INTRODUCTION 1. BACKGROUND OF THE STUDY Livestock production plays a significant role as source of food and of cash income for smallholder farmers in rural areas in Laos. There were 3.7 million pigs in Laos (DLF, 2017). Most of the pig mainly production in Laos is produced under traditional conditions with approximately 75% in rural smallholder pig farms (Souriyasack, 2011). The typical smallholder pig farm relies on a scavenging system for forages and left-over food with little or no supplementation. Supplementary energy-rich feeds are rice bran, broken rice, maize and cassava root, but usually the price makes them out of reach of poor farmers. The only sources of protein that farmers can afford are green plant material and natural vegetables. These feed resources are not available in all seasons and are imbalanced nutritionally, with lack of protein being the major issue. The classical sources of protein used in pig production such as fish meal and soybean meal are almost exclusively imported and out of reach of smallholder farmers. The results are low productivity (Stür et al., 2010) with growth rates often less than 100 g/day (Phengsavanh et al., 2010). This means a production cycle of 1.5 to 2 years to reach market weight of 60 to 70 kg (Phengsavanh and Stür, 2006). The reproductive performance of sows is marked by depressed litter size, a high mortality of piglet and outbreaks of disease. The only options so far available to most smallholder farmers are to make better use of the locally available feed resources and/or to introduce protein-rich plants that are easy to grow such as the perennial leguminous forage Stylosantheses guiensis (Phengsavanh and Stür, 2006). For these reasons the two feed resources chosen for this research were banana pseudo stem (Musa spp) as source of energy and the Taro plant (Colocasia esculenta) as the source of protein. Banana pseudo stems (BPS) from the banana tree are distributed in Laos, as bananas are widely grown for production of fruit for family consumption and sale. The total harvest area of banana trees in Laos was estimated to be 28,600 ha, with yields of 42 tonnes of fruit/ha (MAF, 2017). The stem of the banana trees is referred to as a “pseudo stem” as it appears to be held erected by water, not by lignified fiber as in most trees. After the fruit is harvested this pseudo-stem is either left to rot on the ground or is occasionally harvested, chopped into small pieces and fed to pigs, ducks and chickens (Tien et al., 2013). Banana pseudo stem has 8.5% lignin in DM, more than twice that in rice straw (4.5%). However, a more detailed analysis using Light Microscopy, Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) revealed major differences in anatomical characteristics, with the fiber in banana pseudo stem presenting a tubular structure which would facilitate the movement of water within the stem (Li et al., 2010). It is not known if such a structure is what facilitates the process of chopping the stem with a knife as is done traditionally, usually by women. But it would explain the high content of water in the stem of about 94%, the major nutritional constraint to banana pseudo stem would appear to be the low level of protein about 3-4% in DM (Floulkes et al.,1978). However, an unusual finding was reported presence of 3% of soluble sugars in the liquid fraction which means that almost half of the reported 6% of DM in the banana pseudo stem is present as soluble sugars (Dao Thi My Tien et al., 2010). These have not been identified but the fact that the pseudo stem ensiles readily the pH falling from 4.5 to 3 within 5 days, confirms that they are readily fermentable (Dao Thi My Tien et al., 2010). Taro foliage (Colocasia esculenta) as the source of protein, as taro was found in natural habitats where water is stored, near river banks, streams and ponds in Laos. It was reported that the planted area was 11,335 ha with average root yield of 10.7 tonnes/ha (MAF, 2017). In the study reported by Kaensombath and Frankow-Lindberg (2012) the forage biomass yield at root harvest was 