The value and importance of farm animal genetic resources to cultural, social and economic development

 

G. E. Pollott, Wye College – University of London, Ashford, Kent, TN25 5AH, UK

 

Introduction

Livestock meet an estimated 30 percent of total human needs for food and agriculture in the form of meat, milk, eggs, fibre, fertilizer for crops, fuel and draught power, and also serve as a very important cash reserve in many farming systems. This large contribution to food security comes from approximately 5,000 breeds comprising 40 domestic animal species.  These are the farm animal genetic resources available to mankind. However, within the context of this paper animal genetic resources (AnGR) include all species, breeds and strains that are of economic, scientific and cultural interest to agriculture, now and in the future.

 

Domestic animal diversity (DAD) provides farmers with the raw material to develop livestock that are more productive, more able to resist diseases or better adapted to the adverse conditions which characterize many production environments. Much of the agricultural production involving livestock in the developing world occurs in high stress, low-input production systems.  The biggest threat to AnGR in this area, is the replacement of adapted breeds with unadapted exotic breeds which fail to consistently produce or cannot survive in high stress, low input production environments.   Achieving global food security will require sustainable development of agriculture.  By definition, sustainability is production environment specific and there is and will remain a diverse range of production environments globally.

 

In Asia farm animal genetic resources have been developed over a period of around ten thousand years. This vast resource is now under threat as never before due to a series of factors all working to erode the existing diversity.  The demand for human food has increased dramatically with the population explosion over the last twenty years or so and this is continuing in this region.  Increasingly the demand is for animal protein.  Much of the effort over the last twenty years has been to increase the output in the whole of Asia and this has been achieved.

 

The Asian region possesses the largest livestock population of any region in the world and also has the fastest growth of any region in terms of its livestock industry although recent financial problems may well have slowed this. The proportion of the world’s total livestock population in Asia is, for cattle 32.6%, buffalo 96.6%, pigs 56.3%, sheep 33%, goats 62.7%, chicken 46.4%, ducks 85.3% and 98 % of all yaks. In addition, historically, the region is known as the source of much domestication of livestock and has a large variation in topography and climate, which means that there is likely to be considerable genetic diversity within the region.

 

What is domestic animal diversity?

Species Domestication is a process which, dependent upon the animal species, has been continuing for some 12,000 years. While there may be debate as to further species domestication, certainly domesticated animal species, like plant species, have been developed to suit a wide range of conditions and requirements. This process is expected to continue as human requirements, and management environments, change. Consideration of farm animal biodiversity has only arisen in the last 50 years. The relative time scales of the development of diversity and the recognition of its importance are therefore disconcerting.

 

It is estimated that 75% of world’s food and agriculture produced by <25 plant and animal species and that animals contribute 30-40% of total value of food and agriculture. Of the 50,000 known avian and mammalian species animal production comes from about 40 species. The major species listed by FAO/UNEP (1995) are buffalo, cattle, yak, goat, sheep, pig, ass, horse, dromedary, camel, alpaca, llama, guanaco, vicuna, chicken, duck, turkey, goose, guinea fowl, partridge, pheasant, quail, pigeon, cassowary, emu, nandu and ostrich. The 14 major species account for 90% global livestock production.

 

Breeds Documented breed records were only developed in the last two hundred years or so although breeds have existed and records maintained for centuries by memory and orally.  However, the term "breed" needs defining. The following definition by Turton (1974) is preferred by the Food and Agriculture Organization of United Nations (FAO) as indicated in the World Watch List for Domestic Animal Diversity (WWLDAD) (FAO/UNEP 1995).

           

            "A breed is either a homogenous, subspecific group of domestic livestock with definable and identifiable external characteristics that enable it to be separated by visual appraisal from other similarly defined groups within the same species; or, it is a homogenous group for which geographical separation from phenotypically similar groups has led to general acceptance of its separate identity."

 

The WWLDAD adds: "Thus, breeds have been developed according to geographic and cultural differences, and to meet human food and agricultural requirements. In this sense, breed is not a technical term, but certainly the differences, both visual and otherwise, between breeds account for much of the diversity associated with each domestic animal species. Breed is accepted as a cultural rather than a technical term, i.e. to emphasize ownership."  It is also noted that the term "population" is a generic term but, when used in a genetic sense, defines an interbreeding group, and may refer to all animals within a breed.

