Biotechnology and African livestock sector at the cross-road

UNITED NATIONS Economic Commission

for Africa

Food and Agriculture Organization of the United Nations

BIOTECHNOLOGY AND AFRICAN LIVESTOCK SECTOR AT

THE CROSS-ROAD

Joint ECA/FAO Agriculture Division

MONOGRAPH

No. 6

0

BIOTECHNOLOGY AND AFRICAN LIVESTOCK SECTOR AT THE CROSS-ROAD

by

Prof. S.C. Nana-Sinkam

and

Dr. K.P. Abassa

of the

Joint ECA/FAO Agriculture Division

The views expressed in this document are those of the authors and do not necessarily

reflect the views of the United Nations Economic Commission for Africa and/or

the Food and Agriculture Organization of the United Nations.

July 1993

ORITED

EC88GM2C Si3S?frja

ADDIS

TABLE OF CONTENTS

FOREWORD v

I. INTRODUCTION 1

II. BIOTECHNOLOGY AND LIVESTOCK SECTOR:

PRESENT STATUS OF KNOWLEDGE 3

Definitiont .= 3

Technology Development 3

Manipulation of the Germ Line 4

1. DNA probe and hybridization

2. Gene mapping for Major Histocompatibility Complex {MHO 3. Potymerase Chain Reaction (PCR)

4. Biological Nitrogen Fixing

Cell Fusion and Monoclonal Antibodies ■ 5

Applications 5

Genetics 6

Reproduction 7

.Nutrition 8

Milk Production and Growth 8

Health 9

III. BIOTECHNOLOGY AND AFRICAN LIVESTOCK SECTOR DEVELOPMENT 11

The state of technology Development, Transfer and Application 11

Vaccine Production technologies *. 11

Artificial Insemination (Al) and Embryo Transfer (ET) 12

Biological Nitrogen Fixation Technology 13

In Vitro Plant Culture 13

Impacts of Biotechnology 13

Actual Impacts 13

1. Impact on Health

2. Impact on Reproduction and milk production 3. impact on Nutrition

Potential Impacts 15

1. Potential Impact in the Area of Genetic Improvement and Preservation of Genetic Resources

2. Potential Impact in Reproduction and Milk Production 3. Potential Impact on Health Improvement

iii

4. Potential Impact in the Area of Feed and Feeding 5. Potential Economic Impacts

Constraints to Biotechnology Development and Possible Solutions 20

Weak Agricultural Science and Manpower Development Bases . . 20

Financial Resources Constraints 20

Protectionism 20

Policy constraints 21

IV. CONCLUSION 23

TABLES

Table 1 • The evolution of the science of genetics, landing to modern biotechnology .... 29

Table 2 • Impact of bovine somatotropin (bST) use on animal numbers, feed requirements, and waste production of dairy cows to achieve

1988 US milk production 31

Table 3 - Infectious diseases occurring in animals 32

Table 4 - Examples of diagnostic tests used to monitor fertility and launched

between 1984-1989 33

Table j - Per caput total milk production in selected Sub-Sahara African Countries 34

Table 6 - US animal production efficiencies in 1982 and estimated annual

growth rates 35

Table 7 - Biotechnology in Some African Countries , 36

ANNEXES

Annex A - Glossary of Terms 41

Annex B - DNA Making and DNA Samples Preparation 45

Annex C - Polymerase Chain Reaction (PCR) 47

REFERENCES 49

iv

FOREWORD

We live in a divided world whereby 20 % of its population evolves in a relatively and comparatively close economical, technological and knowledge-wise integrated circle formed by the OECD countries, and the rest, the poorer 80 %, are increasingly excluded

especially the poorest living in the African continent.

The priorities of the global science and technology, especially of the biotechnology agenda are determined, elaborated and set by and in the primary interest of the 20 %.

Over the next 50 years, the world's population is expected to double from its current level to around 10 billion. With the world containing more than 10 billion people in 50 years, the above described ongoing situation is unsustainable, the more so because it is well known and accepted that biotechnology can and is a powerful instrument to effectively cope with basic needs and aspirations of the 10 billion people who will inhabit the planet by the year 2040. Biotechnology can help to meet growing demands for food, medicines energy and raw materials, and to minimize the environmental impact of products, processes and waste. Political will and "considerable investment" will be required if biotechnology

is to play a full role in sustainable development.

The Lagos Plan of Action puts a special emphasis on the use of science and technology as tools for sustained economic development "with transformation". The highest among the priorities set by the Plan was and remains for African countries to achieve "self-suffi ciency in food production". The implication of biotechnology on African development process was considered during the African Expert Group Meeting to Assess the Implications of New Technologies for the Lagos Plan of Action, held in Swaziland on 22-26 October 1984. One of the important recommendations of that meeting was that African nations, at national and regional levels, make a determined effort to "acquire, adopt, and utilize the new technologies of recombinant DNA and of animal and plant tissue cultures" (OAU- EDCO/ST/l/116/85).

During the last few years, there has been an immense and increasing interest in the agricultural usage of living organisms due to unprecedented developments in the field of

biotechnology and genetic engineering. In fact the term "biotechnology" was set to cover

applications of this type of technology in such diverse fields as agriculture, improvements in animal and human health, in energy, etc. Since 1990, UNECA has been involved in sensitizing African policy makers as to what are the advantages and disadvantages of biotechnology and as to how the new technologies could be used for the benefit of African countries, in order to help solve some of their agricultural problems, among others, and to advance their research capabilities and food and agricultural development process.