1,483 kg/ha of DM, provide 260 g/kg of protein; the tuber DM yield was 2,732 kg/ha. Taro leaves are rich in protein (about 20% in DM) with a balance of essential amino acid close to that in an “ideal” protein (Rodríguez et al., 2006). The petioles are rich in sugars which facilitate ensiling the combined leaves and petioles to give a feed with 14-15% CP in the DM (Malavanh et al., 2008; Giang et al., 2010; Hai et al., 2013). Many experiments have demonstrated that ensiled taro foliage can be fed as a source of protein for pigs (Toan and Preston, 2010; Chittavong et al., 2012; Kaensombath and Lindberg, 2012; Hang et al., 2015). The limitation to the use of taro foliage in diets for pigs is the presence of oxalates which form crystalline insoluble salts that cause irritation
HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY BOUNLERTH SIVILAI THE UTILIZATION OF DIETARY LOCAL FEED RESOURCES FOR MOO LATH PIG IN LAOS DOCTOR OF PHILOSOPHY IN AGRICULTURE HUE, 2019 HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY BOUNLERTH SIVILAI THE UTILIZATION OF DIETARY LOCAL FEED RESOURCES FOR MOO LATH PIG IN LAOS SPECIALIZATION: ANIMAL SCIENCE CODE: 62620105 DOCTOR OF PHILOSOPHY IN AGRICULTURE SUPERVISORS: ASSOC.PROF.DR NGUYEN QUANG LINH ASSOC.PROF DR DU THANH HANG HUE, 2019 DECLARATION I declared that this thesis is my original research works It is a scientific research which overall data presented in this thesis are contributed truly and righteously The research works was done under the guidance of Professors in Hue University and collaborative professional researchers All acceptation is evidently indicated to the best of immense knowledge that they have been published in Journal of Livestock Research for Rural Development (LRRD) Hue, April 2019 Bounlerth SIVILAI I ACKNOWLEDGEMENT This thesis describes research on the improving and utilization of forage- based diets for Moo Lath pigs in Laos, I wish to thank Mekong Basin Animal Research Network (Sida/MEKARN II) project and University of Agriculture and Forestry, Hue University for financial support of experiments and the course works in Vietnam This thesis based on the efforts of many people In the first place, I would like to thank all those persons who contributed to obtaining the data and the texts of the various chapters Without their help this thesis would never been written Especially, I would like to express my sincere thanks to Professor Nguyen Quang Linh, Professor Thomas Reg Preston, who always open the gates to scientific research I am also grateful for their supervision and guidance of my research I would like to express my heartfelt thanks to Professor Du Thanh Hang, who supervised the data analysis It would be nice to thank for all of lecturers and researchers in Hue with hospitality while my staying in Hue city I am grateful to Dr Lampheuy Kaensombath and professor R.A Leng for their contributions and helping My sincere thanks also goes to Dr Kieu Borin, regional coordinator of the Sida/MEKARN II project for any support and make the PhD program possible and Dr Chive Phiny for the budgets for travelling and allowances Dr Vanthong Phengvichit and Dr Daovy Kongmanila the country coordinators for providing the immense suggestion on study condition and financial report as well as accountants in National Agriculture and Forestry Research Institute (NAFRI) for arrangement research funds conveniently Also thank my colleagues, friends and teachers in Department of Livestock and Fishery, Faculty of Agriculture (FAG), National University of Laos for their kindly supports My lovely students and their friends whom helped in field works with forage collecting, experiments and sample preparing analysis Last but not least, I would like to thank my family for all their kind regards, encouragement and love Most of appreciation to my wife Linh Thamavong for her patience, effort working hard and taking care for our family during my studying Special thank to my mother for her support, loving and devotion to my three children during studying time Great thanks to my sister Boakeo Phaisilai