Sử dụng thân cây chuối làm thức ăn cho lợn địa phương (kandol) ở vùng núi ratanakiri của campuchia

HUE UNIVERSITY
UNIVERSITY OF AGRICULTURE AND FORESTRY

HUY SOKCHEA

UTILIZATION OF BANANA STEMS FOR LOCAL PIGS
(KANDOL) IN MOUNTAINOUS RATANAKIRI PROVINCE
OF CAMBODIA

DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES

HUE, 2019
i


HUE UNIVERSITY
UNIVERSITY OF AGRICULTURE AND FORESTRY

HUY SOKCHEA

UTILIZATION OF BANANA STEMS FOR LOCAL PIGS
(KANDOL) IN MOUNTAINOUS RATANAKIRI PROVINCE
OF CAMBODIA

SPECIALIZATION: ANIMAL SCIENCES
CODE: 9620105

DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES

SUPERVISOR 1: ASSOC. PROF. TRAN THI THU HONG
SUPERVISOR 2: PROF. LE DUC NGOAN

HUE, 2019
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GUARANTEE
I hereby guarantee that scientific work in this thesis is mine. All results described in
this thesis are righteous and objective. Two papers were published in Journal of
Veterinary and Animal Research, one paper was in International Journal of
Innovation and Animal Research.

Hue, March 2019

Huy Sokchea, PhD student

iii


Acknowledgements

I am very pleased to express my sincere and gratitude to institutions and
individuals, who involved in and contributed to my doctoral thesis. Special thanks to the
Swedish International Development Authority/Department for Research Cooperation
(Sida/SAREC) for financially support of my researches and study in both Cambodia and
Vietnam through the MEKARN program (Mekong Basin Animal Research Network) and
also to my supervisors, Asso. Prof. Tran Thi Thu Hong for her constructive advices and
useful guidance and also to my co-supervisor Prof. Le Duc Ngoan, Asso. Prof. Le Dinh
Phung and H.E. Khieu Borin for their inputs in both experiments and the thesis.

In addition, I would like to thank very much to Prof. Le Duc Ngoan, Asso. Prof. Le

Van An, Asso. Prof. Le Dinh Phung, Asso. Prof. Nguyen Quang Linh and Asso. Prof.
Nguyen Xuan Ba for providing the training courses on advanced method of writing
academic papers; advanced livestock feed and feeding; advanced biology statistics and
experiment design; advanced pig husbandry; and advanced cattle husbandry, respectively
and also thank to the students from Royal University of Agriculture (Mr. Sao Kongkea and
Thim Chan Thy) for helping me in running my experiments and staffs of CelAgrid (Dr.
Chhay Ty, Dr. Miech Phalla, Dr. Chiv Phiny, Dr. Pok Samkol, Mrs. Bou Socheata, Mr.
Son Pov, Mr. Vo Sina and Ms. Chourn Kimyeang) for their contributions during my thesis
development.

Finally, I also would like to convey my sincere gratitude to my wife, children,
parents, parents in law, brothers, sisters and a brother and a sister in-law for their valuable
encouragement and understanding.

iv


Abstract
The overall objective of the study was to effectively utilize banana stems for
improving local pigs performance under village conditions in the mountainous zones of
Cambodia. In this thesis, four studies were performed to meet main specific objective. In
the first study, nine villages of 3 communes and 3 districts with totally 126 respondents
were sampled for this study in order to understand the situation of pig production of
farmers in mountainous Ratanakiri province. As result, all famers preferred keeping local
pigs in the range of 3-5 heads per family and the pigs were fed for 8-12 months to get the
marketable weight of 30-40 kg (ADG 120g/day) with the diet composed of banana stems
3.8% as DM basic that consisted of 2,257 kcal ME/kg DM and 7.8% CP. In the second
study, the experiment was followed by nested model with 3 replicates to determine the
effects of time, C/N ratio and molasses concentration on yeast of S. cerevisiae biomass
production. It was found that the application of C/N ratio at 10/1 as substrate for 24 hours

