This paper presents a historical account of the integrated fish farming, identifies major constraints
in relation to integrated production systems and the role of international and bilateral agencies to
promote the above farming systems in different countries of Asia.
Various types of integrated systems (poultry-fish, pork-fish, ruminant-fish livestock-crustacea) have been discussed.
Integrated farming systems are probably as old as farming itself if the broadest definition of integrated farming is accepted. Acording to this, integration occurs when outputs (usually by-products) of one production sub-system are used as inputs by another, within the farm unit. Thoreticians used to differentiate it from mixed farming, in which production subsystems of a farm are not mutually supportive and do not depend on each other.
Livestock-crop systems (in which crop residues are consumed by livestock and manure is recycled to fertilize the soil) are widespread and rather well documented. Livestock-fish systems, although their main feature is also by-product recycling, however, did not develop spontaneously outside their birthplace (China) and until recently, were poorly understood.
In livestock-fish systems sthe pond performs functions as the soil in livestock-crop systems: through microbial activity the pond ecosystem transforms the inert nutrients of the manure to digestible, proteinrich, live food for the fish. The problem lies in the harvesting of these food organisms, because only a very few fish species sre able to filter feed efficiently the phytoplankton out of the water. Harvesting higher levels of the food chain such as zooplankton is easier, but between each trophic level significant energy losses (as much as 90% of the total) occur. Thus to make livestock-fish integration efficient, suitable fish species are needed which may not be available in the local fish fauna.
HISTORY OF INTEGRATED FISH FARMING
In China integrated livestock-fish systems are documented since the Ming dynasty (14th-17th century). They are thought to be developed under the pressure of high population densities and limited resources. It is important to realize, however, that another Chinese invention, the polyculture of suitable fish species (which feed efficiently at different tropic levels) contributed in a significant way to the success of organic manure recycling.
The basic fish species selected for the Chinese polyculture (silver carp, bighead carp, grass carp) are the most efficient phytoplankton, zooplankton and macrophytic feeders. Moreover, they are readily accepted and consumed by the Chinese population, which facilitated their spread in South Asia together with the migration of this ethnic people.
Data regarding the early phase of Chinese carp introduction are rather scanty, although it is known that they reached Malaysia as early as the end of the 19th century. It is presumed now that integrated livestock-fish farming systems, using a polyculture of Chinese carps, were introduced to Thailand, Vietnam, Malaysia, Singapore and probably to some parts of Indonesia long before Second World War. Integrated fish farming, however, remained a traditional activity of minority ethnic groups outside of China, a practice based on ancient empirical knowledge.
Futher expansion of integrated farming started after the Second World War. In several European countries where carp culture was traditional (Germany, Hungary, Czechoslovakia, Poland), fish-cum-duck and fish-cum-pig production systems were introduced in order to boost animal food production. As the empirical Chniese methods were not always applicable directly among the European climatic and socioeconomic conditions, research work on these systems started, primarily in Germany and Hungary.
The major constraint in adapting the Asian livestock-fish systems in Europe was the lack of suitable cultured fish species needed for an effecient polyculture. Introduction of all Chinese carp species, therefore, started in the late 1950s and was in about a decade its introduction was completed to practically all countries of Europe where warm water fishes were cultured. As Chinese carps do not breed naturally outside their original geographical range, a hatchery technology (different from the Chinese one) was also developed for these fish species.
International an bilateral aid agencies realized very soon the potentials of low-input livestock-fish systems in boosting animal food production in the developing countries. In the Asian region Chinese carps were introduced to Bangladesh, Burma, India, Indonesia, Iran, Korea and the Philippines in the 1960s, to Laos and Nepal in the 1970s and to Bhutan in the 1980s, together with induced breeding methods, hatchery technologies and integrated farming systems. FAO was a pioneer in this respect; most of the developing countries received these technologies through one or another FAO executed project.
The FAO Technical Conference on Aquaculture held in 1976 in Kyoto, Japan, devoted one of its sessions to integrrated farming. The resoulution of this fundamental global meeting, which has come to be know as the “Kyoto Declaration on Aquaculture”, pointed out that “....aquaculture can, in many circumstances, be combined with agriculture and animal husbandry with mutual advantage, and contribute substantially to integrated rural development.” The Regional Office of FAO for Asia and the Pacific (RAPA) was especially active in promoting integrated farmings international workshop and expert consultations were organized or co-sponsored by RAPA on this topic in 1980, 1983, 1985 and 1988.
