Fodder-fish integration practice in Malaysia

by Raihan Sh. Hj. Ahmad

In Malaysia, integrated farming systems (Figure 1) have been practiced since the 1930s, with the production of fish in paddy fields and pig-fish in ponds. Although research shows that these systems are technically feasible and economically viable, socioeconomic factors, such as consumer preference, adoption by farmers, etc., need to be considered. Fodder-fish integration is one widely accepted system.

In the Third Malaysian Plan, fish culture is being promoted in a larger scope. Subsidies are given by the government for pond construction. Fish seed supply is provided as well as training and exten-sion. This system benefits family consumption by providing enough supply of protein. Moreover, it can be a source of additional income.

The fodder-fish integration (Figure 2) utilizes the most commonly used fodder species as fish feeds (Figure 3). These are: napier grass (Pennisetum purpureum), cassava (Manihot esculenta) and ipil-ipil (Leucaena leucocephala).

Land preparation and planting

1. Weed the land.

2. Plant fodder crops.

• Napier grass and cassava are propagated by vegetative means using mature stems. Napier grass cuttings should have 3-5 nodes, three-fourth of which is buried (at about 45° angle). Cassava planting material is 25-30 cm long.
• Ipil-ipil can be direct seeded or transplanted. Direct seeding is done when annual rainfall is 1 200 mm. Seedlings are best transplanted (at 2 cm depth) at the start of the rainy season.

3. Management care

• If possible, put a fence around the area.
• Do not allow grazing of animals.
• Apply fertilizer/compost every month.

4. Harvest the fodder.

• Napier: first cutting at 7 cm from the ground (to encourage vegetative growth) 6-8 weeks after planting. Then, cut regularly every 2-4 weeks, 10-15 cm from the ground.
• Cassava: first cutting 0.5 m from the ground, 8 weeks after planting, then regularly after every 4 weeks.
• Legumes: first cutting 8-12 months after planting, then regularly after every 8-12 weeks, 0.3 m from the ground.

5. Feed preparation

• Leaves of these fodder crops are used as feeds. However, for cassava, the tuber can also be used. The leaves are chopped in small pieces before feeding to hatchlings or fry. For big fish, the leaves are simply placed in the pond.

Fish culture system

1. Pond design

The pond (0.1-0.5 ha in size) should be established near water sources and should be free from flood or drought.

Bunds are built to separate the ponds. Bunds should be between 2 and 3 m and capable of holding a water depth of 1 m. Water is supplied through gravity flow. Screened inlet and output pipes are installed.

A feeding area within the pond is constructed (located at the side). Bamboo poles or trunks of trees can be used.

There are two types of pond:

• Nursery pond - used for nursing 2.5-7.5 cm fry until the desired size is reached.
• Growout pond - bigger than the nursery pond, it is used to raise fish up to marketable size or to grow fish for breeding.

2. Pond preparation and system establishment

• Drain the pond (if the pond is an old one from which the fish have been harvested). Remove silt on the pond bottoms; this can be used as fertilizer.
• Dry the pond bottom until the soil cracks. Plowing it first turns the soil over and facilitates drying.
• Apply lime to condition the soil. Liming activates fertilizers and controls acidic soils which may harm the fish. Quicklime is most commonly used at 200 kg/ha.
• Fill the pond with water 2 weeks after liming. Water should fall from the water inlet into the pond below, so that the water mixes with oxygen from the air. Also check water condition:

- temperature = 22-32°C
- early morning oxygen = 3 mg/litre
- pH = 6.5-8.3

• Add fertilizer to the pond to provide nutrients for fish and plankton growth. Chicken manure can be applied at the following rates per hectare:
• Stock the pond, preferably in the evening.

Option 1: Grass carp is cultured in the nursery pond. After 4-6 months, the fish are transferred to the growout pond with the bighead carp and tilapia.

• Nursery pond (0.2 ha) - 500 pieces of grass carp (10 cm in size).

Option 2: Fish and prawn can be stocked directly to the growout pond.

• Daily management of fishponds

- Check the pond for leaks.
- Clean filters.

If the fish are at the pond surface, feeds are needed. If they are gasping at the surface or the prawn are in the periphery of the pond, aeration is needed. Aerate the pond by stirring the water with a tree branch. Suspend fertilizer additions and later resume with reduced rates.

Also, watch for predators.

- Feed the fish/prawn.
Option 1: After the pond is fertilized, introduce duckweeds. Grass carp feed on duckweeds for the first month. Then, give chopped cassava leaves and napier grass. Feeding is twice a day (morning and afternoon).

Upon transfer into the growout pond, feed the fish with grass and cassava leaves (200 kg/day). For tilapia, cooked maize, food leftovers and chopped cassava are given. The amount depends on the fish behaviour. If the fish are still in the feeding area, more feeds are needed.

Option 2: At the start, feed the fish four times a day. Give rice bran, bread, chopped sago, cassava and napier grass.

For the fish, give feeds inside the feeding area. For the prawn, broadcast the feeds all over the pond. If there are still feeds found in the water, stop feeding.

• Monthly management of fishpond

- Check the pond walls and bottom. Remove any debris which might be a problem at harvest time, e.g. twigs, leaves, etc.
- Check the fertility and turbidity of the water by dipping your arm into the water. If the palm disappears before the water reaches the elbow, there is dense algal bloom.
- Check the fish carefully for any sign of disease.

• About three to four partial harvests can be done using a sieve net before final harvest. For prawn, harvesting is after 6-7 months and for fish, after 10-12 months. Survival rate is about 70-90 percent for fish and about 30 percent for prawn.

3. Potentials

• Environmentally sound
• Prawn/fish is of high (economic) value
• Seed is easily available.
• With polyculture, different water columns are used, minimizing competition for food among different species.
• Acceptable to consumers (as against fish grown in ponds loaded with manure or sewage)
• The fodder crop can last for 5-7 years with minimum maintenance.
• System is open to the introduction of additional components at a later stage.
• Various combinations can be used to get highest yields and incomes.

4. Limitations

• Cannot be applied on a large-scale basis
• Requires high-labour inputs

Budget (in M$) for fodder-fish integration for 1 ha pond

1992: US$1 = M$2.70