Summary of Phd thesis in Animal science: The utilization of dietary local feed resources for moo lath pig in Laos

HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY BOUNLERTH SIVILAI THE UTILIZATION OF DIETARY LOCAL FEED RESOURCES FOR MOO LATH PIG IN LAOS Major: ANIMAL SCIENCE Code: 62620105

SUMMARY OF PHD THESIS IN ANIMAL SCIENCE HUE, 2019 HUE UNIVERSITY

The thesis is completed at University of Agriculture and

Forestry, Hue University

Supervised by:

1. A/Prof. Dr. Nguyen Quang Linh (major)

2. A/Prof. Dr. Du Thanh Hang (second)

1st Thesis Reviewer:

2nd Thesis Reviewer:

3rd Thesis Reviewer:

This thesis will be defended at the Board of Examiners of Hue University, 03 Le Loi St. Hue city, ……..

This thesis can be found at:

- University of Agriculture and Forestry, Hue University

- National Library

- Online webpage: www.hueuni.edu.vn

1. Structure of the thesis

This thesis consists of 101 pages comprising of 5 chapters,

38 tables and 34 figures.

An introduction (3 pages), objective, hypothesis and innovation of thesis (5 pages); Chapter 1 (literature reviews): 25 pages, Chapter 2 (paper 1): 8 pages, Chapter 3 (paper 2): 11 pages, Chapter 4 (paper 3): 11 pages, Chapter 5 (paper 4): 9 pages, and general discussion, conclusion, implication, further research and reference and list of published scientific paper: 8 pages. In the table of content: chapter 1: 11 tables and 6 figures, chapter 2: 4 tables and 5 figures, chapter 3: 5 tables and 10 figures, chapter 4: 9 tables and 10 figures, chapter 5: 3 tables and 4 figures and list of abbreviation (1 page). 2. INTRODUCTION

Approximately 75% of production is produced in tradition by rural pig farmers (Souriyasack, 2011). The typical smallholder pig farm relies on a scavenging system for forages and left-over food with little or no supplementation. The results are low productivity (Stür et al., 2010) with growth rates often less than 100 g/day (Phengsavanh et al., 2010) and low reproductive performance of sows is marked by depressed litter size, a high mortality of piglet and outbreaks of disease. For these reasons the two feed resources chosen for this research were banana pseudo stem as source of energy and the Taro plant as the source of protein.

Banana pseudo stems (BPS) from the banana tree are distributed in Laos, farmers chopped it into small pieces and fed to pigs, ducks and chickens (Tien et al., 2013). The fibre is presented in BPS, a high content of water 94%, low level of

protein 3-4% in DM (Floulkes et al.,1978). However, an unusual finding was reported presence of 3% of soluble sugars in the liquid fraction, it confirms that they are readily fermentable (Dao Thi My Tien et al., 2010).

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 in the mouth of pigs when the foliage is consumed fresh. However, this problem can be resolved by ensiling the taro before feeding (Hang et al., 2011).

the

Brewers’ spent grains’ and rice distiller soluble fed at low levels in the diet (4 to 5% as DM) were shown to protect cattle (Phanthavong et al., 2016; Sengsouly and Preston 2016; Binh et al., 2017) and goats (Binh et al., 2018) from HCN toxicity caused by cyanogenic glucosides present in foliage of “bitter” varieties of cassava. However, no any applied in pig with use these by- products. Its’ properties are acting probiotics/prebiotics to replace antibiotics with either beneficial microorganisms such as Lactobacilli and yeasts that enhance the normal microbial flora in the animals’ digestive system. In latter category are compounds such as β-glucan that are present in the walls of cereals such as barley and rice, and of yeasts. These appear to be

released in natural processes such as occur in the alcoholic fermentation with distillation to give beer and rice wine.

