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Chapter 5: Beyond production systems

Concentrate feed production
Environmental challenges
Domestic animal diversity
Livestock and greenhouse gases
Processing of livestock products

The environmental impact of livestock

THIS CHAPTER assesses the environmental impact of those inputs and outputs of livestock production and processing, which affect the natural resource base beyond the confines of a particular production system. They are the effects of:

• concentrate feed production (which is used about equally by mixed and industrial farming systems) on global land and water quality;

• intensification of all types of animal production systems on domestic animal biodiversity;

• livestock production on air quality and global warming through the emission of greenhouse gases from all systems; and

• effluent from livestock processing on soil and water quality.

Concentrate feed production

For thirty years livestock production and productivity have grown by feeding ever greater amounts of high quality feed. This feed connection has been one of the most debated livestock-environment interactions, because it involves ethical issues of competition of human and animals for food, efficiency and food security. It is also the subject of generalizations based on ill-founded assumptions and might well have a positive effect on global food security (Box 5.1).

Box 5.1 Grain and animal production: the competition and efficiency arguments.

LIVESTOCK ARE often blamed as efficient user of feed- and energy. And indeed, in some systems and especially in some phases of the production (eg. the last phase in a beef feedlot) energy and nitrogen conversion is poor. However, it efficiency seen over the entire production chain. and expressed as input of edible human food/output in human edible food, the picture changes, as shown for example by the following estimates from California.

On a global scale, the picture is not much If it is assumed that all 966 million ton cereals, roots and tubers used for livestock are edible for humans fin effect they are not, as there are considerable preparation losses in milling etch then livestock gets 74 million ton edible protein. On the positive side, the 99 million ton meat' 532 million ton milk and 53 million ton eggs produced globally in 1996 contain 53 million ton protein. So while input is higher than output, If cereal preparation losses on the input side and improved protein quality on the output side is considered, a reasonable balance emerges.

A recent FAO study (1996) shows that the increasing use of feed grains has not had an adverse effect on the provision of cereals for human consumption. on times of food shortages such as in 1974/75, rapid adjustments are made In particular in feed use and food consumption of cereals remained largely unaffected. Indeed, many argue that the use of cereals for feed acts as a global buffer and therefore has a positive effect on global food security.















Source: Baldwin et al., 1992 and FAO, 1996.

Pigs, poultry and intensive dairy and feedlot animals require diets with a high concentration of energy and protein. This is provided by concentrate feed. Concentrate feed is tradable, allowing farmers to separate decisions on feed production and use; and trading these concentrates means that their environmental impact is also traded. Worldwide, trading grain involves a massive transfer of nutrients, depleting production resources, and fertilizing and often polluting the location of final use (Box 4.2).

Environmental challenges

Driving forces
Response: Technology and policy options

Concentrate feed production has an impact upon the natural resource base at various stages of crop production, trade and processing. There are direct effects of cropping on soils, water and air; and indirect effects of the production and supply of inputs to agriculture such as machinery, fuels, fertilizers and pesticides. Crop production also has indirect effects on land use, particularly with regard to deforestation, change of habitats, biodiversity and the aesthetic aspects of the landscape. The challenge therefore is two-fold: first to reduce the environmental impact of the production of crops used for feeds; and second to optimize the use of concentrates so as to limit feed use and corresponding land requirements.


Roughly 21 percent of the 1.4 billion hectares of cropland used globally for cereal production is used for livestock feed production and an additional 10 percent is used to produce oilseeds (primarily grown for oil, the by-product being fed to livestock) and roots and tubers. For the rest, livestock feed is a by-product of agro-processing. For example, cottonseed meal is a high protein livestock feed, but is a by-product of cotton production and is not produced with the primary purpose of feed. Livestock use of the cotton seed may be simply an additional incentive to farmers to grow cotton.

Figure 5.1: Global total utilization of concentrate feed resources ('000 MT per year).

Cereals are a major component of livestock concentrate feed. Of the average global cereal production of 1,854 million tons in the period 19901992, 600 million tons (32 percent) was used for livestock feed; an additional 144 million tons comes from oilseeds and roots and tubers. Another 252 million tons are processing by-products (brans and oilcakes) for which there is little alternative use.

