1. Introduction

Aquaculture is the fastest growing food production sector in the World with annual growth in excess of 10 percent over the last two decades. Much of this development has occurred in Asia, which also has the greatest variety of cultured species and systems. Asia is also perceived as the ‘home’ of aquaculture, as aquaculture has a long history in several areas of the region and knowledge of traditional systems is most widespread. Furthermore, the integration of livestock and fish production is best established in Asia.

In this initial section we introduce the rationale for the study and provide definitions of integrated livestock-fish farming. We then examine the current status and future importance of livestock and fish production being integrated rather than being developed further as specialized, separate activities. Their sustainability and importance in a broader context are then considered.

1.1 Rationale of the Study

Livestock-fish production systems develop to satisfy needs if they fit into the resource base or environment, and if they are socially and economically viable. Macro-level factors may also have a significant influence and there are environmental implications, both on- and off-farm, for the development of sustainable systems (Figure 1).

The current status of livestock-fish systems reflects their evolution in response to changing circumstances: the past history of current systems is not generally appreciated; nor is their future potential apparent.

The rationale for this study is to interpret Asian, especially East and Southeast Asian experience in integrated systems through analysis of their evolution and current status and to consider their relevance for livestock-fish planning in Africa and Latin America.

FIGURE 1

The development of sustainable aquaculture systems involves consideration of production technology, social and economic aspects, and environmental aspects

Source: AIT (1994)

1.2 Definitions of Integrated Farming

Integrated farming is commonly and narrowly equated with the direct use of fresh livestock manure in fish culture (Little and Edwards, 1999). However, there are broader definitions that better illustrate potential linkages. Indeed, the term ‘integrated farming’ has been used for integrated resource management which may not include either livestock or fish components. Our focus is the integration of livestock and fish, often within a larger farming or livelihood system. Although housing of livestock over or adjacent to fish ponds facilitates loading of wastes, in practice livestock and fish may be produced at separate locations and by different people yet be integrated. Chen et al. (1994) distinguished between the use of manures produced next to the fishpond and elsewhere on the same farm. A wider definition includes manures obtained from off-farm and transported in bags, e.g. poultry manure, or as a slurry in tanks, such as for pig and large ruminant manure.

Integrated farming involving aquaculture defined broadly is the concurrent or sequential linkage between two or more activities, of which at least one is aquaculture. These may occur directly on-site, or indirectly through off-site needs and opportunities, or both (Edwards, 1997). Benefits of integration are synergistic rather than additive; and the fish and livestock components may benefit to varying degrees (Figure 2). The term “waste” has not been omitted because of common usage but philosophically and practically it is better to consider wastes as “resources out of place” (Taiganides, 1978).

1.3 Potential Linkages Between Livestock and Fish Production

The main potential linkages between livestock and fish production concern use of nutrients, particularly reuse of livestock manures for fish production. The term nutrients mainly refers to elements such as nitrogen (N) and phosphorous (P) which function as fertilizers to stimulate natural food webs rather than conventional livestock nutrition usage such as feed ingredients, although solid slaughterhouse wastes fed to carnivorous fish fall into the latter category. There are also implications for use of other resources such as capital, labour, space and water (Figure 3). A variety of factors affect potential linkages between livestock and fish production (Box 1.A).

Both production and processing of livestock generate by-products that can be used for aquaculture. Direct use of livestock production wastes is the most widespread and conventionally recognized type of integrated farming. Production wastes include manure, urine and spilled feed; and they may be used as fresh inputs or be processed in some way before use.

Use of wastes in static water fishponds imposes limitations in terms of both species and intensity of culture. Stimulation of natural food webs in the pond by organic wastes can support relatively low densities of herbivorous and omnivorous fish but not a large biomass of carnivorous fish. These biological processes are also temperature dependent. The optimal temperature range is between 25-32°C although waste-fed aquaculture in sub-tropical and temperate zones where temperatures rise seasonally has also been successful. Processing wastes through organisms such as earthworms and insect larvae that feed on them and concentrate nutrients to produce ‘live feeds’ is an alternative approach to raising fish needing high levels of dietary animal protein. Livestock processing can also provide a wide variety of wastes that vary from dilute washing water to high value meat and bloodmeal that can be used as high value fish feeds or feed ingredients. If enough of these types of feeds are available, high density and intensive production of carnivorous fish species can be supported. Aquaculture may also provide inputs and other benefits to livestock production. A variety of aquatic plants e.g. duckweeds and the aquatic fern Azolla have proven potential as livestock feeds; and invertebrates such as snails and crustaceans can be used for poultry feeds.

FIGURE 2

Potential outcomes of livestock-fish integration

Our study focuses on the integration of fish and livestock. The use of cultured fish or fish products as livestock feeds, although currently uncommon, holds promise and is reviewed. Other, more minor beneficial linkages between fish and livestock production include use of fish culture water for drinking/bathing livestock and cooling livestock housing. Nutrients contained in culture water and sediments may be used to produce arable crops for livestock. The viability of these options depends on a variety of factors, including the types of livestock and fish that can be raised profitably and the production systems used.

