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3. Major Types of Integrated Systems in Asia

The role of livestock in the intensive, rice-based farming systems on the major floodplains of China, where aquaculture first developed, was fairly minor and linkages between fish and livestock production correspondingly weak. Applying the principles of waste recycling was, however, integral to sustaining China’s high population densities. In recent decades, as the importance and concentration of livestock and their wastes have increased, these ideas have been applied more widely in China and elsewhere in Asia to reuse livestock waste for fish production. A range of experience and systems now exist.

The growth in production of monogastric livestock and agribusiness concerns has had a major impact on availability of waste for aquaculture. It has also changed the manner in which livestock are raised and marketed. Lower priced livestock products are the result but most are produced by entrepreneurs. Small-holder farmers have often benefited least.

Attempts to scale-down commercial livestock-fish systems for resource-poorer farmers have been uneven because of difficulties of access to, and management of, inputs such as feed and outputs. Alternative livestock systems that produce waste suitable for fish culture are still largely undeveloped. Typical smallholder, ruminant and monogastric production is extensive, making wastes difficult to collect and use. The wastes from poorly fed animals are often low quality. Upgrading such livestock systems can increase the potential for integration with fish culture. Strategic intensification and integration of livestock and fish are alternative paradigms to the conventional models of agribusiness development. Improved efficiency of nutrient use under conditions of nutrient scarcity can be a major benefit of integration. Least-cost production techniques that depend on using several different fertilizers and feeds, rather than a single high-cost compounded feed, is a relevant strategy for both livestock and fish production.

Commercial livestock production and processing typically produce nutrients in abundance, requiring cost-efficient disposal. This offers a different but equally important rationale for integration.

3.1 Current Status


Livestock-fish systems in which waste from animals continuously raised in a pen and fed complete feeds (‘feedlot’) are used as pond fertilizers are the most common type of integrated system outside China (Edwards, 1993). Important characteristics used to classify such systems include type of livestock and fish species and scale of operation. The degree of integration has already been raised in definitions of integrated farming (Chapter 1). Definitions can include whether the fish sub-system receives all the livestock wastes, if livestock waste is used as a single input or as part of a multiple-input system. Since fish production is closely linked to the quality and quantity of inputs, the nutritional value of specific livestock wastes, in fresh or processed form, is also an important descriptor.

The major types of livestock may be classified on their potential for integration with fish culture (Table 3.1). Most fish production data for culture systems fertilized with livestock manure are based on feedlot systems but wastes from animals raised in scavenging systems can also be used. Clearly the latter waste is less easy to collect than waste from animals confined continuously. Some livestock wastes are more acceptable than others; whereas poultry manure from broiler houses is easy to handle and is used widely in agriculture, pig manure is often less acceptable for logistic, religious or aesthetic reasons. This is also reflected in opportunity costs. These may be relatively high for dried poultry waste and low for pig and cattle slurry. Nutrient density is also an important factor as monogastric animals fed high-quality feeds tend to have manure that is more nutrient dense and valuable than ruminants, particularly those raised on nutrient-poor tropical volunteer vegetation.


Matrix of livestock waste qualities and suitability for use in aquaculture

Factors increasing relative suitability for aquaculture

Livestock type





Lack of








































(*** = high to * = low)

Source: Little and Satapornvanit (1997)

Some animal manures contain compounds that cause water quality problems, such as tannins and indigestible fractions. Waste from animals receiving poor nutrition, especially those on diets with high levels of fibre, is particularly unsuitable for fish culture. Other wastes may be contaminated with deleterious compounds such as pesticides, drugs or feed residues that have negative impacts on quality (Table 3.1).



Most integrated livestock-fish systems described in the literature and operating successfully involve the use of manure from feedlot monogastrics. Pig and poultry manure is used fresh, or commonly for poultry, in a dried form for semi-intensive fish culture. Design criteria are given below (Chapter 5).


Native varieties of pigs are well adapted to existing on roots, leafy vegetables, cereal by-products and household food waste (Livingstone and Fowler, 1984). Although they are not ruminants, fermentation in the hind gut is significant and this allows them to grow slowly on a poor diet. An important food item in some cultures is human waste, scavenging pigs playing an important role in nightsoil disposal.

In some cases intensification has been built around waste recycling. Traditional pig production in China was mainly for the production of manure (Ruddle and Zhong, 1988) as is still the case in northern Viet Nam. Weaned piglets are traditionally fattened on considerable quantities of grain byproducts or root crops, especially sweet potato (Ipomoea batatas) supplemented with cultivated and volunteer green fodder. The number of animals raised is therefore related to the production and availability of these feeds, and the number raised per household is low. Pig manure was used to fertilize rice and vegetables, which may explain why the average fish yields in China were as low as only 2 tonnes. ha-1 until as recently as two decades ago, before more widespread introduction of feedlot livestock-fish integration. Fish culture in northern Viet Nam is similarly constrained by the competing use of pig manure to fertilize crops.


Case study of integrated farming in Central Thailand

In Pathum Thani, Central Thailand, a peri-urban area outside the main industrial belt at the time of the survey in 1980, there was a clear dichotomy of monogastric production systems. Farmers were more likely to have small flocks of chickens (>60 percent of farmers) or ducks (>30 percent) than pigs (<15 percent) (Figure 8).

Both the species and scale of production were found to affect the likelihood of their integration with fish culture in the province. Whereas farmers raising pigs were likely to integrate them with fish culture across a range of herd sizes, only farmers with large flocks of either ducks or chickens tended to use their waste for on-farm fish culture. Generally pig herds of less than 30 animals were less likely to be integrated with fish than those of more than 30. Pigs raised in large and small units were similar improved strains, fed and managed in feedlots. In contrast, large flocks of poultry, which were confined throughout their short, well-fed lives, were improved strains and small flocks managed extensively tended to be local breeds.

