The fertility of soils is important in agriculture particularly in making decisions on planting of crops. The plants will grow well and be more productive when planting in fertile and suitable soils. The different kinds of soils and different locations is likely to influence fertility also. Therefore measuring fertility of soils is necessary to know which will give information concerning fertility of soils or suitable plants for cultivating. There are many ways to measure fertility of soils. Planting some indicator plants in that soil and measuring growth and production is one way to do this in a simple and low cost procedure. It is believed that growth of maize will be the best indicator of N status while the development of tillers by the rice plant will indicate P status.

The hypothesis

Plants such as maize and rice will be good indicators of the fertility of soil

Objective

Samples of soil will be taken from different locations and ranked according to the growth rate of maize and rice plants.

Materials and Methods

Treatments

There are two sets of treatments (types of soil and indicator plants), arranged as a 8*2 factorial with 3 replications in a Complete Randomized block design Design ( CRBD) (Table 1).

Type of soil

There are 8 types of soil;

Nc = sand (negative control)

Cl = Clay (0-20 cm. Depth)

Lo = Loam (0-20 cm. Depth)

Rs = Rock soil (0-20 cm. Depth)

Sl = Sandy loam (0-20 cm. Depth)

Sm = Sub soil under Loam (more than 20 cm. Depth)

Ss = Sub soil under sandy loam (more than 20 cm. Depth)

Pc = More fertility soil with (possitive control)

There are two indicator plants

R = Rice

M = Maize

Table 1: Arrangement of treatments
Blocks	1	2	3	4	5	6	7	8
Rice	NcR1	ClR1	LoR1	RsR1	SlR1	SmR1	SsR1	PcR1
	NcR2	ClR2	LoR2	RsR2	SlR2	SmR2	SsR2	PcR2
	NcR3	ClR3	LoR3	RsR3	SlR3	SmR3	SsR3	PcR3
Maize	NcM1	ClM1	LoM1	RsM1	SlM1	SmM1	SsM1	PcM1
	NcM2	ClM2	LoM2	RsM2	SlM2	SmM2	SsM2	PcM2
	NcM3	ClM3	LoM3	RsM3	SlM3	SmM3	SsM3	PcM3

Materials

The following are required:

48 plastic bags

72 maize seeds

72 rice seeds

1 hoe

1 water bucket

1 ruler to measure height

1 weigh scale (200 g)

8 different kinds of soil

Procedure

The soils will be taken at 0-10cm depth from different places around the An Giang University and put into plastic bags (2 litre capacity). 3 seeds or maize or rice will be put in each bag according to the experimental layout in Table 1. A hole is put in the bottomof eacg bag so the excess water can drain away. Water is applied uniformly to all bags each morning and observations made of germination and growth of the plants. When the seeds have germinated 1 or two plants will be removed to leave only one seedling in each bag.

Measurements

The height of the plants will be measured every 5 days

After 28 days, the plants and roots will be removed, washed free of soil, and weighed 30 minutes later, the green parts and the roots separately.

Statistics

The linear regression of height on days will be calculated to determine growth rate in height. The ANOVA GLM option of the Minitab software will be used to analyse the data. The sources of variation will be: soils, blocks and error. When the F-test is significant at P<0.05, the Tukey test in the Minitab software will b used to separate mean values that differ at P<0.05

***********************

Mini-project 2

Effect of method of offering tree foliages to goats on intake and eating/ruminating time

Pok Samkol

University of Tropical Agriculture, Cambodia

Background

Goats have been raised many years by farmers. They traditionally hang the foliages from the sides of the pen, or on some raised structure (Kouch et al 2003a). It has recently been shown that this method results in higher intake and digestibility compared with putting the foliage in a feed trough (Kouch et al 2003b). It is proposed to test this idea with some foliages commonly available in villages in the An Giang area.

Hypothesis

Goats will eat more dry matter when the foliage of a tree is hanging in the pen compared with putting it in the feed trough.

Objective

To improve the feed intake of animals and also to compare both methods, putting the foliage in the feed trough and hanging in the pen.

Methods and materials

Four growing 6-8 kg live weight local weaned goats are confined in cages made frorm bamboo fitted with plastic sheet to collect the faeces and urine separately. Foliages from Kra Kop trees (Cambodian name) (Trung Ca in Vietnam) (Muntingia calabura) , and Cassava will be fed to the goats by putting in the feed trough or hanging in the pen or feeding only the leaves in the feed trough.

Experimental design

A changeover will be applied to 4 local weaned goats with 3 treatments and 4 replicates.

The treatments are two kinds foliage and two ways of offering them to the goats:

Source of foliage:

Muntingia (M) or cassava (C)

Method of feeding:

Foliage hanging (H)
Foliage in feed trough (T)
Leaves in feed trough (L)

The design is a changeover 2*3 factorial arrangement of the 6 treatments (Table 1) which are:

CH: Cassava foliage hanging

CT: Cassava foliage in the feed trough

CL: Cassava leaves in the feed trough

MH: Muntingia foliage hanging

MT: Muntingia foliage in the feed trough

ML: Muntingia leaves in the feed trough

Table 1: Layout of the treatments
	Goat number
Period (days)	1	2	3	4
0-8	CL	CT	ML	MT
9-16	CH	CL	MH	ML
17-24	CT	CH	MT	M H

Feed and feeding system

Muntingia will be collected within the An Giang University and Cassava will be bought from farmers. Feeds will be offered 2 times in the morning and in the afternoon and will be ad libitum (about 20% more than observed intake).

Measurements

Weight of feed offered and refused will be recorded and samples analysed for DM and N. Samples of the feed components will be analysed for water extractable DM and N. Time spent eating and ruminating during 24 hour period will be monitored on the last day of each period.

