1.1 Introduction

In this booklet animal husbandry will be used as a common designation for the keeping of animals to produce meat, milk, fibre (wool), hides (skin/leather), draught power, fertilizers, etc. Pets and game are not included.

Conditions for animal husbandry differ a great deal between continents. There may also be great variation between countries within the same continent or region. East Asia and Southeast Asia, for example, characteristically have limited areas in relation to the size of their populations. Most of the land, therefore, will have to be used to produce food crops for human consumption. Livestock in such areas often have to feed on crop remains, by-products or whatever is available by the roadside, etc. In large parts of the rest of the world - eg. Africa, America, Australia - the size of the areas as such is rarely the chief limiting factor. In addition to food production, part of the soil can be used for feed production. Nevertheless, Asia has the largest number of livestock in the world. The table below shows that the number of livestock in developing countries have increased over the last 10 years, whereas the trend in developed countries is a decrease regarding most animal species. The amount of domestic animals is often reckoned in terms of livestock units according to a conversion factor. In most countries, one livestock unit is equivalent to 500 kg live weight, but the conversion factor may vary from country to country. The total number of livestock units in the world are approximately 1.6 billion, most of which are grazers kept in developing countries. Even though the greatest number of livestock are found in developing countries, the consumption of livestock products per capita is often low in these countries. This is partly due to the low production of the animals, and partly to the size of the human populations. In terms of nutrition, livestock products are valuable. Most people will experience an increased standard of living if the consumption of livestock products increases.

The world's population (in millions) of grass-eating and grain-eating livestock.

The oldest forms of animal husbandry were based on a controlled grazing of partly wild animals. These animals were gradually domesticated. Societies developed in which humans and animals lived in a close interdependent relationship. All over the world, breeds developed being adapted to the shifting conditions for animal husbandry, ea. domesticated breeds with a capacity for depositing fat in the body in plentiful times, so as to provide nourishment during periods when feed is scarce (zebu, fat-tailed sheep, pig). In developing countries, a clear trend during the last hundred years has been to import and crossbreed with more exotic breeds selected for the sake of higher yield. The experiences of transferring new genetic material have been both positive and negative (see chapter 3). Another trend has been an intensified livestock production. Generally speaking, this involves more animals per land unit. Moreover, production systems for meat, eggs, etc. have been developed, the aim of which is to produce as many animal products as possible in the shortest time possible within a minimum area. Intensive production systems are highly efficient. They make it possible to produce livestock products at a price that is acceptable to large groups of people. More extensive forms of animal husbandry, however, are still relevant in connection with projects. Environmental impacts of animal husbandry in developing countries are often focused. And the reasons for the environmental impacts can be complex, involving ecological, social and cultural factors.

1.2 Project categories

Projects and activities within animal husbandry can generally be placed in one or more of the following categories:

· Production of livestock products such as milk, meat, eggs, fibre and furs, as well as draught.
· Initiatives within:
- nutrition and feeding,
- health and veterinary medicine,
- breeding and genetics,
- conservation and management, and
- biogas.
· Technical, professional and financial strengthening of institutions and authorities in order to ensure long-term functioning of animal husbandry activities.
· Assistance in connection with legislation, development of strategies, training and research.

Animal husbandry can also be made an integral part of other agricultural activities, aquaculture and integrated rural development programmes. Establishment of a major livestock project may generate a series of related activities, ea. enterprises providing contributory products such as feed, additives, chemicals and drugs, as well as veterinary services and artificial insemination.

Many industrial and business enterprises may be based on animal husbandry, ea. dairies, slaughterhouses, tanneries, spinneries, preservation factories, etc. These are often prerequisites for an adequate processing and marketing of livestock products. In addition, animal husbandry and related activities, as well as the products yielded by these, may create a need for special transport measures (cf. initial environmental assessment booklets 8 Transport and 9 Industry and energy).

In many developing countries, little has yet been done concerning conservation of genetic material of local livestock. This is likely to be an important task in the near future. Sperm and embryos can be frozen and stored to ensure that valuable genetic material does not disappear for good (gene bank).

This booklet will cover most aspects of animal husbandry. The focus, however, will be on small and medium sized projects and activities practicing extensive and semi-intensive/intensive modes of production based on grazing (cf. chapter 1.3).

1.3 Choice of technology, animal species an breed

1.3.1 Technology

The mentioned division into types of projects is a general one. In general, projects and activities are also designated according to the types of animals in question, and/or the modes of production. The line of animals that are domesticated is long. In developing countries, the following are common: cattle, buffalo, camel, sheep, goat, llama, pig, horse, donkey, poultry (ducks, hens), mink and bees. In rarer cases, more exotic animals are also used, ea. iguana, crocodile, etc. Development projects can vary in size from market-oriented ranches to traditional grazing-based farms and combined farms (livestock combined with agriculture and forestry/agroforestry) on a domestic level. Production can vary from extensive to intensive. Intensive production utilizes feed that has been either harvested from nature or cultivated. The animals are either grazed in paddock, or stallfed. Extensive production modes apply to grazers that are allowed to range freely.

The main conditions for a successful livestock production are: sufficient feed, healthy animals and good breeders. In developing countries, the challenges in these areas tend to be greater than in ea. Europe. In Europe and North America, overproduction can be a problem in animal husbandry, involving a large input of energy, chemicals, etc. Reduced yields are acceptable, and attempts are being made to reduce environmental impacts. In developing countries suffering from scarcity of food, there is often a widespread wish to adopt technology that will maximize the food production. What primarily prevents such a development is lack of capital. A dilemma can arise when considering whether to introduce technology that will produce more food, but will at the same time also cause environmental harm.

Grazing is generally the least cost and labour demanding way of feeding livestock. Yet it is not always the simplest and most profitable. Variable access to grazing land and water can create problems for the production. Precipitation may be seasonal, and there may be great annual differences. Some places may have droughts lasting year after year, causing loss of animals. Browsers, ea. goats and camels, however, may be less affected by fluctuations in food supply, because shrubs and trees tolerate droughts better than grass. Among nomads, pastoralism chiefly involves herding as well as finding the way to the best grazing land available. In addition, it is vital that the animals have regular access to water. The distance to the water sources, therefore, should not be too great. Selection of breeders, castration, milking, blood tapping (the Masai) and slaughtering are important activities among nomads. Most nomads put their animals into fenced enclosures (boma, crawl) at night in order to protect them against predators. Some give their animals a mineral supply, but regular feeding is seldom practiced.