Source: AIT (1983)


Local breeds of poultry can thrive in environments with abundant natural feeds, which are often rich in calcium and animal protein. Ducks are particularly important in the flooded agroecosystems of South Kalimantan and Southern Viet Nam, and in Java where irrigation supports year-round, paddy rice production. Management has become more intensive in many cases. It involves the confinement of poultry (and pigs) for all or prolonged periods to ensure both adequate nutrition and production, and control damage that freely scavenging animals can inflict on crops.

Poultry are also raised in large numbers when local or seasonal food surpluses occur. An abundance of aquatic snails from the lake allowed duck producers to intensify balut duck egg production in Laguna, Philippines, before feed mill-based feeds were available. Meat ducks are purchased and raised for short periods in large quantities to grow on dropped grain in ricefields after the rice harvest in Central Thailand during which time there is little opportunity for waste collection. But prior to slaughter the ducks are fattened intensively at high density producing large amounts of high quality, easily collected waste that is used for fish culture.

Meat ducks herded through rice fields after harvest being transported for fattening on an integrated fish farm

Failure of scaled-down modern systems integrated with aquaculture

Small-scale, feedlot monogastric-fish systems have been shown to be technically viable in on-station and researcher-managed, on-farm trials. However sustained adoption of these types of systems by farmers has been rare. Almost all research has been carried out using waste from ‘improved’ livestock systems, typically feedlot production of pigs and poultry. Such research has normally been carried out without participation of farmers in the design stage and, often, with financial incentives to encourage collaboration.

The normal criteria used for assessment of ‘viability’ are positive internal rates of return, or return to labour or capital. However, these are not holistic enough indicators, given the complexity of small-scale farmers’ livelihoods. Resource-poor farmers have great difficulty sustaining even scaled-down, feedlot integrated systems. In Thailand it was found that production costs, particularly feed costs were high and there were problems in both securing inputs and marketing produce in rural areas. In effect, integration of feedlot livestock and fish for most small-scale farmers is a ‘technological mismatch’ (Edwards, 1998). A recent review of similar, small-scale, egg duck production systems in the same region found that with improved infrastructure, access to feeds and markets had improved. However, farmers still tended to either extensify production by reducing feed concentrate and allowing daytime scavenging or consolidate larger flocks to ensure viable returns (Box 3.B).


Livestock present () and integrated () on fish farms in Central Thailand by type and number of livestock

(a) - PIGS

(b) - DUCKS


Source: AIT (1983)

Small is a relative term for both fish and livestock production. A profitable layer chicken-fish system was described in one area of Northeast Thailand (Engle and Skladany, 1992). Although farm size was within the norm for the region, operations tended to be irrigated and highly capitalized compared with typical, rain-fed farms in the same area. The concentration of operations close to a provincial urban centre also favoured the provision of cost-effective inputs and sale of produce, and the scale of operations was advantageous to both farmers and middlemen (Engle and Skladany, 1992).

The introduction of new types of livestock without consideration of markets has been another cause of failure in livestock-fish systems. Cattle and broiler chicken production were ‘standalone' enterprises in Panama before fishponds were introduced, whereas pigs and ducks were introduced with the fish (Lovshin et al., 2000). The latter subsequently suffered marketing problems because of low demand, which consequently had an inverse impact on fish yields as there were insufficient livestock to fertilize the ponds. Similar problems have been reported in various African countries where meat ducks were introduced specifically to provide manure to fertilize fishponds without due attention to the wider system.


Constraints to integration of traditional livestock and fish production

The small size of backyard poultry flocks confined overnight for manure collection limits their impact in even a small fishpond. Moreover, variations in flock size and structure greatly affect actual waste availability through the year. Increasing flock size so that more waste is available for fertilizing fishponds requires improved availability of supplementary feed and a reduction in mortalities, particularly among young poultry.

The sustainability of traditional livestock production, especially of pigs and poultry that require grain and/or grain by-products is sensitive to the availability of these inputs and markets. Commercial, vertical integration of feedlot livestock using improved breeds and formulated feeds, whilst leading to opportunities for large-scale feedlot livestock-fish culture, may compete for the feeds and markets of backyard pig and poultry producers, reducing their economic viability.

Traditional management of monogastrics has relied on their ability to scavenge food from around the household and the wider environment. Generally, although local strains of livestock produce less meat or eggs from the same quantities of feed than modern breeds, they can survive and convert the poorer quality and variable quantities of supplementary feed typically available to smallholders. However, the practical difficulties of collecting wastes from unconfined animals and the lower quantities and quality of manures produced, has constrained attempts to integrate such systems with aquaculture.

This woman has few chickens herself but collects poultry manure for use in fish culture from a neighbour house

Golden Apple snail (Pomacea canaliculata) is a pest in ricefields in the Asian Region but has been used as feed for poultry, pigs and catfish


Ruminant faecal waste is probably the most commonly used fish pond input in developing countries. In addition to its use in fish culture being limited by competition as a crop fertilizer or fuel, it has an inherent poor quality as a pond input. Wastes from unimproved grazing animals may be too poor in quality to produce acceptable fish yields in small ponds. In an on-farm trial, around 4 tonnes of fresh ruminant manure had to be collected and used to produce only about 20 kg of fish in a backyard 200 m2 pond (Shevgoor et al., 1994). The buffalo manure had low N and P contents and also contained tannins which stained pond water brown, further limiting phytoplankton growth due to reduced light penetration into the water column. Tannins are also known to be toxic to tilapias (Saha and Kaviraj, 1996).

