Evolved on the principles of productive recycling of farm wastes, fish- livestock farming systems are recognized as highly assured technologies for fish cultivation. In these technologies, predetermined quantum of livestock waste obtained by rearing the livestock in the pond area is applied in pond to raise the fish crop without any other additional supply of nutrients.

A. Integrated pig fish farming.

Integrated pig- fish farming is a highly profitable fish culture system, where pigs are reared adjacent to the fish ponds, preferably on the pond embankment from where pig urine, excreta and spilled pig feeds are introduced into the pond water. In one harvest cycle of fish (one year), 2 batches of pigs are grown, 6 months each. This is direct integration system, which is a more efficient method than the indirect integration model, wherein pigs are raised elsewhere and the pig waste is manually applied to the pond daily at a pre-determined dose.

1.   Benefits of pig- fish farming (Direct integration)

• Fish utilizes the feed spilled by pigs and their excreta, which is very rich in nutrients for fish.
• Pig dung act as a suitable substitute to pond fertilizer and supplementary feed for some of the fishes, therefore the cost of fish production is reduced by about 60%.
• No additional land is required for piggery operations.
• Cattle fodders required for pigs and grass carps are grown on the terraced pond embankments.
• Mortality of pig is greatly reduced, as pond provides much needed water for washing the pig- sties and pigs.
• The pond mucks which gets accumulated at the pond bottom due to constant application of pig dung, can be used as an excellent fertilizer for growing vegetables, other crops and cattle fodder.
• Efficient labour utilization.

2. Method

2.1. Pig husbandry practices :

Growth of pigs depends upon many factors including breed and strain, but good management contributes to the achievement of optimum production.

2.1.1. Construction of pig house :

• The pig house can be constructed by using locally available materials such as bamboo and thatch, but the floor must be roughly cemented (so as to be non slippery).
• An enclosed run is provided to the pen so that the pigs get enough air, sunlight and space for dunging.
• The wall should be 1.0 m in height and preferably made of bricks. The upper part of the wall should be provided with wire netting. The height of the pig sty is 1.5 m.
• The floor of the house is slightly slanted towards a drainage canal. The canal is connected to the pond. The drainage canal is provided with a diversion canal leading to a cemented pit, where the wastes are stored in the days when the pond has algal bloom. A built- in shutter is provided in the drainage canal to regulate the flow of wastes.
• Space requirement per pig is 1.5 m2. The roof of the house may be made using thatch or asbestos. Feeding and drinking troughs are constructed alternatively inside the pen, attached to one wall. A bath tub may also be constructed attaching to one wall of the open run.

2.1.2. Selection of pigs :

Pigs with 75% or 50% pure Hempshire blood has been found to be the best for such system. Landrace, large- black, etc. can also be used but not the indigenous varieties. 2- 3 months old weaned piglets are brought to the pig sty for six month rearing.

2.1.3. Number of pigs :

40 to 45 piglets/ ha water spread area for 6 months.

2.1.4. Pig feed:

• Pigs are fed with balanced pig mesh concentrate (PMC) @ 1.5 kg/ pig/ day.
• To overcome mineral deficiency, ‘Sod’ (30 cm × 30 cm bed of grass with all its roots intact and interlocked soil) is provided once a week. However, as PMC (Table-1) is costly, raising pigs with PMC has not been found economical. Through trial & error, one pig feed has been developed, where Colocasia stem & tuber, hotel wastes, rice bran, jubili (the byproduct of a special type of beverage prepared and consumed by the tribal people of Asom), etc. are used.

2.1.4.1. Methods of preparation of pig feed using the ingredients of table-2 :

• Colocasia leaves, stem and rhizomes are cut into small pieces and mixed with the above ingredients (Table-2) except rice bran and jubili and boiled properly. Prior to serving,  jubili and rice bran are mixed.
• Feeding rate : Pigs are fed at ad-libitum. Pigs are fed twice a day i.e. morning and afternoon. In addition, pigs are to be fed regularly with wilted water hyacinth regularly. Cattle fodder, tapioca leaves, banana plants should be cut into small pieces and serve to the pigs.

2.1.5. Health care :

• Pig sties need be washed regularly two times a day in the summer months and once in winter season. Pigs should also be given bath twice a day in summer and once in winter.
• Disinfection of pig sties should be done twice in a week, with quick lime, and potash (KmNO4) respectively. The washed water leads to a fish pond serving double purpose.
• Piglets must be vaccinated against swine fever. They are to be dewormed at the age of 3- 4 months.

2.1.6 Disposal :

After rearing for about 6 months, pigs attain slaughter maturity size (60- 70 kg live weight). These are to be sold out and the new piglets are to be introduced into the pigsty.

2.2. Fish Pond Management Practices

2.2.1. Size : 0.4 to 1.0 ha size of a pond is sufficient to make profit from this integration.

2.2.2. Prestocking management :

Clearance of unwanted fishes, deweeding and liming as in the case of composite fish culture system is done prior to stocking of pond with fish seed.

2.2.3. Stocking :

• In direct integration system, stocking is done after 20 days of introduction of piglets in the pigsty. In indirect integration, 1000 kg/ ha pig wastes is applied in single installment. Pond becomes ready for stocking after 20 days.
• Rate of stocking of fish seed is 9000 nos./ ha preferably with advanced fingerlings.
• Stock is replenished after partial harvesting with a same number of fingerlings of harvested species. After one year, complete harvesting is done.
• Pond is dewatered partially to expose the silt to sunlight. These are to be taken out with the help of bamboo basket. New stock of fish is introduced after proper liming. In second year too, partial dewatering followed by desilting is to be done. At the end of third year, complete dewatering is done to expose the bottom. Complete desilting is done, followed by liming. Thereafter, fish culture is started, after 20 days of introduction of the piglets into pigsties.

• Precautions :

• Monitoring of dissolved oxygen (DO) in the morning is a must particularly in the summer months. DO falling below 3.0 mg/ litre particularly in pre and postmonsoon should be regarded as a warning to control further application of pig dung.
• 2. In large ponds (=0.5 ha), pig dung should not be allowed to fall on a single spot. The collected dung should be divided into 5- 6 parts and applied in prespecified sites selected zones.
• If extensive algal bloom appears on water surface, pig dung, instead of introducing into pond it should be kept collected in the cemented pit.

3.0 Income :

• Production from direct integration per ha water area :-

  Fish : 3000- 3500 kg/ ha.

  Pig : 4000- 5000 kg (live weight)/ 80 pigs/ ha.