was able to improve biomass production of Saccharomyces cerevisiae. In the third study,
the experiment was designed, following to completely randomized design (CRD) with four
treatments and 4 replicates in the purpose of improvement of nutritive values of banana
stems by fermentation with Saccharomyces cerevisiae solution. As result, the fermentation
of banana stems with the addition of Saccharomyces cerevisiae solution could improve
their nutritive values, mainly true protein and crude fiber in the period of 7 days, compared
to the ones without any addition of Saccharomyces cerevisiae solution. In the last study,
the experiment was designed by the randomized completely design (RCD) with 5 dietary
treatments and 4 replicates to determine the optimum inclusive level of fermented banana
stems in the diets on apparent digestibility, growth performance and carcasses quality of
local pigs. As result, the inclusion of fermented banana stems at the 50% into the diet could
improve apparent digestibility and growth performance as mainly compared to the control
diet, however, any inclusion of fermented banana stems into the diet was not quite effect
on carcasses quality.

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Key words: Carcasses quality, digestibility, growth performance, local pig, Saccharomyces

cerevisiae fermented banana stems

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Dedication to
My parents, parents in law, brothers and sisters
My wife Pech Sina
My children, Huy Soknancy, Huy Sokjulie and Huy Sokyannyheng

TABLE OF CONTENT

iii


INTRODUCTION.....................................................................................................................10
1.

Problem statement.........................................................................................................10

2.

Overall and specific objectives of the study.................................................................11

2.1.1. Overall objective............................................................................................................11
2.1.2. Specific objectives..........................................................................................................11
3.

Significant/Innovation of the dissertation....................................................................12

CHAPTER 1..............................................................................................................................13
LITERATURE REVIEW.........................................................................................................13
1.

Pig production in Cambodia.........................................................................................13

1.1.

Pig production systems..................................................................................................13

1.2.

Pig production in mountainous zones..........................................................................14

2.

Fibrous feeds for pigs....................................................................................................15

2.1.

Roles of fibrous feeds.....................................................................................................15

2.2.

Fractions of fibrous feeds..............................................................................................16

2.2.1. Cellulose.........................................................................................................................16
2.2.2. Hemicellulose.................................................................................................................16
2.2.3. Lignin.............................................................................................................................17
2.3.

Fibrous feed movement process in the digestive tract of the pigs..............................17

2.4.

Effect of fibrous feeds on intake...................................................................................17

2.5.

Effect of fibrous feeds in pig diet..................................................................................18

2.5.1. Digestibility....................................................................................................................18
2.5.2. The digestive tracts’ health...........................................................................................19
2.5.3. Growth performance.....................................................................................................20
2.5.4. Carcass quality..............................................................................................................21
3.

Available and local fibrous feed resources...................................................................21

3.1.

Banana pseudo stems.....................................................................................................22

3.1.1. Nutritive value...............................................................................................................22
3.1.2. Utilization.......................................................................................................................22
3.2.

Rice bran........................................................................................................................23

3.2.1. Nutritive value...............................................................................................................23
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3.2.2. Utilization.......................................................................................................................24
3.3.

Rice distiller’s by-product.............................................................................................25

3.3.1. Nutritive value...............................................................................................................25
3.3.2. Utilization.......................................................................................................................25

4. Yeast fermentation................................................................................................................26
4.1.

Fermentation..................................................................................................................26

4.2.

Factors affect Saccharomyces cerevisiae biomass........................................................27

4.2.1. Carbon and nitrogen ratios...........................................................................................27
4.2.2. Temperature and pH.....................................................................................................28
4.3.

Effect of microorganism and organic acids on animal production and health.........28

4.3.1. Saccharomyces cerevisiae yeast.....................................................................................28
4.3.2. Enzyme and organic acids.............................................................................................29
4.4.

Solid state fermentation................................................................................................29

4.4.1. Concept...........................................................................................................................29
4.4.2. Solid state fermention of agricultural byproducts......................................................30
4.4.3. Advantages and disadvantages.....................................................................................30
References..................................................................................................................................31
CHAPTER 2..............................................................................................................................48
UNDERSTANDING PIG PRODUCTION IN RATANAKIRI PROVINCE........................48
Abstract......................................................................................................................................48
1. Introduction.........................................................................................................................49
2. Methodologies........................................................................................................................50

2.1.