1.4 Relevance of Integrated Farming

The integration of fish and livestock production is probably closer today, and more important than ever before (FAO, 2000). On a global basis most cultured freshwater fish are produced in Asia in semi-intensive systems that depend on fertilizer nutrients. Moreover, with increasing need for multipurpose use of water resources, community water bodies used for watering livestock are increasingly stocked with fish seed and their management intensified. Several studies of smallholder aquaculture in Bangladesh, India, Thailand and Viet Nam indicate that livestock wastes are the most commonly used input. Fish yields may not be optimized for a variety of reasons but livestock wastes purposely used in ponds, or draining into them, support the production of most cultured fish in Asia.

FIGURE 3

Main and secondary linkages in livestock-fish integration (P = processing)

An analysis of China, the ancestral home of aquaculture, indicates that whilst intensive practices based on formulated pelleted feed are developing rapidly, much of the vast increase in China’s recent inland aquaculture production is linked to organic fertilization, provided by the equally dramatic growth of poultry and pig production. Trends in those parts of Asia which are undergoing rapid industrialization and urbanization suggest that livestock-fish systems can retain a relative advantage over intensive aquaculture for production of low-cost carps and tilapias. A strong link to the use of livestock wastes remains even when high-quality supplementary feeds are available and widely used.

A major issue is the potential competition for, and relative efficiency of the use of, limited amounts of feeds between livestock and farmed fish. This has both local and global implications. Supplementary feeds, such as ricebran and oil cakes, which are traditionally fed to livestock, are often in demand for feeding fish. Continued growth in demand for livestock and fish has raised alarm bells over the sustainability of feed supplies and the impacts of such growth on the environment.

1.5 Sustainability Issues at Micro- and Macro-Levels

Sustainability may be considered at global, national, regional, community and household level and from a variety of perspectives. Sustainability as defined by an ecologist, may be very different to that by an economist, but most can support the essence of that in the Brundtland Report (WCED, 1987) which incorporates social and economic as well as environmental concerns. Important questions relate to the role of integration of aquaculture with livestock to improve sustainability of food production in socially and economically advantageous ways while safeguarding or improving the environment. For this to occur, the roles of culture and institutions both have to be considered also since they are major forces for change or conservatism. A major issue of this book is how integration, rather than specialization and separation, of livestock and fish production can enhance sustainability at all levels and perspectives.

1.5.1 MICRO-LEVEL

The interpretation and measurement of sustainability have become focal points of rural development. In a smallholder farmer’s world, key parameters of sustainability have been identified as high levels of species diversity, nutrient cycling, capacity (total production) and economic efficiency (Lightfoot et al., 1993; Bimbao et al., 1995; Dalsgaard et al., 1995). At the micro-level, watershed, community, farm, plot and pond may be used as a basis for assessing sustainability, but the role of people is central to development.

Most poor rural people do not rely entirely on their own land to sustain them. Typical livelihoods are complex and depend on a variety of resources, many of which are off-farm (Ellis, 1992). At the heart of the issue of ‘sustainability’ are peoples’ livelihoods (Box 1.C). Holistic thinking is required to analyse and describe livelihoods with a focus on peoples’ relative strengths rather than ‘needs’. Building up assets is a core component of empowerment (Figure 4). How the inclusion of intensified management of aquatic resources can support, or detract, from this process is indicated in Table 1.1.

People base their livelihoods on a range of assets in addition to financial capital that include natural, human, physical and social capital. A pentagon can represent these five types of asset or capital although in practice there is overlap between them (Figure 4). Understanding trends in peoples’ assets over time can indicate if positive or negative developments are occurring, and if livelihoods are deteriorating or improving. The approach can be applied on a community, group or household level to inform and guide the development process. Knowing about the assets of different wealth and social groups in the same community can allow better targeting of poorer people and monitoring of changes that occur. The impacts of shocks of various types, and how assets are used to reduce vulnerability, are important aspects of assessing livelihoods.

Forging links between ecosystem theory and farming system analysis (Dalsgaard et al., 1995) can be useful, provided that the results are placed within a broader framework of sustainability issues. A range of different system attributes has been identified that provides measures of how livestock and fish can improve sustainability of farming systems (Table 1.2). As sub-systems within the wider farming system (Edwards et al., 1988), fish culture and livestock can improve nutrient recycling and concentration. This feature is important in both nutrient-rich, peri-urban systems and nutrient-poor, rural situations (Little and Edwards, 1999). Diversity, stability and capacity can all be enhanced through inclusion of livestock and fish on farms, as can both economic efficiency and the scope for future change or ‘evolvability’.