A further major constraint is the collection and transport of low-value, bulky ruminant manures. Fish culture, however, may be integrated with traditional livestock management practices through linking the needs of livestock for watering, wallowing or overnight corralling. The need to handle and move bulky ruminant manure may thus be negated by strategic husbandry practices. Communal or individually-owned water bodies designed to allow the walk-in entry of large ruminants without physical destruction of embankments can allow low-cost ruminant waste input as well as conservation and concentration of nutrients from the watershed as a whole. Temporary overnight corralling and/or midday wallowing for water buffaloes in small areas may further concentrate wastes. Farmers can therefore ‘harvest’ nutrients from their own and others livestock at little cost. The relationship between herders and crop growers in West Africa in which livestock are rented to deposit dung overnight in an area to be planted to crops gives a working example how manure could be managed in fish culture. In Northwest Bangladesh, the overnight tethering and supplementary feeding of cattle around the house allows drainage of urine into nearby borrow pits, enhancing the productivity of an important source of fish consumed by the household.

Rabbits and guinea pigs fertilizing fishponds in Northeast Thailand

Moina, the water flea, commonly used to raise juvenile fish intensively can be produced in earthen or concrete ponds on a variety of livestock wastes and inorganic fertilizers


Non-conventional livestock encompasses both ‘micro-livestock’, a term coined for species that are inherently small and seldom considered in the broader picture of livestock development (NRC, 1991) and invertebrates, which may be produced as either direct food items for humans or constitute part of the diet of other livestock or fish. Over 40 multipurpose species with promise for smallholders were identified in an exercise involving 300 animal scientists in 80 countries. Many will produce wastes that can be readily collected because of their small size and confinement during production and are suitable for aquaculture.

Small individual size, and limited demands for food and space make micro-livestock increasingly attractive to resource-poor people. Micro-livestock, including both rare breeds of domesticated species and wild animals with potential for domestication, often retain local importance to small-holder families and have potential for larger markets, especially in cultures that value wild or bush meat.

Non-conventional livestock that can grow and reproduce on feeds that do not compete with human or other livestock are particularly interesting. Some invertebrates can be included in this category and are locally important as sources of food and fibre.

Pasture/crop by-product fed

These include geese and rabbits for direct human consumption; and silkworms which are mainly raised to produce high value, natural silk fibre. Geese and rabbits have played important roles in small-holder systems in which pasture and field crop by-products are available. Silkworms have been an important component of small-scale farms in parts of Asia for millennia.

The high intake, poor digestion strategy of geese means that their manures would probably function in a similar way to that of the grass carp in fishponds. In contrast, the copraphagy of the rabbit may reduce nutrient levels of their manure; rabbit manure, however, is widely prized as a fertilizer and has been found to be a useful fish pond input in Africa (Breine et al., 1996).

Woody waste

Termites are some of the most commonly used feeds in recently developed smallholders fishponds in parts of Southeast Asia. However, unsustainable harvesting of wild mounds normally quickly eliminates this potentially important food source as its rate of regeneration is usually far too low to permit even medium term use. However in Ghana, harvesting of termites for poultry is carried out sustainably by placing moist cow dung over termite nests shielded with tins. The termites burrow into the dung and some can then be fed to the chickens daily (NRC, 1991). Although actual quantities are small, termites are high quality feeds for a range of fish species and poultry. Where woody waste is produced in large amounts, their controlled production is a possibility.

3.2 Upgrading Traditional Livestock Systems for Aquaculture

Changes in traditional livestock systems have direct implications for peoples’ welfare, biodiversity and the wider environment. The place of livestock within farming systems has always been dynamic and, particularly in marginal environments, reflected the resource base. Intensification of animal production has often been a critical part of improving rural livelihoods generally and a key issue is whether upgrading of livestock can become a key part in promotion of rural aquaculture.

‘Upgrading’ suggests an increase in productivity and importance of the animal within the farmer’s system; normally genetic and management changes may constitute upgrading. Changes in germplasm alone rarely support long-term change.

Sericulture produces several by-products that can be used as inputs for aquaculture


Key indicators of the potential for upgrading

  • Can the resource base support improved feeds and feeding strategies?

  • What consequences do new, on-farm feeds have for the current farming system?

  • Do introduced strains thrive under the production conditions?

  • What are the consequences for maintaining animal health? Is veterinary support available?

  • What is the likely demand for more animal products with the same or different characterisitics?

  • Will upgrading management allow waste collection and use in aquaculture and does this negatively impact on current methods?

  • What are the disadvantages and risks inherent with ‘upgrading’?


The upgrading of livestock systems in developing countries has often resulted in a total loss of traditional breeds and management methods. A focus on improving yields rather than meeting the needs of the farmers and consumers has often been counterproductive in Least Developed Countries. Typically efforts have been made to develop a modern poultry industry in parts of Africa, whilst smallholder production has been largely ignored. However, improved management, disease control and strategic supplementary feeding can vastly improve productivity (Box 3.D).

Sometimes upgrading has occurred in response to markets or demand changes; the poorer meat quality and body shape/size hastened the decline of the indigenous Mongkon pig in Viet Nam despite their advantages in terms of tolerance to heat and low input diets. Farmers also prefer modern breeds because they grow faster whether fed traditionally, as in northern Viet Nam, or mainly on formulated feed in the south of the country. There has often been a failure to fully understand the complex role of traditional livestock production in rural livelihoods. After the purposeful destruction of the native creole pigs in Haiti because of fears of their possible role in transferring African swine fever to North America, modern breeds of pig failed to meet small-scale farmers’ needs and a synthetic version of the traditional breed had to be ‘reinvented’ (MacKenzie, 1993).