It is true that biotechnological research is in progress in few African countries, however, biotechnological capabilities vary widely due to variations in available local bio resources, scientific and technical infrastructure, low levels of international market development, low degree of cooperation with international biotechnological structures, and due to failures to set of specific national priorities in science and technology. There is also a serious lack of coordination and duplication of efforts among African countries. African countries are technically and scientifically isolated, although more 90,000 African scientists work outside of Africa mainly because of lack of the needed environment conducive to their development and full evolvement.

Advances in genetic engineering and biotechnology offer a wide range of potential solutions to some of the basic food production and nutrition problems facing African countries. Increased food production can be achieved using genetic engineering through

modification of the genetic make-up of plants, the incorporation of nitrogen-fixing genes

into cereal crops to make them less dependent upon chemical fertilizers, through increased resistance of plants to pests, by increasing the nutritional value of foods through the insertion of desirable genes into specific crops. Fermented foods (foods in which micro-organisms are intentionally grown) are common in Africa. Microbes are thousands of times simpler genetically than plants or animal cells, grow 70 to 80 times faster and can be improved by genetic engineering or by simple scientific selection.

Genetic engineering will likety provide the tools required to accomplish needed changes in the processing of African foods. At least 25 % and perhaps as much as 60 % of the food produced in Africa is lost to insect, rodent and microbial spoilage. At least a portion of these losses can be avoided by proper harvesting and processing of the crops.

Fermentation widely practised in Africa can lead the way to expanded food supplies in the form of Single Cell Protein (SCP) grown on inedible substrates, Microbial Biomass Protein (MBP) grown on edible substrates, and serve as a means of processing and preserving the food supply. Fermented foods such as Nigerian ogi (a weaning food for infants produced by the fermentation of maize, sorghum and millet), Kenyan Uji, South African mahewu, Nigerian gari, cassava flour and fufu, which are obtained from fermented cassava, Ghanaian kenkey, and sorghum or maize (Bantu) beer are important parts of the African diet. Other African food varieties obtained through fermentation processes include iru, produced by the fermentation of locust beans, cowpeas, soybeans, or benniseed, and m'bannick, a drink obtained by fermentation of whole cow milk. Most of these fermentations can be upgraded, expanded and improved.

UNECA believes that, as African countries grow aware of the potential benefits of biotechnology, many of them will take the steps that will allow researchers to perform goal-directed research and development and encourage farmers and entrepreneurs to capitalize on the results of African and foreign research in this new field. It is true that constraints may come from the fact that:

(a) African educational systems are not conducive to the biotechnological education and training of the multidiscipiinary and high quality researchers required;

(b) Taking individually, and also because of the brain drain, African countries in general do not possess adequate technological resources and/or the scientific competence to take up hioscience research and development or the technical capability to develop scale up to downstream enterprise processes;

, (c) There is a lack of capital investment funds for creating a bioscience-based enterprise.

In addition, social and political constraints often act to discourage entrepreneurial initiatives;

(d) Lack of resources also prevent international organizations such as FAO, World Bank, UNIDO, etc. from undertaking large, wide-ranging programmes to transferring biotechnol ogy and its benefits to African countries although these institutions can promote projects with noticeable impacts at local and regional levels. For example steps to increase the capabilities of existing institutions performing R & D biotechnology can accrue the benefits to African countries. UNIDO has taken steps to establish and make operational, an African

biotechnology network. Such network, with efficiently implemented programme, can help overcome or circumvent some of the constraints underlined above, especially in the field of coordination of R & D among participating centres and avoid duplication and waste of efforts. FAO has taken the step to set up the global Gene Bank and has launched several

projects to protect some African endanger species.

UNECA argues that, given the acute nutritional problems that exist in Africa, and the

potential for overcoming some of them through the application of biotechnological

advances, African countries should emphasize the consideration of specific areas in which

modern biotechnology research and its results can be applied to agriculture in general, to

food processing and especially to the livestock sub-sector.

There is no doubt that the present degraded situation of the livestock would have been avoided, if Africa, had proceeded with the application of adequate livestock policies, if it had effectively made use of the available conventional technologies in the areas of disease control, feed and feeding, breeding and genetics and had been deeply involved in research and development. The continent has failed to carried out its green revolution, remains stuck with' obsolete techniques of livestock production and could also miss the on-going exciting world party of biotechnology revolution on which nations and their scientific communities are now relying to solve the world food crisis problem.

Certainly, biotechnology has the potential to induce profound modification of agricultural practices, considerable productivity increase and drastic decrease in costs while curbing environmental damage due to traditional agricultural methods. As such; it is seen as Africa's long-term solution for the long-standing technical problems overwhelming its agriculture sector. No wonder UNECA has put it under considerable scrutiny as two related publications were released by the Commission's staff in the course of 1992 alone. The question as to if biotechnology is being developed, adapted, transferred, appropriated and used in the specific area of livestock development in Africa and what tangible impacts have occurred as result of this exercise have not, however, been addressed. They need to be answered now if the continent is to grasp, without a delay, the good opportunities that

are offered.

We live in a world of global interdependence which faces environmental, economic, social and political problems and challenges of unparalleled nature and scope. Unfortunately the needed radical solutions are, however, hardly accepted by dominant decision makers.

Nevertheless, the globalization of human and world-affairs is no longer a question of faith, it has become a reality. We swim together or we sink together.

