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
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.
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 |
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.
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.
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.
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