Biochar, the by-product from the carbonization of fibrous residues at high temperatures of 500-1000 °C was originally identified as an ameliorating agent in soils and as a vehicle for sequestering atmospheric carbon (Lehmann, 2007) with associated beneficial effects on crop and plant growth (Lehman and Joseph, 2015; Preston, 2015). In pigs and chickens, it has been shown to be effective as an agent to facilitate the degradation of phytotoxins and mycotoxins (Gallo et al., 2015; Prasai et al. 2017), as well as that enhances activities of microbial providing habitat communities (Leng, 2017). 3. OBJECTIVES OF THE THESIS

1) To determine the effect of replacing ensiled taro foliage with ensiled banana pseudo stem as foliage based die for Moo Lath pigs in Laos

2) To investigate the effect of a low concentration of rice distillers’ byproduct or brewers’ grains as additive feed in the foliage based diet for Moo Lath pigs

3) To evaluate the effect of rice distillers’ byproduct and biochar as additives on growing and feed conversion of native Moo Lath pigs in Laos 4. HYPOTHESES OF THE RESEARCH

1) Ensiled taro foliage combined with ensiled banana pseudo stem will be contributed suitable inclusive level as foliage based- diet supporting for digestibility and improving growing for Moo Lath pigs

2) Small amounts (4% of diet DM) of either brewers' grains or rice distillers' byproduct (Quilao) supplemented in foliage based diets would support increased growth rate and reproductive performance in Moo Lath pigs.

3) Supplementation of biochar in a forage-based diet would be affected on growth performance and feed conversion of native Moo Lath pigs 5. INNOVATION OF THE DISSERTATION

The innovation of this dissertation is the use of low concentrations (4% of diet DM) of agro-industrial by-products such as brewers’ grains, rice distillers’ residues and addition of biochar (1% of diet DM) as additives feed that appear to act as “prebiotics”, enhancing the growth and feed conversion of indigenous Moo Lath pigs fed on local feed resource of ensiled foliage of Taro (Colocasia esculenta) and banana pseudo-stem (Musa spp).

CHAPTER 1 LITERATURE REVIEW

1.1. The role of pig production

Smallholder farms are practice accounted for 86.5% of total pig production in 2017 (MAF, 2017). Around 64% of pig rising is for home consumption especially in cultural events, accumulation capital and generated cash income (Stür et al., 2002). Souriyasack (2011) implied that approximately 75 % of pigs are produced in small-scale systems and 25% is derived from commercial farms. There are total number of pigs of 3.7 million heads in whole country, with local pigs are accounted of 3.2

million pigs (DLF, 2017). Meat required to consume for Lao people is 57 kg/capita, with pork are 14.6 kg in 2017 1.2. Currently typical pig farming in Laos

Pig rearing system in Laos can be clarified into three main categories such as smallholder pig production (small scale), semi- intensive (medium scale) and commercial scale (large scale) farming. Smallholder pig farms are approximated of 86.5% of pig production (MAF, 2017). In this system, pig farmers are poor addition feeds for pigs, with no protected from disease, with poor nutrients. Semi-intensive pig farming is defined as small family business farming system by raise pig including indigenous pig and cross breed pig. It can definite relatively high level of inputs. The commercial pig farms in Laos are arisen as enterprise sectors under domestic investors and the typical commercial pig farms. Mostly pigs used are exotic breeds such as crossed breed of Large White, Landrace, Duroc Jersey and some of hybrid (Wilson, 2007). 1.3. Feeds and feeding practical management

Feeds derived from agricultural by-products mainly rice bran, broken rice, polished rice and also maize and cassava root are a source of energy diet for pigs. The green plants are taro foliage, banana pseudo stem, thick head, paper mulberry and green amaranth, and vegetarians such as pumpkin tops and sweet potato leaves. Feeds derived from leftover materials rice distillers’ waste and household scraps are traditional knowledge to use as feed for pigs