More intensive grazing systems may involve various measures to increase the yield of the grazers. Fenced enclosures are expensive, but can be necessary in order to control the animals and to prevent other livestock from intruding into the pastures. If no natural shades exist, it may be necessary to build simple sheds or roofs for protecting the animals against direct sunlight. Parasites may disturb livestock production in some tropical areas and chemicals are often used to protect the animals. One method is to apply chemicals by spraying, or by letting the animals walk through a bath with chemicals added to it (cattle dip). In connection with intensive pastoralism, the animals are commonly given a feed supply, especially in periods when pasture is scarce. The grazing are usually limited, and a careful adjustment of the number of animals will be necessary if the feed available is to ensure a satisfactory growth of the animals. Removal of shrubs, fertilization, use of high-yielding grasses and legumes, and rotation grazing are also common cultivation measures in connection with intensive grazing systems.

Animal husbandry near densely populated and urban areas tends to differ from animal husbandry in more peripheral and remote areas. Easier access to the markets is important for the sale of livestock products, among other things because products such as milk, butter and cheese have limited keeping quality. Fresh products may be a prerequisite of a high price. Another advantage is reduced transportation costs. This does not just apply to transportation of products to the markets, but also transportation of any equipment back to the farm. The infrastructure may be better, as may the availability of know-how and extension services. Higher prices on the products will enable the farmers to employ equipment and technology that would otherwise lack an economic basis. The possibilities of utilizing by-products from food industries and other industries are better. In some places, the advantages of keeping livestock near densely populated and urban areas have led to large concentrations of livestock in fairly small areas. The sale of eggs, in this connection, is a special case. Eggs have a better keeping quality than some other livestock products; at the same time, they are fragile and must be packed and transported carefully. The distribution of eggs often takes place locally, direct to the consumer or retailer, without passing through processing plants or other intermediary links. Egg production, moreover, is the type of livestock production in which most people in developing countries are engaged. Even in big cities, many people keep hens in their back yard for producing their own eggs.

Animal husbandry as an integral part of a mixed agriculture has been common in many countries from of old. Products such as traction, high-grade protein and fertilizers have been in great demand in agricultural societies. Some forms of agroforestry (cf. booklet 3 Forestry) also comprise livestock. Such combined farms often constitute ecologically well-adapted forms of production. In addition to the value of the manure, it can also be valuable to include grasses or legumes in a mixed system of crops. If the areas are so small that they must be reserved for food production, the livestock will have to live on by-products such as straw. This is the case in large parts of Asia. The low feed value of straw leads to a low production of meat and milk. Recently, methods for improving the nutritional value of such rough-ages have been developed. A relevant method is ammonia treatment by means of urea, which at the same time is an important nutrient for ruminants. In some areas in developing countries, stall feeding of livestock is common all year round. This applies to ea. the mountain sides of Kilimanjaro and Mt. Kenya in Africa and other high-altitude areas where agriculture and horticulture are particularly intensive. Many who lack sufficient feed for their animals gather it from common land, often on the lower levels, and bring it to their animals daily. This form of farming is generally called "cut and carry". In this way, the yield of the animals and the amount of manure are increased, which is crucial for the global crop production. Animal husbandry can also be combined with aquaculture (cf. booklet 5 Aquaculture). Poultry droppings, for example, can fertilize aquaculture ponds, either by means of poultry swimming on the water or by the fertilizer being carried to the pond to be dropped. The result will be increased growth of weeds and aquatic plants providing feed to fish.

Livestock manure is a valuable product that is high in nutrients such as nitrogen (N), potassium (K) and phosphorus (P). Use of livestock manure can play an essential role in a sustainable agriculture aimed at the highest possible degree of nutrient recycling. In addition to fertilizing food plants and other useful plants, the livestock manure can be utilized as fuel, in which case the nitrogen is lost while the potassium and phosphorus remain in the ashes. If the manure is handled inadequately, however, most of the nitrogen may evaporate as ammonia, whereas good handling will produce plant nutrients that may minimize the need to buy chemical fertilizers. Only a minor part of the nitrogen in the feed will be absorbed in the animal eating the feed. Most of the nitrogen from the feed, as well as liberated nitrogen from the basal metabolism, is therefore left in the manure and urine.

Use of biogas from manure is gradually gaining entry into various developing countries. Production and storage of methane produced on manure can take place in simple installations. Most of the nitrogen and all the phosphorus and potassium still remain in the manure after the methane has been extracted. The fertilizer value is still high and can be used on the fields, for fertilizing fish ponds, etc. Biogas is a renewable resource which can reduce the exploitation of wood, charcoal and other fuels that may be scarce.

Land use in connection with animal husbandry varies a great deal. Nomadic pastoralism and other forms of free grazing require the largest ranges. As much as 30-50 hectares per livestock unit are needed in the most marginal grazing regions. Intensive modes of production may require large areas for the cultivation of feed. In the most fertile parts of the world, where harvesting can take place up to three times a year, only small areas are needed to provide a cow or an ox with feed. Here the amounts of crop remains and byproducts often decide which is a sustainable number of animals.

In some parts of the world where there are large pastures with little alternative usefulness, ea. in South America, North America and Australia, meat production will be a natural choice as long as it is carried out in an ecologically acceptable way. Grazing will also ensure the recycling of most of the nutrients, although the utilization of N tends to be fairly low.

Meat production based on ruminants fed with concentrates accounts for a low utilization of the energy and can therefore not be regarded as sustainable.

Management entails that potential feed and livestock resources are developed and utilized in such a way that the productivity is maintained (sustainable utilization). Livestock production depends on the feed resources available. Considering the population growth that has taken place in many developing countries, the need for arable land and areas for other purposes has increased. To a great extent, this has affected the pastures, as these are in many places considered as communal property. Development of management plans for grazing land is a challenge that requires insight into the area's topography, flora, fauna, operational conditions and, not least, ethnic, cultural, social and economic conditions. Good, detailed maps are helpful in this work.