Statistical analysis

The data will be analyzed with the GLM option of the ANOVA software of Minitab Version 13.31. Sources of variation are animals, feeding system, foliages and interaction feeding system*foliages and error

Mini -project 3

Effect of method of offering tree foliages to goats on digestibility and N retention

Lê Thị Thúy Hằng

An Giang University

Background

The major cause of low productivity of livestock, especially in the tropical regions, is the inadequate and poor quality of feeds. The main feed resources for animal are permanent pastures, crop residues and other agroindustrial by-products. Goat production in Vietnam is based on small farms and the most important feed is grass from the edges of roads, fields and ponds. However, it has been shown that rates of production are much higher when goats are fed on browse than on grasses (Dahluddin19--) and that infestation with intestinal neamatode parasites is much less for the former system (Seng Sokerya and Rodríguez 200??). The method of offering the browse has also been found to be important with higher intakes and digestibility when foliage of cassava, Jackfruit and mulberry were suspended in the pen rather than being given in the feed trough (Theng Kouch et al 20??).

Hypothesis

That the digestibility of the foliage from Muntingia calabura by goats will be higher when it is suspended in the pen compared with offering it in the feed trough.

Objectives

4 goats will be used to study the effect on digestibility and N retention when offered the foliage of Muntingia calabura by hanging it in the pen compared with putting it in the feed trough.

Materials and Methods:

Treatments and design:

There are two factors:

Source of foliage:

Cassava (C)
Muntingia (M)

Method of feeding:

Hanging the foliage in the pen (the whole branch) (H)
Putting the foliage in the feed trough (T)
Putting only the leaves in the feed trough (L)

The design is a changeover 2*3 factorial arrangement of the 6 treatments (Table 1) which are:

MH: Cassava foliage hanging

MT: Cassava foliage in the feed trough

ML: Cassava leaves in the feed trough

CH: Muntingia foliage hanging

CT: Muntingia foliage in the feed trough

CL: Muntingia leaves in the feed trough

Table 1: Layout of the treatments
	Goat number
Period (days)	1	2	3	4
0-8	CL	CB	ML	MB
9-16	CH	CL	MH	ML
17-24	CB	CH	MB	M H

Feeding system

Foliage of muntingia is collected as whole branches. Cassava is purchased from farmers as leaves plus petiole (so as not to affect the production of roots). For MH and CH, the branches of muntingia and the leaves plus petioles of the cassava are hung from a bamboo stick above the pen. For MT and CT these feeds are placed in the feed trough. For ML and CL the leaves are separated and put in the feed trough. In all cases feeding is ad libitum at an estimated level of about 20% above actual intake. Days 1 to 4 of each period are for adaptation to the new treatment; on days 5 to 8 faeces and urine are collected; on day 9, samples of rumen fluid are taken by stomach tube 2 hours after offering the feed in the morning. The time table of activities is in Table 2.

Table 2: Time table of activities
Days	1-4	5-8	9	10-13	14-17	18	19-22	23-26	27
Adaptation	****			****			****
Collect faces & urine		****			****			****
Collect rumen fluid			*			*			*

Faeces are collected twice daily and stored at -20 ºC until analysed. Urine is collected in a bucket with 50 ml of 25% sulphuric acid to maintain the pH below 4 so as to prevent escape of ammonia.

Measurements:

The foliage of Muntingia is separated into stem, petiole and leaf; the foliage of cassava is separated into petiole and leaf. In each case the proportions are recorded and analysed for DM and N and water soluble DM. Weights of feeds offered and refused are recorded. During the collection period samples of feed offered and the refusals, and faeces, are collected and stored at -20ºC until the end of the collection period when samples are bulked and analysed for DM and N. Urine is collected daily stored in a bucket and at the end of the collection period is weighed and analysed for N. Rumen fluid is analysed for pH immediately after collection, 5 ml is acidified with sulphuric acid and 5 ml fixed with formal saline for later counting of the protozoa (this sample should not be frozen but kept at room temperature).

The goats are weighed at the beginning of each adaptation period in the morning before offering feed.

DM is determined by micro-wave radiation (Undersander et al 19??) and N by the kjeldahl method (AOAC 1990). Rumen ph is measured with a digital electronic meter and ammonia by distillation (AOAC 1990). Samples for protozoa are counted according to the method described by Nguyen Thi Hong Nhan et al (20??) recording separately the small and large protozoa.

References

Mini-project 4

Effect of method of processing cassava leaves on intake by mong cai pigs and HCN content of the leaves

Nguyen Duy Quynh Tram

Hue University

The problem

Cassava (Manihot esculenta Crantz) is an annual root crop grown widely in tropical and sub-tropical regions. In Vietnam cassava is an important food crop, and annual root production is about 2 million tonnes (GSO 2001) the majority of which is used for animal feeding and production of starch. The composition of cassava when harvested is: 49% root, 46% foliage, 5% leaves. Cassava leaves on average contain 21% crude protein in the dry matter. Using cassava leaves as a supplementary source of protein in animal diets is a means of reducing the cost of feed and increasing the income for the farmer.

The hypothesis

The HCN content will be reduced by wilting
The pigs will eat more cassava leaves when they are wilted compared with feeding them fresh

Objectives

The objective of the study is to evaluate effects on digestibility and nitrogen retention in pigs of feeding cassava leaves in fresh or wilted form.

Materials and methods

Treatments and design

The two treatments will be :

CH : Cassava leaves chopped into small pieces (2-3cm) and fed immediately after chopping (offered once daily).
CHW: Chopped into small pieces (2-3cm) and wilted for 8 hours in sunlight and overnight before feeding (offered once daily).

The experimental design will be a single changeover arrangement (Table 1) with 4 replicates (pigs).

Tab le 1: Layout of the experiment
Pig No Period\	1	2	3	4
1	CH	CHW	CH	CHW
2	CHW	CH	CHW	CH

Animals and housing

Four local pigs (Bauxin breed) with weight about 10 kg and age of 3 months will be used.

The pigs will be housed in bamboo metabolism cages that allow the separate collection of urine and faeces. The size of the metabolism cage is 1m x1.5m

The experimental period will be 10 days: five days for adaptation period to allow the pigs to become familiarized with the new diet and a five days period for collection of faeces and urine.