Long term development and ecological success will neither be attained by Japan, by the

United States by Europe, by any other country without an appropriate social global equity;

the main condition for solving extreme poverty. Raising the standard of living in the poorer

nations, especially those in Africa, and reducing the speed of the world's population increase without excessively overburdening the environment, is the very challenge biotech

nology must help us face.

This monograph, which forms part of the series of analyses on biotechnology and the African agricultural sub-sectors, elaborates on the current knowledge of biotechnology advances and applications in livestock production elsewhere and in Africa, and discusses related impacts, constraints and solutions specific to the livestock sector of the continent.

(—sx.

Nana-Sinkam

^ouulX

Director

Joint ECA/FAO Agriculture Division

I. INTRODUCTION

The use of livestock as source of high-quality protein to supplement staples in human

diet, manure as fertilizer, fibber for clothing or other forms of comfort and traction for crop

agriculture is as old as the mankind. In Africa, however, animal agriculture has more meaning. Indeed, rural resource-poor households directly exchange livestock (sheep and goat essentially) for grains where marketing is not organized and where access to cash is limited. These households also use livestock as source of wealth (cattle particularly in

pastoral societies) and rely on it for readily cash income that is badly required to meet immediate needs such as acquiring agricultural inputs, paying school fees, funding funerals and other various social events. They, further, rely upon livestock to cement relationship and social links that are very crucial for assistance in time of crisis. At the national level, the economy of many African countries (e.g., countries of Sahel, Botswana and to some extent Zimbabwe) largely depends on exports of livestock products.

With the above attributes, the livestock sector appears as one of the major supports of the existence of more than 80 per cent of the African population which are represented by the poor rural households. This means that the considerable social and economic importance of the sector must be emphasized. Essentially, it must be realized that without the sector, the already precarious subsistence life of these households would be further distorted.

For the preceding reasons, one would expect Africa to list the livestock sector among its top priorities and to endeavour that, by all means, it is an economically viable industry.

The reality, unfortunately, is totally different. In fact, the latest UNECA report on survey of economic and social conditions in Africa (ECA, 1992) shows that the continent's livestock population grew at an annual average rate of less than 1 per cent over the period 1980-1989 contrasting utterly with its burgeoning human population growth whose average annual rate was over 3 per cent. Losses in the sector amounted to US$ 4.7 billion per year during the period and per caput meat production declined from 11.5 kg in 1980 to 10.7 kg in 1990. Over the same decade 1980-1990, imports of livestock products increased by 3 per cent per annum in the face of 4.1 per cent decrease per annum in export revenues. The decade also saw a drop in self-sufficiency from 91.2 (in 1980) to 88.2 per cent (1990) and an increase in trade deficit from US$ 1.7 billion to 2.5 billion.

We believe that Africa would not have arrived at the above alarming livestock economy if, through the development and application of adequate livestock policies, it has effectively made use of the available conventional technologies in the areas of disease control, feed and feeding, breeding and genetics and has been deeply involved in research and development. The continent has failed to carried out its green revolution, remains stuck with obsolete techniques of livestock production and could also miss the on-going exciting world party of biotechnology revolution on which nations and their scientific communities are now relying to solve the world food crisis problem.

Certainly, biotechnology has the potential to induce profound modification of agricultural practices, considerable productivity increase and drastic decrease in costs while curbing environmental damage due to traditional agricultural methods. As such, it is seen as Africa's long-term solution for the long-standing technical problems overwhelming its agriculture sector. No wonder ECA has put it under considerable scrutiny as two related publications was released by the commission's staff in the course of 1992 alone. The questions as to if biotechnology is being developed, adapted, transferred, appropriated and used in the specific area of livestock development in Africa and what tangible impacts have occurred as result of this exercise have not, however, been addressed. They need to be

answered now if the continent is to grasp, without a delay, the good opportunities that

are offered.

This monograph elaborates on the current knowledge of biotechnology advances and

applications in livestock production elsewhere and in Africa, and discuss related impacts,

constraints and solutions specific to the livestock sector of the continent.

II. BIOTECHNOLOGY AND LIVESTOCK SECTOR : PRESENT STATUS OF KNOWLEDGE

Definitions

A wide array of definitions are used to typify the nature of biotechnology which is a contraction of 'biological technology'. According to The European Federation of Biotech nology quoted in Henderson (1987), biotechnology is an integrated use of biochemistry, microbiology and chemical engineering in order to achieve the technological application of microbes and cultured cells. The Office of Technology Assessment of the U.S. Congress (OTA, 1989) referred to it as " any technique that uses living organisms, or substances from those organisms, to make or modify a product, to improve plants or animals or to develop micro-organisms for specific uses". Mantel I (1989) calls it an 'integrated use of biochemistry, microbiology and chemical engineering to exploit plant materials and genetic resources for the production of specific products and services'.

It is clear from these definitions that biotechnology is of a complex nature. This is substantiated by IDRC (1985) which observes that 'biotechnology... embraces so exten sive, expansive and diverse a spectrum of biological principles, phenomena, materials, organisms, reactions and transformations that no longer can it logically be considered in the singular as a collective or mass noun'. For the present purpose, we will use one of the most comprehensive definitions ever suggested and which is from Dr. Hardy, former Director of life sciences at Du Font. Dr. Hardy quoted in Elkington (1986) identifies biotechnology as " the technology that enables the use of biological system as a product, as a process to make a product, or as a service" and subdivides it into three types based on the enabling process: these are organismal, cellular and molecular. All theses types, he says, involve genetic engineering. Organismal biotechnology takes place at the level of the whole organism and has been in practice for centuries to improve organisms used in fermentation as well as in animal and plant breeding. Cellular biotechnology which takes place at the cell level and involves cell culture, regeneration and fusion, is relatively new.