1.3.2 Animal species and breed

Animal species: Choice of animal species as part of development projects is generally determined by natural conditions, culture and traditions in the area (cf. chapter 2). Nevertheless, domestic animals have often been introduced into certain areas in which they have previously been non-existent, with varying success. Small species such as guinea pigs, rabbits, poultry and goats are easier to introduce to farmers who are not used to animals other than, for example, cattle. Otherwise, the feed base will be decisive as to which species one should invest in. Relatively large amounts of feed or extensive grazing areas are needed to provide a milk cow with maintainance and production feed. Dairy goats can be a viable alternative. Moreover, they are easier to handle and transport, particularly in steep terrain.

Animal husbandry, especially milk production, requires a certain infrastructure with access to supplies of concentrates, drugs, veterinary services, oxen (bucks) or artificial insemination, etc. Other things needed may be a collection system and organized distribution of milk and milk products, as well as good market facilities. Milk production based on cattle, buffalo, sheep or goats is far more efficient with regard to the utilization of resources than meat production based on the same animal species. This, therefore, ought to be considered as an alternative if the farmers are willing to try. In many cases, two or three dairy goats per family can provide an important supply of animal protein to children as well as grown-ups. With regard to meat production with limited feed resources, poultry, pigs, rabbits and guinea pigs are more efficient than ruminants. Grits and domestic refuse can provide an important portion of the feed for swine and poultry. Large ruminants in tropical areas and developing countries are often fed below the maintainance requirements. The production, therefore, will be minimal, with an unreasonably large consumption of feed per unit of meat produced. Under some conditions, a combination of cattle and sheep or goats will be favourable because these three species exploit the pastures differently and supplement one another; they exploit to some extent different pasture plants. Goats, for example, utilize brush much better than the other two species. In periods of extreme drought, therefore, goats can pose a greater threat to shrubs and young trees than other species. Introduction of animals that may damage the biological diversity must be prevented (cf. chapter 3.3).

Domestic animals can be divided into two main categories: monogastrics and ruminants. The difference between these two main groups is important regarding the utilization of resources. The most typical monogastrics among domestic animals are pigs. Even if poultry is equipped with an extra craw, they are also generally regarded as monogastrics. This anatomic construction involves that these animals can only utilize easily digestible feed of a kind that can be broken down by the body's own enzymes.

Plant material that is rich in cell wall substances (cellulose, hemicellulose, lignin) is virtually indigestible by monogastrics. As to other monogastric animals (horse, donkey, rabbit), the appendix (and colon) has evolved into a fermentation compartment with a function almost equivalent to that of the rumina of ruminants. Ruminants have developed a fermentation compartment which is situated in front of the intestinal canal, in which billions of micro-organisms secrete enzymes capable of breaking down the bonds that keep cellulose and hemicellulose together. In this way, the animals are enabled to utilize the nutrients. This symbiosis between ruminants and their micro-organisms is the very foundation of livestock production based on coarse feed and plant material which could otherwise not be utilized as nutrition, neither for animals nor for humans. As ruminants can utilize the protein produced by stomach microbes, they can do without high-quality feed protein. As a prerequisite for this, however, they need to have access to simple nitrogen compounds (NPN = non-protein-nitrogen) that the microbes can utilize in their process of synthesizing protein for their own bodies. Ruminants, therefore, can be said to have good adaptability.

Breed: Questions concerning breeds can be delicate. Projects should involve surveys of which breeds of the relevant species exist in the area. One also ought to find out whether breed is an important or touchy issue. One ought to consider whether the development project can be based on local breeds, or whether it is recommendable to introduce or cross in other breeds. Any new breed must be clearly superior in order to justify the extra costs which this introduction will incur, as well as the risk of diseases which it may entail. Local breeds will generally be more resistant to diseases existing in the area than imported breeds. Nevertheless, new breeds are often introduced with the intention of making the production more efficient as well as improving the product quality. Under various conditions, this is both quicker and cheaper than improving already established local breeds. Adaptation to the local environment must be a decisive criterion when the question of introducing a new breed is considered. Introduction through crossing, however, will be less critical, because animals with 50 or 25 per cent of local genes will retain a great part of their adaptability to the local environment.

2.1 The ecology of animal husbandry

Natural conditions are largely decisive for the development of domestic animals, ea. the camel in arid areas and the water buffalo in humid areas. Occurrences of diseases are another factor influencing the spreading of animal species. These are often transmitted by insects or in some other way. In Africa, large areas are unsuited for cattle production on account of the tsetse fly which transmits sleeping sickness. Some areas can be quite inaccessible to domestic animals because of the pressure of diseases. In other areas, however, local types of cattle have evolved a certain power of resistance against micro-organisms (trypanosomes), while imported animals may be more vulnerable. In East Africa, there are cattle that are resistant to the much dreaded East Coast Fever, and also partly to the cattle plague. In spite of this, large areas of many tropical countries can be said to have preserved rich ecosystems due to the fact that cattle husbandry has been difficult or impossible, thus preventing agricultural development.

Much is still unclear concerning the origins of domestic animals. Most investigations suggest that cattle, sheep, goats and pigs originally came from Central or West Asia. The llama, which belongs to the camel family, has its origins in North or South America. Ancestors of our single and double hump camels presumably immigrated to Asia across the Bering Strait. Various breeds have gradually evolved adapting themselves to varying climatic conditions. A typical example is cattle, of which there are two main types: Bos taurus without a hump and Bos indicus (zebu) with a hump. The zebu cattle, of which there are various types, are generally better adapted to tropical climates than European cattle. The camel is, of course, especially capable of sustaining arid conditions, since it can manage without water for several days. Besides, the camel generally takes nourishment from the leaves and twigs of shrubs and trees (browse) and only to a small extent from grass, which is scarce under extremely dry conditions.