1.4. Utilization of forage-based diet for pigs 1.4.1. Taro as protein sources for pigs

Taro (Colocasia esculenta) is traditionally forage that cultivated by farmers, it also arises naturally in Laos. It is contained a high potential source of protein in pig diets. Taro is sources of amino acid closed to ideal protein with similar contents compare to soybean meal (Rodríguez et al., 2006). Use of taro was increased in CP digestibility and N retention (Rodríguez et al., 2009). Ensiled taro leaves could be replaced up to 50 % of the soybean protein by improving growth performance and carcass traits of crossbred large white pig and native Moo Lath Lao pigs (Kaensombath and Erik Lindberg, 2012). 1.4.2. Banana pseudo stem in pig diets A mixture of ensiled banana pseudo stem and taro foliage has been contributed to improve intake for native Moo Lath pig (Manivanh and Preston, 2016). The researchers subjected to use banana pseudo stem combining to taro leave and also replacing with rice bran in traditionally performance by farmers for crossbreed pig and Mong Cai sows (Hang et al., 2014; Duyet et al., 2013), duck diets (Dao Thi My Tien et al., 2013) and pig diet (Chhay Ty et al., 2014). However, high fiber content appeared to decreased digestibility of DM, OM, NDF and N retention when ensiled banana pseudo-stem replaced taro foliage silage in crossbreed pig (Hang et al., 2014).

1.4.3. Brewers’ grain and distillers’ by-product

Rice distillers’ by-product (RDB) are the residue derived mainly from yeast fermentation process of rice of polished rice to make rice wine. Rural smallholder farmers have been successfully used RDB as a protein sources for pigs (Manh et al., 2009;

Taysayavong and Preston, 2010; Manivanh et al., 2012; (Phiny et al., 2012). Brewers’ grains and rice distiller soluble fed at low levels in the diet (4 to 5% as DM) were shown to protect cattle (Phanthavong et al., 2016; Sengsouly and Preston 2016; Binh et al., 2017) and goats (Binh et al., 2018) from HCN toxicity caused by cyanogenic glucosides present in foliage of “bitter” varieties of cassava. However, no any applied in pig with use these by- products.

1.4.4. Biochar as a feed additive in animals

Primarily study with 1 % of biochar is applied on the growth and feed conversion including reduction methan emission in cattle (Leng et al., 2014; Sengsouly and Preston, 2016) and goats (Silivong et al., 2016; Le Thi Thuy Hang et a., 2018). The benefit of biochar is possibility bind toxins or degraded some organisms in the gut of animal microbiome (Leng, 2017). Prasai et al. (2016) that supplementation of biochar improved egg yield and feed conversion. whilst, supplementation of 1 % rice husk biochar in chicken diet reduced coliform bacteria and E-coli in faces, but had no impact on live weight gain (Hien et al., 2018).

CHAPTER 2 EFFECT OF REPLACING ENSILED TARO FOLIAGE WITH ENSILED BANANA PSEUDO STEM ON INTAKE, DIGESTIBILITY AND NITROGEN RETENTION IN MOO LATH PIGS

Introduction

Banana pseudo stem is traditionally and commonly used by farmers as feed for pigs, and cattle in Laos. This research aimed to test the effect of different proportion of ensiled banana

pseudo-stem combined with ensiled taro foliage on intake, digestibility and nitrogen retention in growing Moo Lath pigs. Materials and Methods Treatment, experimental design and feeding management

Four native Moo Lath pigs (LW at 30 kg  2.63 kg) were used with arranged in a 4x4 LSD with 4 pigs and 4 levels of ensiled banana pseudo stem (0, 5, 10 and 15% in DM basis) replacing ensiled taro foliage. Experimental periods lasted 10 days: 5 days for adaptation and 5 days for collection of urine and feces. Sample collection and analysis

Feeds offered and refused were weighed daily. The urine and feces were collected. All samples were analysed for DM, CP, CF and ash. The data were analyzed (Minitab, 2016). Results and discusion Feed intake and apparent digestibility

Feed intake, coefficients of digestibility, daily N retention, and N retention as proportion of N digested, all declined linearly as the proportion of ensiled banana pseudo-stem in the diet was increased with the trend being more pronounced in the case of crude fiber. However, the data on N retention show clearly that the protein provided by ensiled taro foliage was superior biological value compared with the combination of banana pseudo-stem Table 2.3. Intake and apparent digestibility of diets

Diets, % DM basis

BS10 BS15 SEM p

BS0 BS5

921.2 917.6 914.9 910.1 11.19 0.913

Feed intake, g/d DM Apparent digestibility, %

88.5a 84.9ab 83.6b 83.6b 1.06 84.9a 80.7ab 80.3ab 77.2b 1.38 68.6b 2.00 81.6a 74.9ab 71.6b 83.6b 1.04 88.9a 85.6ab 84.1b