Integrated fish farming was actively promoted by other organizations as well. Some of the most important ones are the following: the International Center for Living Aquatic Resources Management (ICLARM) organized an international conference on integrated agriculture-aquaculture farming systems in 1979 and promotes these even outside of Asia; the Asian Institute of Technology (AIT) is engaged in research, development and advanced training in such systems since 1979; the Centre on Integrated Rural Development for Asia and the Pacific (CIRDAP) initiated studies in 1986 on integrated farming and organized a regional workshop as a follow-up in 1988. As a result of concentrated efforts of several international and national institutions, our knowledge on integrated livestock-fish systems improved substantially.
In order to promote research, traning and information exchange in integrated fish farming in the Asia-Pacific region, the Network of Aquaculture Centres in Asia (NACA), now an independent intergovernmental organization, assigned one of its four Regional Lead Centres to this topics. The Asia-Pacific Regional Research and Training Centre for Integrated Fish Farming was set up with FAO/UNDP support in Wuxi (Jiangsu Provience, China) and since 1981 it organizes annually four month training courses. To date 232 participants, (78% of them coming from the region), received practical training in integrated fish farming methods developed in China. In 1989 NACA published a textbook on the subject: Integrated Fish Farming in China (NACA, 1989).
TYPES OF INTEGRATED LIVESTOCK-FISH SYSTEMS
One of the classical Chinese systems is the integration of fish culture with duck raising, and it is widely practised within its original geographical range (China, Hong Kong and Taiwan). Theoretically this is the best possible integration; ducks raised on the pond surface drop their nutrient-rich manure food in the pond; the fish gather protein-fich natural food from the pond ecosystem or may consume directly the feed spilled by the ducks.
This method was introduced to practically all countries of the region, however, it is seldom used on a commercial scale outside of the original geographical range. In many countries of Southeast Asia, egglaying duck breeds are raised rather than the white, peking-tpe meat ducks, to scavenge on rice stubbles without formulated feeds. In most cases it proves to be uneconomical to keep the dusk confined to the pond and feed them with complete feeds. The market demand (especially that of the local rural markets) is very limited for the Peking-type meat ducks in most of the developing countries.
Substituting the duck with geese in the integrated system has proven sucessful both technically and economically in some countries (China, Hong Kong, Taiwan, Philippines), although this change does not resolve the general problem of having a narrow market niche for the product. Moreover, geese are usually more susceptible to diseases than ducks.
Raising egg laying hen or broiler chicken in poultry-houses built above the fishponds or on the dikes is not a traditional method of integration, but it is becoming popular in countries where formulated poultry feeds are manufactured locally and are available at reasonable prices (e.g. in Thailand, India, Malaysia and the Philippines). This type of integration occurs both in large, commercial ventures and small farms, usually close to urban markets. In Islamic countries, where pork is nor raised, egg layers or broiler chicken are the best choice for integration.
This method is another classical Chinese integrated fish farming system widely practised in its original geographic area. This system was well-established by immigrant Chinese in several Southeast Asian countries (such as Thailand, Malaysia and Singapore and later also in other parts of Asia (e.g. in India, Nepal and Bhutan). With small pigsties constructed over the fishponds, bigger ones on the dikes, pig manure reaches the pond directly or after being collected and fermented in suitable pits. Fresh pig manure is regarded as highly efficient foe pond fertilization and fish can utilize directly the feed spilled by the pigs.
Pig-fish integration is thus an efficient one form of integration technical point of view, although the pigs do not benefit much from being above or around fishponds. Problems of this systems are of an economical nature: farm-gate prices of pork fluctuate substantially in Asia as well, rendering pig raising uneconomical especially in bad years. Another limitation of integrated pig-fish systems is the ban on pork consumption by Islamic communities in some of the most populous countries of Asia.
