Bali cattle are the indigenous cattle of eastern Indonesia and have great cultural and religious significance for the people of that area. Indonesia's domestic livestock population has been shrinking for the past 20 years and the last economic crisis has further aggravated the situation as many local cattle farmers had to sell off their livestock to pay for urgent daily needs. Many areas of eastern Indonesia are non-arable and suitable solely for livestock production. In more arable areas of Bali, though the gross marginal income per hectare in arable land for production of vegetable products is generally higher than that for livestock, integrating animal production is a valuable adjunct to cropping as animal manure help to maintain organic fertility and stability of the soils. Efforts are needed to promote methods to increase farm-gate profitability and downstream product quality of animal production. Investing in methods that maximise the value of indigenous cattle resources is hence of importance to the Bali Cattle Research and Development Centre.

The Bali Cattle Research and Development Centre has two cattle feedlots with a full capacity of 135 head capacity. Another feedlot for 100 cattle is planned along with the construction of an abattoir-meat processing factory beside the Centre. This conceptual paper will presents the overall material flows expected of the Research Centre and the future feedlot-abattoir-meat processing factory at the Udayana University's Technology Park in Bali, Indonesia. The Complex will generate an estimated 8 m3 of solid wastes (manure, offal, bones, garbage, compound and garden wastes) daily and 9 m3 of wastewater and sewage. An integrated bio-system is proposed that can manage all solid and liquid wastes and to convert them into value-added products that can be used in the Complex and to generate additional income. With the bio-system,  zero waste and zero discharge can be achieved at the Complex. All solid and liquid wastes will be used for fodder crop cultivation, and other income generating activities e.g. poultry, crocodile farming, plant nursery and aquaculture. The complex will employ more than 60 persons.
 

1.0 Background

Under Repelita VI, the Indonesian sixth five-year development plan (1995-2000), there is strong government support for the development of a high quality domestic beef industry in eastern Indonesia. The Bali Cattle Research and Development Centre (BCRDC) plays an important role in this national effort and does research in meat science and nutrition of the Bali cattle as well as reproduction of cattle and meat processing. 

A small, state-of-the-art cattle feedlot, abattoir and meat processing (smallgoods works) factory (Bali Integrated Meat Processing Complex - BIMPC) is now under construction and to be located beside BCRDC (see map) at the Technology Park of the Udayana University, Bali. This factory is being built with 100% private sector funds but an AusAID grant has been granted for 50% of approved training activities. 
BIMPC will :
(a) constrct a feedlot/cattle holding yard for 100 animals
(b) construct an abattoir for 5 cattle and 10 pigs per day (Monday-Saturday) slaughter capacity
(c) contruct a small goods meat processing factory
(d) provide employment in excess to sixty people. 

The objective of this paper is to incorporate the principles of zero wastes and to present conceptual scenarios for integrated waste management at the project site (BCRDC-BIMPC) (Map 1).  The proposed scenarios using integrated bio-systems will use of all solids and liquid wastes from BCRDC and BIMPC. All the wastes of biological origin from the 6 hectare site will be treated and converted into value-added by-products or into materials to be used within the project site. The integrated bio-system will also generate income or savings and provide employment and/or sustainable livelihoods for the squatter families in the area. The data presented here is therefore purely based on estimates. 
 

2.0 Resources and Wastes

Resources at BCRDC (see photos-set-1) includes (a) a calf shed with 35 calves and (b) a recently constructed feedlot for 100 animals. Calf weight is estimated as 150 kg each and based on the daily generation of 5 % its weight in excretement, the 35 calves would produce about 260 kg of fresh manure. Liquid wastes with wash water and sewage from the research center is estimated to total about 3 m3 per day.

BIMPC plans to construct another a feedlot/animal holding yard for another 100 animals. Based on excretement of 7 % per head of 250 kg cattle, about 2.5 m3 of fresh manure and feed wastes will be generated per day. The planned abattoir will slaughter 5 cattle and 10 pigs per day and 6 days a week. BIMPC (including the small goods factory for processing meat) will generate per day about 4.0 m3 waste water, 2.5 m3 of fresh manure from the animal holding area, about 550 kg offal, blood, fat and bones; and about 1.0 m3 gut materials. 