 

During the long period of domestication and development, species of animals, like plants, have undergone considerable change as a result of selection pressures. Some of these pressures were natural - for example, the climate changes occurring in Europe around 3000 BC when an essentially hot and dry climate became cold and wet. Genetic variation also arose as humans migrated with their domestic animals to different environmental/climatic conditions. These influences continue today. The gene combinations developed provide a vast array of resources available for exploitation for the benefit and survival of humans. Clearly there are breeds of one or more animal species in most human environments which perform according to human requirements.

 

While the most important criterion for evaluating breeds in developed countries is performance (usually output), breeds in developing countries are usually recognised by other criteria. Such breeds have low output because they often have little or no inputs and grow and survive in conditions that are far from ideal. Output is not, therefore, a reasonable criterion for valuing breeds but continues to be quoted by the livestock production industry. It is well recognised that many breeds in difficult environments exhibit highly desirable traits. These include reproduction under severe nutritional stress, disease tolerance or resistance, and resistance to heat or cold stress.

 

Within breed variation It is often forgotten that animals vary within a breed as well as between breeds. Thus the maintenance of variation within a breed is important. Hammond and Leitch (1995) suggest that the variation that exists within a certain species can be divided in half, with 50% being due to between breed differences and 50% due to within breed differences.

 

Specialised lines The global breeds and breeding companies that now exists have tended to develop specialised lines of livestock. Whereas these may be ‘artificial’ they do represent new combinations of genes and contribute towards domestic animal diversity. They also contribute considerably to food production.

 

The physical environment It is a fundamental principle of genetics that:

 

Phenotype = Genotype + Environment.

 

This is not a precise mathematical statement but implies that the outward appearance of an animal is not only dependant on the genes that it carries but also the external influences that have interacted with those genes to produce the animal as we see it. This is often overlooked in a number of different contexts.

 

Firstly, the transporting of genes from one ‘environment’ to another does not guarantee the same product. Hence the use of temperate breeds in tropical countries often results in disappointing performance. Secondly, the evaluation or characterisation of a genotype is impossible because it must take place in the context of its environment. This means that the characterisation of livestock breeds must include relevant details of the physical environment in which the animals were kept.

 

Most agricultural production involving domesticated livestock in the developing world takes place in stressful, medium-input or high stress low input production systems.

 

Domesticated animal diversity and world food resources

Domestic animal diversity is an important part of world food resources. Animal products are produced in many different systems and areas due to this diversity. Livestock contributes 41 percent of agricultural GDP (Steinfeld, Bangkok, 1998, personal communication) with about half of this being food (Hammond and Leitch, 1995). The contributions of the non-food outputs from livestock are in some cases more valuable than the food itself. The social and cultural contributions of animals are also extremely important even though they cannot easily be valued in economic terms.

 

Over the last 12 years, global animal production has increased by 27% and total global meat production by an average of 2.9% per annum. A dramatic 7.7% annual increase in meat production has occurred in Asia (FAO, 1996a, 1997). However, over 800 million people still suffer from chronic malnutrition and over 200 million children lack sufficient food for full development (FAO, 1996b). Food production will have to double over the next thirty years if minimum nutritional standards are to be met. Available natural resources will be threatened unless drastic action is taken to reverse present trends. It is estimated that the demand for meat and milk will rise by 300% and 155%, respectively, by 2020 (Rosengrant et al., 1995).

 

The pressures on animal production systems are increasing rapidly. In 1996, the FAO World Food Summit published the Rome Declaration on World Food Security and World Food Summit Plan of Action (FAO, 1996c) which emphasized the need to promote the conservation and utilization of animal genetic resources to combat threats to food security. It is essential that the genetic diversity available is fully exploited in a sustainable manner to meet this increasing demand for meat and milk from livestock.

 

 

 

The need for balance

Animal production is a crucial component of agriculture and the sustainability of many farming systems relies as much on animals as on plants. Neither can be ignored nor eroded without serious consequences. Similarly, agriculture is itself only one component of the global ecosystem and to some, it is an intrusion on the original biodiversity. Clearly balance is needed between the human needs and the maintenance of biodiversity for future survival. The maintenance of biodiversity is in the long-term interests of all insofar as it contributes to sustainability, food security and survival.

 

There are cases, however, where livestock production may create problems. For example, intensive pig and/or poultry units can cause major pollution problems while the global movement of livestock feed causes massive shifts in resources in the long-term: feedstuff producers fail to replenish their land with nutrients while the recipients suffer nutrient pollution which may seriously affect crop production, water quality etc. There is already good evidence to support this. Nevertheless, it is likely that future animal production will involve further intensification (Steinfeld et al., 1997) and solutions have to be found. Livestock has been blamed for desertification and deforestation (especially in the Amazon) and yet, "Livestock do not move, produce or reproduce without our wanting it. They are completely dependent upon us and inseparable. Livestock do not degrade the environment, humans do" (Steinfeld et al., 1997).