0.004 0.002 <0.001 0.002

25.3a 24.7ab 4.8ab 3.8b 6.9bc 5.5c

24.1b 4.8ab 7.9ab

23.9b 5.4a 8.8a

0.013 0.31 0.32 0.008 0.39 <0.001

16.0a 13.0b 63.1a 52.7b

11.5bc 47.4bc

9.7c 40.6c

0.65 <0.001 2.28 <0.001

74.0a 65.4ab 59.2bc

51.7c

2.39 <0.001

DM CP CF OM N balance, g/d Intake Feces Urine N retention g/d % of N intake % of digested N (BV) Conclusion

 Apparent digestibility of DM and CP, daily N retention and N retained as percent of N digested, all declined linearly as ensiled banana pseudo-stem replaced ensiled taro foliage.



It is apparent that the biological value of the protein in the ensiled taro foliage is superior to that in the combination of ensiled banana pseudo-stem and soybean meal

CHAPTER 3

A LOW CONCENTRATION OF RICE DISTILLERS’ BYPRODUCT OR BREWERS’ GRAINS ON DIGESTIBILITY AND NITROGEN RETENTION IN NATIVE MOO LATH PIGS

Introduction

Brewers' grains have been widely used as protein supplements in diets of pigs and cattle. However, recent research Binh et al. (2017) suggests that they may also provide other benefits, as a source of "prebiotics". The hypothesis that small

amounts (4% of diet DM) of either brewers' grains or rice distillers' byproduct would support increased growth rate in local Moo Lath pigs. Materials and methods Treatments, design and Feeding management

Six pigs (native Moo Lath pig breed) with average initial live weight of 29.3  2.3 kg with 3 diets: CTL; BG 4% and RDB 4%. A double 3*3 LSD with periods of 10 days: 5 days for adaptation and 5 days for measurement of data Data collection and analysis

Feed offered and refused, Urine and feces were recorded daily. The samples were analysed for DM, N, CF and ash (AOAC, 1990). The data were analysed (Minitab, 2014). Results Feed intake

DM intake was increased respectively by inclusion of BG

and RDB in the diets. Table 3.3. Mean values for DM intake and % CP of the diet consumed by Moo Lath pigs

SEM p Diets, as % DM basis CTL BG4% RDB4%

Feed intake, g/d DM intake CP intake CF intake OM intake DM intake, g/kg LW 703b 805a 777a 90.3b 101.2a 104.5a 127.2b 138.2a 143.0a 82.5c 86.2a 84.3b 27.8a 21.5c 25.5b

13.38 <0.001 1.73 <0.001 2.87 0.001 0.53 <0.001 0.53 <0.001 ab Mean values within rows with different superscript differ at P<0. 05

Apparent digestibility

Apparent digestibility for DM, OM, CF and CP were

increased by both supplements. Table 3.4. Mean values for apparent digestibility by Moo Lath pigs

Apparent digestibility, % CTL BG4% RDB4% SEM

Dry matter Crude protein Crude fiber Organic matter 84.5b 87.5a 75.6b 79.4ab 79.5b 86.2a 84.7b 87.8a 89.6a 80.7a 88.7a 89.9a 0.84 <0.001 1.41 0.032 1.11 <0.001 0.81 <0.001

ab Mean values within rows with different superscript differ at P<0. 05 Nitrogen balance

N intake and N retained was greater on the BG and RDB diets increases in DM intake induced by the supplements. There was no advantage from supplementation with BG. The biological value of the protein was increased by both BG and RDB Table 3.5. Mean values for N balance by Moo Lath pigs

CTL BG 4 % RDB 4 % SEM

p

N balance, g / d

14.5b 3.2 2.2a

16.2a 3.4 2.1a

16.7a 2.9 1.5b

0.28 0.19 0.17

<0.001 0.23 0.010

Intake Feces Urine N retained g/day g/day# % of digested N

0.35 0.27 1.91

9.00c 10.2b 73.8b

10.7b 10.3b 83.1a

12.3a 11.3a 87.2a

<0.001 <0.001 <0.001 ab Mean values within rows with different superscript differ at P<0. 05 Discussion



 BG and RDB, each at concentrations of 4% of diet DM, improved feed DM intake and apparent digestibility of DM, CP and CF. N retention was increased by RDB but not by BG and the biological value of the protein was increased by both supplements. It is suggested that the positive effects on pig performance, of both BG and RDB, may have been due to the presence of β- glucan, a component of the cell wall of cereal grains and yeasts.