The feedlot, abattoir and small goods factory will require a labour force in excess of 60 people who will generate sewage and some garbage. BCRDC and BIMPC is on a 6 ha site and it is estimated that about 1.0 m3 of general compound wastes will be available per day; this includes garbage, fallen leaves, weeds and trimmings from bushes and trees, rejected plant biomass from the fodder field,  etc. BCRDC is not connected to a municipal wastewater treatment system and also does not have a septic tank.

3.0 Scenario 1 for Minimal Waste Management

Minimal waste management is the general practice in Bali for small scale slaughter house operations (Fig.1.) and in many other developing countries. In Scenario 1, all solid wastes at BCRDC-BIMPC will be collected and dumped at a site so that Nature can take care of it through natural degradation. This management approach may need 3 persons (current daily wage is about 10,000 Rp in Bali) and require low investments for basic equipment (animal pull-cart and tools). The dump site could be in the University campus if permission is granted. Liquid wastes from the feedlots, such as urine and wash water, will flow into drains (Photo-2) (photo by Simon Appleby. 1999) that runs along the feedlots and lead into a ditch or shallow ponds to allow natural evaporation and percolation into the ground. Dried sludge needs to be removed ocassionally. The University is not connected to a wastewater treatment plant and so BCRDC and BIMPC will need to to treat sewage and waste water from the abattoir. There are currently no septic tanks at the project site.

The environmental hazard in Scenario 1 is expected to be maximum, i.e. from odour, house flies, and leaching of nutrients into the ground. The site (Bukit Badung area of southern Bali) is more arid than the rest of Bali but still has rain twice daily in the wet season and in the dry season it can rain twice or three times a week. Surface runoffs will be a problem in the wet season. Health risks can be kept minimal by workers using hygienic habits.
 

4.0.  Scenario 2 with Livestock-Abattoir-stabilization tank-vermicompost-fodder crop System

Scenario 2 is a basic integrated bio-system  (see Fig. 2) and consists of the sub-systems with 
(a) a stabilization pond/tank 
(d) vermiculture-compost 
(e) fodder crop.

The system is designed to use all the solid and liquid wastes. It is labour intensive and requires significant amount of land space but with low investments in machinery and fossil energy inputs. The basic idea is to provide more effective management to stabilise both solid and liquid wastes and to process them so that the nutrients can be recycled into cattle fodder. The approach is to compost and vermi-compost all solid wastes. This will reduce the waste biomass by about 50 % in volume.  Waste water from the stabilisation tank will be used  to irrigate the fodder crop and to maintain moisture in the compost/vermi-compost. 

4.1.  Stabilization Pond/Tank

This sub-system requires that concrete open drains be laid in order to collect and transport all wastewaters including pre-treated sewage effluent BCRDC and BIMPC, rainwater and surface runoff to a central large pond or a concrete, rectangular and open tank (e.g. 5 x 20 x 2.5 m). The tank will have a holding capacity of about 200 m3 of waste water. Grid and fat traps are needed at appropriate points in the drainage system.  Labour is needed to manually remove sediments from drains and grid trips. A water-sludge pump is needed for ocassional pumping of the tank materials into the fodder crop fields. The tank or pond also serves to store water for irrigation.

4.2. Compost 

The compost serves as the carbon sink for all solid and organic waste from the complex. With a maximum loading of 8 m3 of solid wastes per day and composting time of 2 months, if a 2m wide and 1 m high windrow is created (by hand), the daily added length to the windrow will be 4 meters. About 200 m long of 1 x 2 m wide windrow will be achieved before the first matured compost is obtained and a working area of about 250 m x 5 m wide would be required. It is recommended that the compost be turned every 3-4 days during the first month and every 10 days until it matures. The resulting compost will be about 50 % of the input volume and about 20 % moisture content.

Materials for the compost are 
(a) animal manure 
(b) dried sludge from drains 
(c) garbage from workers 
(d) residues of cattle fodder from the feedlots 
(e) compound plant litter and rejects from fodder harvests
(f) gut material from abattoir 
(g) offal
(h) crushed bones

The windrow may need to be protected from heavy rain and strong sunlight. This can be done cheaply with the help of a overhanging wired trellis to allow a climbing plant to provide permanent cover and at the same time producing a vegetable or a fruit. It is expected that all the compost generated during the first and second year will be used for the fodder crop.