The greater ecological similarity of low external input than intensive systems to natural ecosystems reduces adverse environmental impacts (Kautsky et al., 1997). But very low input systems, especially in nutrient-poor environments, may not adequately support livelihoods, driving poor people to ever more extractive and unsustainable practices off-farm. Small external nutrient injections may enhance performance or help to regenerate degraded agro-ecosystems (Kessler and Moolhuijzen, 1994). The productivity and stability of farming systems in Machakos, Kenya, improved considerably as incomes from off-farm employment were reinvested in agro-forestry, livestock and horticulture. Intensification of livestock and soil management have also reduced land degradation in heavily populated parts of Uganda (Lindblade et al., 1998). Integration of livestock and fish at a community or watershed level may have more potential than household-level in some situations.

FIGURE 4

Asset pentagon to analyse sustainable rural livelihoods

Source: Carney (1998)

TABLE 1.1

How the integration of fish culture into small-holder crop/livestock systems affects asset accumulation and livelihoods

Framework for role of capital assets in sustainable livelihoods adapted from Scoones (1998) and Carney (1998)

TABLE 1.2

How livestock and fish improve the sustainability of farming systems

1.5.2 MACRO-LEVEL

Sustainability viewed at a macro-level may include global, national, regional and watershed contexts. The expected dramatic increases in global trade following recent WTO agreements are expected to have wide ranging impacts on the nature of food production and viability of farming systems. Agribusiness is positive about the effects such measures will have on sustainability of food product (Box 1.D) but other groups fear a rapid undermining of poorer national economies and marginalization of small-holders with little market leverage.

Global trends in resource use for livestock and fish production, trade and consumption are important for understanding constraints at the farm, or even plot or pond level. One example of how macro and micro-level sustainability issues can interact, and be affected by institutions, is the changing basis of pig and fish production in the Red River Delta of Northern Viet Nam (Box 1.E).

Pig and poultry production using modern systems have been challenged as unsustainable in the long term on a global basis because of dependence on concentrates, which are based on non-renewable, fossil-fuels (Preston, 1990). Examples exist where modern systems, following ‘shocks’, have collapsed. These include oil exporting countries where oil price decline, and associated revenues made imported concentrates and poultry production uneconomic. Cuba saw major disruption in its imported, concentrate-based livestock industry as Soviet Union support was withdrawn and favourable terms of trade shifted. Even if concentrate feeds can be used economically, and the wastes productively reused for aquaculture, there may be inequities in the system that prove unsustainable in the longer term. Thus, an analysis of current systems using sustainability indicators can lead to the development of relevant research agendas. Given its complexity, some advocate the use of consensus indicators of sustainability in aquaculture production (Caffey and Kazmierczak, 1998).

The need for alternatives to the narrow range of feed ingredients used in most concentrates has been identified as urgent, especially for the tropics where little research has been conducted so far (Preston, 1990). In China, the substitution of semi-intensive aquaculture integrated within farming systems by intensive, feedlot production has been advocated on the grounds of improved productivity and reduced negative environmental impacts (Box 1.F). The analysis, though flawed, does identify a general tendency towards intensification of aquaculture. This may have particularly large impacts since intensive aquaculture is relatively more profligate than livestock in its use of feed resources and is more polluting. The major species raised intensively (salmonids and shrimp) are fed diets high in fishmeal (Naylor et al., 1999) and often have large impacts on the local environment. Potentially the intensification of semi-intensive culture of carps an tilapias will have even greater impacts on the environment through raising demand for such feeds (Naylor et al., 1999).

Difficulties in maintaining feeds or disposing of wastes will probably be only part of the problem of sustaining intensive livestock and fish systems on a macro-level scale. Control of pathogens may prove a more important constraint and pose greater threats to human populations (see 6.1.4). Densities of pigs exceed 9 000 animals km-2 in parts of Western Europe as economies of scale and demand for cheap pork favour intensified production close to concentrated markets. The cost of disease epidemics such as classical swine fever, and the difficulties in their control at such levels of density, are prompting a rethink and new legislation (MacKenzie, 1998). Similar experiences are occurring with intensively raised fish such as the Atlantic salmon and black tiger shrimp. Control of pathogens through isolation is particularly problematic because of the need for water exchange in intensive systems.

High input, export driven agriculture (agronomy, animal husbandry and aquaculture) is more likely to be non-diverse (monoculture), highly extractive and polluting (little recycling) and unstable in the face of environmental change. Moreover, its economic efficiency can be drastically affected by the vagaries of global markets. Smaller livestock units spread more evenly, based on local production of feeds and disposal of wastes, are likely to improve the sustainability of the livestock and associated farming systems.

Intensification is important, however, to ensure that smaller scale systems are economically viable and sustainable. Improvements in productivity at the local level have also been shown to be important globally. Low productive ruminants have been implicated in the increase in greenhouse gases, which could undermine sustained food production worldwide (see 4.2.1).