Healthy soil and sustainable growing

["TradingPostPaul" <tradingpost@riseup.net>]

http://www.ias.unu.edu/proceedings/icibs/ibs/songhai/index.htm

Technique for Maggot Production - The Songhai Experience
Fr. Nzamujo O.P.
Songhai Centre, Poto Novo, Benin
email: songhai.benin@intnet.bj
Other contact persons: Kike Ladipo, Songhai Centre.
 
Maggot is the larvae of the domestic fly (Musca domestica). The Songhai
Centre in Porto-Novo has facilities for and engages in the mass production
of maggots as a solution to the high cost of feed in fish and livestock
production. 

A brief review of a maggot production enterprise in Songhai is outlined
below. 

1) Role of maggot in development 
i) Provides a source of nutrient for fish, quail, turkeys and guinea fowls.

ii) Provides fertilizer for crop production. 
iii) Protection of the environment as wastes are concentrated and
decomposed. 
iv) The technology for maggot production is simple and cost effective for
farmers. 

2) Choice of site for Maggotry 
Maggottries should preferably be located away from human residence - in
places where there are trees. The leaves of the surroundings vegetation
serve to absorb offensive odor from the maggotry and reduces the ambient
temperature. 

3) Housing 
The building should preferably be oriented in an East-West direction to
reduce the effect of direct sunlight on the substrate. 
 

Specifications : The garble roof type of building with openings at the top
and sides for ventilation is recommended. The roof can be made of
corrugated iron sheets or thatch. At songhai, the following dimensions are
in use : 
Height of building: 
Floor to eaves = 2 meters 
Floor to ridge = 3.2 meters 
Wall of building: 
Open sided building with very short walls to allow for optimum free flow of
air. The dwarf wall should be 0.4 meters higher than the maximum water
level in the surrounding canal. 
Floor : The floor of the building is flat concrete and plastered. The
rectangular building has a central passage (0.8m wide) in the middle with
substrate tanks arranged on either sides of the passage. 
Substrate tanks : Maggot substrate tanks are open shallow concrete tanks
where the fly larvae are cultured. Each tank is 1 meter square and 0.1
meter deep. Each side has railings of 0.12m. 
Collecting tanks : These are narrow tanks 0.3m wide and 1 meter length
running parallel to the substrate tanks where escaping maggots are trapped
and harvested maggots are cleaned. At Songhai, we have 180 substrate tanks
located on 307.1 sq meters of floor space 
Surrounding Canals (or gutters) : The entire building housing the maggotry
is surrounded by a canal (or gutter) containing water to prevent the
invasion of ants and other crawling predators. This canal which is 1meter
wide is used in raising tilapia and catfish which feeds exclusively on
stray maggots and phytoplanktons in water. 
 
4) Maggot Culture 
To produce maggots, the following prerequisites must be satisfied : 

    * House fly (Musca domestica) 
    * Suitable substrate 
    * Fly attractants 

In Songhai Center, the substrate used is fermented grain residue namely
brewery spent grain. The fly attractants include animal manure like pig and
poultry wastes ; animal offal from the abattoir, dead lizards, birds, rats
and other animals - we also use decaying fruits like mangoes. Mango is a
good attractant. 

Production Procedure : 
Maggot production is an aerobic fermentation process. 
To produce maggots, proceed as follows : 

    * In a clean substrate tank (1m x 1m) place 4 shovel full of fresh
animal manure and 6 shovel full of fresh brewery spent grain. Mix them
together.
    * Cut the animal offal into small pieces (10cm length) and spread them
in the middle on top of the substrate.
    * The flies are attracted immediately to lay eggs.
    * During dry weather, water the prepared tanks, using a watering can.
    * Small maggots are observed about 6 hours later ( after first contact
of flies with substrate)
    * Water the substrate daily. The drier the weather, the more frequent
the watering. Avoid water logging of substrate.
    * The maggots attain optimal size in 3 - 4 days and are then ready to
be harvested. Minimal temperature of 30 C or more is required for maggot
production.

Other points to note : 
During unfavorable weather, decomposition is slow and the substrates should
be turned daily, before the first harvesting. At about 6 days old, maggots
become slow and relatively insensitive and are ready to be transformed into
adult flies. 

5)  Harvesting of maggots 
Harvesting of maggots begins on the 4 th day after 1st contact of fly with
substrate. The maggots are of the right size at this stage. 

To harvest, proceed as follows : 

    *   i) Water the substrate (few seconds later, the maggots migrate to
the surface of the substrate). 
    *  ii) Place fresh brewery waste and some fresh pig or chicken manure
at the corner nearest the migration terminus. 
    * iii) About 30 min later, the maggots are attracted to the substrate.
Scoop the maggots with a hand spade into the collecting tank where the
remaining brewery waste is removed with a broom. Harvest the clean maggots
into a rubber or plastic bucket. 
    * iv) Wood ash is sprayed on maggots in the bucket to prevent them from
escaping. 
    *  v)  Harvesting is done twice daily (morning and afternoon).The
morning field constitutes 73.7% of the daily total. 

At Songhai, a 1m x 1m substrate tank yields 2.5-3.3.5Kg of maggot per day. 

6) Factors affecting yield of Maggots 
Season of the year 
a) Production is low during harmattan and dry weather 
b) Temperature >= 30?C 
c) Humidity - Production is better in humid conditions 
d) Quantity of fly attractants / baits - More the quantity of attractants,
the more number of flies and the greater the number of maggots produced. 
e) Predators - Rats at night ; lizards and birds in the day ; ants if not
prevented cover the field of maggots. 
f) Operators skill can affect the quantity of maggot produced 

7) Utilisation in Songhai 
Aquaculture : Feeding of fresh maggots to tilapia and catfishes is done
twice daily. (late in the morning and later afternoon). An average of 100
Kg/day of fresh maggot is used for 87 concrete ponds of about 50 m2 and 0.5
m depth each. 
Poultry: Fresh maggots are used as basic component of feed for quail,
chicks. Fresh maggots are included in the ration of poultry and guinea
fowls. 
Fertiliser : The spent substrates are used to fertilize directly plants in
the field (ring application in mango, banana, papaw plantation) In farm
yard manure, the spent substrates are incorporated into the compost
production. 

8) Preservation of Maggots 
By sundrying of steamed maggots and placing in airtight containers. 

9) Chemical Composition of maggots 
Dry Matter      24,7% 
Crude protein  47,5-50,1%  
Lipid               19,3% 
Cellulose          23,2% 
Minerals          9,1% 
Ca                   1,5% 
P                     1,2% 
Mg                  0,3% 
K                    1,3% 
Na                  4528 ppm 
Mn                196,5 ppm 
Fe                  425,7 ppm 
Cu                 19,7   ppm 
Zn                 235,8 ppm  

10) Constraints of Production
Problem..........       Solution
Waterlogging of substrates during rains..........       Since the orientation 
of
the building is impossible after construction, increase the eave or height
of the dwarf wall. Wind breaks are also useful around the building.
Harmattan or dry air which dries the substrate faster...........        Water
substrates frequently. Turn substrates after every harvesting.
Direct Sunlight on substrates..........         Cover the open sided walls 
with
bamboo mats or dark colored plastic sheets well arranged for ventilation.
Ants (Soldier ants)..........   Maintain water regularly in the canal.
Inspect and repair cracks inside the building
Birds..........         Line traps are used for birds outside.Trap nets are 
also
placed in the open walls.
Lizards..........       Place trap nets in the open walls.
Rats..........  Place trap nets in the open walls
Human vigilance ..........      The operator should also be vigilant enough to
harvest the maggots earlier before they could pass to the next stage.