The soil on the project site is usually thin (3-4 inches deep only) but is actually of good quality and will grow good crops of corn and forage. Addition of compost will further improve soil features. 

4.3. Vermiculture

Vermiculture needs less land space as it provides an opportunity for a vertical operation but will require more labour and infrastructural investments. If all the daily input of 8 m3 solid wastes is used, it will need about 400 m2 space for the whole operation (1 third of space for composting) and the operation will produce about 2 m3 of vermi-compost and about 7 kg of earthworms daily. Vermi-composting will use a starter of 1-2 kg of earthworms per starter per m2 with a daily feed of an equal weight of the earthworms. It can generate about 5 kg of earthworms and about 1 m3 vermi-compost after 3 months from 4 m3 manure. Waste water can be applied directly on vermi-composts to maintain the moisture content. At the start of the project, earthworms need to be recycled as starters. Excess earthworms can be sold as fish bait by tourists, or used as animal feed e.g. for poultry, fish. The sieved vermi-compost has a market value of about 500 Rp per kg in Bali. 

4..4. Fodder Production

King grass (also known as Elephant grass, Napier grass (Pennisetum purpureum)) yields about 20 T/year (dry weight) and can be cropped several times (5-6) a year. It has 6-10 % crude protein in fresh cuts. Under normal management, stands are invaded by weeds and so they have to be ploughed up and replanted every 2-3 years as protein content and digestibility also decline in older plants. Thus a five-year stand may still give high harvested yields  but it is of a rather poor quality feed.

The grass is planted in the same way as sugar cane (Saccharum officinarum L.), i.e. the culms are cut into pieces, each with three nodes, and are buried in the soil just deep enough to cover the second node and to leave the third above the ground. 

Leucaena is a legume tree and its foliage can be used as either fodder, in a (zero grazing) cut-and-carry operation, or as browse for pastured animals. It is highly palatable, digestible, with 22-28% protein. The leaves stay green well into the dry season, long after grasses and other sources of forage have turned brown. Foliage or pods may be eaten fresh or processed into dried pellets. High mimosine content of Leucaena renders it toxic to monogastrics if fed beyond a token inclusion rate but rumen flora can break mimosine down into a harmless byproduct. Fodder yield can be very high (50 ton/ha/yr) when properly managed (coppicing, etc.). Though Leucaena is considered as the king of fodder crops in the tropics, psyllid louse plagues can sweep and kill the plant quickly. In Indonesia Gliracidia sepium and Gliracidia maculata, which has a lower palatability, nutritional quality and yield but is not affected by psyllid and will be used at the project site. New psyllid tolerant Leucaena cultivars from South America are available. Mixed cropping of  Leucaena with Gliracidia is therefore recommended. The Photo-3 (photo by Simon Appleby. 1999) shows King grass in the middle and Gliracidia at the sides. 

If cattle consume 2.5 % the weight of their body as feed (DW) per day, and if the ration contains 20% broken rice, 10% corn, 20% copra meal, 10% king grass, 20% gliracidia, 20% rice straw treated with urea, then 200 heads of 250 kg cattle would require per day 250 kg King Grass and 125 kg Gliracidia. At least nine ha of land are needed to grow the fodder needed. 

The project site will have 4 hectares of land for fodder production and can produce enough fodder for only 75 cattle, after wasteage adjustments. The rest of the fodder must be purchased. 

5.0. Scenario 3 with a complex integrated bio-system

Scenario 3 is a complex integrated bio-system with several sub-systems that can be added to an operational Scenario 2. This sytem will incorporate income-generating activities.

There are two groups of activities and are aimed to generate value-added products from wastewater and the solid wastes before they are used for making compost or sent to the fodder crop fields. The addition of each sub-system will depend on the economic justification, market demand of the products and social acceptance of products generated. Suggested sub-systems for this site to enhance or maximise the use of wastes are: 

5.1.0 Activities using wastewater
5.1.1. biogas technology
5.1.2. aquaculture 
51.3. Reptile farm pond

5.2.0. Activities using solid wastes
5.2.1. maggotry 
5.2.2. poultry 
5.2.3. plant nursery 
5.2.4. reptile farming and tourism

A schematic diagram showing the various opportunities to introduce sub-systems to Scenario 2 are given in Figure 3.

