Luận án tiến sĩ nâng cao hiệu quả sử dụng Bauhinia acuminata trong chăn nuôi dê - Nghiên cứu tại Lào

HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHONEVILAY SILIVONG IMPROVED UTILISATION OF BAUHINIA ACUMINATA FOR GOAT PRODUCTION IN LAO PDR DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES HUE, 2020 luan an HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHONEVILAY SILIVONG IMPROVED UTILISATION OF BAUHINIA ACUMINATA FOR GOAT PRODUCTION IN LAO PDR SPECIALIZATION: ANIMAL SCIENCES CODE: 9620105 DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES SUPERVISOR 1: ASSOC. NGUYEN HUU VAN SUPERVISOR 2: DR. DUONG THANH HAI HUE, 2020 luan an GUARANTEE I hereby guarantee that scientific work in this thesis is mine. All results described in this thesis are righteous and objective.

They have been published in Journal of Livestock Research for Rural Development (LRRD) http://www.org Hue University, 2020 Phonevilay Silivong, PhD student i luan an ACKNOWLEDGEMENTS The research in this PhD thesis was conducted at the farm and laboratory of Department of Animal Science, Faculty of Agriculture and Forest Resource, Souphanouvong University, in Luangprabang Province, Lao PDR with supported from Mekong Basin Animal Research Network (MEKARN II) project for funding this theses research and the scholarship for the PhD degree. I am grateful for the support from all of those people and institutions. I am greatly indebted to my main supervisor, Associate Professor Nguyen Huu Van and co-supervisor, Dr. Duong Thanh Hai for his mentoring and constructive advice during my studies.

He made me much more confident as a scientist and researcher. His patience and encouragement during my illness and positive criticism made it possible to accomplish this work. My special thanks to Professor Thomas Reg Preston and Professor Dr. Ron Leng, my teacher and adviser, for all your valuable guidance and support during the study.

I would also like to extend sincere thanks to Professor Dr. Ewadle, International Coordinator MEKARN II project; Dr. Vanthong Phengvichith, National Agriculture and Forestry Researcher Institute (NAFRI), Lao PDR; Dr. Kieu Borin, MEKARN II regional coordinator for their facilitation, help and support to the whole course.

Professors, lecturers and assistant lecturers in Hue University of Agriculture and Forestry and MEKARN II program, for giving me care and useful knowledge. Warm thanks are extended to my father, Mr. Souk Silivong for his great help and support. My mother, Ms.

Khampoun Silivong for her assistance and encouragement, my older brothers and sister Mrs. Kesone Silivong, Mr. Vone Silivong, Mr. Sonexay Silivong and younger sister Mrs.

Bounmee Silivong for their supported and encouragement; to my wife, Mrs. Souksadar Vongyalud and my son Phetsamone Silivong and my daughter Souphaphone Silivong for their love. I would like to warmly thank Mr. Khamlek and Mr.

Phonesavath, and Mr. Siphone, my analysis assistants and my colleagues in the Department of Animal Science, Faculty of Agriculture and Forest Resource, Souphanouvong University. All of my friends in the PhD program 2017-2020 from the three countries: Laos, Vietnam and Cambodia, for sharing the culture, friendship and creating a warm atmosphere throughout the time of the course. I would like to thanks all the people who contributed to this study.

ii luan an ABSTRACTS This study was aimed at the utilization of locally available feed resources for increasing growth performance and reducing enteric methane emissions from goats in Lao PDR. Five experiments (two in vitro and three in vivo) were carried out and presented in four chapters of this dissertation. Experiment 1 evaluated the effect on methane production from leaves of Bauhinia acuminata and Guazuma ulmifolia of an increasing level of water spinach as source of soluble protein. Experiment 2 and 3 were studied the effects of water spinach and biochar on enteric methane emissions and growth performance in local goats fed Bauhinia acuminata and molasses, or cassava root chip, as the basal diet.

Experiment 4 aimed to determine the effect of different protein sources (cassava foliage or water spinach) with or without of brewers’ grain (5% of diet DM)) on feed intake, digestibility, N balance and growth performance of local goats. Experiment 5 was to determine the effect of biochar and leaf meal from sweet and bitter cassava leaves, on methane production in an in vitro incubation of Bauhinia acuminata and water spinach as basal substrate. The main findings of the study were that: (1) Goats fed Bauhinia acuminata responded with improved diet digestibility, N retention and growth rate when the Bauhinia acuminata was supplemented with water spinach; (2) However an important negative effect was that the improvement in diet digestibility by supplementation with water spinach led to increases in methane production per unit diet DM digested; (3) Supplementing Bauhinia acuminata foliage with leaves from a bitter variety of cassava reduced the in vitro production of methane when compared with supplementation by leaves from a sweet variety of cassava; (4) Ensiled brewers’ grains fed as an additive (5% as DM) to a diet of Bauhinia acuminata improved the digestibility, N retention and growth rate of goats. The degree of improvement was greater when the Bauhinia acuminata was supplemented with cassava foliage instead of water spinach; (5) Biochar fed at 1% of a diet of Bauhinia acuminata and cassava foliage was as effective as brewers’ grains in improving the growth rate of the goats.