and her husband, my younger sister Boasone Sivilai and my uncles’ family for their help in looking my mother, supporting me spiritually throughout studying, writing thesis and my life in generally II ABSTRACT The research was objected to investigate the effect of ensiled taro foliage combined with banana pseudo stem as basal diets, using by-product of rice distillers or brewers’ grains, and biochar as feed additive supplemented in the diet of native Moo Lath Lao pig Four experiments were conducted to comprising on the thesis The first experiment (Chapter 2): Four pigs were used in the experiment with 30 kg 2.63 kg LW An experiment was arranged in a 4*4 Latin Square Design with diet levels of ensiled banana pseudo stem of 0, 5, 10 and 15% replacing ensiled taro foliage and soybean meal Apparent digestibility of DM and CP, daily N retention and biological value (BV), all declined linearly as ensiled banana-pseudo stem replaced ensiled taro foliage It is appeared that the BV of the protein in the ensiled taro foliage was superior to combination of ensiled banana pseudo stem and soybean meal In the second experiment (Chapter 3): A small amount of either rice distillers’ byproduct (RDB) and brewers’ grain (BG) were added in the ensiled forage-based diet Six female native Moo Lath pigs (29.3 2.3 kg LW), fed a basal diet of ensiled banana pseudo-stem, ensiled Taro foliage and broken rice were allocated to a 3*3 double Latin Square Design Three treatments were BG 4%, RDB 4% or no supplement (CTL) Both supplements improved feed intake, digestibility and N retention, with indications of greater responses in N retention and in the biological value of the protein for the rice distillers’ by-product It is suggested that the beneficial effect of both supplements may have been due to the presence of β-glucan, a component of the cell wall of both cereal grains and yeasts, that is shown to have immunological, health-benefiting effects in animal In the third experiment (Chapter 4): The supplements would bring similar benefits during the stage of pregnancy and lactation in Moo Lath gilts Twelve native Moo Lath pig gilts (80.8 ± 3.9 kg LW) were used in the experiment Three dietary treatments in a completely randomized design with replications were: CTL: No supplement; RDB 4% or BG 4% in diet DM basis The pig gilts gained more body weight during gestation, and were heavier at the end of lactation, when their diet was supplemented with 4% BG or 4% RDB The litter sizes from dams supplemented with 4% RDB were heavier at birth, and at weaning, and grew faster than litters from un-supplemented gilts Supplementation III of BG4% or RDB 4% appeared to have no effect on piglet mortality at birth or during lactation, nor on live weights of piglets at birth or weaning, and did not affect overall feed DM intake However, DM feed conversion was improved by 60% when the Moo Lath gilts were supplemented with 4% RDB In the fourth experiment (Chapter 5): The study was to evaluate the effect of biochar compare with rice distillers’ by-product fed a forage diet on growing pigs Twenty native Moo Lath pigs (15.8 ± 1.3 kg LW) were housed in individual concrete pens There were four dietary treatments arranged as a completely randomized design The treatments (% in diet DM) were: no additive (CTL), 4% rice distillers’ by-product (RDB), 1% biochar (BIO) and the combination of RDB and BIO (RDB+BIO) The growth rate tended to be better (p=0.089) and feed conversion was improved (p=0.048) for both additives, fed separately or together, when compared with the control diet There were no benefits from combining both additives compared with feeding each one separately Keywords: Local forage, prebiotic, additive feed, indigenous pig, biological value, growing, pregnancy-lactation, piglets IV DEDICATION To my family with my respectful gratitude: Parents, my wife (with daughter and son), older and younger sisters ແດ່ຄອບຄົວທີ່ແສນເຄົາລົບຮັກຂອງຂ້ອຍ: ພໍ່ແມ່, ພັນລະຍາ (ພ້ອມດ້ວຍລູກສາວ ແລະ ລູກຊາຍ), ເອື້ອຍ ແລະ ນ້ອງສາວ V TABLE OF CONTENTS DECLARATION I ACKNOWLEDGEMENT II ABSTRACT III DEDICATION