The environmental impacts of crop production are site-specific, depending on a whole range of natural and socio-economic conditions and technologies. Some specific characteristics of feed concentrate production are:

• Feed is generally produced in more intensive systems in agro-ecological zones of high potential than in erosion-prone marginal areas. This is shown by the fact that the 32 percent of the cereals used for feed is produced on only 21 percent of the total cereal cropland. In the high potential areas, feed can be produced at low costs, while the costs associated with the risks of producing crops under marginal conditions are usually prohibitive. This is reflected in the low grain to meat price ratios that prevail in, for example, the Sahelian countries; and

• Feed use most commonly represents the lowest opportunity cost, and it would therefore be incorrect to charge the full environmental cost to feed, because in many cases this was not the primary use of the produced commodity. Typically, feed concentrates are real surpluses, and feed production takes place in high potential areas.

By the mid 1980s concentrates accounted for about a quarter of all feeds for livestock; this proportion was growing at about 0.2 percent points annually. Concentrate feeds comprise about 40 percent of all feeds in the developed countries and 12 percent in the developing world.

Trends in global utilization of concentrate feeds

Figure 5.2 and Table 9 Annex 2 show concentrate feed use for different systems, world regions and species. Land-based production systems used more concentrate feeds than industrial production systems. The industrial systems combined consume 500 million tons or 44 percent of total feed concentrates; industrial pig and poultry systems are the largest single users accounting for almost one-third of the total.

Figure 5.2: Concentrate fees use.

North America, eastern Europe and CIS, and eastern Asia each consumed over 20 percent of the world's total concentrate feeds, and western Europe used an additional 16 percent. Africa and Latin America still have very low levels of consumption. Starting in the late eighties, growth in global consumption flattened due to recession and market saturation in the OECD countries and structural adjustments in the former centrally planned economies. The main growth, however, has occurred in China and in South East Asia and these will remain the main determinant for future growth (Box 5.3).

Driving forces

Increasing human populations, growing income and accelerated urbanization in the developing world are the prime driving forces for the rising demand for animal products and, hence, for concentrate feed production. Growing demand for concentrate feed leads to area expansion and intensification, and thus potentially exerts a wide range of pressures on the environment. Area expansion is the least important with 0.1 percent annually compared with growth in crop production of 1.9 percent per year (Alexandratos, 1996).

The small increase in the area of cropland is at the expense of other forms of land use, mainly grazing and forests. This, in turn, places potentially greater pressures on that land, with subsequent threats to habitats and biodiversity. The extent of this pressure needs to be put in the context of overall land use. In developing countries, land with potential for cropping, including marginal areas, represents some 40 percent of their total unused land surface, mainly in the humid and sub-humid zones of Africa and Latin America. Of this unused land, it is estimated that in the year 2010 less than one-third will have been brought under cultivation (Alexandratos, 1996). Thus, while changes in land use may look significant in some countries or locations, their extent will be limited at the overall level. The exception is deforestation where cropland development accounts for up to 60 percent of the annual deforestation rate, as shown in Chapter 2. But recently there has been little net change in the area of grazing land in developing countries as a whole (WRI, 1994), although the conversion of grazing to crop land has been a significant component of increased pressures on grazing livestock in, for example, the dryland areas of India and Africa.

Table 5.1: Environmental pressures and components of the environment affected by feed concentrates demand.

Sources of environmental pressures

Impact on environmental components



Demand for concentrate feeds

Land use

Habitats and biodiversity

1. Human population.

1. Expansion of crop area.

1. Loss of habitat diversity.

2. Incomes and demand for livestock products

2. Forest and grazing land loss.

2. Increased pressure on natural and crop and livestock species diversity although some reduction of pressure on fragile ecosystems.

3. Livestock production using concentrate feeds.

3. Use of marginal croplands.

Water use

1. Use of irrigated croplands for feed crops.

Landscape and amenity

Production of concentrate feeds

1. Loss of landscape diversity and countryside amenity value.

1. On-farm production of concentrate feed

2. Irrigation water utilization (rates, husbandry and drainage systems).

2. Export and import of concentrate feeds.

Air pollution

Fossil fuel use

3. Competition for food or feed uses.

1. Greenhouse gas emissions (CO2)

1 Increased mechanization (risks of soil damage, effects of energy use).

Cropping systems and intensity

-from forest clearance.