For ages, grazing has generally provided the foundation of livestock production based on ruminants. Grazing land can be divided into natural pastures and cultivated pastures. According to the quality, natural pastures can in turn be divided into different types, such as:

Rain forests usually have low productivity as pastures. In Africa, elephant grass (Pennisetum) is a common grazing plant in the rain forest, whereas Imperata species are more common in Asia. Nitrogen-fixing grazing plants are uncommon in rain forests. Such pastures, therefore, can be improved by the introduction of leguminous plants, ea. Stylosanthes.

Dry forested land are areas with less rain than in rain forests. The largest areas are found in Central and East Asia, but they also occur in West Africa, Australia and in Central and South America. Production in these areas is moderate. Forest fires can convert dry forested land into savannas.

Savannas, steppes and semi-dry thorn-bush land constitute the largest ranges, in Africa as well as in Latin America. They can be described as open grassland with some scattered trees and shrubs. The quality of these pastures can be excellent, but variations can be considerable with precipitation ranging from 500 to 1200 mm annually.

Mountain grazing generally takes place at heights between 1100 and 3000 metres above sea level. There may be great amounts of precipitation, 1000 - 5000 mm per year, and in some years there are hardly any dry periods at all. The turf is usually short, with few leguminous plants, but with different types of herbs. Many species that are common in the temperate zone also thrive here.

Cultivated pastures are pastures that have been cleared and sown with more productive (improved) grasses and/or legumes. Cultivated pastures can be divided into different types:

Permanent or perennial pastures. These consist of mixtures of perennial grass species with or without leguminous plants and herbs. Those species that manage best tend to become dominant. Occasionally, such pastures are "freshened up" by means of sowing. They are characterized by great productivity and are therefore well suited for milk cows and fattening of feeders. Except for tropical America and Oceania, there are only small areas with permanent cultivated pastures in the tropics. In humid tropical areas, possibilities of establishing permanent pastures are fairly good.

Short-term pastures or fields consist of mixtures of grass and/or leguminous plants or other fodder plants to be cultivated in rotation with food crops. They are often grazed for periods of 2 to 5 years before the land is ploughedand used for crop plants, etc. The advantage of this system is that it improves the structure as well as the fertility of the soil.

Temporary or annual pastures are used in connection with the most intensive forms of grazing systems. This often includes pure stands of grasses, legumes or other fodder plants. Such pastures are characterized by large yields at a relatively high cost as compared with perennial pastures.

While grazing, especially two factors are decisive as to how much feed is available for the animals. One is the plant growth which to a great extent depends on the cover of plants, the nutritive state of the soil and precipitation. The other is the stocking rate (animal density). In many areas where the range is communal property, the users have tended to keep more animals than the pasture could sustain. As a consequence, the pastures have often suffered depletion, the result being little or no production (cf. paragraph 3.2).

Shrubs and trees as feed (browse) have recently become more widespread. This generally involves nitrogen-fixing plants with leafage that is especially rich in protein. They can therefore be used as a protein supplement to other kinds of feed which is low in protein. Deep roots make such plants keep green into the period of drought. Numerous such plants exist, but Leucacna leucocephala and Gliricidia septum are among the most common. These plants can either be grazed directly or harvested (stripped) manually and given to the animals. The latter will particularly be the case wherever the shrubs and trees are tall, or if the animals are kept in stalls (zero grazing) or in feedlots. A disadvantage of these plants is that some of them may be poisonous if large amounts are used as feed. The leafage can also be dried and used as a protein supplement for monogastrics.

2.2 Socio-cultural conditions

Traditions that have evolved over a long time under specific natural conditions often play a part in animal husbandry. This applies to societies that base most of their survival on livestock (nomads) as well as societies in which livestock are an integral part of a more complex agriculture. To nomad societies, such as the Bedouin, the Turkana and the Masai, domestic animals represent not only a source of food and income, but also security, bank, status, etc. The number of animals may in some cases be more important than the amount they produce. The supply of feed and water decides when and where the nomads must move. In later years, more and more nomads have chosen to settle down. In order to utilize pasture resources in areas where drinking water is scarce, both animals and water are sometimes transported by lorries. Droughts and desertification, or bush overgrowth, in areas where pastoralism is practiced may signal that the balance between humans, livestock and environment is about to collapse. The reasons may be population growth or structural changes in the society. As a consequence, the production system of the nomads may not be sustainable in terms of the natural resource base.

In settled cultures, the element of domestic animals varies a great deal. The diets of some have traditionally included very little food of animal origin. In many population groups, the ability of adults to digest lactose has disappeared. This is due to the fact that the process of synthesizing the enzyme lactase, which is necessary for breaking down lactose, may cease after infancy. The ability to digest meat, eggs and fish, however, is not affected by this. Nevertheless, the possibilities of producing feed may be so small that livestock production is in reality out of the question. The intake of animal protein thereby becomes marginal. FAO recommends a daily intake of 20 gram per person. In many developing countries, large population groups are far below this limit.

Traditions, religions, taboos and other socio-cultural conditions may influence which types of domestic animals are found or not found in an area. In keeping with Islam, one should not eat pork, which leads to a low consumption of pork in the Arabic world and other Muslim countries. Another example applies to parts of India where cows are considered as holy, and can therefore be milked but not slaughtered.
In large parts of the world, women have a central role in food production. This especially concerns food for sustenance. The womens' burden of work can be considerable in such societies. In addition to domestic chores, they may also have to cultivate the soil, tend the animals, procure feed and water, etc. In many African societies, milking and the making of milk products are exclusively the domain of women. Sales of various livestock products can often make livestock an important source of income to women. At the same time, this may keep the supply of nutrition to the whole family at a satisfactory level.

Pastures are in many places communal property and can, for example, be owned collectively by a village. Such a situation may have the effect that everybody tries to get as much as possible out of the common land. This may lead to such a high density of animals that little feed is left for them. The growth may virtually stop. Attempts to reduce the number of animals may fail because the leaders of the village tend to be the biggest keepers of animals on the common pasture. Division of common land into individually owned areas can be complicated and time-consuming.