The results of this study indicated that supplementation of foliage from water spinach or cassava improved growth of local goats fed Bauhinia acuminata as basal diet. HCN present in the leaves of cassava could be the reason for the reduction in methane emission. Ensiled brewers’ grains and biochar fed to goats as additives probably act as “prebiotics” to improve growth performance and assist in detoxification in the animal. Key words: N-balance, protein solubility, bauhinia, water spinach, solubility N- balance, rumen ammonia, biochar, prebiotics, HCN iii luan an DEDICATION To my parents, my wife Souksadar Vongyalud, my son (Phetsamone Silivong) and daughter (Souphaphone Silivong) To: My country (Lao PDR) iv luan an TABLE OF CONTENT GUARANTEE.IV TABLE OF CONTENT.IV LIST OF FIGURES.VII LIST OF TABLES.X LIST OF ABBREVIATIONS, SYMBOLS AND EQUIVALENTS.

SIGNIFICANT/INNOVATION OF THE DISSERTATION. GOAT PRODUCTION IN LAO PDR. ROLE OF GOAT PRODUCTION IN LAOS. GOAT POPULATION AND DISTRIBUTION.

GOAT PRODUCTION SYSTEMS IN SMALLHOLDER FARMS. GOAT BREED AND BREEDING. CONSTRAINTS OF GOAT PRODUCTION IN LAO. POTENTIAL OF GOAT PRODUCTION DEVELOPMENT IN LAO.

GOAT NUTRITION AND METHANE EMISSION. NUTRIENT REQUIREMENT FOR GOAT. LOCAL AVAILABLE FEES RESOURCES FOR GOAT IN LAO.35 v luan an REFERENCES. EFFECT OF WATER SPINACH ON METHANE PRODUCTION IN AN IN VITRO INCUBATION WITH SUBSTRATES OF BAUHINIA ACUMINATA OR GUAZUMA ULMIFOLIA LEAVES AND MOLASSES.59 MATERIALS AND METHODS.

EFFECTS OF WATER SPINACH AND BIOCHAR ON METHANE EMISSIONS AND GROWTH PERFORMANCE OF GOAT FED BAUHINIA ACUMINATA AND MOLASSES OR CASSAVA ROOT CHIPS AS.71 MATERIALS AND METHODS. EFFECT OF REPLACING WATER SPINACH (IPOMOEA AQUATICA) BY CASSAVA (MANIHOT ESCULENTA CRANTZ) FOLIAGE AND/OR BREWERS’ GRAINS ON FEED INTAKE, DIGESTIBILITY, N RETENTION AND GROWTH PERFORMANCE IN GOAT FED BAUHINIA ACUMINATA PLUS CASSAVA ROOT CHIPS AS THE BASAL DIET.95 MATERIALS AND METHODS.105 vi luan an CONCLUSIONS. EFFECT OF SWEET OR BITTER CASSAVA LEAVES AND BIOCHAR ON METHANE PRODUCTION IN AN IN VITRO INCUBATION WITH SUBSTRATES OF BAUHINIA ACUMINATA AND WATER SPINACH (IPOMOEA AQUATICA).107 MATERIALS AND METHODS.117 GENERAL DISCUSSION AND CONCLUSIONS.127 vii luan an LIST OF TABLES CHAPTER 1. LITERATURE REVIE Table 1.

The number of goat in Lao PDR. Estimated of animals requirement (2017-2020). Daily Nutrient Requirements for Meat Producing Goats. Nutrient Requirements of Mature Does.

Important fodder tree and shrubs in the Lao PDR. Chemical composition of fodder trees and shrubs leaves. EFFECT OF WATER SPINACH ON METHANE PRODUCTION IN AN IN VITRO INCUBATION WITH SUBSTRATES OF BAUHINIA ACUMINATA OR GUAZUMA ULMIFOLIA LEAVES AND MOLASSES Table 1. Composition of diets (% DM basis).

Ingredients of the buffer solution (g/liter). The chemical composition of feed (% in DM, except DM which is on fresh basis). Mean values for gas production, percentage of methane in the gas, methane production (ml), DM solubilized and methane production per unit DM solubilized according to leaf source (Bauhinia and Guazuma) and level of water spinach. EFFECTS OF WATER SPINACH AND BIOCHAR ON METHANE EMISSIONS AND GROWTH PERFORMANCE OF GOAT FED BAUHINIA ACUMINATA AND MOLASSES OR CASSAVA ROOT CHIPS AS THE BASAL DIET Table 1.