Molecular biotechnology occurs at the molecular level and utilizes techniques such as recombinant DNA. Cellular and molecular biotechnology. Dr. Hardy points out, "are expected to be in orders of magnitude more effective than organismal biotechnology because they eliminate the sexual barriers to movement of genetic materials and, in the case of molecular biotechnology, permit any transfer of natural or synthetic genes."

It thus appears that biotechnology is a centuries old aggregate science that has evolved into recently created techniques (i.e., "modern biotechnology") for which the essential and common foundation is made up of genetics and engineering. The techniques which, together, form the basis of genetic engineering are the recombinant deoxyribonucleic (DNA) technology, the monoclonal antibody technology and the new cell and culture technology (World Bank, 1990).

Technology Development

An adaptation by World Bank (1990) from OTA (1984) and Wyke (1988) of the major steps in the evolution of the science of genetics that leads to modern biotechnology is presented in Table 1. It took a long road and more than 100 years since Mendel laid down

rules and explained the mechanism of inheritance to arrive at the Recombinant DNA

Technology, the technique that revolutionized the science of genetics for the profit of

mankind. The 1970s and 1980s saw electrifying discoveries with attributes of one species

of animal transferred into another species of animal or plant in a move that creates transgenic animals and plants. Cells of different origins are fused to produce hybrid entities

capable of active functioning (e.g., hybridomas for monoclonal antibodies) in what is called cell fusion technology. Plants are regenerated and propagated from their cells or tissues in what is known as tissue and cell culture technology. Desired embryos are obtained in vitro or in vivo, micromanipulated, stored and transplanted into surrogate mothers of the same or different species in what is referred to as multiple ovulation and embryo transfer technology (MOET). Today, it is like nothing more, in the biological sciences, is impossible and anything can be produced anywhere. It is only a question of cost whose frontiers are

being approached very rapidly!

Recombinant DNA, cell fusion and tissue culture, multiple ovulation and embryo transfer techniques are seen as the actual world core technologies from which scientists has generated and continue to create other new techniques at an unprecedented pace. It is worth noting that no one can tell at this stage of keen protectionism (see chapter III) the number of useful discoveries that can be readily used in animal husbandry since, as some experts put it, new creations may be monthly and even daily in the world. Many of these

discoveries including MOET, artificial insemination, embryo splitting are highly publicized,

however, and are described in the various and now available biotechnology books and

papers (e.g.; Nana-Sinkam etal., 1992; Haribou, 1992). In the following, some additional pieces of information on selected technologies are provided with respect not only to animal

related technologies but also to those applicable to the production of plants on which

animals rely for their food.

Manipulation of the Germ Line

The manipulation of the genetic material (i.e., the DNA essentially) of plants, animals and various types of micro-organisms in process known as recombinant DNA (rDNA) technology is at the,origin of most of the today's advances. Many techniques are derived from it and the other few ones such as cell/tissue culture, MOET and cell fusion are increasingly becoming intermediary steps in achieving "goals" that genes code for. Let's note that every biological function that exits or that we want to induce or create must be commended by the genes and that deletion or addition of a gene or a group of genes may generally mean a removal or a creation of a specific function. Here are some germ line related new techniques that need to be known.

1. DNA Probe and Hybridization

By heating DNA from a mammalian or any organism cell, the two strands of its double helix can be separated. A pure single-stranded DNA fragment complementary in sequence to the DNA or RNA one desires to detect is obtained by cloning from the organism of interest or synthesized using chemical methods if the sequence is short. That single- stranded DNA is the probe. When this probe combines with its homologue or complemen tary genetic material (DNA or RNA), the double-stranded DNA is reformed in a process referred to as hybridization.

The probe is tagged with a label, usually a radio isotope in order to follow its incorporation into double-stranded molecules during the course of hybridization reactions. Examples of how DNA samples and probes for hybridization assay are made are shown in Annex B.

Genes are found in the chromosomes. Chromosomes are located in the DNA. DNA is found in the nucleus which is located in every cell. The nucleus and the cytoplasm covered by the cell wall form the cell.

2. Gene mapping for Major Histocompatibility Complex (MHO

This consists in identifying on a given genome the group of genes which are responsible for resistance to various diseases. These genes are located next to each other and form what is referred to as MHC. MHC genes tend to be inherited together. There is a wide

variation among them and their products between animals. The same MHC type can only

be found in family related animals which justifies its role in the inheritance of specific

immune responses.

3. Polymerase Chain Reaction (PCR)

PCR is a new DNA replication procedure which is first unveiled in 1985 and which multiplies copies of a given DNA sequence directly and exponentially. Millions of copies

of any selected fragment can be synthesized in a matter of hours. The great quantity of DNA produced in an amplification is easily visualized and manipulated. This makes analyses of genetic material remarkably much simpler. The technique (see Annex C) which exploits an enzyme that synthesizes DNA in the cell, the DNA polymerase, is now causing a dramatic increase in the pace of molecular biology advances.

4. Biological Nitrogen Fixing

Nitrogen is generally a limiting nutrient in agriculture. Though it is plentiful in the form of gas in earth's atmosphere, higher plants cannot use it in this form. It must be first fixed i.e., combined with other elements such as carbon, hydrogen and oxygen before it can be used by these plants. The ability to fix atmospheric nitrogen is limited to certain group of organisms some of which are in free-living state and others in symbiotic associations with higher plants. Examples of the well known symbioses include legume- Rhizobia and Azolla-Anabaena. Specific genes of desired functions can now be inserted in the organisms. Likewise, the reason why many non-legume plants cannot be associated with fixing bacteria can be eliminated by providing their genome with the genes encoding the missing ability. Further, there is a hope that germ line manipulation will, one day, allow higher plants to fix directly the abundant earth's atmospheric nitrogen.