Livestock systems, however, generally have to be improved in terms of the collection and quality of waste for productive integration with aquaculture. In practice, livestock manure from unimproved systems may be too small in quantity, too poor in quality, or simply unavailable because of competition from alternative uses, to be of relevance for aquaculture. Where livestock/crop interactions are already under threat, for example in Nepal, sustainability of crop yields are already dropping because of intensified practices and declines in livestock. In contrast, increased demand for milk and intensified cropping of a fodder crop rotated with cereals is leading to more livestock and greater sustainability in the Punjab (Fujisaka, 1995).

The quality and quantity of wastes are influenced by the diet and other factors (Chapter 5). The collectability of livestock wastes depends on feeding and housing arrangements. Clearly, waste can be collected more fully and efficiently in animals confined for all or most of the production cycle. However, larger numbers of animals raised more extensively, but confined for part of the production cycle, can also produce substantial quantities of waste. Moreover if quantity and quality of feed consumed during the period of grazing/scavenging are high, this is reflected in the quality of the waste.

Several factors mitigate against the ability of smallholders to increase number, confine and feed livestock enough to benefit from using their waste for fish culture. The limited ability of monogastrics to utilize diets high in fibre has reduced the scope of improvements to traditional systems of raising pigs and poultry. The number of monogastrics that could be raised has been linked to the availability of grains and/or root crops surplus to direct human consumption needs. The processing of staple foods such as maize and rice within the household has been a critical source of brans and broken grains suitable for feeding livestock in traditional systems. Commercialization of food production that leads to processing grain off-farm leads to losses in opportunities for small-scale livestock, unless a concomitant increase in fodder crop production occurs.


Upgrading scavenging poultry diets and management in Ethiopia

More than 60 percent of rural families in the Ethiopian highlands keep chickens and women own and manage the birds and control the cash from sales. Average egg production of scavenging hens is around 40 eggs bird-1 year-1. In a trial with a women’s group, it was found that improved housing and management such as provision of water, removal of eggs and prevention of broodiness improved production to over 100 eggs bird-1 year-1. These results were obtained using the local strain of hen vaccinated against Newcastle disease. Supplementation with maize only, noug cake (a locally available protein-rich oil cake) only, or the two feeds combined increased yields to more than 200 eggs bird-1 year-1. The highest production was obtained on the maize only diet, confirming that the scavenging chickens were limited more by lack of energy than by protein. This approach to upgrading scavenging chickens can increase the returns from this activity and, as both flock size and plane of nutrition is enhanced, increase the amount and quality of collectable wastes for aquaculture.

Source: Dessie and Ogle (1996)

Recent research with farmers has identified promising strategies for breaking this dependence by using feed inputs available on-farm such as sugar cane as energy sources (Preston, 1990). High quality forages such as mulberry, hibiscus and cassava leaves can provide some or all of the protein needed in tropical livestock systems (FAO, 1999a) but for monogastrics suitable protein sources may ultimately constrain such systems (Kroeske, 1972). Soybean fodder and small fish have been used successfully for pig production in the few cases in which these are available. The ability of ducks to utilize low-fibrous plant material such as duckweed has also been shown.

Small-scale farmers may have a continued relative advantage in the production of ruminants and village poultry because of their forage-feeding base and special characteristics (taste, texture, ‘organic' origin). Non-conventional livestock that can be reared to substitute for forest or bush meat may fill a similar niche that is expanding in many places where industrial food production is becoming the norm. In general, however, these systems must be upgraded to a level of productivity that meets the farmers' rising expectations. Clearly, some degree of intensification of livestock is necessary for any integration with fish culture to be sustainable. Market development and veterinary support, however, are often critical to the development of such improved systems.


The adoption of semi-feedlot systems with controlled grazing/browsing for part of the day and confinement with supplementary feeding for the remainder of the day and night-time may have the greatest potential for upgrading livestock production and allowing integration with aquaculture by small-holders (Figure 6). This combines the low-risk advantages of traditional systems with enhanced productivity producing more and better quality livestock waste that can be collected for use in fish culture. Aquaculture can, therefore, become a focus for improving overall nutrient use on-farm. The nutrient-poor status of small-scale farms contrasts with the high losses of nutrients, particularly N, which occurs before collection and reuse. The N from backyard poultry waste and urine from ruminants is often almost completely lost. Whole-farm strategies that incorporate fish culture may enhance conservation and recycling of these nutrients, particularly if livestock are raised in improved, semi-feedlot systems. Such systems may also favour the strategic import and use of nutrients as feeds or fertilizers on to the farm. However, substantial and cost-effective improvements in productivity of the whole system probably require both better recycling and use of more inputs.

Making pig feeds in southern Viet Nam using local resources by cooking village rice bran and water hyacinth together

A major problem with upgrading scavenging poultry flocks to a size that their manure can have an impact on fish production is poor survival of starter birds, and poor availability and/or cost of supplementary feed for growing birds. The strategic use of higher quality feed for starters and use of alternative supplementary feed for adults can increase flock size, and quantities and qualities of waste available (Khalil, 1989). The adoption of heat stable vaccines to prevent Newcastle’s disease has had a major impact in areas where available (Alders and Spradbrow, 2000). The collection of waste from scavenging poultry overnight is often possible even when they remain unconfined; roosting of birds over ponds can be encouraged with strategic feeding and placement of perches/ cover. Manure can even be collected under tree branches or within housing by placing sheeting under roosting positions and feeding stations. The sheets, which can be old textile material or split fertilizer bags can then be washed or suspended in the fishpond.