Previous research with BG (Amaefule et al., 2006) and RDB (Luu Huu Manh et al., 2003) have used as source of protein. As far as we are aware, this is the first report on the use of these supplements at low levels as source of prebiotics (Fuller, 1989; Vanbelle et al., 1990). It is suggested that presence in both the supplements of β-glucan, a carbohydrate component of the cell wall of cereal grains and fungi including yeasts. Conclusion

CHAPTER 4 EFFECT OF A LOW CONCENTRATION OF RICE DISTILLERS’ BYPRODUCT OR BREWERS' GRAINS ON PREGNANCY AND LACTATION OF NATIVE MOO LATH GILTS AND THEIR PROGENY

Introduction

In a previous experiment Silvai and Preston (2017) showed that BG and RDB, each at concentrations of 4% improved DM intake and digestibility in native Moo Lath pigs. The objective was to test if these supplements would bring about similar benefits during pregnancy and lactation in native Moo Lath gilts. Materials and methods Treatments and experimental design

12 Moo Lath gilts (BLW at 80.8± 3.9 kg) were fed ad libitum a basal diet of broken rice and ensiled BS with ensiled TF. The three treatments in a CRD with 4 replications were: No supplement (CTL); RDB 4% and BG 4% of diet DM Data collection and analysis

Feed offered and refused was recorded. The gilts weight, litter size, piglet weights at birth and at weaning days, mortality of piglets and new estrus was recorded. Samples were analysed for DM, CP, CF and ash (AOAC, 1990), and all data were analysed (Minitab, 2016). Results Body weight change during pregnancy and lactation

Moo Lath 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. Table 4.3. Llive weight (kg) of Moo Lath gilts

Conception Pre-parturition Post-parturition Weaning

CTL 85.3 102.5 96.1 70.6

p BG 4% RDB 4% SEM 5.34 0.6 6.07 0.78 5.76 0.89 3.39 0.24

77.8 106.1 98.6 77.2

79.4 108.6 100.1 78.9

Table 4.4. Changes in weight of Moo Lath gilts

CTL BG 4% RDB 4% SEM

p

Changes in live weight, kg

Conception to pre-parturition 17.2b 28.3a 10.9b 20.9 a Post-parturition -21.4 -25.5 Parturition to weaning 22.4 24.6 Weight loss, % 13.3 16.8 Weaning to oestrus. Days

29.2 a 20.8 a -21.2 21.5 13.5

2.27 0.08 2.13 0.01 3.92 0.69 4.68 0.89 2.37 0.52

Piglet production

Litters from Moo Lath gilts supplemented with 4% RDB were heavier at birth and at weaning, and tended to grow faster, than litters from un-supplemented gilts Table 4.5. Mean values for weight of litters from Moo Lath gilts

CTL BG 4% RDB 4% SEM 5.14a 0.599 Birth, kg Weaning (at 28d, kg) 23.9a 3.01 683a 130 ADG, g/d

6.39ab 29.5ab 855ab

7.65b 39.1b 1072b

p 0.047 0.036 0.061

ab Means without common superscript differ at p<0.05 Health and mortality

Supplementing the Moo Lath gilts during pregnancy and lactation with BG or RDB had no effect on piglet mortality at birth or during lactation on piglet live weights at birth and 28 days weaning Table 4.6. Numbers of piglets born and surviving to weaning