Cell Fusion and Monoclonal Antibodies

Antibodies are protein molecules produced by certain white blood cells in response to antigen (foreign proteins) introduced in the body. They are a basic constituent of animal disease-fighting immune system. It is not easy to obtain antibodies from immunized animals antibodies necessary to protect against a specific pathogenic agent. The operation is tedious, slow and can not guarantee isolation of a specific antibody. Scientists, in TQ75, has developed a technique that fuses myeloma (cancer) cells with antibody-producing cells from an immunized donor and obtained a hybrid cell called hybridoma. The hybridoma has the ability to multiply rapidly and indefinitely in culture and to produce an antibody of predetermined specificity, known as monoclonal antibody. The hybridoma technology now allows production of standardized reagents (antibodies) and analysis of virtually any antigenic molecule.

78 per cent of earth's atmosphere is made up of nitrogen gas.

Applications

Recent advances in biotechnology have unveiled many opportunities and are changing things around in such a fast and astonishing way that, in the field of livestock production and development, many centuries old conventional practices that are part of the 'struggle' to increase production and yield subject to decreased production costs and environmental degradation are becoming rapidly obsolete. Because the number of applications is commensurate with the unprecedented pace of discoveries mentioned earlier, it would be unrealistic to portray a review of all today's biotechnology applications to livestock production. The following is a highlight on the intervention domains of some of the tools that are being developed. These domains are related to animal genetics, health, nutrition,

reproduction and growth.

Genetics

As said earlier most of the biotechnology advances that we witness today deal with genetics which has become one of the most exciting and challenging biological fields of our time. Genetical manipulations are also controversial as we learn that human beings can now decide characteristics to breed into plants and animals (including man) and

organisms.

The conventional way of breeding animal for desirable traits has always been time

consuming and discouraging. Selection for a trait may take many generations, easily 10

to 15 years or more. Evermore frustrating is the fact that only some categories of traits respond easily to selection. These are essentially growth parameters which, under certain

management conditions, will also show little or slow response. Reproductive characters which are probably the most important to the breeder and the producer, are the most

difficult to select thus to improve. Heritability (which is used to measure the likelihood of transmission of genes from parents to progenies) is poor to nil for these characters, a

situation that makes geneticists hopeless in their own area of expertise as the characters

defyingly fail to respond to selection. Moreover, many animal science students refuse to major in animal breeding and genetics not only because of the heavy load of statistics needed to measure responses to selection but also because of the frustration resulting from

selecting for traits whose origins, the genes, cannot be seen and manipulated easily.

Tnere is another frustration in conventional animal breeding and that is the lack of easy way to bring, into a local stock, desirable traits from another stock found elsewhere at

thousands of miles away. Animals are imported from given ecozones to completely

different ones. Diseases are exchanged in the process and, worst still, genetic and

environment interactions prevent them from doing adequately the job they are brought in

for. They may even die before the reproduction endeavour begins. Further, crossbreeding local animals with exotic breeds for dairy production is generally unsatisfactory as performances usually start decreasing after the F1 (i.e., progenies of the first cross) stage.

Since the early 1980s, advances in the technology of gene transfer have allowed

production of transgenic animals. It has been first done in mice and now in pig, sheep,

rabbit and cattle. One good example of this is the transfer to sheep of the gene for the

synthesis of human blood clotting factor 1X and its expression at low frequency in the milk. It is believed that the ability to produce transgenic animals will result in a total reorganization of the conventional animal breeding theory. With the help from MOET, exchanges of genes to upgrade animals can now be easily done regardless of distance.

The time s'pent improving a breed is to be short due to rapid multiplication of the desired

genotypes. Genome of embryos can be modified with insertion of adaptation or other specifically desired genes before shipping them. Thus, access to the genetic material is no longer a problem: we can see it, we can manipulate it. Reproductive traits can now be improved by replacing, altering or adding the encoding genes and breeders using monoclonal

antibodies can now identify specific gene carriers. The ultimate advantage of all this is that the cost of breeding farm animals is expected to decrease drastically.

Reproduction

Many reproduction related problems, as seen above, are taken care of by genetic processes. However, biotechnology offersVnore to the reproduction of farm animals. The technique of embryo splitting which produces two genetically identical individuals is now extended to the production of multiple siblings. Cows can now easily produce identical twins when this technique and embryo transfer are applied. It is worth noting that natural reproductive process almost totally prevents cattle from producing twins.

An outstanding male can now sire thousands of progenies even years after his death without affecting the generation interval thanks to artificial insemination (Al). But this is not the end of it as new discoveries are already bringing bad news to Al technology.

Producers can now replace this technology with embryo technology which because of its

unisex parentage 4 capability, allows a mass production of a given sex of animal and is in

a move to change the naturally occurring sex ratio in favour of females that are so much

needed for increased production.

Al's displacement may also results from the interspecies transfer capability of embryo technology. This does not only conserve the limited germ plasm of exotic and endangered

species; it also eliminates the vertical transmission of species-species diseases from Al.