2.3 Institutional conditions

In many countries, institutions involved in animal husbandry may either be weakly developed or lack resources. This applies to institutions for research and teaching as well as ministries. In most developing countries, animal husbandry comes under the ministry for agriculture, in rarer cases under a separate ministry. Important tasks that require government interference are, for example, regulation of animal density with regard to the pasture resources available, relationships to game and national parks, combating of troublesome livestock diseases, quality-based systems for price grading of livestock products, distribution channels for livestock products, food control, control of the use of chemical pesticides, etc.

In some countries, cooperatives take care of functions that are vital to livestock keepers. Some important international research centres involved with issues concerning animal husbandry are ILCA, ILRAD, ITC, ICARDA and ICLARM (see Glossary at page 23). These institutions have also had problems due to lack of resources.

(introduction...)

In this survey, both direct and indirect environmental impacts are dealt with. It is often difficult to distinguish clearly between these two types of impacts. Causes of direct environmental impacts can be linked to certain features of the project as such. Indirect environmental impacts can result from other types of activities and processes which the project generates, ea. industrialization and urbanization. Indirect environmental impacts can also occur if the project alters socio-cultural conditions in the local community, ea. by migration or changed power structures.

This survey also presents recommendations for mitigative measures that can reduce prospective environmental impacts.

3.1 Overgrazing and soil erosion

Overgrazing is a widespread problem in many developing countries. The most serious impact is reduced feed supply, so that the growth and production of the animals are hindered. In areas where pastures are the communal property of a village or district, the risk of overgrazing is particularly great. A reform or new legislation can be required in order to make the utilization of communal land more efficient. A fee per grazer could be introduced, for example, as well as a quality grading system for meat. Should mitigative measures of this kind be called for, one also has to make assessments of socio-cultural conditions and consequences for, and of, these (cf. chapter 3.7). Land tenure (see also chapter 2).

Impacts of overgrazing can be illustrated by an example in which 100 hectares of good pasture caters for 40 -100 cattle. 1 hectare is presupposed to yield 5.0 tons of grass and the maintenance requirement per animal is 24.6 MJ.

Impacts of overgrazing

This simple table shows that by an increase of the number of animals by 50 per cent from 40 to 60, most of the growth is lost. By doubling the number of animals from 40 to 80, nothing is left for growth and production. The animals lose weight instead of putting on weight. Research shows that cattle, goats and sheep graze on different plants and that the yield can be increased by letting different animal species graze together on the same land. In pastures under stress, only plant species that tolerate intense grazing will remain. Should there be a lack of feed, it is particularly important to adjust the number of animals according to the sustainability of the range. Since the plant production is dependent on the climate, however, this can be difficult. Should, for example, the expected precipitation fail to come, an unforeseen scarcity of feed may result. An emergency solution could be to move the animals to another area containing more feed, or transport feed to the animals. In areas with unstable precipitation, it may be necessary to take precautions by ensuring feed reserves in some way, ea. by means of standing hay or preserved feed.

Overgrazing and animal tracks can cause soil erosion, especially in steep terrain or in areas with much vulnerable vegetation and great seasonal differences in precipitation. Nevertheless, the risk of soil erosion in connection with grazing, especially extensive forms, seems to be generally less than previously assumed. Perennial plants in fields or pastures provide better protection against erosion than field plants that only partially cover the soil, and only in certain periods of the year. A measure for protecting exposed areas could be periodical or protracted enclosures. In some places, ea. in Tanzania, enclosure of pastures is practiced in order to keep them in reserve for periods of crisis.

Increased surface run-off will occur together with increased soil erosion, because the soil's capacity to retain water is dependent on the plant cover. This will lead to a reduced feeding of ground-water, and a reduced water flow in streams and rivers, so that erosion problems may also emerge here. A problem related to erosion is silting. Eroded matter being carried with the water in streams and rivers may cause a reduction in water quality and unwanted deposits and sediments in other parts of the watercourse. The supply of nutrients may exceed the natural level and thus contribute to eutrophication and overgrowing of water sources, so that breeding areas for fish may be damaged. Eroded matter which is retained in artificial reservoirs will be sedimented there. It will thereby reduce the longevity of the reservoir as well as the production capacity of any prospective power plant. Erosion, sediment transportation and depositing are complex processes, and the impacts of encroachments (ea. pastures) can be hard to predict. A precautionary attitude, therefore, is important in the planning and implementation of projects. (More about soil erosion, see booklet 7 Water supply).

3.2 Pollution of air, soil and water

Manure can pollute air by the emission of smell, ammonia and methane. Besides ammonia and hydrogen sulphide (H2S), the most noticeable smelling substances are some cyclic chemical compounds. Ammonia in large concentrations can do damage to the vegetation. H2S gas developing in a manure cellar can, in cases of carelessness and bad ventilation, cause poisoning that may harm, and at worst kill, animals and humans. Smell of manure is normally more unpleasant than harmful. If wet manure is sprayed over fields, ea. by means of watering equipment, fine drops (particles) can float with the wind and be a nuisance for the surroundings.

Methane (CH4) is a gas that is produced in manure and ferments without the supply of air (biogas), but it is also produced in the rumina of ruminants during anaerobic fermentation. As for monogastrics such as pigs and poultry, methane is virtually not produced in the intestinal canal. Methane is a natural greenhouse gas with an impact on the greenhouse effect that is approximately 8 times stronger than that of carbon dioxide (CO2). Methane contributes about lo per cent to the total global heating caused by greenhouse gases. Approximately 15 per cent of the total amount of methane emitted to the atmosphere is produced by domestic animals (ruminants). The rest of the methane derives from rice fields, earth gas, swamps, land fills and wild ruminants. Some therefore contend that approximately 1.5 per cent of the global heating caused by greenhouse gases can be traced back to livestock.

Careful utilization of livestock manure can be difficult if the areas are limited. Pollution may be the result if the amount of manure in an area exceeds the amount that can be utilized by plants and soil. The growth of aquatic plants and algae will increase when excessive nutrients run into ditches, streams and other surface-water sources. This will cause the oxygen in the water to be consumed, and death of fish will ensue. If the pollution becomes a more or less permanent state, the watercourse may gradually overgrow - eutrophication. Phosphorus is generally the minimum factor for the growth of algae in freshwater, whereas nitrogen is the prime limiting nutrient in seawater. Another consequence of large amounts of manure is that the nitrogen may seep down through layers of soil and finally reach the ground-water. As a consequence the level of nitrates in the ground-water may exceed the danger level (see also booklet 7 Water supply). Flies and other insects propagate quickly in manure and can be a nuisance to the surroundings.