CTL

BG 4%

RDB 4%

Number born Total Dead Alive

8.25 0.50 7.75

8.5 0.00 8.50

9.25 0.00 9.25

Number weaned

6.50 1.25

7.25 1.25

8.25 1.00

Alive Died Mortality, % Total Lactation

17.1 11.6

10.2 18.1 10.2 18.1 Table 4.7. Mean weights (g) of piglets at birth and 28 day weaning

CTL

BG 4% RDB 4%

SEM

p

690 3,215

786 3,651

784 3,740

109 594

0.77 0.88

Birth Weaning

Feed conversion

Supplementing of BG or RDB during pregnancy and lactation indicated different value on feed DM intake. DM feed conversion was improved by 60%, when supplemented 4% RDB Table 4.8. DM intake from conception to weaning of Moo Lath gilts

CTL

BG 4% RDB 4% SEM

p

1.3b 1.8a 1.4 29.5ab 6.85ab

1.3b 1.9a 1.4 39.1b 5.21b

1.4a 1.7b 1.4 23.8a 8.71a

0.013 0.025 0.014 3.01 0.61

0.05 <0.01 0.718 0.030 0.019

DM intake, kg/d Pregnancy Lactation Total Piglets weaned, kg Feed conversion ab Means without common superscript differ at p<0. 05 Discussion

The beneficial effects on accumulation of body mass of

Moo Lath gilts during pregnancy and on the weight of their litters

at weaning, as a result of supplementing their diet during

pregnancy and lactation, with small quantities of rice distillers’

by-product, confirm our earlier findings of increased diet

digestibility and N retention in growing Moo Lath pig feeds fed

the same basal diet and RDB supplement (Sivilai and Preston,

2017). The apparent superiority of rice distillers’ by-product over

brewers’ grains was a common finding in both studies. These

positive effects on growth rate and feed conversion are similar to

what has been reported for rice distillers’ by-product in diets of

cattle (Sangkhom et al., 2008; Sengsouly et al., 2016) and for

brewers’ grains in diets of cattle (Phuong et al., 2017) and goats

(Vor Sina et al., 2017).

It is relevant to reflect on the mechanism by which rice

distillers’ byproduct, and to a lesser extent, brewers’ grains,

contribute to the observed improvements in performance of both

ruminant and mono-gastric animals.

We previously suggested (Sivilai and Preston, 2017) that

the benefits of both brewers’ grains and rice distillers’ by-product,

in supporting improved feed intake, digestibility and N retention

in growing pigs, could be explained by the presence in both the

supplements of β-glucan, a carbohydrate component of the cell

wall of cereal grains and yeasts. The beneficial effect of β-glucan

on growth rate and health in weaning pigs was recently reported

by Nguyen Thi Thuy (2017). The immune-modulating effects of

β-glucans, with beneficial health effects in humans and animals

are well known (Novak and Vetvicka, 2008; Waszkiewicz-Robak,

2013).

The question is: what is the mechanism that leads to rice

distillers’ by-product and brewers’ grains being an active source

of β-glucan? It is well understood that the carbohydrate complexes

in the cell wall of cereal grains and yeast need to be modified in

order to make available the beta-glucan and related compounds.

Alkaline followed by acid hydrolysis appear to be the key steps in

this process (Yanelys Garcia, Personal communication). In the

production of rice “wine” the procedure is first the steaming of the

rice, followed by facultative anaerobic fermentation with yeast,

and lastly the boiling of the fermented rice to release the alcohol.

Similar procedures are followed in the production of beer and the

resultant by-product of brewers’ grains. The first stage of

“steaming” (rice wine) and “mashing” (beer) and the initial steps

in the fermentation may facilitate the first requirement for alkaline

hydrolysis; the last stage of distillation in which the fermented

substrate is “acid” would appear to simulate the process of “acid

hydrolysis”.

The challenge is to simulate these actions using more

readily available and lower cost carbohydrate substrates such as

cassava root and cassava root pulp.

 Moo Lath gilts gained weight during gestation, and lactation, when supplemented BG 4% or RDB 4%. The litters size and mortality of piglets supplemented with RDB were improved  Weights of piglets at birth and 28 days weaning, and intake were not affected by supplementation but feed conversion was improved by 60%, when supplemented with RDB 4%.