Feed and feeding system

Cassava root meal will be fed at the rate of 2% (DM basis) of live weight. The cassava leaves will be offered on free choice basis.

Measurements

Urine and faeces of each pig will be collected separately and weighed twice daily and stored at –20 ⁰C. Urine will be collect in a bucket via a plastic sheet and funnel placed below the cage .

To prevent nitrogen losses by evaporation of ammonia, the pH will be kept below pH 4 by collecting the urine in 50ml of 25% sulphuric acid.

The urine and faeces from each animal will be collected for five days and at the end of the period, the faeces will be mixed, ground and representative sample taken for analysis.

Dry matter of feed offered and refused and DM in faeces will be done by micro-wave radiatikon (Undersander et al 19??). Nitrogen in faeces and nitrogen in urine will be determined according to the Kjeldahl method (AOAC 1990).

Statistical analysis

The data will be analysed using the GLM option of the Minitab (version 13.31) ANOVA software. Sources of variation are: source of cassava leaves, pigs, and source of cassava*pigs interaction, and error.

Mini project 5

Manure or biodigester effluent as fertilizer for duckweed

Kansombat Lampheuy

National University of Laos

Background

Duckweed (Lemna minor) is rich in protein of high biological value, and has been fed to pigs (Du Thanh Hang …), ducks (Bui Xuan Men ….; Le Duc Anh….) and chickens (Du Thanh Hang …..). The protein content and the yield increases when it is fertilized with biodigester effluent (Rodríguez and Preston 19..; Le The Chau 19--). Using duckweed as a feed source will decrease the costs of production and so the smallholder farmers will gain more profit from their animal production.

The hypotheses

Duckweed will respond with linear increases in productivity according to the level of fertilizer N up to 200 kg N/ha
Yields will be higher when biodigester effluent is used compared with the raw manure
The N content of duckweed will increase with increasing level of fertilizer N and will be higher when effluent is used rather than manure experiment

Objectives

An experiment will be conducted to compare the growth response of duckweed to increasing concentration of N from two resources (cow manure and effluent from a biodigester charged with the same cow manure).

Materials and methods

Treatments and design

Two factors will be studied:

Source of fertilizer: Cow manure (M) or effluent (E) from a biodigester charged with cow manure

Level of fertilizer: Five levels of fertilizer N equivalent to 0, 50, 100, 150 and 200 kg N/ha.

The design is a split-plot arrangement with level of fertilizer as main plot and the source as split-plot, according to the randomized block arrangement in Table 1.

Table 1: Arrangement of the treatments
Replicate	Level of N
Replicate	50 kg/ha	150 kg/ha	200 kg/ha	100 kg/ha	0 kg/ha
1	M	M	M	M	M
1	E	E	E	E	E
2	M	M	M	M	M
2	E	E	E	E	E

Procedure

Cow manure and biodigester effluent will be analyzed for DM and N, to determine the quantities to be applied according to the treatment and design. Baskets lined with polyethylene film will be used to carry out the experiment. The volume of each is about 50 litres. The experiment will last 20 days and the fertilizers will be applied in 5 equal quantities every 4 days.

The baskets will be seeded with duckweed at the rate of 50g/m2 (about 30 g per basket). The total production will be measured 24 h after seeding and 30 g replaced for the next growth period.

Measurement

The harvested duckweed will be weighed and a sample taken for analysis of DM (every day). Samples of the dried duckweed will be bulked over 5 days for analysis of N and water extractable DM and N.

Samples of the water in the baskets will be taken every 5 days for analysis of N, NH3 and pH. Samples of manure and effluent will be analysed for DM and N every 5 days.

Statistical analysis

The data will be analysed by the GLM option of the ANOVA software of Minitab version 13.31. Sources of variation in the model will be: source of fertilizer, level of fertilizer, interaction source*level and error

Mini-project: 6

Manure or Biodigester effluent as fertilizer for Water Spinach

Ho Bunyeth

Heifer International, Cambodia

Background

Malnutrition is widely identified as a main problem for both human well-being and also animal production in the world, especially developing countries. Because of lack of understanding of the people, especially the poor farmers at the rural areas in Cambodia who run their production with a traditional way, about how to develop their land use as integrated farming system for improving their food security as well as income-generation. Anyway, lack of information of technical system relating to appropriate skills on agriculture makes the farmers with a small land feel less confident or have less attention on their production causing a problem of loss of land among the poor farmer families. Using water spinach as vegetable and animal feeding resource is very common in Cambodia, but usually they use urea as fertilizer. Kean Sophea showed that water spinach responded to fertilization with biodigester effluent with linear increase in yield up to 200 kg N/ha in 30 days. However, there is no information about the different ways of planting the water spinach: from seed or stems. This mini project will be useful to help the farmers with a small plot of land to understand more about the importance of the manure or biodigester effluent for improving the quality and quantity of the water spinach.

The hypothesis

Water spinach will have higher yields when grown from seed than from cuttings

Objective

To study growth of water spinach planted as seed or stems and with fertilizer from biodigester effluent.

Materials and methods

Treatments

There are 2 methods of planting

S Seed ; P Plant material

And 5 levels of N (0, 50, 100, 150, 200 kg N/ha),

arranged as a split-plot design with main plots being level of N and split plots the seed vs plant material.

Block	Replicate	200kg/ha	0kg/ha	100kg/ha	150kg/ha	50kg/ha
1	1	S	P	S	P	S
1	2	P	S	P	S	P
2	1	P	P	S	S	S
2	2	S	S	P	P	P

Materials

· Biodigester as source of effluent

· Materials for land/row preparation

· 20 PVC baskets lined with polyethylene film

· Water spinach (0.5 kg of seed and 5 kg of stem)

· Watering container/sprayer

· Laboratory raw materials

Procedure

The plants will be grown in soil in PVC baskets, lined with polyethylene film and watered 2 times a day. The biodigester effluent will be applied every 4 days added to the soil at the rate of one sixth of the total application.