5.1.0. Activities using wastewater

Four sub-systems are involved here. Fig. 4. shows the water flow from the stabilisation pond/biogas tank to the aquatic plant pond(s), then to the fish and reptile farm ponds, and to the fodder crop fields. Water from the aquatic plant pond can also be used as wash water for the feedlot. The recovery of nutrients from waste water using duck weed is a suitable sub-system for producing high-protein fodder (15-35 % crude protein). 

5.1.1. Biogas technology

In this sub-system, waste water is anaerobic treated using a natural consortium of micro-organisms that break down organic matter under oxygen-free conditions. A gaseous output (biogas) containing a mixture of gases (about 65 % methane, 35 % carbon dioxide along with other gases like hydrogen sulphide) and the effluent with 65 % less BOD (biological oxygen demand) can be obtained. When this process is contained in a digester/reactor, the biogas can be collected, ammonia-nitrogen loss can be reduced and the nutrients in the effluent can be used as a fertiliser. The biogas technology is well-established and can use very low solids to high-solids (15 %) inputs. A careful cost and technology analysis is needed before adding this sub-system as a range of technology and reactor designs are available at different prices. A 40 m3 brick dome-shaped underground digester (about 25 m3 working volume) may cost about 3-4,000 USD to construct in Indonesia. The benefits from this sub-system are :
(a) reduction of BOD
(b) reduction in bacterial counts and coliforms. 
(c) better odor control 
(d) a gaseous fuel generated 
(e) nutrients available in effluent
(f) water conserved

Stabilisation of the waste water by anaerobic digestion to reduce BOD to 65 % and the total bacterial counts are important contributions especially with waste waters from feedlots and abattoirs. As the waste water will ultimately be used in the fodder crop fields, any precautional processes that ensure reduction of bacterial counts would be beneficial. Anaerobic digestion can reduce total coliforms by 4-6 folds to 1,000 -10,000 most probable number per ml after about 30 day digestion at mesophilic conditions.

At BCRDC-BIMPC, the biogas can be used as a fuel for hot water generation in the abattoir. Animal manure will not be mixed with washwater for biogas production but it is unavoidable that some animal manure will find its way along with wash water into the stabilisation tank. The effluent will have a low solid content. Sludge from periodic and partial removal from the tank, can be fed to vermiculture/compost. 

Large plastic digesters (Chara, J.D. et al. 2000) or a special pneumatic gas-collection dome using gas impermeable fabric (Piccinini, S. et al.1998. Photo-3, photo by Piccinini, 1998) can be used over the proposed concrete tank for gas collection. Biogas generation from waste water and sewage is estimated to be low (estimated to be 50 m3 per day from a 200 m3 digester) since manure is not included in the feedlot wastewater. Table 3. provides information for biogas potential from various animals (ESCAP, 1980)

5.1.2. Aquaculture 

Anaerobic digested waste water as well as raw manure and compost are rich in nutrients and have been used to  enhance growth of phytoplanktons and algae which form the basic food for some fishes. With fertilization of pond water, productivity rates ranging from a low 1,000 kg to 10,000 kg fish per hectare per year can be achieved depending on the fishes cultivated and the management provided. Tilapia and carps are popular fishes cultivated in warm countries and can be harvested twice a year. A number of aquatic plants can be grown in shallow ponds and then harvested for use as animal and fish. Duckweed has a unique productivity potential of 20-35 tons (DW) per ha/yr under tropical conditions. It has a high water content (92-94 %). Nutritionally, duckweed is an excellent substitute for soybean meal and fish meal and can constitute 40 % of total feed for layer-chickens or 15 % for broilers. Duckweed grow well in organic and nutrient rich waste waters and can be cultivated in small scale with yields of 100gm fresh weight/m2/day or 22 tons (DW)/ha/yr, as shown in southern Vietnam (Lylian Rodriguez, 1998). Fresh biomass can be mixed directly with dry feed ration. 

If a fish pond is to be constructed, sufficient water supply must be available. A 3,000 m2 with a depth of 3 meters will require 9000 m3 of water. Water loss should be considered as it depends of many factors. The project site has a bore hole that provides access to a underground water supply. Fish production potential from such a pond is about 8,000 kg Tilapia/carp polyculture per year with a harvest every 6 months. The pond has other functions too, such as (a) to serve as a water reservoir for irrigation of fodder crops during the dry season (b) to collect surface runoffs during the rainy season. 
 