 

Extent of farm animal diversity

As the overall extent of genetic diversity within an animal species is not yet known, the scale of the problem of maintenance and use of farm animal resources for future productivity is difficult to assess. Until recently, there was limited information on the number of breeds globally and even less on performance coupled to production environment.

 

One of the first breed surveys (Maijala et al., 1984), showed that the farm animal genetic resources in Europe consisted of 737 breeds across five species of which 240 were at serious risk. In 1991/2, FAO carried out a global survey which formed the basis of the first publication of a World Watch List for Domestic Animal Diversity (FAO/UNEP, 1993). This showed 2719 breeds for 7 species of which 27% were estimated to be at risk. As part of a continuous surveying, monitoring and updating process, the second edition of the WWLDAD (FAO/UNEP, 1995) covered 3,882 breeds of 28 animal species, with 501 of 3019 mammalian and 372 of 863 avian breeds at risk, giving an overall level of about 30% of breeds. This figure may rise further as countries assess their resources more effectively.

 

Why maintain domesticated animal biodiversity?

Domesticated animal diversity is needed to ensure that variation is accessible for future use. The demands and desires of humans are constantly changing, presenting new challenges to producers. In addition, changes are occurring in feed availability, disease, climate, and scope of human interventions. These changes, coupled with the increasing demands for livestock products, exert pressures to achieve the most efficient production system possible.

 

Many indigenous breeds have been discriminated against due to low outputs under inadequate feed levels and/or other stresses. This is unfortunate and, indeed, contrary to basic genetic evidence which suggests that selection for improved performance should be done under the same conditions as those of the performance environment (Falconer 1961). After decades of neglect, local breeds are now considered to be sources of useful genetic variation (Frankham, 1994). Often, the value of a local breed has only been realised after it has either been reduced to low levels or disappeared. Identification and evaluation of useful attributes is extremely important so that source breeds are not lost. Even where there is adequate genetic variation, selection within a breed is usually slow with rates of change being around 1-2% per annum. It is often advantageous to cross with a desired breed and to select for the desired trait.

 

Maintaing breed diversity and sustainability

In almost all cases of genetic erosion, economic pressure at farm level (usually politically based) persuades the producer to change to genotypes, or breeds, which yield higher immediate returns. This is of significance in poorer societies where both the pressure for survival and the need to make short-term gains are great. Such decisions are, however, almost always independent of overall efficiency and maximization of long-term sustainable use of resources. They are often related to subsidies whether direct or indirect (externalising costs is an indirect subsidy in this context) or directly to policies. Farmers are often aware of the unsustainability of the system adopted but must follow the policy due to economic reasons. At the same time, some decisions (e.g. decreased milk prices) may result in increased levels of human nutrition even if these cause problems in longer term (e.g. the EU Common Agricultural Policy produced lakes of milk and mountains of beef and butter). The problem is that the timeframe for achieving political gains is not in tune with that for maximising the efficiency of the whole production system.

 

Rather less obvious but no less problematical is the general failure to take into account all aspects of the system when calculating economic values. There is often a failure to internalise all costs. An example is the considerable increase in mature size of cattle when exotics are crossed with local breeds in the tropics. The resultant F1 adult requires considerably more feed for maintenance. Another example is the costing of intensive units of exotic stock without any regard to the processing of effluent. The subsidies provided to encourage artificial insemination (AI) or mechanisation also have effects on genetic erosion and the environment. For example, mechanization will lead to the reduction of draught animals which may affect soil structure and accumulation of crop residues.

 

One of the obvious means of erosion is breed replacement. This has happened several times throughout history. In the UK for example, the Shorthorn took over from the Longhorn only to be replaced by the Dutch Friesian which has more recently essentially been substituted by the Holstein-Friesian from North America. Breed substitution is facilitated by technologies such as AI and, more recently, embryo transfer (ET) which allows immediate breed replacement, potentially increasing the rate of genetic erosion.