Large ruminants (buffaloes, cattle) are integral part of Asia farms and will remain so in the foreseeable future despite some advances in farm mechanization. However, there are significant obstacles in this respect to integrate them with fish production. First of all, most of these animal are allowed to grazeing rather than kept and fed in feedlots, their manure is scattered all over the farm and/or the pasture. They may be padlocked at night, but the manure collected in the enclosur is traditionally used to fertilize crops by small farmers. The manure of ruminants comtains less nutrients than that of poultry and pig, especially when it is collected from the fields after being dried and/or leached out. For these reasons there are very few true integrated fuminant-fish systems in the region, although cattle and buffalo dung are widely used to fertilize nursery fishponds.
In some countries integrated goat-fish and sheepfish systems were also tested with encouranging results(e.g. in India, Indonesia and the Philippines). However, these systems are not expected to make a significant impact in the region.
Integrated farming in coastal aquaculture has no traditions at all, but in the 1980s some farmers in Thailand shifted from poultry-fish to poultry-fresh-water prawn integration. As freshwater prawn farming is practised at a semi-intensive level, it can be successfully integrated with poultry. However, the efficiency of manure utilization in such systems will not reach the levels offered by a well designed fish polyculture.
Semi-intensive coastal ponds producing both milkfish and marine shrimp were found to be suitable for integration with poultry and pig in the Philippines and with poultry and small ruminants in Indonesia. Due to the polyculture of several fish/shrimp species these brackishwater systems have been proven o be rather efficient. However, the problem is that marine shrimp culturists focus on intensive monocultural systems and practically abandoned the traditional milkfish/shrimp production methods.
A complex systems of integrating egg-laying poultry with fish, marine shrimp, brine shrimp (Artemia sp.) and salt production was also tested and found technically feasible in the Philippines. Brine shrimp production requries fertile water manure-fed and nutrient-enriched by 200 layers in a 20 hectares farms system. This experimental system, which was as complicated as the classical silkworm-fish-mulberry systems in China, demonstrated well the almost limitless potentials of integrated livestock-fish/crustacean systems.
CONSTRAINTS OF INTEGRATED LIVESTOCK-FISH SYSTEMS
In the early years of aquaculture development there were high expectations related to integrated livestock-fish systems because of their potentials in increasing productivity of farms, improving income of farmers, providing fuller employment and better nutrition for the family and spreading of economical and biological risks in the production process. The rationale behind these expectations was that by introducing integrated farming, farmers can produce within their farm unit most of the necessary nutrients thereby reducing the dependence on external inputs and costs of production. Unfortunately, these overly optimistic did not materialize; few of the integrated livestock-fish systems survived the termination of the aid programs which promoted their introduction.
A closer look at the nutrient and energy balance of production gives the obvious answer. In true subsistence farms outputs are consumed within the farm unit (which includes the farmer and his family), however, such farms do not exist in rural Asia. Marketed outputs are creating deficits, external inputs can not be avoided. In fact, even in the famous integrated systems of China, it appeared that these systems really show an ingenious diversity and respectable efficiency, but are far not universal in the Chinise aquaculture. Most farms depend on imported rather than recycled outputs, such as livestock feeds, macrophytes and snails collected from adjacent natural waters, human excreta from urban areas, etc.
Another limitation is that integrated systems with low level of external inputs produce rather low-value filter-feeding fish species with restricted demand outside China and Chinese communities.
In countries with improving living standards (e.g. Hungary in Europe and Thailand in Asia) low public acceptance of Chinese carps has led to a significant decrease in the production of these species over the past decade, reducing thereby the efficiency and importance of integrated farming. Market limitations may hinder the sale of animal products produced in integrated systems, like in the case of duckand pig-fish integration.
Livestock-fish integration is beyond doubt well suited to resolve the manure disposal problems of medium and large-scale commercial animal husbandry enterprises. Such feedlot-type farms (e.g. poultry, pig and dairy farms) which depend on commercial feeds create environment pollution problems because of the insufficient arable land to utilize the manure produced in the production process. The absorption capacity of pond ecosystems (especially under the tropics) is considerably higher than that of the edaphic systems, therefore manure disposal needs less area and is cheaper in ponds than on land. In such cases, however, emphasis is on the disposal rather than on the utilization of the manure, such systems are invariably overloaded, leading to considerable wastage of nutrients and the constant massive fish mortality due to dissolved oxygen depletion. This may be alleviated by using fish species less susceptible to low dissolved oxygen levels (e.g. tilapais or air-breating fishes), but thesespecies are less efficient in harvesting the natural food produced in the pond than a well-balanced polyculture of suitable cyprinids.