In many developing countries, the problem is too little manure rather than too much. In connection with intensive animal husbandry for industrial production of livestock products, however, problems of too much manure per area unit may arise. With regard to such projects, care should be taken to ensure that the manure is spread over a sufficiently large area. The need of a spreading area (minimum area per animal manure unit) will vary according to climate, soil type, plant growth and the feed contents of nutrients, especially nitrogen (N) and phosphorus (P). One animal manure unit can be reckoned as equivalent to the release of P (or N) of ea. a cow (one standard cow) per year. The number of animals per animal manure unit regarding other domestic animals will depend on the amount they release. The capacity of the animals to bind N and P in the body, and thereby traces of this in the livestock produce, is limited in proportion to the contents in the feed. It is important, therefore, that the feed does not contain much more than what the animals can make use of. As for the ruminants, which need carbohydrates in order to synthesize protein, it is important that one pays attention to the carbohydrate/N balance and tries to make it as optimal as possible. This is different with monogastrics. They have a lesser capacity to break down phytate, which is the compound to which most of the phosphorus in grain and other kinds of feed is bound. Consequently, the contents of phosphorus in the feed must be higher than would have been necessary if the physic phosphorus had been more easily accessible. A preparation has recently been developed containing the enzyme phytase. When it is mixed into the feed, the digestibility of physic phosphorus increases so much that it becomes unnecessary to add unorganic phosphorus to, for example, pig and poultry feed.

Fertilization of fish ponds by means of livestock manure may cause pollution of watercourses (see booklet 5 Aquaculture).

Despite these potential negative impacts, it should be stressed that livestock manure, if applied with care, in most cases will benefit the environment. This is both due to the contents of plant nutrients and to the fact that manure can also be used to produce biogas, thereby contributing to saving forests and other sources of energy.

3.3 Special impacts of livestock-based industries and transportation

Different types of livestock-based industries are listed in chapter 1.2. Below is a brief survey of expected environmental impacts. These should be considered prior to the projects. For a more thorough presentation of environmental impacts of industrial projects, see booklet 9 Industry and energy.

· Increased water consumption (both ground water and surface sources), which can affect the supply of water to other users.
· Discharge to air, water and soil.
· Land use conflicts.
· Alterations in social and economic structures in the area.

Surplus of feed can also cause environmental conflicts. This can perhaps be most clearly seen in areas with food industries and other industries that have by-products that are difficult to get rid of except when being used as feed. Such by-products chiefly come from mills, breweries, distilleries, preservation industries, butcheries, fish processing plants, etc. Domestic animals can serve as useful processors of offal and by-products into valuable food products, while at the same time contributing to reducing environmental problems.

Environmental impacts can be considerable in connection with large tanneries. In addition to a great consumption of water, large amounts of waste (skin and hair) can cause pollution. The waste can be utilized as a fertilizer if a mud separator is employed to collect it. Chrome is often used in the tanning process, which may cause considerable pollution problems. From butcheries, byproducts such as blood, entrails, stomach and intestinal contents, bone, etc. can represent serious sources of pollution. If treated in the right way, however, these by-products can yield valuable feed, fertilizers or other products.

Large-scale livestock production requires access to transport (see also booklet 8 Transport). This concerns feed, fertilizers as well as products. Infrastructure such as roads, railway, water installations, electricity and telephone may be necessary in order to make full use of the livestock project. Transportation of live animals has traditionally taken place by herding, partly over long distances. If the flocks are large, such herds can have negative environmental impacts in the form of dust, tracks, etc. In connection with livestock projects, transportation mostly takes place by lorries which results in dust, noise and strains on poor country roads. In the rainy season, it can often be difficult, not to say impossible, to travel outside the main roads. Transportation of live animals requires special care to protect the animals against unnecessary suffering or even death during transport. Livestock products to be stored or transported fresh over long distances in the tropics require refrigeration. Refrigerator and freezing facilities often contain environmentally hazardous CFC gases. There ought to be facilities for tapping such gases when the equipment is disposed of.

Need of transportation can also be an issue in connection with more decentralized projects, especially where livestock production for sale is concerned. The need as well as provision of transport should be taken into consideration already during the planning of the project.

3.4 Loss of valuable genes

Increased efficiency in agriculture and animal husbandry may lead to loss of valuable genes. The focus has particularly been directed towards genetic resources in plants. This is due to the fact that many cultivated plants are self-fertile or clones being marketed as homogeneous lines or hybrids. When these supplant local varieties from a cultivated area, reduced genetic variation and loss of valuable genes may be the result. For a more detailed account of this, "The convention on biological diversity" (UNEP 1992) can be consulted.

In general, the risk of losing genes of domestic animals is smaller, as domestic animals are cross-fertilizers. Loss of genes can happen if imported exotic breeds totally replace local ones. Commercial poultry production is especially vulnerable, because some local poultry breeds are in danger of becoming extinct. Such standardizing of production systems creates a form of monoculture, reducing the possibilities of subsequent alterations, which might be desirable. Experience, by FAO for example, shows that subsistence households and hobby producers often take great interest in local poultry breeds, and that these breeds will therefore be preserved. One should nevertheless note that The World Poultry Science Association has appealed to FAO to take initiatives to preserve genetic resources in poultry. Replacement of local swine breeds by improved swine breeds from the industrialized countries is widespread wherever commercial pork production is established in developing countries. Measures may be called for to preserve local swine breeds. An alternative to preserving local breeds is to improve them by crossing in imported breeds, as well as making selections in the new mixed population under current environmental conditions. Crossing and selection will make it possible to preserve valuable genes in the population, provided they do not have a strongly negative effect on the properties which selection is meant to improve. The frequency of local genes may become lowered, but research has shown that the decline takes place slowly and that loss of important production and resistance properties, being governed by many genes, will not happen for generations. Such improved and upgraded local breeds are also likely to become valuable elements in a three or four breed crossing programme aimed at efficient and economical pork and poultry production in developing countries.