V TABLE OF CONTENTS VI LIST OF TABLES .IX LIST OF FIGURES XI LIST OF ABBRIVIATIONS AND SYMBOLS XIV INTRODUCTION 1 BACKGROUND OF THE STUDY AIMS AND OBJECTIVES OF THE STUDY 2.1 Aims of the thesis 2.2 Objectives of the thesis HYPOTHESES OF THE RESEARCH 4 INNOVATION CONTRIBUTED OF THE DISSERTATION REFERENCE CHAPTER 1: LITERATURE REVIEW 10 1.1 PIG PRODUCTION IN SMALLHOLDER OF LAOS 10 1.1.1 The role of pig production 10 1.1.2 Pig population and consumption 10 1.2 CURRENTLY TYPICAL PIG FARMING IN LAOS 11 1.2.1 Smallholder pig farming 12 1.2.2 Semi-intensive pig production 15 1.2.3 Commercial scale pig production 16 1.3 Feeds and feeding practical management in smallholder pig farms 17 1.3.1 Feeds derived from agricultural by-products 17 1.3.2 Green plant materials as feeds for pigs 18 1.3.3 Feeds derived from leftover materials 18 1.4 CONSTRAINTS AND OPPORTUNITY IN SMALLHOLDER FARMS 18 1.4.1 Main problem in smallholder pig production 18 1.4.2 Opportunity improvement of pig productivity 19 VI 1.5 ALTERNATIVE USE OF LOCAL FEED RESOURCES FOR PIGS 20 1.5.1 Taro foliage (Colocasia esculenta) 20 1.5.2 Banana pseudo stem (Musa spp) by-product 22 1.6 UTILIZATION OF FORAGE-BASED DIET FOR PIGS 23 1.6.1 Taro as protein sources for pigs 23 1.6.2 Effect of taro foliage on apparent digestibility and N retention in pigs 23 1.6.3 Effect of taro foliage on growth performance of pigs 24 1.6.4 Effect of taro foliage replacing by banana pseudo stem in pig diets 25 1.7 GRAIN FERMENTED BYPRODUCTS AS SUPPLEMENT FEED FOR PIGS 27 1.7.1 Rice distillers( Khi-Lao) by-products 27 1.7.2 Brewery grain( Khibeer )by-product 29 1.8 UTILIZATION OF GRAIN FERMENTATION BYPRODUCTS 32 1.8.1 Use of rice distillers’ by-product or brewers’ grains as protein sources 32 1.8.2 Effect of rice distillers’ by-product or brewers’ grains as supplement feeds 33 1.8.3 The use of biochar as a feed additive in animals 33 1.9 NUTRIENT REQUIREMENT OF PIGS 34 1.9.1 Dietary protein requirement 34 1.9.2 Dietary energy requirement 35 REFERENCES 36 CHAPTER 2: EFFECT OF REPLACING ENSILED TARO FOLIAGE (COLOCASIA ESCULENTA) WITH ENSILED BANANA PSEUDO STEM (MUSA SPP) AND SOYBEAN MEAL ON INTAKE, DIGESTIBILITY AND NITROGEN RETENTION IN MOO LATH PIGS 49 CHAPTER 3: A LOW CONCENTRATION OF RICE DISTILLERS’ BYPRODUCT OR OF BREWERS’ GRAINS ON DIGESTIBILITY AND NITROGEN RETENTION IN NATIVE MOO LATH PIGS FED ENSILED BANANA PSEUDO-STEM (MUSA SPP) AND ENSILED TARO FOLIAGE (COLOCASIA ESCULENTA) 58 CHAPTER 4: EFFECT OF A LOW CONCENTRATION OF RICE DISTILLERS’ BYPRODUCT, OR OF BREWERS' GRAINS ON GROWTH RATE AND FEED CONVERSION DURING PREGNANCY AND LACTATION OF NATIVE MOO LATH GILTS AND THEIR PROGENY 70 VII CHAPTER 5: EFFECT OF RICE DISTILLERS’ BYPRODUCT AND BIOCHAR AS ADDITIVES WITH A FORAGE-BASED DIET FOR GROWING AND FEED CONVERSION OF NATIVE MOO LATH PIGS 83 GENERAL DISCUSSION AND CONCLUSION 95 GENERAL DISCUSSION 95 CONCLUSIONS 97 IMPLICATIONS FUTURE RESEARCH 98 3.1 Implications 98 3.2 Future research 98 REFERENCES 99 LIST OF PUBLISHED SCIENTIFIC PAPERS 102 VIII Dry matter intake, growth rate and feed conversion There was no effect of the additives on feed intake (Table 5.3; Figure 5.2) Growth rate tended to be better (p=0.089) and feed conversion was improved (p=0.048) for both additives, fed separately or together, when compared with the control diet The improvements in weight gain were 20.1 and 22.9% for biochar and RDB added separately and 22.9% for the combined additives For feed conversion the relative degrees of improvement were 10.6, 12.2 and 9.30% There were no benefits from combining both additives compared with feeding each one separately Table 5.3 Mean values for change live weight, feed intake and conversion for Moo Lath pigs fed rice distillers’ by-product, biochar or both Live weight CTL BIO RDB BIO+RDB SEM p ab Initial, kg 15.9 15.8 15.6 16.0 0.62 0.692 Final, kg 36.5 40.5 40.1 41.6 1.52 0.423 Daily gain, g/d 179 215 220 220 9.51 0.089 DM intake, g/d 787 850 859 874 41.7 0.58 DM conversion (kg/kg) 4.43b 3.96a 3.89 a 4.02 a 0.13 0.048 Mean values without common superscript are different at p