Inadequate feeds and their poor utilization are key constraints to improved ruminant systems. The greater use of crop by-products, undergrowth of tree crops and improved fodders, particularly legumes, have been promoted to, and adopted by, farmers. The three strata forage system in which grasses and ground legumes (first stratum), shrub legumes (second stratum) and fodder tress (third stratum) allows good quality feed to be produced year-round in dryland farming areas of Bali (Devendra, 1995). The introduction of multitiered feeding and polyculture in these terrestrial agroecosystems is analogous to the multiple feed/ space niches typical of fertilized fish ponds stocked with a polyculture of fish.

The use of supplementary concentrates such as ricebran can further improve performance, especially of pregnant and lactating animals. The biggest challenge is to improve the feeding value of the large amounts of fibre (ligno-cellulose) available. The use of pretreatment using alkali or urea, which improves fibrous feed quality, has been promoted but is not widely adopted by farmers, except in China where it has been successful (FAO, 1997). Although the use of multinutritional blocks, providing nitrogen and micro-nutrients, are being used in several countries to improve the utilization of low quality feeds (Leng et al., 1991), in practice their use is often constrained by their poor availability to farmers in rural areas (Peacock, 1996).

Improved feeding often develops with increased confinement of ruminants on smallscale farms in Asia. Animals that are stalled some or all of the time, and fed cut-and-carried forages and/or concentrates, tend to show increased productivity and produce wastes of higher quality and collectability (Chapter 5).

Both low nutrient density and high concentration of tannins negatively affect water quality and limit the amount of faecal wastes that can be used in fish culture. An optimal strategy under many conditions would be to use solid wastes to fertilize crops and to collect urine and washing water for fish culture. Normally, collection and retention of urine N in the farming system is problematic. Generally the urine simply soaks away or is absorbed by bedding and solid faecal waste. Use of greater quantities of bedding materials high in carbon (C), such as straw or stover, improves N conservation but these may be unavailable in the quantities required. Nitrogen is also lost or becomes refractory under such conditions (Anderson, 1987). Pens can be constructed with a thin sloping concrete floor to direct urine and washing water into a plastic bag. Where concrete is unavailable, elevated wooden pens, which are often used for stalling small ruminants, can be sited directly over the pond. In practice, however, livestock are often penned away from the pond and waste has to be collected and carried. There is a need to develop practical methods to collect urine, perhaps using simple plastic sheeting and bags.

Herding ducks in the Red River Delta. Overnight confinement and supplementary feeding allows collection of wastes for use in fish culture

Washing a plastic sheet placed to collect manure and waste feed from scavenging ducks penned overnight


In many situations livestock wastes will be only one of several nutrient inputs used to raise fish. Livestock wastes may be too few, low quality or available irregularly. Multiple inputs are used in both subsistence and commercial fish culture with livestock waste to capitalise on an occasional or seasonal abundance of other wastes and byproducts and to improve the overall balance of inputs into the pond.

The use of multiple inputs usually suggests that livestock production does not dominate fish economically. Use of livestock manure alone usually suggest that aquaculture is a relatively minor component of the overall system.


Various factors may limit the number of livestock that a farmer can manage and integrate with fish culture, reducing wastes to levels below optimum. Edwards et al. (1983) found that problems marketing duck eggs, and high feed costs, constrained small-scale farmers maintaining even 30 ducks over small ponds (200 m2) as feedlots. Farmers with limited numbers of poultry for their pond area need additional nutrient inputs to optimize productivity. Extension of multiple input systems can increase overall levels of inputs used by small-scale farmers, although often not to the levels considered optimal by researchers (Thu and Demaine, 1994; Ahmed et al., 1995; AASP, 1996). In a project in Bangladesh the frequency of poultry waste used as pond inputs increased from only 3 percent of farmers to nearly 30 percent after extension (Table 3.2). Comparative figures for cattle manure, inorganic fertilizer and rice bran reflected higher initial use.


Change in frequency of pond inputs before and after extension in Kapasia Thana, Gazipur District, Bangladesh

Input type

Percentage of households



Cattle manure



Inorganic fertilizer



Rice bran



Poultry manure



Source: Modified after Ahmed and Saha (1996)


Use of wastes from ducks fed supplementary food, in addition to inorganic fertilizationd


Food Conversion Ratioc

Fish (kg)

Duck eggs (No.)

Ducks onlya




Fish only




Fish + Ducks




a Duck wastes include all wastes (excreta plus waste feed).

b net fish yield for a 330 m2 earthen pond over a 90-day period, extrapolated from fish growth in 5 m2 tanks.

c Food conversion ratio of fresh village ricebran to weight of eggs produced from a flock of 15 muscovy ducks (4:1 female:male).

d Inorganic fertilization at 3 kg nitrogen ha-1day-1, 1.5 kg phosphorous ha-1day-1.

Source: Little and Edwards (1999)

Supplementing low-nutrient density wastes from scavenging animals with other inputs is particularly common. Farmers in Udorn Thani, Thailand used a variety of inputs, in addition to livestock manures including a variety of plant leaves, and rice bran (AASP, 1996). The wastes collected from limited numbers of scavenging ducks fed a supplement at night can increase fish yields in systems fertilized inorganically by over 40 percent. Additionally, the overall efficiency of the limited ricebran used on the farm is improved and products diversified (Table 3.3). In small ponds, the relative amounts required are also affordable, given the value of the fish produced (Edwards, 1996).