Measurements

The growth rates of the plants will be measured as the height every 4 days. Measurements will be made before applying the fertilizer. The biomass will be separated into stems and leves and each analysed for DM, N, water extractable DM and N.

Statistical Analysis

The data will be analysed using the GLM option of the ANOVA software of Minitab, version 13.31. Sources of variation are: plant material, level of N fertilizer, the interaction of plant material*N level and error.

Benefits

This field research study will be used as a resource base of “learning by doing” to help the poor farmer families with a small plot of land can develop their indigenous knowledge and practical skills as well as improving their land use for integrated farming system and other agricultural productivity. Based on their limited resources, but strong commitment and best practice, the inputs will become more productive to assist them in order for improving and sustaining their living condition through a small scale of agriculture production which is ecologically and economically sound.

(Mini-project No 7)

Effect of the urea level on biomass production of water spinach (WS) grown on soil or in water

Ly thi Luyen

Goat and Rabbit Research Centre, Bavi, Vietnam

Background

Water spinach has a very high biomass yield. It is a vegetable resource in tropical regions for humans and animals, such as pigs, rabbits, poultry and fish. It is very easy to grow by the farmer. The traditional practice is to use urea as the fertilizer for water spinach but there is no information on the optimum level to use.

Hypothesis

Biomass yield will be higher when water spinach is grown on soil rather than in the water. There will be a linear response in yield up to the application of 150 kg N/ha

Objectives

Water spinach will be grown on soil and in the water in plots/ponds made from baskets lined with polyethylene, and with increasing levels of urea up to 150 kg/ha.

Material and methods

Location

The experiment will be done in the An Giang University during a 4 week growing period.

Treatments

The experiment has two sets of treatments:

Water or soil as planting medium;
5 levels of N as urea (0, 25, 50, 100, 150 kg N/ha over 28 days)

Design of experiment

The treatments will be arranged in a split-plot design in which the mainplots are the levels of fertilizer and the spilt plots are the planting medium. There will be two replications, arranged as blocks, of each of the treatment combinations (see the table for thelayout)

Layout of experiment (S = soil; W = water)

		El of urea-N, kg/ha
Block	Replicate	150	0	50	100	25
1	1	S	W	S	W	S
1	1	W	S	W	S	W
2	2	W	W	S	S	S
2	2	S	S	W	W	W

Baskets lined with polyethylene (capacity about 50 litres) will be used. baskets are use in experiment. A layer of soil (5 cm) is placed in the baskets for the water treatment. Water will then be added to a depth of 25cm. For the soil treatment the depth of soil will be 25cm. Holes will be made in the polyethylene in this treatment so that excess water can drain away. The soil will be obtained close to the experiment area.

In both soil and water treatments the urea will be applied at 4 day intervals over a period of 28 days.

Measurements

· The height of the water spinach will be measured every 4 days

· Total biomass will be harvested at the end of 28 days and separated into leaves and stems

· Analysis of DM and N, and of water extractable DM and N will be made on the samples of stems and leaves, using the micro-wave radiation method (Undersander et al 19??) N will be deternmined by the kjeldahl techniqe and CP calculated as N*6.25 . Water extractable DM and N will be determined by the method described by Ly et al (19??).

Statistical analysis

The data from the experiment will be analysedusing the GLM option of the AN OVA software of Minitab (verfsjion 13.31). Sources of variation are plantiong medium, level of N, interaction medium*N level and error. The treatment means which show significant differences at the probability level of P<0.05 will be compared using the Tukey comparison in Minitab software.

Mini-project 8

Effect of dimensions of plastic biodigester (width:length ratio) on gas production and composition of effluent

Bui Phan Thu Hang

Cantho University

Background

The human population continues to increase in developing countries, creating increasing demand for animal products. Thus the animal production in developing countries has also increased very quickly, and as a result more manure is produced. Biological water pollution by waste water from the animal excreta is an emergency problem in rural parts of the Mekong delta. Many households there are still using river and canal water as drinking water directly or with insufficient treatment such as sedimentation. People commonly use the water for washing dishes, clothes and their bodies. Livestock production will continue to increase in the near future. The amount of excreta will increase and accompanied with it will be water pollution, which will become a more serious problem. For this reason, it is necessary to encourage animal farms to treat waste water (Tran Thi Phan and Takesi Watanabe 2002).

To solve the problem of pollution from the animal excreta, there are some ways that can be applied at present. The plastic biodigester is one of the most efficient technologies for small scale animal farms because of its low investment, fast payback, simplicity and positive effect on pollution (Bui Xuan An and Preston 1999).

The plastic biogas digester is a means of generating biogas and organic fertilizer from human and livestock excreta through anaerobic fermentation (Vo lam and Takesi Watanabe 2002). However, retention time, the dimensions of the plastic biodigester, kinds of manure all have an effect on gas production and composition of the effluent. Most fermentation tubes are about 1m in diameter and 10m long, which is a length : diameter ratio of 10:1. Recent research has shown that gas yields are higher in small biodigesters with a length : diameter ratio of 3:1 (San thy et al 2003).

It is therefore planned to carry out an experiment comparing three ratios of 3:1, 5:1, 8:1, using experimental biodigesters of 60cm diameter. These will be 2m, 3m, and 5m long each 60cm diameter.

Hypothesis

Gas yields as a function of digester volume will be higher, and there will be greater conversion of organic to ammonia-N, when the length: diameter ratio is decreased.

Objectives:

· To identify the suitable ratio of length and diameter, which can produce higher gas production

· To determine total nitrogen, ammonia nitrogen, pH of the effluent from biodigesters with different length : diameter ratios

Materials and methods

The experiment has three treatments consisting of different dimensions of plastic biodigester:

B2: plastic biodigester is about 2 meters long and 60 cm diameter

B3: plastic biodigester is about 3 meters long and 60 cm diameter

B5: plastic biodigester is about 5 meters long and 60 cm diameter

Procedure:

Three biodigesters are made from tubular polyethylene film (internal diameter 0.637m), enclosed in brick walls, with internal measurements about 64cm wide and 60cm high to ensure the correct dimensions of the digesters, and to provide a liquid volume in the proportion of 75% of biodigester capacity volume.