Site selection and duration............................................................................................50

2.2.

Sample size.....................................................................................................................50

3. Statistical analysis..................................................................................................................51
4. Results and discussion...........................................................................................................51
4.1.

General information about targeted sites....................................................................51

4.2.

Family profile.................................................................................................................52

4.3.

Banana information.......................................................................................................53

4.4.

Livestock information...................................................................................................53

4.5.

Pig raising system..........................................................................................................54

4.6.

Pig production and health.............................................................................................55
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4.7.

Pigs breed and breeding................................................................................................56

4.8.

Feed and feeding systems..............................................................................................57

4.9.

Diseases and prevention................................................................................................60

4.10.

Pigs market demand......................................................................................................60

4.11.

Problems and solutions on pig production...................................................................60

5. Conclusion..............................................................................................................................61
References..................................................................................................................................61
CHAPTER 3..............................................................................................................................65
EFFECT OF TIME, C/N RATIO AND MOLASSES CONCENTRATION ON

SACCHAROMYCES CEREVISIAE BIOMASS PRODUCTION..........................................65
Abstract......................................................................................................................................65
1. Introduction.........................................................................................................................66
2. Material and methods.........................................................................................................67
2.1.

Yeast strain and preparation........................................................................................67

2.2.

Experimental design......................................................................................................67

2.3.

Measurements................................................................................................................68

2.3.1. Yeast density..................................................................................................................68
2.3.2. Identification of yeast....................................................................................................69
2.3.3. PCR amplification of the ITS region............................................................................69
2.4.

Cultivation process of yeast..........................................................................................70

2.5.

Analytical procedures....................................................................................................70

2.6.

Data analysis..................................................................................................................70

3. Results..................................................................................................................................71
3.1.

Density of yeast..............................................................................................................71

3.2.

Identification of yeast....................................................................................................71

3.3.

Effect of time on Saccharomyces cerevisiae biomass...................................................72

3.4.

Effect of C/N ratio on Saccharomyces cerevisiae biomass...........................................73

3.5.

Effect of molasses concentration on Saccharomyces cerevisiae biomass....................74

4. Discussion............................................................................................................................75
5. Conclusion...........................................................................................................................78
References..................................................................................................................................78
CHAPTER 4..............................................................................................................................82
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IMPROVING NUTRITIVE VALUES OF BANANA STEMS BY SACCHAROMYCES

CEREVISIAE SOLUTION FERMENTATION......................................................................82
Abstract......................................................................................................................................82
1. Introduction.........................................................................................................................83
2. Materials and methods.......................................................................................................84
2.1.

Experiment I..................................................................................................................84

2.1.1. Location..........................................................................................................................84
2.1.2. Experimental design......................................................................................................85
2.1.3. Banana stems fermenting process................................................................................85
2.1.4. Chemical analyses..........................................................................................................86
2.1.5. Statistical analyses.........................................................................................................86
2.2.

Experiment II.................................................................................................................87

2.2.1. Experimental design......................................................................................................87
2.2.2. Statistical analysis..........................................................................................................87
3. Results and discussion........................................................................................................87
3.1.

Experiment I..................................................................................................................87

3.1.1. Results............................................................................................................................87
3.1.2. Discussion.......................................................................................................................91
3.2.

Experiment II.................................................................................................................93

3.2.1. Results............................................................................................................................93
3.2.2. Discussion.......................................................................................................................96
4.

Conclusion......................................................................................................................97

References..................................................................................................................................97
CHAPTER 5............................................................................................................................102
EFFECT OF INCLUSION OF FERMENTED BANANA STEMS IN DIETS ON
DIGESTIBILITY, GROWTH PERFORMANCE AND CARCASS QUALITY OF LOCAL
PIG (KANDOL).......................................................................................................................102
Abstract....................................................................................................................................102
1. Introduction........................................................................................................................103
2. Materials and methods.....................................................................................................104
2.1.

Location........................................................................................................................104

2.2.