Commercial systems

Commercial, integrated livestock-fish systems are best developed in countries such as China, Taiwan and Thailand where vertically integrated feed companies have exploited rapidly growing markets for meat and social, market and physical conditions are optimal for using the large amounts of waste through semi-intensive fish culture. Increasingly these are complex, multi-input systems in which the use of formulated feeds, aeration and improved strains are being adopted to increase yields and returns. The evolution of integrated fish culture in China gives a particularly interesting profile of how heterogeneous conditions stimulate different practices. Several studies based on data in the 1980s do indicate some important trends in the country’s transformation (Box 3.E).


Changing integrated systems in China

Complex, multiple input systems were typified by state and commune managed integrated farms in China during the 1980s (Edwards, 1982). These contrasted with traditional household systems in which fish yields were highly dependent on large quantities of green fodder consumed by grass carp, in addition to small amounts of pig and human waste. The dikepond systems of the Zhujiang Delta were particularly complex involving multiple inputs, especially those relating to production of silkworms (Ruddle and Zhong, 1988). These systems, having reverted to household responsibility under the rural reforms in the late 1970s, have also been most affected by the drive to industrialization and urbanization in recent years.

Prevailing prices in the 1980s favoured a grass carp-dominated polyculture based on pasture grass fertilized with pig manure, which was more profitable than the direct use of pig manure in ponds stocked with filter feeding fish or feeding pellets. This reflected the lower price of filter feeding fish even then, compared to grass carp and low cost of labour. Feeds at this time were also relatively high priced, low quality and poorly suited for the mainly planktivorous species raised Yang et al. (1994).

Aquaculture has had a variable development in different regions in China but its traditional practice is associated with provinces to the south and east; in other areas, particularly in the north, aquaculture is relatively recent. It is therefore unsurprising that the level of intensification is uneven and Chen et al. (1995) analysis of practices by province gives a clear picture of emerging trends that have since become more apparent. Integration with livestock in the 1980s was of crucial importance to inland fish culture, with more than 80 percent of ponds receiving manure of some type (Table 3.4). The systems were characterized by the range of manures, and other inputs used. A trend towards specialization of livestock and fish production was evident as only 22 percent of farms raising fish were physically integrated with livestock at the time. The investment in feeds in the mid-1980s was already much more than fertilizers; all fertilizers together cost less than 8 percent of total nutrient costs. Farmers were also spending more on inorganic fertilizers (56 percent of total fertilizer cost) than manures (human 12 percent; pig/cattle 28 percent and poultry 4 percent).

High yielding systems used most high-quality feeds and grass and snails, and they also relatively more highly stocked with ‘fed’ fish, grass and black carps, and omnivorous fish. In lower input systems (and poorer provinces), filter feeding fish dominated and fertilizer use (Figure 9) was relatively more important. However, even in ‘low’ yielding systems, feed costs were 80 percent or more and fertilizer only 20 percent. Certain other differences were identified between provinces. In Hunan, a ‘medium’ level fish yielding but livestock-dense province, a majority of ponds had livestock physically integrated (73 percent), presumably as opportunity costs of the waste were low. Generally medium-yield fish farmers had the most livestock and were best diversified with respect to other sources of income. High yielding fish farms had intensified stock management, spent more on feed, fuel and equipment and specialized more in valuable fish species. They tended to raise fewer livestock and derive less of their income from off-farm labour. Less than 3 percent of fishponds were physically integrated with livestock suggesting greater specialization and the reduced value of livestock waste at a certain level of intensification of fish culture.


Feed and fertilizer inputs in integrated systems for three areas with different levels of production in China

Composition by weight (t ha-1 year-1)

Composition by cost (percent)




















High quality









Low quality









Pellet feed

































Livestock manure









Poultry manure









Total manure























Source: Chen et al. (1995)

In locations where market and physical conditions are suitable for both livestock and semi-intensive fish production and the concentration of livestock production lowers the opportunity cost of the wastes such as Chacheongsao and Nakon Pathom provinces near Bangkok in Thailand, direct physical integration of livestock and fish production develop as in livestock dense provinces of China. Fluctuating livestock prices are common under such conditions and Edwards (1985) showed that fish production makes a significant contribution in covering losses when livestock prices are low.

The trends towards simplification of integrated systems with single species of livestock raised at high density, and the use of supplementary feed and aeration has developed over the last two decades in China. There has also been substitution of livestock-fish integration with more feed-based, fish production and diversification to higher value species (Cremer et al., 1999). This appears to be mainly occurring in areas close to the major, richer markets where land is most limited, fish prices are high and high quality feeds are available. Nationally the situation still reflects dependence, and increased growth, on fish raised in fertilized ponds and it is clear that China will need to depend on integrated concepts to sustain inland aquaculture (Box 3.E).


Percentage yield by fish species in three areas of productivity in China

Source: Modified from Chen et al. (1995)

Inorganic fertilization

Farmers with limited numbers of livestock may use fertilization based on both livestock wastes and inorganic fertilizers. Inorganic fertilizers may be a cheaper form of N and P than purchased livestock manure in many situations (Table 3.5), and highest yields may be achieved without, or with relatively low loadings of manures. This may be particularly the case for phytophagous fish such as Nile tilapia. In highly productive ponds fertilized with inorganics (4 kg N.ha-1 d-1), there may be no significant benefit of including chicken manure in tilapia monocultures (Knud-Hansen et al., 1993). Green et al. (1994) recorded similarly high yields (>20 kg. ha-1 d-1) of Nile tilapia using higher levels of chicken manure in combination with inorganic fertilizers.