Conclusions

CHAPTER 5 EFFECT OF RICE DISTILLERS’ BYPRODUCT AND BIOCHAR AS ADDITIVES FOR GROWING AND FEED CONVERSION OF NATIVE MOO LATH PIGS

Introduction

RDB fed in small quantities (4% of the diet) also acts as a prebiotic. It increased N retention in pigs (Sivilai and Preston, 2017) and improving growth and feed conversion in pregnant- lactating gilts and growth rate of piglets to weaning (Sivilai et al., 2018). Feeding biochar to animals is a recent development. The objective was to evaluate the effect of biochar on the growth rates of Moo Lath pigs fed forage diet and to compare with RDB. Materials and Methods Animals, treatment, design and management

Twenty Moo Lath pigs (15.8 ± 1.3 kg) were fed four dietary treatments arranged in a CRD with 5 replications: CTL, RDB 4%, BIO 1% and RDB+BIO added in the diets. Data collection and analysis

The pigs were weighed every 14 days and feeds offered and refused were recorded daily with samples were determine for DM, CP, CF and ash (AOAC, 1990). The data were analyzed (Minitab, 2016). Results Dry matter intake, growth rate and feed conversion

There was no effect of the additives on

feed intake. Growth rate tended to be better and feed conversion was improved for both additives. There were no benefits from

p 0.692 0.423 0.089 0.58 0.048

16.0 41.6 220 874 4.02 a

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 CTL BIO RDB BIO+RDB SEM Live weight 0.619 15.9 15.8 15.6 Initial, kg 1.52 36.5 40.5 40.1 Final, kg 9.51 215 220 179 Daily gain, g 41.7 DM intake, g/d 850 859 787 DM conversion (kg/kg) 4.43b 3.96a 3.89 a 0.13 ab Means without common superscript are different at p<0.05 Discussion

The positive effect of RDB on growth rates and feed conversion of the Moo Lath pigs agrees with previous results where: RDB 4% improved N retention by 36% and the biological value of the nitrogen by 18% (Sivilai and Preston, 2017) and RDB4% increased the litter weight of weaned pigs by 67% and the overall feed conversion by 64% (Sivilai et al., 2018).



To our knowledge, the feeding of biochar to pigs has not previously been reported. The degree of response observed in this experiment with growing pigs (20-23% and 11-14% for growth and feed conversion) is similar to the 15 and 18% improvements in growth and feed conversion reported for biochar fed to cattle (Sengsouly and Preston, 2016). Biochar and RDB each increase pig growth rate and efficiency but they were effected when they combined. Conclusions

In pigs, 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



It is postulated that biochar and distillers’ byproduct recommended to bind toxins from the feed which are either excreted in the feces or degraded by some organisms in the animal’s gut microbiome.

GENERAL DISCUSSIONS AND CONCLUSIONS The reasons for using indigenous pig breeds such as the Moo Lath in rural areas of Laos, usually in some form of semi- scavenging system have been well documented (Phengsavanh et al., 2011).

Bananas are grown everywhere in Laos and there is a long tradition of chopping the pseudo-stem and feeding it to pigs and poultry. However, this abundant feed resource has received little attention from researchers. By contrast, Taro have been thoroughly researched as a component of diets for pigs (Chittavong et al., 2012; Kaensombath and Lindberg, 2012; Hang et al., 2015). The only negative attribute the high level of oxalic acid has been shown to be controllable by ensiling and supplementation with a source of calcium (Hang et al., 2011).

The objective of this thesis was to test a number of initiatives which would lead to better utilization of these two forages abundantly available in tropical ecosystems when fed to indigenous native “Moo Lath” pigs.