Preparation for Saccharomyces cerevisiae banana stem fermentation....................104
4


2.3.

Experimental designs..................................................................................................105

2.4.

Diets and feeding..........................................................................................................106

2.5.

Sample collection of digestibility and feeding trial....................................................107

2.6.

Chemical analyses........................................................................................................108

2.7.

Statistical analyses.......................................................................................................109

3.

Results and discussion.................................................................................................109

3.1.

Apparent digestibility and nitrogen balance.............................................................109

3.1.1. Results..........................................................................................................................109
3.1.2. Discussion.....................................................................................................................110
3.2.

Growth performance...................................................................................................111

3.2.1. Results..........................................................................................................................111
3.2.2. Discussion.....................................................................................................................114

4.

Conclusion....................................................................................................................116

References................................................................................................................................116
CHAPTER 6............................................................................................................................122
GENERAL DISCUSSION AND CONCLUSIONS...............................................................122
1.

GENERAL DISCUSSION..........................................................................................122

1.1.

Situation of local pigs’ production in Cambodia.......................................................122

1.2.

Saccharomyces cerevisiae and its application.............................................................123

1.3.

Nutritive value improvement of banana stems through fermentation.....................124

1.4.

Banana stems-local pigs’ production system.............................................................125

1.5.

Improving of banana stems by fermentation for local pigs’ production.................126

2.

GENERAL CONCLUSIONS.....................................................................................131

3.

IMPLICATIONS AND FURTHER RESEARCH....................................................131

3.1.

Implications..................................................................................................................131

3.2.

Further research..........................................................................................................132

REFERENCES............................................................................................................................132

5


LIST OF TABLES
Table 1: Proximate composition of rice bran (% air dry weight basis)...........................................24
Table 2: Sampling of each village in Ratanakiri.............................................................................51
Table 3: Family profile by commune/district.................................................................................52
Table 4: Animal population by communes.....................................................................................54
Table 5: Average number of animals per household......................................................................54
Table 6: Feed resources for local pig in Ratanakiri (% of interviewed householder).....................57
Table 7: Chemical composition of the feeds in DM basic..............................................................58

Table 8: Estimated amount of feed intake (g DM/day), ME intake and nutritive value of the diet. 59
Table 9: The medium for yeast fermentation..................................................................................68
Table 10: Density of yeast in feed active dry yeast product...........................................................71
Table 11: Gene sequences of DNA bands from yeast detected by Gene bank................................72
Table 12: Effect of time on Saccharomyces cerevisiae biomass (g L-1)..........................................73
Table 13: Effect of C/N ratio on Saccharomyces cerevisiae biomass (g L-1)..................................73
Table 14: Formulation of fermentation of banana stem and rice bran in DM basis........................85
Table 15: Chemical composition of the feeds in DM basic............................................................85
Table 16: Chemical composition of fermented banana stem at the different treatments.................88
Table 17: Chemical composition of banana stem and rice bran (DM basic)..................................93
Table 18: Chemical composition of fermented banana stem at the different treatments.................93
Table 19: Chemical composition of ingredients used in the diets.................................................106
Table 20: Diets for digestibility and feeding study (% DM).........................................................106
Table 21: Apparent digestibility of treatmentary diets (%)...........................................................109
Table 22: Nitrogen balance of the pigs in different treatments.....................................................110
Table 23: Mean value of feed intake of pig in different treatments..............................................111
Table 24: Average daily gain and feed conversion ratio of pigs in different treatments...............111
Table 25: Mean value of carcass traits of pig fed different treatmentary diets..............................112
Table 26: Back fat thickness (mm) and loin eye area (cm 2) of pigs in different treatments..........112
Table 27: Mean value of pH, color, marbling and water holding capacity of meat in treatments. 113

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LIST OF FIGURES
Figure1: Non-starch polysaccharide components (Choct et al., 2010)...........................................16
Figure 2: Mean of S. cerevisiae biomass at C/N ratio of 5/1..........................................................75
Figure 3: Mean of S. cerevisiae biomass at C/N ratio of 10/1........................................................75
Figure 4: Mean of S. cerevisiae biomass at C/N ratio of 15/1........................................................75
Figure 5: Effect of fermented times at each treatment on DM........................................................90