Economic comparison of different fertilizers with respect to available nitrogen (N), phosphorus (P), and carbon (C) (US$ = 25 Baht)


(Baht. 50 g-1)

(Baht. Kg-1)

(Baht. Kg-1)

(Baht. Kg-1)

Chicken manure




















a Wet weight;
b assumes 40 percent dry weight of total N is available (Knud-Hansen et al., 1991);
c assumes 10 percent dry weight of total P is available (Knud-Hansen et al., 1993)
d assumes 50 percent dry weight of organic C oxidizes to dissolved inorganic carbon (DIC).

Source: Knud-Hansen et al. (1993)

The benefits of using high levels of inorganics may be constrained by their availability or opportunity cost. Other species may benefit more from use of manures, especially when high levels of inorganic fertilization may be less appropriate such as for carp polycultures which include a detritivore. Supplementation of organic wastes in low-input, chemically fertilized ponds increased the growth rate of mrigal, the detritivorous Indian major carp compared to controls (AASP, 1996).

Supplementary feed

Supplementing limited livestock manure with direct feeding of fish is an alternative strategy. The impact of supplementary feed on yields of fish in ponds fertilized with livestock waste is affected by many factors. The level of natural feed to some extent affects the efficiency with which fish utilize supplementary feed. More natural feed allows use of more high-energy supplements to ‘spare’ the protein requirements and support the growth of more fish (Chapter 5) The optimal levels for supplementary feeding are complicated by the variable levels of waste feed that are mixed with the manure which may be considerable. Purchasing supplementary feed for fish in livestock-fish systems may not be cost effective however, especially if feeding rates are high.

A reduction in feeding costs of more intensive systems by fertilizing ponds with livestock manure is another strategy that has attracted the attention of farmers and researchers alike. As feed cost typically comprises about 80 percent of operating costs of intensive aquaculture systems (Shang, 1981), any improvement in food conversion efficiency is desirable. Clearly, the fish species raised need to be suitable for culture in waste-fed, planktonrich systems. Green et al. (1994) found that the tambaqui (Colossoma macropomum), in contrast to the Nile tilapia, grew poorly in fertilized systems without supplementary feed. Increased levels of inputs have consequences for overall loading rates, water quality and fish yields (Chapter 5).

Microphagous Nile tilapia fed pelleted feed in duck manured, mechanically aerated ponds in Taiwan yielded up to 18 tonnes ha-1 however (Liao and Chen, 1983) in systems that produced most of the low cost tilapia exported to the USA. Hepher and Pruginin’s (1981) description of commercial polycultures in Israel indicates that fertilization with livestock waste and inorganics was an essential component of high-yielding semi-intensive systems in that country. Feeding only in the later stages of the culture period, when the nutritional needs of the fish exceed the level supported by natural feed alone may also reduce feed costs. Green et al. (1994) found that at densities of 1 fish m-2, tilapia could be raised on poultry waste alone for the first 90 days of a 137 day production cycle without any differences in final yield.


Summary of factors affecting use of inorganic fertilizer and feeds with livestock wastes

  • Are inorganic fertilizers available and will their opportunity cost affect their use by the farmers?

  • Is the farmer raising mainly plankton-feeding fish, or species that feed in other niches within the pond?

  • How expensive are inorganic and organic fertilizers when costs per unit of available nutrient are considered?

  • What is the quality of wastes with which the feeds are being supplemented? Many ‘wastes’ contain spilled feed.

  • What is the economically optimum level of supplementary feeding for the type of wastefed aquaculture being used?

  • Are supplementary feeds only profitable for nursing and fattening fish?

3.3 Integration with Agro-Industry


Global market integration and commercialization greatly increase the volume of animal waste (de Haan et al., 1997). As incomes increase, a greater proportion of animals and animal products are processed. Large quantities of homogenous wastes produced during production and processing of feedlot livestock make for economic use of such by-products for fish feeds under a variety of conditions. Re-feeding manure and slaughterhouse waste back to livestock and fish has been common in recent history (Chapman, 1994). Early accounts of trout production indicate a dependence on old horses as fresh meat (Schaeperclaus, 1933) or as a substrate for maggots used as feeds (Rumsey, 1994). However, the use of meatmeals has come under increased scrutiny recently after ineffective processing of slaughter wastes led to outbreaks of bovine spongiform encephalitis (BSE) in cattle. Fish and shrimp meals are widely used as ingredients in both animal and fish feeds. Both livestock production wastes i.e. manure and slaughterhouse wastes (blood, bones and viscera) may be processed into conventional feed ingredients used by feed mills (Figure 10), although only the latter is widespread.

The most important environmental impacts of processing livestock result from the discharge of waste-water (de Haan et al., 1997). This area is least developed with respect to integration with fish culture. A major problem in developing countries is the tendency for processing plants to be located in peri-urban areas where infrastructure and markets are best developed but land and water are limiting.

Other major differences between modern and traditional agro-industry are the facilities and scale of operation. There are large differences in the type and quantities of by-products produced that depend on the type of livestock and processing waste (Box 3.G).

Regulation of the size and distribution of processing operations can encourage the recycling of processing wastes through aquaculture. In Thailand, as road and other infrastructure have improved, chicken processing plants are moving away from flood-prone rice growing areas in provinces near Bangkok to the centres of broiler production within maize growing, upland areas. Hybrid catfish farms which utilize much of their wastes, are similarly relocating to these areas (Ingthamjitr, 1997).


Comparison of possible strategies for using livestock production and processing wastes in aquaculture

Source: Little and Edwards (1999)

A major constraint to the use of most tannery waste is the use of chromium in the tanning process. Chromium is particularly toxic to fish and other aquatic organisms. It is a major problem in the Calcutta wastewater-fed fisheries, causing seasonal mortalities and undocumented risks to humans from consumption of such fish.