5.1.3. Reptile Farm Pond

The reptile farm sub-system is an optional sub-system and has been suggested because of the opportunity for high-income generation from crocodile hides. Water and feed resources are both available at the project site. 

Crocodiles are not native to Bali and there are no crocodile farms in Bali. There is no prohibition but a government permit is needed. Crocodiles can be fed with fish, offal, meat rejects, condemned animals and almost any animal of reasonable size. Hides can cost upto 800 USD each and even if crocodiles are fed with cheap beef (USD 2.50/kg) it could be still profitable as the conversion rate of young crocodiles is about 1.8-2:1 to 1. Crocodile meat is said to taste like chicken and could become a special tourist food delicacy in Bali and crocodile skin can be processed into souvenirs and skin-products. Crocodile skin from different ages can be used but hides are usually taken from 2-year old animals. Souvenirs can be made from teeth, claws, feet, etc.

The Indonesian island of Komodo is the habitat for the world largest living lizards (Varanus komodoensis). They can grow to over 3 metres long and weigh up to 135 kilograms. It has a long head and neck, and a narrow, deeply forked tongue. The body is usually black or brown with yellow bands, spots, or mottling. The legs are short and powerful, and the tail has a whiplike end.  They have taken the name "Komodo" and are also commonly known as Komodo dragons as the resemble the legendary dragons. Komodo dragon lizards spend most nights inside small caves that they have dug. They feed on live and dead animals. Female Komodo dragons lay about 28 eggs at a time. They are a protected species and would be an added attraction if the reptile farm is open to tourists. 
 

5.2.0. Activities using solid wastes

The scheme to use solid wastes may involve 4 additional sub-systems to Scenario 2, i.e. maggotry, poultry, plant nursery and reptile farming. The integration of these sub-systems into the main system is shown in Figure 5. 

5.2.1.  Maggotry

Maggotry is the cultivation of common house-fly larvae (maggots) which can be done with simple village-level technology. Insect larvae production may also be produced under computer-controlled closed environment with high capital investments as it is done to produce the larvae for the production of fly parasites that are then used for biological fly control. There is also a growing demand for flies in exotic pet food (fish, lizards, amphibians, etc.) in some countries. Solid wastes from BCRDC and BIMPC can be used for house-fly maggot production.

The common housefly (Musca species) is probably the most efficient breeder. There are also larger maggots, such as waxworms (Tenebrio molitor), mealworms (Galleria mellonella) and others (Black solder fly larvae) that could be considered, but breeding of insects is not a casual activity as it demands care. Insects and insect larvae have a high protein content and can be raised using plant biomass, and/or nitrogenous materials (e.g. manure, offal, brewery spent grains). The use of housefly maggots as poultry (chickens, quails (USDA Photo by:Ken Hammond), ducks, turkey, guinea fowls) and fish feed is also practised in some countries, e.g. Benin in Africa. 

Maggots can be grown in concrete trays of 1 m2 and 0.1 meter deep and in a completely netted house or shed to prevent the escape of flies as a measure for prevention of any possible disease transmission (Nzamujo O.P., 1999 , Photo by Michael O. Agho, Nigeria). It takes 4-6 days for the maggots to mature for harvesting and can yield about 3 kg fresh weight per m2 space per batch. The main substrate is manure and offal. A 150 m2 area using 10 trays per day can produce about 30 kg of maggots per day from about 1 m3 of wastes.

5.2.2. Poultry

A one kilo chicken has a market price of 10,000 Rp. This is equivalent to a day's wage of an unskilled labourer in Bali. The poultry sub-system is to make use of products from vermiculture and maggotry. The potential for poultry feed production on 1 m2 area per day using available solid wastes is :
(a) 500 gm for housefly maggots (based on 3 kg maggot harvest per 6-day batch culture)
(b) 50 gm for earthworms (based on 5 kg earthworm harvest per 90-day batch culture)
(c) 100 gm duckweed (L.Rodriguez et. al 1998) using waste water

1 kg of worms/maggots will have about 20% dry matter. If 40 g of worms per 750 g chicken were fed each night, that would provide around 35% of the dry matter intake for each chicken, with a very high protein content, balancing out the day's less nutritious foraging. If a production target output is 25 broiler chicken per week, about population of about 250 chickens is to be maintained. The maggot feed requirement would be about 50 kg per day. About 200 m2 space would be required using 100 m2 growing space. 250 free-range chickens would need about 2500 m2 to provide forage for its needs (A. Ajuyah, 1999). 1000 m2 land would be needed for the maggot-poultry operation. High-priced poultry like quails and guinea fowls can also be considered to cater for special restaurants for tourists in Bali.