Figure 6: Effect of fermented times at each treatment on ash.........................................................90
Figure 7: Effect of fermented times at each treatment on CF.........................................................90
Figure 8: Effect of fermented times at each treatment on CP.........................................................91
Figure 9: Effect of fermented times at each treatment on TP.........................................................91
Figure 10: Effect of fermented times at each treatment on DM......................................................95
Figure 11: Effect of fermented times at each treatment on ash.......................................................95
Figure 12: Effect of fermented times at each treatment on CP.......................................................95
Figure 13: Effect of fermented times at each treatment on TP.......................................................96

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LIST OF PHOTOS
Photo 1: Banana plants farming in upland......................................................................................53
Photo 2: Jungle banana plants........................................................................................................53
Photo 3: Banana stems cutting........................................................................................................59
Photo 4: Broken rice cooking.........................................................................................................59
Photo 5: DNA band of three DNA samples from 3 colonies (A-C) of yeast on agarose gels.........72
Photo 6: Banana farming..............................................................................................................105
Photo 7: Collected banana stems..................................................................................................105
Photo 8 &9: View of the pens for digestibility study...................................................................107
Photo 10: Measurement of back fat thickness..............................................................................113
Photo 11: Measurement of loin eye area......................................................................................113
Photo 12: Color and marbling score.............................................................................................114
Photo 13: Measurement of meat pH.............................................................................................114

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LIST OF ABBRIVIATIONS

ADB

Asian Development Bank

CF

Crude Fiber

CP

Crude Protein

DM

Dry Matter

FAO

Food and Agriculture Organization

FCR

Feed Conversion Ratio

GDAHP

General Directorate of Animal Health and Production

GDP

Gross Domestic Product

MAFF

Ministry of Agriculture and Forestry and Fishery

NIS

National Institute of Statistic

OM

Organic Matter

PDAFF

Provincial department of agriculture, forestry and fishery

TP

True Protein

VAHWs

Village Animal Health Workers

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INTRODUCTION

1.

Problem statement
Cambodia population is over 16 million, annually growth rate of 1.5% and

population density of about 91 habita per km 2 in 2018. Agriculture is one of three
economic sectors which contributed 26.3 % of national GDP in 2016. Livestock sub-sector
contributed about 2.8% to the national economy and 11.96% of agricultural GDP (MAFF,
2017). However, pig production shared about 48% of the total livestock production (FAO,
2011). In 2016, pig population was reached 2,970,624 heads (annually growth rate 2%),
and 98% of pig population produced by smallholders (MAFF, 2018). About 5% of
smallholders raised local breeds (Borin et al., 2012), due to more resistant to infectious
diseases and more adapting to local climate frequency and environment and they also have
a higher capacity to digest higher fibrous feed and more reproductive than exotic ones
(Rodríguez and Preston, 1997; Len et al., 2009b). The smallholders have turned in a very
low level of production due to low input and lack of technical knowledges and experiences
in animal husbandry (Wallberg et al., 2011). Total of 54.7% of smallholders fed their pigs
with local resources and agricultural byproducts (Borin et al., 2012). Ström et al. (2017)
indicated that partly and/or fully utilization of the unconventional feeds was potential and
sustainable alternative of pigs’ production, mainly for smallholder pigs’ production as it
could alleviate the production cost and risks.
Banana was one of the fruit trees with totally cultivated land of 24,000ha after
mango of 42,000ha, produced over 240,000 tons of fruits and 960,000 tons of residues
yearly in Cambodia (NIS, 2015). Seven of the 25 provinces in Cambodia reported to plant
banana on at least 1,000 ha. Kampong Cham led other provinces with 5,000 ha of banana
plantation and with 819 ha in Ratanakiri (data from provincial department of agriculture in
2019), but only 350 ha in 2013 (NIS, 2015). With these cultivated areas, about 3,300 tons
of banana stems residue remained in the field with improperly and sufficiently utilization.
In addition, Jungle banana plants grew naturally for year-rounds in somewhere around the
10

farms or sometimes in the farms and along the ways to the farms as well, so it was very
hard to estimated how many hectares of the banana plants were. However, they were only
harvested as feed of the pigs in some months of the year, especially in the period of
cultivated banana plants and other feed resources were in minority or extinction.