Adding value to livestock wastes through simple on-farm processing has now developed where conditions are suitable: typically in the vicinity of larger towns and cities; and usually by entrepreneurs well connected with urban markets. In one study, livestock processing wastes in Pathum Thani, Thailand were more commonly used by farmers with diversified farming systems (livestock, fish, vegetables, orchard), than rice farmers adopting fish production (Edwards et al., 1983). Location of aquaculture within peri-urban zones also makes the use of other agro-industrial by-products possible. These include waste human food from canteens and restaurants and food processing wastes. In Thailand and some other parts of Asia, noodle processing waste, stale noodles and bread products, and soybean, brewery and distillery wastes are commonly used. Many of these products are also used for feeding livestock, particularly pigs (Figure 11).


By-products from livestock and processing waste

  • The biological oxygen demand (BOD) of wastewater from red meat slaughterhouses may be over 25 kg BOD. tonne live weight-1, of which 10 kg is from blood, compared to less than 10 kg BOD. tonne live weight-1 for poultry.

  • Tanneries typically produce around 100 kg BOD tonne raw hide-1

  • Dairies produce less than 5 kg BOD tonne of milk processed-1

  • Markets also affect the value of the processed livestock. For example, whereas offal may be highly prized and preferentially consumed in some markets, in others it is a disposable waste

Source: de Haan et al. (1997)


Green blowfly larvae used to process pig manure to fish feed

Limited land and/or water availability may preclude conventional integrated waste-fed aquaculture. The production of a live feed, such as the green blowfly larvae, Lucilia sericata, on pig manure and its use as a substitute for a pelleted feed for intensively raised African catfish (Clarias gariepinus) in cages placed in ponds stocked with Nile tilapia (Oreochromis niloticus) was demonstrated.

Key outcomes were

  • Catfish production of 6 tonnes year-1 based on the manure from a standing herd of 1000 fattening pigs was demonstrated

  • The static water pond in which the catfish cages were suspended ensured that environmental impact of both pig and catfish systems was minimal

  • Integration of tilapia with catfish improved nitrogen retention by over 30 percent

  • Manure after maggot production still retained more than half the original nitrogen content but its reduced moisture content increased its value as a horticultural input

  • Catfish fed maggots alone over an eight week culture period grew to market size (100g)

  • Catfish fed maggots alone fed had slightly lower survival (75-80 percent) than pellet-fed fish(>84 percent), possibly due to their voracious feeding that led to physical damage

Source: Nuov (1993); Nuov et al. (1995)

Live-feed organisms

The use of livestock manures as substrates for livefeed organisms such as insect larvae or crustaceans for feeding high-value fish also has potential where land costs prohibit semi-intensive aquaculture. Live feeds can be used as complete diets or to supplement pelleted feeds for fish species such as hybrid Clarias catfish raised in intensive systems (Box 3.H). Such low-tech solutions not only produce fish but also increase the value of the original waste, principally by reducing smell and moisture level.

Maggot production based on pig manure. Green blowfly (Lucilia sericata) larvae are raised in batches over 4-5 days and fed to African catfish

Maggots being produced in manure placed next to fish ponds can be pushed into the water to feed the fish

Feeding broiler chicken intestines to Pangasius catfish

Slaughter house wastes

Commercial examples of poultry slaughter house wastes being used as feed after simple processing for carnivorous fish such as Clarias catfish and snakehead exist in Asia (Box 3.I). The rapid deterioration of viscera and other slaughterhouse wastes restricts their use to areas close to the source. In Thailand such wastes are usually refrigerated on-farm and may be traded. The advantages of an export industry that both stimulate employment producing value-added products and produces food for sale locally are clear (Box 3.J).


Percentage of farms in Central Thailand using various fertilizer and supplementary feed inputs for fish culture (a) waste food from human consumption and agro-industry (b) animal by-products and animal feed (c) vegetable matter.




Source: AIT (1983)


Chicken slaughter house waste fed to catfish

Poultry slaughter house wastes are in great demand for feeding hybrid Clarias catfish (C. macrocephalus x C. gariepinus) in Thailand. The practice has evolved on the back of a booming industry and export of boneless chicken meat in which broilers are processed in-country producing large amounts of by-products. Heads, viscera and thighbones, that constitute about 10 percent of the liveweight of the broiler are the main by-products fed fresh after simple on-farm grinding and mixing with a binder.

Food conversion ratios of 4-5 (wet:wet basis) are attained under farm conditions in which yields of the air-breathing hybrid catfish may exceed 100 tonnes. ha-1. Competition to purchase slaughterhouse by-products has resulted in segmentation of the recycling business with wholesalers contracting waste, to further remove meat scraps for human consumption before use of residual waste for catfish feed.

Effluents from the fish culture systems are minor as water exchange is minimal and increasingly is pumped into neighbouring ponds in which polycultures of herbivorous fish are raised in fertilized, semi-intensive systems.

Source: Little et al. (1994)

After processing of broiler chickens in Thailand about 10 percent of the liveweight is used for feeding hybrid Clarias catfish


Feeding maize to catfish

1st order benefits

  • Local maize and soybean production stimulates broiler production

  • Broiler production waste used to raise herbivorous fish

  • Local labour used for de-boning chicken

  • Chicken slaughter wastes used to raise catfish

2nd order benefits

  • Expertise in feed manufacture stimulates development of value-added feed ingredients and knowledge

  • Benefits to crop farmers (stable markets)

  • Benefits for peri-urban skilled and unskilled employment

  • Low-cost chicken and fish products for sale benefit local consumers

  • Reduction in polluting effluents

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