1. Cropping systems (crops and rotations).

-from soil organic maker loss.

Soil condition

-from energy consumption.

1. Erosion and downstream impacts of crop area expansion.

2. Cropping frequency.

2. Salinization of irrigated areas.

3. Husbandry practices (soil conservation, manuring etch.

3. Decreasing fertility status (phi, N,P,K, micro-nutrients, organic matter).

Crop input utilization

4 Losses in physical status (water holding capacity, bulk density, compaction).

1. Fertilizer and pesticide use*

Water resources

2. Mechanization.

1. Reduction in availability of irrigation water.

3. Transport and trade.

2. Aquifer resources depletion.

Water quality

1. Contamination of water run-off and drainages with

N. P and pesticides

2. Eutrophication of aquatic life in water bodies.

3. Drinking water quality.

Source: compiled from Hendy et al., 1995.

Table 5.1 summarises the direct and indirect pressures on arable land and their effect on various components of the environment. First, all cultivation results in soil loss and invariably depletes soil nutrients and organic matter. Excessive soil losses result in land degradation and, off-farm, in siltation, reduced water holding and contamination of water supplies. Soil erosion and salinization in irrigated areas causes a loss of 6-7 million hectares per year or 0.5 percent of the global cultivated area (El Swaifi, 1991). On a pro rata basis, concentrate feed production would thus be responsible for the degradation of about 1 million hectares per year.

Second, increased crop production impacts upon the availability and quality of water. Irrigated areas are likely to grow by 23 million hectares or by 19 percent in net terms by 2010 (Alexandratos, 1996) although at a declining rate as increasing water scarcity constrains development. Asia currently uses about 54 percent of its stable water supplies while SSA uses less than 5 percent. Low recharge rates in many areas, such as in Central Asia (Aral Sea), western USA and parts of WANA show that irrigation is often not sustainable. The amount of water used for livestock production is, however, relatively minor. For example, Jordan uses about 8 percent of its usable water for feed and drinking water. Depletion of water resources affects surrounding and downstream habitats. Inappropriate management of irrigation has led to waterlogging and salinization. Suarez (1992) estimated that up to 50 percent of the global irrigated area may be affected to some extent. Water quality is also affected by pesticide residues.

Third, increased crop production also entails a decline in biodiversity through habitat loss and alteration in land use, combined with the specific effects of crop production, such as pesticide use and some tillage practices. Intensive cropping practices can also lead to reduction in genetic diversity in the crops grown, for example through the loss of traditional varieties.

Fourth, concentrate feed production requires nonrenewable resources, such as fossil fuels. Its use varies widely, but can be substantial. In crop production, energy is consumed directly for all field crop operations, threshing, transport, irrigation and others, as well as indirectly to produce inputs such as machinery, fertilizers and pesticides. Energy consumption is generally higher per hectare of cropland in developed than in developing countries, because fertilizer and mechanization levels are greater. They require between 40 to 60 percent and 30 to 40 percent of total requirements, respectively.

Table 5.1 summarises the potential positive and negative impacts of changes in land use, cropped areas, cropping intensity and yields. The occurrence and effects of these impacts vary between locations. Negative impacts are not always important, depending on the management of crop production and soils.

Different crops exert different pressures on the environment. Crops differ in the degree of depletion of soil moisture and water resources, in their relative demands on soil nutrients and in their pesticide needs. In general, cereal crops, and in particular maize, cause greater environmental damage than other crops, because of heavy fertilizer and pesticide use, high water demand and poor ground-cover in the early stages of plant development. On the contrary, potential impacts are lowest for legume crops, such as soybeans and pulses. Environmental risks due to nitrate and phosphate losses are greatest from maize and wheat, while risks of soil nutrient depletion are greatest in cassava and sweet potato (Table 5.2).

Table 5.2: Relative contribution to sources of environmental impacts on soils and water of different crops providing livestock feed.

Relative magnitude of impacts of crops on different components of the environment


Erosion (risk and contribution)

Nutrient loss (leaching and run-off depletion)

Water use (soil moisture fertility status)

Nutrient demand (impact on soil

Pesticide use (impacts on biodiver biodiversity and pollution)











































Sweet potato






*, ** and *** indicating low, moderate or high potential impact.

Source: Hendy et al., 1995.

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