Wang et al. (2016) reported that banana stems could be considered as an alternative
of traditional forage sources. Pigs are generally fed in fresh basic by chopped and pasted
together with rice bran, plus some cooked rice or/and kitchen waste (Wallberg et al., 2011).
Chhay ty et al. (2016) showed that banana stems has very low dry matter and nutritive
values, but it could be improved by fermentation with indigenous microorganism (IMO)
(Michael et al., 2016). Duyet et al. (2013) also found that 50:50 mixtures (DM basis) of
banana stems and taro foliage could be ensiled satisfactorily without any additions. In
addition, supplementation with a combination of 3% nitrogen, 0.4% sulphur and 0.25%
phosphorus produced the highest protein content up to 8.98% which higher than the
control one of 4.91% (Rochana et al., 2017).

2.

Overall and specific objectives of the study

2.1.1. Overall objective
To utilize banana stems effectively for improvement of local pig performance
under mountainous village conditions in Cambodia.

2.1.2. Specific objectives
The specific objectives of the study were:


To understand the situation of pig production of ethnic farmers in mountainous
Ratanakiri province;



To determine the effects of time, C/N ratio and molasses concentration on yeast
of Saccharomyces cerevisiae biomass production;
11




To improve nutritive values of banana stems through the fermentation with the
Saccharomyces cerevisiae solution; and



To determine the optimum inclusive level of fermented banana stems in diets
on apparent digestibility, growth performance and carcass quality of local pig.

3.

Significant/Innovation of the dissertation
The improvement of nutritive values of banana stems through fermentation with

Saccharomyces cerevisiae for the feed of local pigs is acceptable alternative to the farmers,
mainly those who living in mountainous areas in Cambodia. All papers in this thesis were
firstly published in Cambodia.

12

CHAPTER 1
LITERATURE REVIEW
1.

Pig production in Cambodia
Pig population were totally 2,970,624 heads and it accounted for 98 percent of all

small livestock raised in 2016 (MAFF, 2018). The highest density of 78.9 head/km 2 was
found in Prey Veng Province and the lowest density of 0.74 head/km 2 in Koh Kong,
however the density in Ratanakiri province was also low of only 2.70 heads/km2 (Sitha,
2012). The pork consumption is gradually increasing about 9.29 kg per capita (FAO,
2012), following to the population. Cambodian people needed about 894,108 head pigs a
year in 2018, but the local production did not meet the demand, so the Ministry of
Agriculture, Forestry and Fishery (MAFF) officially permitted 1,250 pigs to be imported
from Vietnam and Thailand.

1.1.

Pig production systems
Pig production is categorized into three systems such as household/backyard, semi-

intensive and intensive (MAFF, 2018). This is quite same as in Thailand, Vietnam, Lao,
Myanmar and Philippines (FAO, 2011). Household production accounted for 76% (MAFF,
2018) and most of them were interested in the fattening pigs, a few kept the pigs for
breeding purposes (NIS, 2015). They mostly utilized locally available resources such as
rice bran, rice distiller by-product, vegetable wastes, cooked rice, kitchen waste and some
concentrate feed for their pigs (Ström et al., 2017). By utilization of these local feed
resources, the production cycle was longer from 7-10 months to get the weight from 70100 kg (Tornimbene et al., 2012), than semi-intensive system that was only 5.5 months

averagely to get from 93-95kg by using homemade feed from cereal grain or using some
concentrate. In addition, most of the household pig producers relied mainly on village
animal health workers (VAHWs) for the vaccination and the treatment of their pigs and
13


60% of them could earn the benefit from their pig production, whereas 70% of the semiintensive producers could treat and vaccinate their pigs by themselves and get net margin
from a fattening pig about 33$/head (Sen and Sorn, 2002; FAO, 2012). According to
Tornimbene et al. (2015), less than 1% of the pig producers operated on the intensive
system with automatically feeding and drinking system. The high quality of concentrate
and disinfections of drinking water are utilized in this system to get more productivity. The
fattening period is averagely 4.94 months to get about 106 kg. The commercial farms
generally apply the “all in, all out system” to easily manage the health status of pigs and
reduce the risk of transmission or spreading of disease, that the mortality rate was very low
about 1% in nursery, 2% from weanling to finisher (MAFF, 2017).