 

Bringing desirable genes into a population by crossbreeding has become a major practice in some parts of the world. In developing countries, the driving force has been the potential to substantially increase food output. Steane (1996) pointed out that while such programmes may have initial benefits, the main danger to animal diversity is the continuing trend to crossbreed only with exotic semen and/or animals. This practice of backcrossing only to the exotic breed is often (incorrectly) referred to as "upgrading" and appears to be based on the premise that developing country breeds are unimproved and thus not useful. There is no doubt that valuable genetic improvements in farm animals in the developed world are of real value in crossing programmes in developing countries. However, the question has to be asked: under what conditions did the improvement take place? In many cases, there appears to be little or no consideration of the contribution of the selection environment (for example, high feed availability, low stress levels, different market demands etc.) and no consideration of the longer-term genetic implications. In fact, crossbreeding is often dependent on the development of local breeds to act as the mother of first cross animals and thus planned crossbreeding should result in a regular programme of breeding from the purebred local animals.

 

Crossbreeding is an essential tool for improving food production efficiency but programmes must be properly designed to maximise gains and minimise problems. In dairy cattle, there appears to be almost universal support for the Holstein-Friesian breed as, in the right environment, it has the highest milk yield of all breeds. But, its butterfat levels are amongst the lowest. In a continuous back-crossing programme, use of the Holstein-Friesian can spell disaster in developing countries. Indeed, problems have already developed due to its poor reproductive performance. Why does this situation occur?  From a peasant farmer's point of view, the first-cross is almost a miracle. The local indigenous cow which produces little milk (on no additional feed) suddenly, as a crossbred, produces several times more milk (but with additional feed). The exotic breed is given full credit for the transformation and the farmer requests more of the same, leading to erosion of the local breed.

 

Further genetic erosion can take place during the choice of traits for selection. The phenomenon of correlated response can be used to advantage but can equally cause problems. There is always a tendency to select those traits which are highly heritable and easy to measure since these will give the greatest response. An example has been the almost universal selection for milk yield based on the first lactation (standardised to 305 days). While this allows early assessment of sires, due to an associated gradual decrease in calving interval, in some circumstances the overall effect has been detrimental usually under both stressful and good conditions (Simm and Pryce, 1998). In many circumstances, average lactation per day per year or, better still, per lifetime will provide a better evaluation (see Veerkamp et al., 1995 for more information) particularly if realistic production costs are taken into account. Similarly, selection for growth rate in beef cattle has been in vogue in many countries for many years with some impressive results. However, the "value" of growth rate has not taken into account the associated response in mature adult body size and the consequent increased feed requirement for maintenance (and greater susceptibility to feed deprivation with its concomitant reduction in fertility). In many environments where feed is a limiting factor, the additional maintenance requirement may have to be met with imported subsidised concentrate feed.

 

 

Efficient use of resources

Efficiency concerns the use of combinations of resources and yet, all too often, animal breeding is regarded as a solution in itself, which is far from the reality. Animal breeds have been developed under specific conditions for specific products and any changes may mean that that particular breed is no longer the most effective. The common factor linking all aspects of future livestock production must be efficient use of resources for sustainable food production. The challenge is to provide adequate food from resources that also must be maintained for future generations. In this context, efficiency is a measure of input/output relationships. It is interesting that the recent financial meltdown in Asia has stimulated a reappraisal of the value and role of agriculture and of the use of local resources.

 

Given the difficulty of identifying the real economic situation for production, it is not surprising that the economics of biodiversity loss is even more difficult to specify. This is addressed by Perrings et al. (1995) and emphasises several crucial issues regarding the value of ecosystem resilience. They point out that, "all the general models (of climate change) predict an increase in the range of environmental conditions within which economic and ecological systems will have to function in the future, the loss of resilience in key ecosystems must be a matter of concern" (p.307). There is no reason to believe that this does not apply to agroecosystems. It may be necessary to deal with an even greater range of production environments than experienced to date. The approach taken by the Perrings et al. study needs to be extended to provide the required practical methodologies to conserve domesticated animal biodiversity.

 

Table 1. Characterisation of commercial and small-holder systems of livestock production (Adapted from Anderson, 1994).

 

Criterion

Commercial

Small farmer

Genotypes

Artificial selection for production traits. Few genotypes, low genetic variation

Natural selection for adaptation. Diverse genotypes between and within breed

Husbandry

Very technical. High use of external inputs

Traditional. Low input systems

Function

Specialised

Multi-purpose

Relation to environment

Control of natural environment

Adaptation to natural environment

Socio-economic role

Produce a return on investment

Sustain family needs

Type of system

Uniform

Very varied

Livelihood dependents

Few

Many

Food output

High

Moderate

Risk

High

Low

 

 

Valuing livestock systems

Many of the problems associated with the farm animal genetic resources may be due to incorrectly assessing the value of livestock to many farmers. The approach taken in highly developed commercial enterprises is unlikely to be applicable to the majority of livestock enterprises, which are owned by subsistence farmers with very small enterprises. Table 1 characterises the two types of system.