Chemical composition of dietary ingredients (% in DM, except DM which is on fresh basis). Mean values of feed intake by goats fed Bauhinia acuminata supplemented with water spinach (WS) or biochar (BC) or not supplemented. Mean values for live weight, live weight change, feed DM intake and DM feed conversion for goats fed a basal diet of Bauhinia acuminata foliage and molasses.79 viii luan an Table 4. Mean values of apparent digestibility and N balance in goats fed Bauhinia acuminata and molasses supplemented with water spinach (WS) and biochar (BC) or not supplemented (No-WS; No-BC).

Mean values of rumen pH and ammonia, and ratio of methane to carbon dioxide in eructed breath of goats fed Bauhinia acuminata and molasses supplemented with water spinach (WS) and biochar (BC) or not supplemented (No-WS; No-BC). Mean values of feed intake by goats fed Bauhinia acuminata and cassava root chips supplemented with water spinach (WS) or biochar (BC) or not supplemented. Mean values for live weight, live weight change, feed DM intake and DM feed conversion for goats fed a basal diet of Bauhinia acuminata foliage and Cassava root chips. Mean values of apparent digestibility and N balance in goats fed Bauhinia acuminata and cassava root chips supplemented with water spinach (WS) and biochar (BC)or not supplemented (No-WS; No-BC).

Mean values of rumen pH and ammonia in goats fed Bauhinia acuminata and cassava root chips supplemented with water spinach (WS) and biochar (BC) or not supplemented (No-WS; No-BC). EFFECT OF REPLACING WATER SPINACH (IPOMOEA AQUATICA) BY CASSAVA (MANIHOT ESCULENTA CRANTZ) FOLIAGE AND/OR BREWERS’ GRAINS ON FEED INTAKE, DIGESTIBILITY, N RETENTION AND GROWTH PERFORMANCE IN GOAT FED BAUHINIA ACUMINATA PLUS CASSAVA ROOT CHIPS AS THE BASAL DIET Table 1. Layout of the digestibility/N retention study. Chemical composition of dietary ingredients (% in DM, except DM which is on fresh basis).

Mean values of apparent digestibility and N balance in goats fed Bauhinia acuminata supplemented with water spinach or cassava foliage, with (BG) and without (No-BG) brewers’ grains. Mean values of feed intake by goats fed Bauhinia acuminata plus cassava root. Mean values for live weight, live weight change, DM intake and DM feed conversion for goats fed Bauhinia acuminata supplemented with cassava or water spinach foliage, with or without brewers’ grains (interaction effects).103 ix luan an Table 6. Molar VFA proportions in rumen fluid from goats fed Bauhinia acuminata supplemented with water spinach or cassava foliage, with and without brewers’ grains.

EFFECT OF SWEET OR BITTER CASSAVA LEAVES AND BIOCHAR ON METHANE PRODUCTION IN AN IN VITRO INCUBATION WITH SUBSTRATES OF BAUHINIA ACUMINATA AND WATER SPINACH (IPOMOEA AQUATICA) Table 1. Composition of substrate (% DM basis). Ingredients of the buffer solution (g/liter).110 x luan an LIST OF FIGURES CHAPTER 1. LITERATURE REVIEW Figure 1.

Fermentation pathways in the rumen. EFFECT OF WATER SPINACH ON METHANE PRODUCTION IN AN IN VITRO INCUBATION WITH SUBSTRATES OF BAUHINIA ACUMINATA OR GUAZUMA ULMIFOLIA LEAVES AND MOLASSES Diagram 1. A schematic view of the in vitro system to measure gas production in an in vitro incubation.60 Photo 1: Bauhinia acuminata.61 Photo 2: Guazuma ulmifolia. The in vitro system made from recycled "pep" water bottles.

The substrate residue filtered though cloth. Effect of Bauhinia (BA) and Guazuma (GU) leaf meals on gas production at increasing incubation intervals. Effect of increasing level of water spinach on gas production at increasing incubation intervals. Effect of foliages from Bauhinia (BA) and Guazuma (GU) on methane content in the gas at increasing incubation intervals.

Effect of increasing level of water spinach on methane content in the gas at increasing incubation intervals. Effect of leaf meals from Bauhinia (BA) and Guazuma (GU) on substrate DM solubilized at increasing incubation interval. Effect of level of water spinach on substrate DM solubilized at increasing incubation intervals. Effect of leaf meals from Bauhinia (BA) and Guazuma (GU) on methane per unit DM solubilized at different incubation intervals.