1.2.

Pig production in mountainous zones
Local pig (Kandol) production played the important role in the livelihood of ethnic

people living in mountainous areas of Cambodia. The scavenging-system was traditionally
applied due to lesser inputs of labor, feed and investment, but some also confined by
fencing or tethering (RUA, 2014). The main sources of feed were from scavenging by
eating worms, insects and some leaves of the plants for protein sources and roots of plants
for energy sources as pigs were fed daily only one meal in the morning. The growth rate of
pigs may depend on availability of nutrition. The local pigs ranged from 1-5 heads were
preferred in this system as they could withstand a harsh environment and poor nutrition
(Choeun et al., 2008; RUA, 2014; Velazco et al., 2013; Osbjer et al., 2015). The female
pigs were more popular because they were more beneficial for productivity and the sows

were crossed naturally without any payment for boar’s service.

The common infectious diseases, parasite and malnutritional and inadequate feed
supply were still the big concern for this system. In addition, the ethic people mostly
needed to be away from the house for their subsistence farming in several months that
caused lack of feed supply and malnutrition. Their technical experiences and knowledge in
14


the local pig production were also limited, due to poorer extension service. They have just
followed the experience from their ancestors. 65% of them kept the pigs for traditional
ceremony, 21% for breeding and 14% for family income generation (RUA, 2014).

2.

Fibrous feeds for pigs
Fibrous feeds were potentially utilized as pigs’ feed, mainly for extensive or semi-

intensive production in order to alleviate the production cost. However, most of them are
bulky poor-quality cellulose roughage, containing high crude fiber and lower dry matter
content. Kass et al. (1980) suggested to application of 7-10% fiber in the diet of
monogastric, otherwise it speeded up the movement of nutrients through the digestive
system, leading less absorption.

2.1.

Roles of fibrous feeds
Fibrous feeds have affected all aspects of gut physiology and they are a major

energy source for these bacteria, and therefore markedly affects microfloral

diversity/toxicity. They are the important components in pig rations that provide the
majority of energy for pigs, but they also limit feed intake, digestibility and absorption,
affecting growth performance. Dietary fiber is very difficult to digest by enzymes in the
small intestine but can be partially fermented in the hindgut. It is a key factor determining
nutrient utilization in the diet. More dietary fiber supply caused less palatability and
diarrhea, but it also needs to consider gastrointestinal consequence of ingestion rather than
just taste (Brownlee, 2009). Serena et al. (2008) reported that dietary fiber has a high-water
holding capacity, slows the rate of nutrient absorption. Most of them are degraded by
bacteria in either the small or large intestine. Energy produced by microflora in the hindgut
can satisfy up to 30% of the maintenance energy requirements of the pig. In addition, the
hindgut fermentation can generate 17% of the total digestible energy derived from the diet
in growing pigs and 25% in sows (Shi and Noblet, 1993). These end-products of
fermentation can supply 24% to 30% of the energy needs for growing pigs (Yen et al.,
15


1991). Pig's ability to utilize dietary fiber is positively related to age and weight of the pig
and they can uptake energy from fibrous feeds during hindgut intestinal fermentation
through the intestinal wall. The energy value of plant foliage is quite lower than
concentrate feed ingredients such as cereal grains. Consequently, a wider range of fibrous
feedstuffs may be appropriate for use in diets of late finishing pigs, but small amount fiber
was included in pig diets to support normal physiological activity in the digestive tract.

2.2.

Fractions of fibrous feeds
This is mainly referred to non-starch polysaccharide. Polysaccharides are divided

into two groups: Starch and glycogen, and non-starch polysaccharides. In practical diets
fed to pigs, both of these groups of carbohydrates are present in relatively large quantities.