 

It is not surprising that the value and importance of the animals will vary between the different types of system. In the commercial system the value of the animals is economic and may be estimated and compared in financial terms. In the non-commercial systems the animals, as well as having a value within the family economy, also have a socio-cultural significance. These are difficult to measure in economic terms.

 

Avila (1987) gives details of the value of livestock to households in semi-commercial conditions in Zimbabwe (Table 2).

 

Table 2. The use of livestock in semi-commercial conditions in Zimbabwe (Avila, 1987)

 

Function

Cattle

Goats

Sheep

Donkey

Pig

Poultry

Wildlife

FOOD

 

 

 

 

 

 

 

Meat

X*

X

X

 

*

X

X*

Milk

 

X*

X

 

 

X

 

Eggs

 

 

 

 

 

X

 

TRACTION

 

 

 

 

 

 

 

Preparation

of land

X*

 

 

X

 

 

 

Cultivation

X*

 

 

 

 

 

 

Transport

X*

 

 

X

 

 

 

DUNG

 

 

 

 

 

 

 

Fertiliser

X

X

X

X

 

X

 

Fuel

X*

 

 

 

 

 

 

Methane gas

*

 

 

 

*

 

 

WEED CONTROL

X

X

 

 

 

 

X

SOCIO-ECONOMIC

& CULTURAL

 

 

 

 

 

 

 

Savings

X

X

X

 

 

 

 

Food exchange

X

X

X

 

X

X

 

Payments

X

X

 

 

 

 

 

Rituals

X

X

 

 

 

X

 

Ornamentation

X

X

 

 

 

 

X

% FAMILIES WITH ANIMALS

57

52

5

30

6

79

 

* Research priorities in NARS

 

Clearly the animals kept in these households in Zimbabwe were used for many purposes and their importance to the families was immense. A small indication of how the role of animals was considered by the government can be seen from the indication in Table 2 of the topics covered by research. In some cases research is being carried out on topics of no concern to these households and many of the aspects of livestock of concern to the families were not being researched. In fact, Anderson (1994) concludes that “these values are often only apparent to the farmers that own these animals and therefore an important part of any animals genetic resource conservation programme must be the exploration and understanding of the knowledge and valuation of the animals genetic characteristics as seen from the farmers point of view”.

 

In many countries animals kept in non-commercial households are not deemed to exist and rarely enter statistics or the calculations involving the true value of livestock to the country. This is particularly true of the food contribution of livestock to the population’s needs, since much livestock output is consumed within the home and never enters into trading arrangements.

 

Conway and Barbier (1990) (quoted in Anderson, 1994) suggest four criteria for sustainability; productivity (including profitability), stability (including resistance to negative external causes of change), flexibility (sustainability in the narrow sense) and equity (social and cultural, inter and intra-generational). The table below gives an evaluation of the sustainability of exotic and local breeds as found in many countries.

 

Table 3. The sustainability of exotic and local breeds in tropical countries (Anderson, 1994).

 

Criterion

Exotic

Local

Productivity

Highly productive but under favourable conditions. Specialised products.

Low to moderate under diverse conditions. Multiple products

Stability

Require the constant importation of breeding stock. Little resistance to disease and extreme climates

Resistance to diseases and climatic extremes. Small populations

Flexibility

Selected for specific conditions. Prolific.

Tolerant to changes in the environment. Able to fulfil various roles.

Equity

Highly priced and expensive to maintain

Low prices and reduced maintenance costs

 

 

The use of exotic stock high-stress low-input environments is unlikely to prove sustainable. The key question is whether the environmental conditions that they require are both economic and likely to be sustainable themselves.

 

Conclusions

Diversity in domestic animal genetic resources has been shown to be essential as a major way of reducing risk in livestock systems. Where environmental conditions are able to support high input systems then they are the preferred option. However, a large proportion of the world’s livestock and livestock farmers are found in areas where this is an unlikely scenario. The use of well-adapted local breeds is their main option. Such breeds have the potential to improve their genetic characteristics if suitable improvement mechanisms are possible to implement.

 

Acknowledgements

The assistance of David Steane, Chief Technical Advisor to the FAO project on ‘The conservation and use of farm animal genetic resources in Asia and the Pacific’ is gratefully acknowledged.

 

References

 

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