They will be inoculated with effluent from a working biodigester and then charged with cow manure at a rate of 5 kg dry matter per 1 cubic meter liquid capacity. The manure is charged to each biodigester at exactly the same time. The manure is put into the biodigester when fresh and mixed with water in quantities that will result in a retention time of 20 days. The quantities of manure and water to be added daily to the biodigester are shown in Table 1.

Table 1: The ratio between fresh manure and water
Constants
Plastic width (m)	1
Circumference (m)	2
Internal diameter (m)	0.637
Loading rate, kg/m3	5
DM of Manure, %	20%
	B2	B3	B5
Biodigester length (m)	2	3	5
Volume (lit)	6367	955	1592
Liquid volum (%)	75	75	75
Liquid vol (lit)	477	716	1194
Retention time (day)	20	20	20
Daily input (lit)	23.9	35.8	59.7
Manure DM (kg/day)	2.4	3.6	6.0
Manure FM (kg/day)	11.9	17.9	29.9
Water (lit/day)	11.9	17.9	29.9

Gas production is measured daily by collecting the gas using inverted plastic tubes of 50 diameter permanently connected to the gas outlet, supported inside with a bamboo frame, and suspended in drums filled with water (Santhy et al 2003). Measurements are made three times per day. Samples of fresh cow manure and effluent will be taken daily on days 21 to 30 and analyzed for dry matter, total N, ammonia-N, and pH. The first 20 days of the experiment is for adaptation. Total N and ammonia are determined by Kjeldahl procedures (AOAC 1990). DM content is determined by micro-wave radiation (Undersander et al 1993).

Statistical analysis

There is one replicate of each treatment as this is a pilot observation to find out if the configuration is a factor determining the performance of the biodigester.

References:

AOAC 1990 Official Method of Analysis. Association of Official Analytical Chemical .15^th edition (K Helrick editor) Arlington pp1230

Bui Xuan An, Preston T R and Dolberg F 1997 The introduction of low-cost polyethylene tube biodigesters on small scale farms in Vietnam. Livestock Research for Rural Developement (9) 2: http://www.cipav.org.co/lrrd/lrrd9/2/an92.htm

San Thy, Preston T R and Ly J 2003: Effect of retention time on gas production and fertilizer value of biodigester effluent; Livestock Research for Rural Development (15) 7 Retrieved August 8, 2003, from http://www.cipav.org.co/lrrd/lrrd15/7/sant157.htm

Tran Thi Phan and Takesi Watanabe 2002 Development of the new technologies and their practice for sustainable farming systems in the Mekong Delta. Proceeding of the 2002 annual workshop of JICAS Mekong Delta Project. November 26-28, 2002. College of Agriculture, Cantho University. Cantho. Vietnam.

Undersander D, Mertens D R and Thiex N 1993 Forage analysis procedures. National Forage Testing Association. Omaha .

Vo lam and Takesi Watanabe 2002 Development of the new technologies and their practice for sustainable farming systems in the Mekong Delta. Proceeding of the 2002 annual workshop of JICAS Mekong Delta Project. November 26-28, 2002. College of Agriculture, Cantho University. Cantho. Vietnam.

Mini-project 9

Nutritional Evaluation of Plants Species Using the Water Extraction of Dry Matter and Nitrogen Technique

Miech Phalla

UTA Cambodia

Background

There are many kinds of plant species that can be used for animal feed that are derived from local resources. Use of these plants will make farming systems more sustainable for poor farmers in the developing countries around the world especially in the tropics. However, many farmers don’t know or neglect some useful plants that can be used for animals feed. On the other hand, we don’t always know the nutritional value of these plants so this study will help us to recognize the differences in nutritive value among some plants, in the local area.

The hypothesis:

The dry matter and water extraction indices will be different among different plants species and will be related to literature values for digestibility of DM and N.

Objective:

Measuring the dry matter and nitrogen losses when plant samples are suspended in nylon bags in a washing machine during a 90 minutes cycle have been shown to be closely correlated with in vitro and vivo digestibility indices.

Materials and Methods:

Treatments

These are a range of plant species including trees, shrubs, water plants and grasses

Procedure

Samples of foliage from trees, shrubs, water plants and grasses will be collected and separated into stem, petiole and leaf, all of which will be weighed in the fresh state to determine the proportions of each of the components. Samples of each component will analysed for DM by the micro-wave radiation method (Undersander et al 19??) and for N (AOAC 1990). Dried samples will be ground and evaluated by the water extraction technique to determine the water extractable DM and N method (Ly et al ???). Where possible values for digestibility of DM and of N will be obtained from the literature (Göhl 19??) and compared with the values obtained by the water extraction method.

( No 10 )

Increasing the germination capacity of tree cuttings

Sorn Suheang

RUA, Cambodia

Background

Fodder trees are important in farming systems as besides being a source of animal feed, they also act as “sinks” for storing carbon dioxide, help to prevent erosion and in many instances help to restore or improve soil fertility. A constraint to more widespread use of fodder trees is that to establish them often takes a long time.

Recently it has been demonstrated in Colombia (T R Preston, personal communication), that the rate of germination of tree cuttings can be accelerated by “peeling” the bark (or cortex) from the point of the cutting that is to be planted. These observations were made with mulberry (Morus albus) and Gliricidia sepium trees. It is proposed to carry out similar studies using some trees available in Vietnam.

The hypothesis

It is believed that peeling the bark from the lower 2-3 cm of tree cuttings will accelerate the time taken for the cutting to germinate and form a root system.

Objectives

A number of forage trees (Trichanthera gigantea, Ceiba petandra, Sesbania grandiflora and Muntingia calabura) will be studied, half of which will have the lower 2-3 cm of the cuttings peeled prior to planting.