Non-starch polysaccharides (NSP) are divided into cell wall components and non-cell wall
components.

Figure1: Non-starch polysaccharide components (Choct et al., 2010)

2.2.1. Cellulose
Cellulose is the most common non-starch polysaccharides in cell walls. Cellulose is
not digested by small intestine enzymes secreted by pigs, but it may be fermented by
microbes in the small or large intestine (Cummings and Stephen, 2007).

16


2.2.2. Hemicellulose
Hemicellulose is also the most common non-starch polysaccharides in cell walls. It
differs from cellulose that it is a branched-chain polysaccharide composed of different
types of hexoses and pentose (Cummings and Stephen, 2007).

2.2.3. Lignin
Lignin is not a carbohydrate, but it is closely associated with plant cell walls (Lunn
and Buttriss, 2007). Lignin is resistant to enzymatic and bacterial degradation. As a
consequence, plants with a high concentration of lignin are poorly digested. Carbohydrates
that are not components of the plant cell wall but are considered non-starch
polysaccharides include pectins, gums, and resistant starches (Lunn and Buttriss, 2007).

2.3.

Fibrous feed movement process in the digestive tract of the pigs
Pigs are the monogastric animal, so lack of fiber degrading enzyme to breakdown

of complex-carbohydrates like cellulose, hemicellulose and lignin. The complex
carbohydrate is a major component of fibrous feeds like rice bran and banana stems (Swain
et al., 2014). Fibrous digestion generally takes place in the caecum and colon, where
cellulolytic bacteria break down fermentable carbohydrates that have escaped digestion in
the stomach and small intestine (Kass et al., 1980). According to Ogle (2006), high fiber
content reduces the nutrient digestibility, mainly protein and carbohydrate.

2.4.

Effect of fibrous feeds on intake
Young pigs had a minimum requirement for a crude fiber level of 6%, and feeding

diets with a high fiber content affected negatively feed intake and nutrient digestibility
(Mateos et al., 2006). Bulkiness of higher fibrous feeds led to slower growth rates and
poorer feed efficiency. Therefore, fiber levels are often kept quite low in diets of the young
pig, but they can be increased, following to their growth rate because feed intake capacity
increases in relative terms. However, young pigs fed the diets containing less energy and
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more fiber had the greatest feed intake, gain weight and feed efficiency (Beaulieu et al.,
2006). This may not always respond negatively to diets with a high fiber content for young
pigs.

Feed intake decreased when the banana stems-taro silage replaced rice bran (Tien et
al., 2013). Dietary nutritional value intake was also decreased when rice bran replaced the
ensiled mixture of taro and banana stems (Chhay et al., 2014). There were several reasons
that may influence daily feed intake by increasing dietary co-products inclusion. First, pigs
had to adapt to the reduced density and therefore, increased bulk volume of feed intake
required to maintain energy intake and pigs may have reached a physical limitation

because of gut size (Avelar et al., 2010). Second, some alternative ingredients may have
contained antinutritional factors that contribute to reduced feed intake (Heugten, 2001).
Third, the high level of added fat required to compensate for the low energy content of coproducts may have decreased feed intake (Fowler, 1985). However, higher fiber
ingredients are generally less expensive than lower fiber ingredients, so they are very
suitable for the farmers to use in pig diets in order to get lower production cost and more
economical.

2.5.

Effect of fibrous feeds in pig diet

2.5.1. Digestibility
Digestibility of fibrous feeds increased as the pigs increased in age and weight and
it may also differ with the properties of the fiber. Addition of 1g NDF/kg diet resulted in
reduction of between 0.03% and 0.08% of ileal apparent protein digestibility (Dégen et al.,
2007). Ngoc, (2012) also indicated that increasing fiber content in the diet decreased the
nutrient digestibility and mean retention time. Soluble fiber reduced the apparent and true
ileal digestibility of protein and amino acids as well as the fat and the energy more than
insoluble fiber (Dégen et al., 2007). Apparent digestibility of DM, CP and N retention
were decreased when rice bran replaced the ensiled mixture of taro and banana stems
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