finally, I wish to express special thanks to the MEKARN Project II for generous contribution towards financial support that made this thesis, my education and career goals possible ABSTRACT The objectives of this study were (i) evaluated the potential of feeding value of the cassava pulp to local yellow cattle (ii) to study the effect of brewers' grain and cassava foliage (Manihot esculenta Cranz) as protein sources for Lao local cattle fed cassava pulp-urea as basal diet, (iii) to evaluate the effects of source of cassava leaves (sweet or bitter at 4% DM) and with or without of brewers’ grain at 4% DM in an in vitro rumen fermentation on gas and methane production using the ensiled cassava pulp supplemented with urea as basal substrate (iv) to evaluated the basis of the method for incorporating cassava foliage as the protein-fiber source in a fattening system for local Yellow cattle based on ensiled cassava pulp (derived from processing of cassava roots for starch production) The result of first experiment were the pH was changed with the level of pit depth the pH was high when collected sample in surface and pH decreased when collected deeper and DM was between 20 to 25% Gas production and DM mineralization values after 24h fermentation in an in vitro incubation showed cassava pulp was slightly inferior (