Materials and methods

Treatments and design

There are two factors:

Effect of peeling

Peeled (P)
Not peeled (NP)

Tree species:

Trichanthera gigantean (TG)
Ceiba petandra, (CP)
Sesbania grandiflora (SG)
Muntingia calabura (MC)

The individual treatments are:

TGP: Trichanthera gigantea (peeled)
TGNP: Trichanthera gigantean (not peeled)
CPP: Ceiba petandra (peeled)
CPNP: Ceiba petandra (not peeled)
SBP: Sesbania grandiflora (peeled)
SBNP: Sesbania grandiflora (not peeled)
MCP: Muntingia calabura (peeled)
MCNP: Muntingia calabura (Not peeled)

There are 8 replications of each treatment arranged in a split-plot design with effect of peeling being the sub-plot and the tree species the main plots.

The layout is shown in Table 1.

Table 1: Layout of experiment
Replicate	1	2	3	4	5	6	7	8
TG	TGNP	TGP	TGNP	TGP	TGP	TGNP	TGP	TGNP
TG	TGP	TGNP	TGP	TGNP	TGNP	TGP	TGNP	TGP

CP	CPP	CPP	CPNP	CPNP	CPP	CPP	CPP	CPNP
CP	CPNP	CPNP	CPP	CPP	CPNP	CPNP	CPNP	CPP

SB	SBP	SBNP	SBP	SBP	SBNP	SBP	SBNP	SBP
SB	SBNP	SBP	SBNP	SBNP	SBP	SBNP	SBP	SBNP

MC	MCNP	MCP	MCNP	MCNP	MCP	MCNP	MCNP	MCP
MC	MCP	MCNP	MCP	MCP	MCNP	MCP	MCP	MCNP

Procedure

The tree cuttings (about 30cm long) are planted in plastic bags (2 litre capacity) filled with a mixture of soil and composted organic matter. Peeling is done by removing with a knife the bark from the lower 2-3 cm of the cutting.

Measurements

Records are kept of the day the first green shoot appears on the stems, and when the first leaves are formed. At the start of the experiment the length above ground of the cuttings and the diameter at the mid-point are measured. At the end of 28 days, the cuttings are removed from the bags and the number and mean length of the roots is measured.

Statistical analysis

The data will be analysed by the GLM option of the Minitab AN OVA software, version 13.31. Sources of variation in the model are: peeling, species peeling*species interaction and error.

MINI-PROJECT 11

Scavenging characteristic of local and exotic chickens.

Sopha Xaypha

NAFRI, Lao

Background:

Nowadays, the population growth in the region is so fast that protein becomes a limiting resource. Poultry production plays very important role to solve this problem in the world. To reduce the high cost product of animal feed, however, it is necessary to develop appropriate technologies for non-ruminant feeding. Duckweed is a water plant with high protein content that can be produced by the farmer, so an experiment will be conducted on “scavenging characteristics of local and exotic chickens when they have access to duckweed as a protein source.”.

Hypothesis:

Local birds will begin to eat the duckweed sooner than the exotic birds. Exotic chicken will prefer to eat soya beans and broken rice rather than the duckweed

Objective:

To compare the local chicken and exotic chicken in their capacity to select the local feed (duckweed).
To study the proportions of broken rice, soya beans and duckweed consumed by local chicken and exotic chicken when they have free access to these feeds

Materials and methods

Treatments

There are two treatments each with two replications:

Exotic chicken
Local chicken

Design of experiment

The experiment will be a randomized block design (CRBD). The pens of local and exotic birds will be allocated at random within each block.

Block 1	Pen with 4 local birds	Pen with 4 exotic birds
Block 2	Pen with 4 exotic birds	Pen with 4 local birds

Feeding systems

Three kinds of feed will be offered in separate feeders: Broken rice, soyabean meal and fresh duckweed. Fresh feed is provided twice a day morning (7:00 am) and afternoon (17:00 pm.). The duckweed will be fed fresh and will be put in the feeder at the same time as the soya bean meal and the broken rice. Residues are collected and weighed before adding the new feed. Water is available all the time. The duration of the trial is 20 days.

Measurements

Feed intake record every morning and afternoon for each ingredient.

The birds will be weighed every 5 days in the morning before feeding

At the end of the trial the birds will be slaughtered to observe the contents of the crop

Analysis will be made of DM, N and the water extractable DM of each of the feeds

Statistical analysis

The data will be analysed using the GLM option of the Minitab (version 13.31) ANOVA software. Sources of variation are: bird ecotype and error

Mini-project 12

Teaching exotic chickens to scavenge

Bounlieng K

NAFRI, Vientiane, Lao

Background

Mostly, exotic breeds of chicken are raised in confinement and fed on concentrated feeds. However, for poor farmers this system is too expensive and use of local birds in scavenging systems is generally preferred. Exotic breeds have the potential for higher rates of production but it is generally believed that they have lost the capacity to scavenge for their feed. It is possible that given the opportunity to learn (from peers in the same pen) they may be able to scavenge effectively.

The hypothesis

The exotic birds can learn to scavenge when they are raised with the local birds in the same pen

Objective

To study the capacity of exotic birds to select local feeds when raised with local birds.

Materials and methods

Treatment

There are two treatments:

E: Exotic birds raised in the pen

EL: Exotic birds raised with local birds in the same pen

Experiment layout

Two treatments with two replicates in a CBRD arrangement as in the table

Replicate 1		Replicate 2
EL	E	E	EL

Animals

18 exotic and six local birds of about six weeks of age will be used in the experiment

Procedure

There will be two periods each of 10 days. In period 1, the birds in treatment “E” and “EL” will have access to broken rice, soybean meal and duckweed. In period 2, the local birds will be removed from treatment “EL” and the feeds on offer will only be broken rice and duckweed for birds in both treatments.

At the end of the experiment the birds will be slaughtered to measure the contents of the crop.