Reproduction can further benefit from the advances in biotechnology through oocyte

fusion and cloning techniques. Homozygous females are produced using two female ova

mutually fertilizing each other without male gamete intervention in an amazing female-fe

male crosses. Cells of embryos obtained this way (or any other embryos) are fused to ova or even somatic cells whose nuclei have been destroyed and are then multiplied indefinitely (i.e., cloned). The result, in other words, is the regeneration in multiple copies of the

homozygous females from a single embryo cell with all the process occurring without a male animal or a male gamete. Copies of any already proven animal can be so obtained, making embryo technology probably the easiest, the most wanted and the cheapest reproductive technique for today and the future.

Monitoring fertility in farm animals is another area of important applications of new advances Jn novel biotechnology. It involves, among other things, measuring blood and milk fertility hormones, sperm fertilizing ability, detection of oestrus and early pregnancy.

The use of monoclonal antibodies and DNA probes as powerful diagnostic agents for this monitoring process is now in effect as these agents have the ability to detect minute quantities of the indicators of interest. An idea of how these agents or kits have become

commercially important is given in the section on the applications of biotechnology to animal

health presented in this chapter.

The generation interval (Gl) is the average of the parent when their progeny which must replace them is bom. In the conventional breeding, Gl has a tremendous effect on genetic progress which it decreases when animals are kept for long time in reproduction.

Embryos are produced from the genome of only one parent or from two mate gametes. With this method, one pronucleus of newly fertilised ovum is destroyed by ultraviolet light beam, and the other is permitted to duplicate before the cell cleaves, thus restoring diploidy.

Depending on which pronucleus is destroyed, the embryo will be of only paternal or maternal origin but will always be female and 100 per cent homozygous. The same technique is used to selectively destroy the female pronucleus in an ovum where the cell surface has been treated to allow polyspermy, -making a male-male cross possible.

Nutrition

Feeding is the most expensive part of animal agriculture. It is expected to account for 70 per cent or more of the total production cost in dairy, pig, and cattle fattening operations.

Legumes are the best natural feedstuffs because of their high digestible protein content.

They are capable of thriving in association with nitrogen-fixing bacteria but are not available in great quantities as grasses which lack this capability. Moreover, the lignin content of grasses together with their invasion by tannin and silica make them highly indigestible by

ruminants.

Some plants and/or their fruits are simply toxic to animals. Others lack essential nutritive factors. Further, some nutritionally important species are rare and suffer from inadaptation when moved from their natural habitat. The nitrogen-fixing organisms mentioned above may also suffer from stress due to inadaptation to drought, soil salinity and other conditions.

Now, with the genetic engineering incorporating nitrogen-fixing genes into various plant species, production of nitrogen-fixing grasses will revolutionize range animal production.

That genes are also being incorporated into nitrogen-fixing organisms to correct the stress inadaptatiort problem and into rumen micro-organisms to enable their digestion of lignin, hemi-cellulose complexes and of other chemical inhibitors in the feedstuffs, gives livestock producers great opportunities to increase productivity of farm animals and decrease their

cost of production.

Transgenic rumen micro-organisms have also been released which reduce rumen methane production and increase rumen microbial production of specific amino acids from pasture.

They further play an important role in the detoxication of plant poisons. For example, a

ruminant bacterial inoculum obtained from goats in Hawaii was successfully introduced

into cattle rumen in Australia to detoxify mimosine found in Leuceana forage (Jones and

Mearrity, 1986 quoted in Baker, 1991). Overall, it is expected that the use of genetic engineered rumen microflora for a more efficient utilization of plant nutrients will offer another great opportunity to decrease demand for feed grains and, hence, the demand for land in many areas around the world.

The possibility of reducing forage shortage problems is another advantage from biotech nology. Like in animals, transgenic plants can also be produced with genes encoding the desi ^ traits such as pest resistance, adaptation to cold, drought, salinity representing goou candidates. With this and other techniques breeders can now help obtain, at desirable quantities, the quality forage needed at affordable costs.

Milk Production and Growth

The new developments in Growth Hormone <GH) production that now allows, thanks to genetic engineering, a considerable amount of milk produced per cow, ewe, doe... is a ready made problem solving recipe with respect to the poor animal protein intake prevailing in many parts of the world. GH referred to as a 'nitrogen-fixation' agent in mammals (OECD, 1992), improves carcass composition (i.e., amount of lean meat in comparison to fat deposited) and milk production efficiency (i.e., kg milk produced per kg feed consumed) in farm animals. As shown in Table 2, GH brings a tremendous economy in feed and dairy cows while increasing the milk yield per cow. In order words, fewer animals are now

The rumen micro-organisms are essential to the digestion of forage ingested by ruminants.

They increase rapidly in number depending on the quality of the forage and many of them become source of protein for the host (the ruminant) as they are digested and serve as food for this host.

needed to produce the same amount of milk and at reduced cost. Moreover, GH is known to increase growth rate by 36 per cent and reduce visceral fat by 30 per cent in lamb.

This, certainly, helps meet the increasing demand for low-fat content meat as the increase in meat fat is associated with high risk of cardio-vascular diseases in man.

There is another interesting aspect of biotechnology as it is applied to milk production.

Many people in the world have poor tolerance to lactose in cow milk resulting in diarrhoea or constipation or both. Recombinant DNA technology will now permit cows to produce low-lactose quality milk.