Introduction of new cattle, goat and sheep breeds in developing countries generally takes place through crossing with local breeds, not through substitution by new pure breeds. Such crossing and subsequent selection under local environmental conditions will preserve valuable local genes. FAO (1992) has recommended that selection in order to improve and preserve local breeds should take place in a so-called Open Nucleus Breeding System, where it is allowed to cross in animals of the same breeds or of other breeds having the desired properties. In many industrialized countries, a high degree of standardization of cattle breeds over large areas and between countries is taking place. This development, however, is still not common in most developing countries.

3.5 Infection pressure and diseases, and impacts of medication

When localizing a livestock project, the risk of serious diseases should be taken into consideration. Some livestock diseases can be transmitted to humans and wild animals and thus pose a threat to the environment. Generally speaking, the heavier the stocking rate in an area, the greater is the risk that infectious diseases may break out. An area in which a major animal husbandry project is established ought to have a satisfactory veterinary service.

Livestock production in tropical areas is vulnerable to a series of infectious diseases. Bacteria, virus, protozoa and worms which are rare or non-existent in temperate areas exist here. Examples are foot-and-mouth disease (virus), anthrax (bacteria), trypanosomiasis (sleeping sickness, caused by a protozoan) and various intestinal worms. Most of these diseases rarely have dramatic effects in extensive forms of production, but they can strike hard in intensive ones.

Many parasites flourish around water sources and feeding places, and full exploitation of few water points may increase the risk of diseases breaking out. Problems of illness can often occur in connection with a too intensive exploitation of areas in proportion to their capacity. Inadequate or incorrect nutrition or lack of minerals and vitamins can be decisive in regard to the extent of an outbreak of a disease. One should especially be cautious with regard to animals being kept in cages or bins (ea. poultry, pigs, rabbits).

Domestic animals introduced from outside often lack the power of resistance that local species have evolved throughout generations. In addition, pressure of infection may build up in the environment so that also local breeds become vulnerable to diseases. Conversely, local breeds and wild animals might pose a risk to imported breeds, partly by a direct pressure of infection and partly because preventive treatment/vaccination does not always reach the animals of all livestock keepers.

Experience shows that in the cool highlands in the tropics exotic livestock may be introduced or crossed with local breeds to the effect that the production capacity is greatly increased. Many diseases are less troublesome in the highlands and easier to control.

Many of the most common diseases can be controlled by means of a vaccination programme. Examples are vaccination against cattle plague, anthraz and some clostridial infections among various animal species. Vaccination is generally a cheap alternative as compared to drug treatment. Moreover, it is within the reach of many less prosperous livestock keepers. Curative drug treatment may be so expensive that only intensive forms of operation make use of such opportunities. When establishing a veterinary service, it is important to be aware of the limitations of such services when the majority of the livestock keepers are very poor. Preventive treatment by means of chemicals (spraying/cattle dip) also tends to be expensive and beyond the reach of extensive forms of animal husbandry.

Intensive animal husbandry often makes use of large amounts of drugs. In many places, it has been documented that drugs are used inappropriately or in incorrect doses. As a consequence, the desired effect is not achieved. Environmental impacts of medication can be considerable if it is not done safely. Especially two groups of drugs have been focused in this connection: parasiticides that are applied externally to the animal, and antibiotics that are given as injections or through the mouth, on their own or mixed with the feed.

Chemical insecticides being used to fight ticks, flies, horseflies, etc. are either very persistent (not easily broken down) in nature (chlorinated hydrocarbons such as DDT, Lindan) or, if not safely used, extremely poisonous for the users (phosphoric insecticides). Use of these insecticides is still widespread in many developing countries. Remnants of them may spread to the environment and accumulate in the food chain. In some places, high levels of such chemicals have been detected in an important nutrient such as mother's milk (cf. booklet 13 Use of chemical pesticides).

With regard to the antibiotics group (antibiotics and chemotherapeutics), great concern is attached to the development of resistant microbes that can infect humans and cause diseases that may be difficult to treat. For the same reason, treatment of many animal diseases has already become more difficult. If antibiotics are used as a growth-promoting drug, which often happens in connection with industrial modes of animal husbandry, special care must be taken. Much of the antibiotics that are given to animals finally end in the surroundings. This is most evident in connection with fish farming (see booklet 5 Aquaculture), but treatment of mammals will also cause a great deal of the drugs to end in the environment, either in their original form or as converted into other substances that can be equally harmful. It is still unclear how high the risk of establishing resistant environmental bacteria is, and what possible impacts this will have, but there is good reason to be aware of the problem.

3.6 Other ecological impacts, and consequences for landscapes

When drilling wells to supply ground-water to animals and humans, preliminary surveys have to be made to ensure that the sources are not emptied, or that the water table is not periodically lowered too much. This may have impacts, not only for the water supply, but also for the vegetation in the area. The quality of the ground-water, which may be important to health, should also be examined. See booklet 7 Water supply for a more detailed account of these conditions.

If an animal husbandry project is established near to game reserves and/or national parks, it may be relevant to consider whether a buffer zone ought to be created in the border area. Major land-demanding projects may require that large forested areas are cut. Various types of forest in the tropics, ea. rain forests, are vulnerable to clear-cutting (see booklet 3 Forestry).

Initiatives within animal husbandry may visually alter a landscape. Careful development of operational plants and installations, adaptation and cultivation of landscapes should be considered during the planning and implementation of projects. A project may at best contribute to making a landscape more scenic rather than ruining its contents and quality. Operations may also affect historical relics, burial sites and other objects that are important locally. Preliminary investigations may be required in order to avoid conflicts.