Another problems in such farms may arise from the discrepancy between the intensity of the livestock and fish sub-systems. While the feedlot-type animal production is by nature highly intensive, the fish subsystem is semi-intensive and, secondary in its importance. With investment in fish kept at a bare minimum operational cost and with the value of livestock products far exceeding that of the fish, these farms are obivously optimizing the livestock sub-systems rather that optimizing the fish sub-systems.
The problems of introducing livestock-fish integration in the small farms of Asia are basically different. Small farmers generally do not have feedlot-type livestock production. Animal manure, is needed to fertilize the most important crops (e.g. vegetables produced for family consumption). If fish production was introduced in such farms, ponds tend to be underfertilized. External inputs (like feeds and fertilizers) are in short supply and in most cases there is no cash available to purchace these.
In integrated livestock-fish systems there is a minimum density of animals to be kept above the fishponds or on its dikes to make the fish sub-system operational. For instance on a pond of 0.1 hectare at least 50 ducks or 10 pigs would be needed in the tropics; a number far exceeding the requirements of the family and the amount of animal feeds produced on the farm itself. This means that introduction of livestock-fish integration will make the farmer dependent on external inputs and external markets, which increase the risks of farming. In order to avoid such additional risks, farmers may choose to purchase fertilizers rather than formulated animal feeds to boost their fish production.
The willingness of the small farmer to operate integrated livestock-fish farming and the success in running such a venture is dependent on two factors: his entrepreneurial spirits and the existence of reliable markets in the vicinity. This explains the rarity of such cases but at the same time provides raionale for the Asian countries. The number of knowledgeable and enterprising small farmers is increasing all over the region, and the existence of markets around urban centers creates a sound economical infrastructure for relatively small integrated livestock-fish to produce high-value commodities.
Using integrated livestock-fish systems to resolve the environmentally safe manure disposal of feedlottype animal husbandry farms will certainly gain momentum in Asia with the proliferation of such ventures. Despite the fact that only some 15% of the total nitrogen introduced to the fish sub-system will be recovered in the fish yield, these systems are extremely useful environmentally, because over 80% of the nitrogen input “disappears” (volatilizes or is immobilized in the sediment), with only a small amount (not more than some 2%) getting to the environment in the drained water of the fishponds.
Because of their efficiency in “processing” organic wates, integrated systems will certainly expand and may include in the future fish-fish or shrimp-fish systems in order to resolve the environmental problems created b highly intensive, feedlot-type fiah/shrimp farms. Because of the limited marketability of Chinese carps, attention will shift to the production of more valuable species (e.g. tilapias, cat-fishes, gouramies, etc.) in integrated systems.
Small farmers will need further support in training, demonstration, extension services, credit and marketing in developing socially and economically sound integrated livestock-fish systems in carefully selected areas (usually close to urban centers). Farmers in more remote, underdeveloped regions should also not renounce integrated farming; but instead of promoting livestock-fish integration, rice-fish farming should be introduced or forage crops should be produced on the dikes to feed a grass carp dominated polyculture. Such crop-fish systems proved to be extremely useful in triggering general rural development by introducing a valuable cashcrop (rhe fish) in remote areas of Bhutan, Laos or Nepal, where livestock-fish systems could not be developed.
As a result of extensive research work on integrated fish farming systems in the psat decade, our technical knowledge on such systems has considerably improved and socio-economical studies were also implemented in the region. Efforts of the international development agencies, however, should be continued to promote the development of improved systems for the small farmers. While the more commercial types of integrated fish farming systems will certainly keep expanding through the efforts of the private sectors, responsible national agencies should provide continuing support to the small farmers in adopting and operating such systems.
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NACA (1989). Integrated fish Farming in China. NACA Technical Manual 7. NACA, Bangkok, Thailand, 278 pp.