Health

Diseases are a major source of animal (human included) suffering and of tremendous losses in livestock production. They can be of viral, bacterial, parasitic, genetic, metabolic and many other origins. The number of the infectious diseases alone shown in Table 3

gives an idea of the long list of pathologies farm animals can be exposed to. Diseases can

be epidemic causing excessive damage in a very short period of time in an extended population or endemic with damage restricted to a farm or a region. Many of them are

insect transmitted or use wild animals as reservoirs, which make their control very difficult.

In general, when death does not occur, animals carrying a given disease may drag it on for

a long period of time resulting in a considerable reduction of their economic value.

It is estimated that some US$ 4 million per year is lost from diseases in cattle alone in the USA (NRC, 1982). Experts attribute this, in part, to a lack of information which is essential for the improvement of breeding methods regarding genetic resistance and a lack of knowledge about the immune function in food producing animals. They also blame the lack of adequate diagnostic reagents to identify pathogens responsible for the diseases.

With the monoclonal antibody technology, specific reagents can now be developed for the diagnosis of specific pathogens. For example, strains of the same infectious agents can now be differentiated easily from each other and so are the pathogens that induce similar symptoms in the sick animals. In livestock sector, earliest impacts on health emanate from diagnostic products as by the end of 1989, over 100 easy-to-use test kits were available and used by veterinarians and farmers. According to OECD (1992), fertility monitoring is currently the largest single area of application for diagnostic kits (see

Table 4).

Monoclonals also offer a mechanism to improve methods of selective breeding. They are used to identify not only gene systems that influence susceptibility to infectious diseases but also genes which control the inheritance of disease resistance and other desirable performance traits, something the conventional methods of producing typing reagents cannot do. With precise typing (which means that monoclonals help obtain good

genetic profiles of breeding stock and detect debilitating genes with high specificity) and

the use of ova transplantation there will be a great acceleration of selective breeding.

Monoctonals are further useful in immunization which remains one of the most economic ways of preventing specific diseases. Current conventional vaccines which use attenuated organisms or killed whole organisms or inactivated toxins or viral split products may be associated with problems of impotency, instability, reatogenicity (i.e., adverse side effects) and actual transmission of diseases. Genetic engineered vaccines obtained thanks to monoclonals and recombinant DNA technology, in the contrary, are stable and safe since only a single or small number of components of the infectious organism is needed to produce them. These novel vaccines are also cheaper than the conventional vaccines (Bachrach,

1981).

Another aspect of conventional methods of disease control is the use of insecticides or other chemicals to kill vectors and ectoparasites. The trouble is these products have never eradicate the ill-conditions. Rather, they are used over and over again, cause excessive environment pollution and damage, are not cost effective and may be toxic to animals and man. Genetic engineering and monoclonals can now be used not only for the perfect identification of genes of resistance to ectoparasites and insertion of these genes into the genum of breeding stock but also for safe and environmentally friendly drugs that have specific effects on the vectors.

10

III. BIOTECHNOLOGY AND AFRICAN LIVESTOCK SECTOR DEVELOPMENT

The Statfe of Technology

Development, Transfer and Application

As recognized earlier, Africa has failed to carry out its own green revolution. The techniques used in agricultural production in general and livestock development in particular are obsolete. The conventional research activities are minimum. With this gloomy picture, one does not expect the continent to show encouraging signs of higher than conventional technology development neither will one be surprised to realize that little or no transfer and application of biotechnology has occurred (see Table 7). It is within this constraint that biotechnology development and application in Africa will be covered.

Vaccine Production Technologies

Africa is stuck with the conventional methods of vaccine production (i.e., old biotech nology) with all the related problems mentioned earlier (see health section in the applications of biotechnology in chapter II). Laboratories are relatively well equipped in a number of countries to do this with Nigeria producing all the vaccines and sera it needs, Egypt producing not only vaccines and sera but also performing tissue culture. Mali, Ethiopia, Cameroon, Niger, Senegal export various vaccines to other African countries.

An ILCA production (Chigaru et al. 1989) indicates that most National Agricultural Research Systems (NARs) with the exception of Egypt, have no laboratory of modern molecular or cellular technology capabilities. Generally, African countries simply cannot produce novel vaccines. Only ILRAD and to a lesser extent ICIPE in Kenya, among the International Agricultural Research Centres (lARCs), have facilities for molecular research involving recombinant DNA technology.

At ILRAD, scientists are doing a wonderful job using genetic engineering but their work is limited to protozoan diseases and essentially trypanosomiasis and theileriosis. They are working in collaboration with other world laboratories to identify and elucidate the basic structure of African bovine MHC types particularly those associated with improved resistance to the parasites of interest. They are also working on techniques needed to identify and quantify drug resistance particularly with respect to common trypanocides and have developed DNA probes which are used with PCR technique to detect African trypanosome infections. These probes have proved highly specific for a parasite subgenus, species or sub-species and ILRAD is now able to determine if a person or animal is suffering from trypanosomiasis and precisely what species or strain of the parasite is causing the disease. This helps the disease control workers to prescribe better treatments.

ILRAD's sophisticated molecular probes are being tailored for use in the field where they will help understand how the disease behaves there, what trypanosome species occur in what areas and how often the parasite infect their tsetse fly and mammalian hosts. With

this, epidemiologists will have better knowledge of the spread of the disease and the areas

where people and livestock are at risk. Let us note that the traditional methods used to identify trypanosomes include microscopic examination of mammalian blood smears and tsetse fly organs. Because many trypanosomes can be distinguished from others only by

inoculating samples of each parasite type into experimental animals and then observing the

responses that differ according to the infecting parasite type, these methods are often inadequate and unreliable. Finally, by mapping the genomes, isolating genes that encode

parasite antigens recognized by monoclonals and transferring DNA from one cell and

ii

organism to another, ILRAD endeavours to discover the molecules causing lethal effects of parasite infections and the molecules which may be used for the production of safe and effective vaccines against the parasites.