In Paper 1 (chapter 2), the experimental diets were (% DM basis) ensiled banana pseudo-stem: 0, 5, 10 and 15% the results were supported evidence for the decision made in the conclusion to restrict the level of ensiled banana pseudo-stem to 10%.

local

In Paper 2 (chapter 3) was a follow-up to findings by fellow researchers (Phanthavong et al., 2016; Sangkhom et al., 2017; Binh et al., 2017; Sengsouly et al., 2016) that byproducts of beer manufacture rice wine (brewers’ grains) and fermentation-distillation. It was suggested beneficial presence of β-glucan, a component of the cell wall of both cereal grains and yeasts, that is unknown for RDB and BG in pig diet, as this result is positive effect on digestibility and N retention

The follow-up to the previous experiment in paper 3 (chapter 4) was the testing of the same two additives in the diets of pregnant and lactating native Moo Lath gilts and their progeny to weaning. The 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. Litters from dams supplemented with the additives were heavier at birth, and at weaning, and grew faster than litters from un-supplemented gilts. Supplementation of the dams 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

The experiment described in Paper 4 (chapter 5) was also a follow-up to findings by colleagues (Leng et al., 2012; Silivong and Preston, 2016; Sengsouly and Preston, 2016) that biochar appeared to have “prebiotic” properties when fed to cattle and goats. Biochar was fed at 1% of the basal diet of taro-banana pseudo stem in a comparison with RDB at 4%. 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. Whilst considerable research needs to be done, the possibility is that biochar and RDB bind toxins or immobilize anti-nutritional compounds in feeds which are either excreted in the feces or degraded by some organisms in the animal’s gut microbiome, thesis concluded:

1) The biological value of the protein in ensiled taro foliage was not recommended to have more than 10-15% of ensiled banana pseudo-stem in a diet based in ensiled taro foliage for native Moo Lath pigs.

2) Additives (4% in diet DM) in the form of rice distillers’ byproduct or brewers’ grains, improved feed intake, digestibility and N retention, with a greater response in N retention and biological value of the protein for rice distillers’ byproduct.

3) These additives also improved performance of gilts when fed throughout pregnancy and lactation with specific benefits in weight of piglets weaned and overall feed conversion.

4) Biochar fed at 1% of diet DM, appeared to support equal benefits in growth and feed conversion in Moo Lath pigs as the 4% addition of rice distillers’ byproduct. It is suggested that both these additives act as “prebiotics” in neutralizing anti-nutritional components in the feed thus enhancing animal performance and wellbeing.

Development,

Research

for

LIST OF PUBLISHED SCIENTIFIC PAPERS 1) Sivilai, B., Preston, T.R. and Kaensombath, L., 2016. Feed intake, nutrient digestibility and nitrogen retention by Moo Lath pigs fed ensiled banana pseudo-stem (Musa spp) and ensiled taro foliage (Colocasia esculenta). Livestock (6), Rural http://www.lrrd.org/lrrd28/1/boun28006.html

for Rural Development,

2) Sivilai, B. and Preston, T.R., 2017. Effect of level of dietary protein on growth and feed conversion of Moo Lath pigs fed a mixture of ensiled taro foliage (Colocasia esculenta) and of ensiled banana pseudo-stem (Musa spp). Livestock Research (34). http://www.lrrd.org/lrrd29/2/boun29034.htm

3) Sivilai, B. and Preston, T.R., 2017. A low concentration of rice distillers’ byproduct, or of brewers’ grains, increased diet digestibility and nitrogen retention in native Moo Lath pigs fed ensiled banana pseudo-stem (Musa spp) and ensiled taro foliage (Colocasia esculenta). Livestock Research for Rural Development. 29 (123). http://www.lrrd.org/lrrd29/6/lert29123.html 4) Sivilai, B. Preston, T.R., Hang, D.T. and Linh, N.Q., 2018. Effect of a 4% dietary 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. Livestock Research for Rural Development, 30 (20). http://www.lrrd.org/lrrd30/1/lert30020.html

Development,

Rural

for

5) Sivilai, B., Preston, T.R., Leng, R.A., Hang, D.T. and Linh, N.Q., 2018. Rice distillers’ byproduct and biochar as additives to a forage-based diet for growing Moo Lath pigs; effects on growth and feed conversion. Livestock (111). Research http://www.lrrd.org/lrrd30/6/lert30111.html

6) Sivilai, B., Hang, D.T., Linh, N.Q. and Preston, T.R., 2018. 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. Livestock Research for Rural Development, 30 (54). http://www.lrrd.org/lrrd30/3/lert30054.html