Measurements

Daily intake of each feed and composition (DM and N)

Contents of the crop and the different components

Body weights of the birds taken every 5 days

Statistical analysis

The data will be analysed using the GLM option of the ANOVA softare in the Minitab (version 13.31) programme. Sources of variation are: treatment and error

Mini-project 13

Evaluating vegetative protein source for monogastric animals

Amornsak Ngamsaeng

Khon Kaen University, Thailand

Background

Usually, soybean meal and fish meal have been used as sources of protein in diets for monogastric animals for example pigs, ducks, chicken, but the prices are high, which results in high costs of production. Thus use of local feed resources can help to reduce costs of production and improve the income to small holder farmers. Many researchers (Bui Xuan Men 19??; Du Thanh Hang 19??; Le Thi Men 19??) reported that water spinach and duckweed have potential as protein sources when combined with energy rich feeds which are low in fiber (e.g. cassava root meal, sugar cane juice, broken rice). However, both water spinach and duckweed are low in methionine.

The hypothesis

1. On basal diets of cassava root meal, a mixture of both water spinach and duckweed will increase growth rate of ducklings more than either water spinach or duckweed as the only supplement.

2. The ducklings will grow more when they are fed diets with added synthetic DL-methionine than on a diet without synthetic methionine.

The objectives

1. To study use of either water spinach or duckweed and mixture of both as protein sources in diets of cassava root meal for growing ducklings.

2. To study of use of synthetic methionine as a supplement in diets of cassava root meal supplemented with duckweed and/or water spinach

Materials and Methods

Design of the experiment

A 3x2 factorial arrangement with two replicates in a Completely Randomized Design will be used.

Treatments

There are two factors and two replicates as follows:

Factor 1 is source of protein

W : Water spinach
D : Duckweed
WD : Mixture of both water spinach and duckweed

Factor 2 is supplementation of synthetic methionine

M: supplemented
NM: non-supplemented

Lay out of experiment (1, 2 are replicates)

WM1	WD1	D2	WM2
WDM1	W1	W2	DM2
DM1	D1	WD2	WDM2

Experimental animals

Animals will be 48 duckling(about 1 week of age)

Feed and Feeding

Diets will be prepared with 50% of dry matter from cassava root meal and 50% of dry matter from water spinach or duckweed or mixture (60:40 on fresh basis) of both. The water spinach is chopped finely before mixing with the cassava root meal. Duckweed will be mixed with cassava root meal without chopping. Three similar diets are prepared with 0.3% (on dry matter basis) DL-methionine.

The ducklings will be fed ad libitum on each of the treatments according to the layout of the experiment, feeds being offered twice daily at 07:00 a.m. and 17:00p.m..

Water will be available all the time.

Measurements

These are:

Feed offered and refused (fresh and dry basis)

Live weights at 5 days interval

Feed composition (DM and crude protein)

Statistical analysis

The data will be analysed using the GLM option of the Minitab (version 13.31) software. Sources of variation are: protein sources, methionine, methioine*protein sources interaction and error.

Mini-project 14

Water spinach and broken rice as low cost feed resources for growing rabbits

Hongthong Phimmasan

PAFO, Laos

Background

The water spinach is a creeping water plant and easy to plant with a very high biomass yield which is a good source of protein. It is a vegetable very suitable for animal production in Southeast Asia conditions. Water spinach is also widely used for human food and can be fed to rabbits, pigs and poultry. For these reasons it is considered that water spinach can be a low cost feed for rabbits at small-holder farmer level. Water spinach is a local feed resource that can be planted close to the house and is thus readily available as a means of reducing the cost of feed, giving an opportunity to increase their incomes.

It has been reported by Miech Phalla (personal communication) that rabbits can grow on eater spinach as the sole feed but the growth rate was faster when 20 g/day of broken rice was also given.

The hypothesis

The hypothesis to be tested is that there will be benefits in animal performance from adding broken rice to a basal diet of water spinach and that the optimum economic level will be in the range of 10 to 20 g/day, and that the economic optimum will not be the biological optimum.

Objectives

The aim of the study is to determine the effect of different levels of broken rice(BR) as a supplement to fresh water spinach for growing rabbits

Materials and methods

The experiment will be carried out from 1 August to 30 August 2003 in the ecological farm of the An Giang University.

Treatments, animals and design

The treatments are five levels of broken rice (0 , 15, 10, 15 and 20 g/day) with two replications. Individual treatments are:

T0: BR 0 g /d + WS offered ad libitum 2 Rep

T5: BR 5 g/d + WS offered ad libitum 2 Rep

T10: BR 10 g/d + WS offered ad libitum 2 Rep

T15: BR 15 g/d + WS offered ad libitum 2 Rep

T20:BR 20 g/d + WS offered ad libitum 2 Rep

The experimental animals are ten recently weaned rabbits.

The design is a randomized random block with blocks being the replications (see Table 1).

Table 1: Layout of experiment
	Level of broken rice, g/day
	0	5	10	15	20
Block 1 (cages 1 to 5)	1	4	5	2	3
Block 2 (cages 6 to 10)	10	6	7	8	9

The rabbits are allocated to the cages on a stratified weight basis (see example below). The rabbits are weighed and arranged in order of ascending weight, and allocated to the cages as per the following example

Cage no	1	2	3	4	5
Rabbit LW, g	10	12	13	15	16
Cage no	6	7	8	9	10
Rabbit LW, g	17	17	17	19	20

Feeding system

Leaves attached to stems of water spinach will be hung in the cage, by tying them to a bamboo stick over the cage. The broken rice will be given in a bowl which is tied to the cage. The rabbits will be adapted to confinement in individual cages during a preliminary period of one day after which the experiment will start.

Digestibility of the diets

Faeces will be collected on days 10 to 15 to determine digestibility of DM and of N.