5.2.3. Plant Nursery

The plant nursery makes use of the compost for growing potted plants. This is intended to generate income. The choice of the type of plants will depend on the local market, these could be ornamental plants, horticultural trees or even plants for forestation. Ornamental plants have probably the highest local demand because of tourism in Bali. The volume of compost for potted plants needed will be small. The sales of compost as bulk material for landscaping, or bagged for retail sales (500 Rp per kilo) are future opportunities when the fodder crop fields have a reduce demand for compost.

5.2.4. Reptile Farm and Tourism

Crocodiles or komodo dragons can be fed with fish, offal, meat rejects, condemned animals and almost any animal of reasonable size. Crocodile hides can cost upto 800 USD each and even if crocodiles are fed with cheap beef (USD 2.50/kg) it could be still profitable. Feed conversion of young crocs on a dry matter basis is around 1.8-2:1, i.e. when fed with 10 kg of meat scraps, the crocodile will gain 1 kg. 

Crocodile meat is said to taste like chicken and could become a special tourist food delicacy in Bali and crocodile skin can be processed into souvenirs and skin-products. Crocodile skin from different ages can be used but hides are usually taken from 2-year old animals. Souvenirs can be made from teeth, claws, feet, etc.

6.0 Material Flow Analysis and Income Generation.

In Scenario 1, the daily costs for collection and disposal of 8 m3 solid wastes and the general cleaning of the compound for 3 persons would be 30,000 Rp. This excludes the costs of spades and an animal cart for transporting the wastes to the dump. This scenario does not consider recovery the materials (compost) from the dump. Waste mangement is therefore a necessary expenditure without any returns or material recovery. 

In Scenario 2, the assumption is that BCRDC-BIMPC will demonstrate its stewardship to the environment and their responsibility to stabilise and provide basic treatment to both the solid and liquid wastes. This effort will require an investment to construct a network of concrete drains and the concrete stabilisation tank. There is a potential to collect 9 m3 wastewater in addition to rain water and surface runoff. Waste management activities will include (a) vermi- and compost all solid wastes (b) treat all wastewater (c) use effluent for irrigation. The daily input of 8 m3 of solid wastes will generate 3-4 m3 composted material daily after 2 months from the start of the operation. All compost will be used on 4 hectare of fodder crop field which can produce an estimate 130 kg/day fresh weight of mixed fodder. An economic overview  for Scenario 2 (Table 4) indicate that there is a positive economic balance and with the creation of 10 jobs. 

In Scenario 3, the objective is to use sub-systems that can generate value-added products before the solids are sent for composting and before the water is sent to the fodder crop fields. Table 5 provides estimates of inputs to each sub-system, the land area needed for the operation and estimated outputs, along with uses and economic value of the products. About 20 persons are needed for the whole operation and a daily economic value of products is about 1.9 million Rp per day. With labour costs of 0.2 million Rp per day, there should be a positive economic balance.
 

Table 5. Inputs and Outputs of subsystems in Scenatio 3 with Economic Value of Outputs

Conclusion

The paper presented 3 scenarios as options for waste management and utilisation for the BCRDC and BIMPC in Bali. While Scenario 1 concerns only the disposal of the solid and liquid wastes, Scenario 2 provides a simple option for stabilizing the manure as compost and recycling its nutrients and that in the wastewater into fodder for cattle. Scenario 3 takes this a step further with the conversion of nutrients into products (poultry, fish, ornamental plants) for sale. Designing other activities such as tourism that can provide further economic input to the system further ensures economic sustainability. The paper presents opportunities for additional income generation as well as provides 20 new jobs along with an environmentally sound way of management of solid and liquid wastes. It also adds a tourist attraction to Bali. 

The authors hope to put this idea presented in this paper into a project proposal for funding in the future.
 

References

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Nzamujo O.P. 1999. Technique for Maggot Production - The Songhai Experience.
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