Animal husbandry, especially grazing, is a major factor regarding the development of cultivated landscapes. Such cultivated landscapes can be conservation-worthy and in need of management in order to prevent over-growth or any other alterations. For example, the Masai and their animals grazing on the mountain slopes by the Ngorongoro crater in Tanzania no doubt have great socio-cultural value, not to speak of their importance for tourism. Considering conservation and management, however, it is crucial that other economic and cultural interests do not suffer. Conservation of areas based on traditional forms of animal husbandry must take place in agreement with the local population. Those who may suffer losses on account of the operations should receive an acceptable compensation.

3.7 Social impacts

Initiatives concerning grazing require surveys of existing terms of tenure and privileges tied to the areas. Specific conditions attending communal ownership may create conflicts if initiatives are aimed at making the management more efficient (cf. chapter 2.2).

Conflicts may occasionally arise between forestry and livestock interests. It may be necessary to consider the livestock project against the consequences of a reduction in forested areas, for example. Questions concerning food supplies, subsistence, risk of erosion, local climatic changes and preservation of a biological variety should be considered in this context.

Major projects based on sales of products beyond the local area should not be started until a market survey has been performed. Questions concerning processing, preservation and transportation of the products should also be closely considered. Wherever the conditions are favourable, decentralized livestock projects may have their advantages, ea. better feed supplies, less pressure of infection and better utilization of manure and other by-products. Establishment of cooperatives, cooperative groups, etc. can be advantageous under such conditions.

Major projects may cause the removal of people from their settlement areas, and/or initiate an unintended immigration into the project area by people looking for work or possibilities of trading. In either case, the project ought to assess the need to make provisions for settlement, so as to minimize risks of pollution, spreading of diseases, increased and uncontrolled exploitation of natural resources and social conflicts.

It is important that the establishment of livestock projects takes place in agreement with the local population. Herding is normally carried out by men or young boys who often have a good knowledge of which is the best pasture and where water can be found. In many places, moreover, women are in charge of the family household and health, in addition to having the responsibility for collecting water, feeding and tending the animals. Introduction of new animals may increase the burden of work for women. With regard to milking and the making of milk products, an improved technique can relieve the work pressure, since traditional methods are often time-consuming. If there are insufficient amounts of feed and water near the household, women may have to spend much time collecting feed and water rather far away from their homes. Introduction of draught animals, ea. donkeys, may somewhat alleviate the situation. Experience shows that women and children to a greater extent than men are affected by pollution from fertilizers, as they spend more time near to home and the animals. Pollution of water sources from manure can also be a reason why women will have to collect water from farther away than previously.

3.8 Impacts of other existing or planned activities

Several types of activities in the vicinity of an animal husbandry project can adversely affect the project or reduce its output. Industry and energy production may pollute the area, having a negative impact on grazing, for example, due to fallout of toxic substances or acid rain. Changes in the use of land involving the clearing of land for houses, industry, systems of transportation, etc., can reduce the area available for livestock production.

It is important that new animal husbandry projects take existing environmental problems and land use plans into consideration before they are launched.

4 Relevant literature

ADB 1991: Sector Paper on Livestock, Asian Development Bank, December 1991.

Behnke R. H. 1992: New Directions in African Range Management Policy. Pastoral Development Network, Paper 32c, Overseas Development Institute, London.
FAO 1992: Expert Consultation on the Management of Global Animal Genetic Resources, Rome, Italy 7-10 April 1992.

Kossila, V. L. 1984: Location and Potential Feed Use. Pages 4-24 in F. Sundstol and E. Owen (eds.): Straw and Other Fibrous By-products as Feed. Elsevier, Amsterdam, 604 pp.

Payne W. J. A. (eds.) 1990: An Introduction to Animal Husbandry in the Tropics, Tropical Agriculture Series, Longman, London, 4th ed. 881 pp.

Shonmugarotnam N. Vedeld T. Mossige A and Bovin M. 1991: Resource Management and Pastoral Institution Building in Dryland Africa. Report to the World Bank. Draft. Norwegian Centre for International Agricultural Development, Agricultural University of Norway.

Swallow B. 1992: Environmental Issues and ILCA Research Agenda. In S. Ehui and M. E. Lipner (eds.): Livestock and Resource Management Policy: Issues and Priorities for Research. Proceedings Research Planning Workshop, ILCA, Addis Ababa, Ethiopia 24-27 March 1992.

UNEP 1992: Convention on Biological Diversity, Environmental Law and Institutions Programme Activity Centre, June 1992, 52 pp.

Glossary

Animal manure unit	= unit for amount of manure
Bedouins	= nomadic tribes inhabiting the deserts of Arabia and North Africa
Boma	= enclosure for a herd of animals (often with dwellings)
Browse	= graze on shrubs
Crawl	= enclosure for a herd of animals
Cultivated pasture	= land that has been tilled or prepared for grazing
Dipping	= bathing of animals in water containing insecticides, especially against ticks ("dips" = bath)
Feedlot	= pen for fattening animals
FAO	= Food and Agriculture Organisation of the United Nations
ICARDA	= International Centre for Agricultural Research in the Dry Areas
ICLARM	= International Centre for Living Aquatic Resources Management
ILCA	= International Livestock Centre for Africa (Addis Ababa)
ILRAD	= International Laboratory for Research on Animal Diseases (Nairobi)
ITC	= International Trypanotolerance Centre (Gambia)
Livestock	= domestic animals
Masai	= a people living in East Africa, noted as competent livestock keepers
Monogastrics	= animals having one stomach
Pastoralism	= rearing of animals on grazing land
Phytate	= organically bound phosphorus (P), hexaphosphorus-inositol
Protozoan	= uninucleate animal
Ranch	= large farm for rearing grazers
Range	= area in which plants or animals grow or live
Ruminant	= animal that chews the cud
Savanna	= flat grassy plain (pampas in South America)
Spraying	= sprinkling of livestock with insecticides (especially against ticks)
Stall feeding	= keeping and feeding animals in a stall
Steppe	= flat grassy plain
Tick	= mite that attaches itself to the skin of animals
Tsetse fly	= fly transmitting the pathogens of sleeping sickness (trypanosomiasis)
Turkana	= a people living by Lake Turkana in Kenya
Zebu	= Indian type of cattle (Bos indicus)
Zero grazing	= indoors feeding/the animals are fed with cut grass