Materials needed

The broken rice 50g /day X 30 days = 15 kg
The water spinach 10kg /day (will buy every day)
The basket to keep feed; 1 basket for water spinach and 1 for broken rice

Measurements

Will be measured:

Daily water spinach offer and and refusal
Daily broken rice intake and refusal
Live weight at 5-day intervals
Digestibility of DM and N

The water spinach that is offered and refused will be separated into leaves and stems to determine the proportions. The leaves and stems that are offered are analysed for DM (micro-wave radiation according to Undersander et al 19--), N (AOAC 1990) and water extractable DM and N by the methods of Ly et al (19--). Faeces are analysed on fresh basis for DM and N by the previously defined methods..

Statistical analysis

The data will be analysed using the GLM option of the ANOVA software of Minitab (version ??). Sources of variation in the model are: levels of broken rice, blocks and error.

Mini-project 15

Effects of different substrates and levels of seeding on reproductive rate of earthworms

Chu Manh Thang

NIAH, Vietnam

Background:

Recently, the use of the California Red worm (Eisenia foetida) as an agent for recycling live stock manure has received increasing attention (Preston and Rodríguez 2002). The products of this process are the worm castings (“worm compost”) and the worms themselves. The worm compost has been used as a fertiliser (Nguyen Quang Suc et al 2000) and the worms themselves can be fed to chickens as a high quality protein supplement (Rodríguez et al 1995).

The hypothesis:

There are two hypotheses:

The rate of reproduction of earth worms will be higher on cattle manure than on poultry manure
Increasing the seeding rate will increase the rate of breakdown of the substrate

Objectives:

The objectives are to determine the effect of different substrates (cow and poultry manure) and the initial proportion of worms in the substrate on the rate of growth and reproduction of earth worms and rate of breakdown of the substrate.

Materials and design

Location

The experiment will be conducted in An Giang University.

Experimental design

The treatments are five seeding rates of adult California Red worms (Eisenia foetida) and two sources of substrate (manure derived from cattle and poultry). The proportions of earth worms are 0.5, 1.0, 1.5, 2.0 and 2.5% of earth worms in the fresh manure (Table 1).

The experimental layout is a completely randomized block design with two replicates . The experiment will last for 28 days.

Table 1: The experimental layout
Treatments	0.5	1.0	1.5	2.0	2.5
Seeding earth worm, (g)	500	1000	1500	2000	2500
Cow manure, (g)	9500	9000	8500	8000	7500
Poultry manure, (g)	9500	9000	8500	8000	7500

Sampling and measurements

The worm seed stock and the fresh manure are mixed and placed in plastic baskets.

The DM of the substrate will be analysis at weekly intervals to adjust to the optimal humidity for earth worms. At the end of experiment the adult worms, immature worms, worm eggs and residual substrate will be separated and weighed.

Statistical analysis

The data will be analysed by analysis of variance using the General Linear Model procedure of the Minitab Software (Version 12). The model is:

Yij = µ + ai + bj + (ab)ij + eij

Y = Response parameter

µ = Overall mean.

a = Effect of seeding rate i

b = Effect of kind of substrate j

e = Error

ab = Interaction between seeding rate and substrate

Mini-project 16

Effect of age of leaves from forage trees on nutritive value

Ngo Thuy Bao Tran

An Giang University

Background:

Farmer observations in the Mekong delta (Nguyen Thi Hong Nhan, personal communication) that the “new” leaves on the Trichanthera gigantea tree have higher nutritive value than older leaves are supported by the research in Cambodia, in which leaves from young re-growths (about 2 months old) had higher digestibility than leaves from plants grown for root production and which were 5 months old when the leaves were harvested (www.cipav.org.co/lrrd/lrrd157/7/chhaty157.htm) . It is proposed to test if this true for other trees. The trees to be tested are: Cassava, Hibiscus rosa-sinuensis, Gliricidia sepium, Acacia auriculiformis, Erythrina variata and Muntingia calabura.

Samples will be taken of leaves at the top and from the bottom of mature trees. They will be dried and analysed for DM, N and water-extractable DM and N using the washing machine technique

The hypothesis:

Young leaves will have higher nutritive value than old leaves when assessed by the water extractable dry matter and nitrogen technique.

Objectives:

Samples will be taken of leaves at the top and from the bottom of mature trees. The trees to be tested are: Cassava, Hibiscus rosa-sinuensis, Gliricidia sepium, Acacia auriculiformis, Erythrina variata and Muntingia calabura.

Materials and methods

Treatments

The two treatments are the ages of the leaves, and the species of the tree/shrub, from which they were collected, it being assumed that the leaves at the top of the tree or shrub are the young leaves and that the leaves at the bottom are the old leaves.

Measurements

The fresh leaves are analysed for DM by the micro-wave radiation method (Undersander et al 19??), N (AOAC 1990) and water extractable DM and N (Ly et al 20??).

Khon Kaen University, Thailand

Background

Objective

Materials and Methods

Treatments

There are two indicator plants

Materials

Procedure

Measurements

Statistics

Background

Hypothesis

Objective

Methods and materials

Experimental design

Feed and feeding system

Measurements

Hue University

The problem

Pig No

Period\

Background

The hypotheses

Objectives

Materials and methods

Treatments and design

Procedure

Measurement

Statistical analysis

Background

The hypothesis

Objective

Materials and methods

Measurements

Statistical Analysis

Goat and Rabbit Research Centre, Bavi, Vietnam

Background

Hypothesis

Objectives

Material and methods

Location

Treatments

Statistical analysis

Bui Phan Thu Hang

Cantho University

References:

UTA Cambodia

Background

The hypothesis:

Objective:

Treatments

Procedure

Increasing the germination capacity of tree cuttings

RUA, Cambodia

Background

The hypothesis

Objectives

Treatments and design

Procedure

Measurements

Statistical analysis

Background

The hypothesis

The objectives

Materials and Methods

Design of the experiment

Treatments

Feed and Feeding

Measurements

PAFO, Laos

Background

The hypothesis

Objectives

Materials and methods

Measurements

Chu Manh Thang

An Giang University

Background:

The hypothesis:

Materials and methods