As for scientists at ICIPE, they have discovered that some strains of bacteria found on the skin of waterbucks are very lethal to tsetse flies. With powerful biotechnology tools, genes coding for the toxic bacteria substance can be identified, inserted into other bacteria for a mass production of the substance. Alternatively, genes that permit association of waterbucks with the toxic substance-producing bacteria can be inserted into bovine genome. In tick control area, ICIPE has also discovered The Tick Resistant Antigen Indicator (TRAI) molecule that brings hope not only for the detection and selection of animals that are genetically resistant to ticks but also and essentially for the production of safe vaccines

against the ticks.

Overall, ILRAD and ICIPE's encouraging achievement in advanced biotechnology devel opment are expected to provide farmers with environmentally hazard-free methods of control of ticks, tsetse flies and the parasites they host. The resulting economic gain which is expected to be substantial could be better if other Africa-based institutions develop or transfer novel biotechnologies for the control of many other pathogens that cause havoc in the continent's livestock sector (see section on impacts).

Artificial Insemination (Al) and Embryo Transfer (ET)

Al is probably the most used old biotechnology in Africa. It is a common practice in many Eastern and Southern countries particularly in the cattle industry. There are indications (Chigaru et al., 1989) that farmers in Kenya obtain through a network of sub-stations, high quality pedigree dairy and beef bul|s from the Central Artificial Insemi nation Station (CAIS) located at Kabete. Tanzania which has 100,000 crossbred (zebu x exotic) cattle held in small-scale herds, uses Al to promote smallholder dairy production in Mbeya and Iringa regions. In Ethiopia where Al started over 50 years ago in Eritrea, commercial dairy and small scale cattle farms obtain the technology through a network which covers the Ethiopian Highlands in an upgrading of local breeds programme.

Zimbabwe, Botswana and Malawi also upgrade their indigenous breeds using Al and mostly

Friesian semen.

Ui ike in the Eastern and Southern Africa, the Al practice in Western and Central parts of the continent is generally at the exploratory state though Nigeria and Cameroon are

employing it in some crossbreeding programmes. The technique has been used in Dahra Research Station (Senegal) in the 1960s and 1970s and trials have been carried out in

Ghana some time ago but has faced with disease and logistic problems.

The more sophisticated ET technology, as far as it is concerned, is rare in the NARS of

Africa. With the Exception of Zimbabwe where some private dairy farms have limited application of ET, no African country truly uses the technology for livestock development.

Some experiments in ET have been initiated at EISMV in Senegal in 1988 with the collaboration of Canada but stopped at the academic curiosity level.

Three lARCs (i.e., ILRAD, (TC and ILCA) have Al programmes in Africa particularly in The Gambia and Kenya and use it as an adjunct technology in their trypanosomiasis control

programmes. It is only at ILRAD that ET is well developed with regular production of Ndama and Boran calves and common embryo splitting prior to implantation. Here again, the technology is an adjunct tool for the laboratory research activities and help ILRAD decrease the cost of its experimental animals production.

12

Biological Nitrogen Fixation Technology

There is an African Association for Biological Nitrogen Fixation (AABNF) which met in Nairobi (Kenya) in 1984. Though most countries are, in general, involved in nodule collection, strain/plant testing and Rhizobium inoculants production, only a few of them such as Kenya, Nigeria, Senegal, Zaire and Zimbabwe produce inoculant for wide country distribution. Zimbabwe exports inoculants to African and Asian countries.

At the lARCs level, IITA produces inoculants for legumes in its alley cropping programme.

ILCA also uses Rhizobium technology and produces inoculants for its forage agronomy programme and for the distribution to the NARS.

In Vitro Plant Culture

This technology is new in Africa. It is adopted by most countries in North Africa but does not exist in most Sub-Sahara African (SSA) countries even at the experimental level.

Zimbabwe is the only SSA country where in vitro culture research is in progress but it deals with tobacco. A gene bank funded by GTZ with in vitro culture facilities in Kenya is yet

to be put in practical use.

Within the lARCs, IITA is the leading institute in vitro plant culture but much of the work is done on food crops for direct human consumption. In the field of forage grass production, ILCA has an adequate facility for plant in vitro culture and is using the technique for the

dissemination of Brachiaria species among the NARS.

Impacts of Biotechnology

Actual Impacts

1. Impact on Health

The old way of producing vaccines, though not always reliable, has contributed to the control of some diseases in Africa. Some countries have become self-sufficient in many types of vaccines (e.g., Nigeria). Others even export to outside of Africa (e.g., Zimbabwe) or to African countries (Senegal, Niger, Cameroon, Ethiopia). However, the global production remains insufficient as the majority of countries are net importers of vaccines and will continue to be so in the future. Further, most of the local laboratories producing these vaccines are state owned; thus their economic viability is uncertain. Moreover, the locally produced vaccines are not always good, resulting in a reluctance of countries of a given economic grouping to import vaccines produced in a member country or in an increased appetite for imports from outside Africa. The refusal of many ECOWAS countries to buy vaccines produced in member countries and the import of South African vaccines coming through Botswana in the 1980s are a perfect example of this situation.

Although ILRAD has been very active in developing novel technologies that is needed for the control of Trypanosoma and Theileria species, the laboratory is probably still far from releasing genetically engineered, specific and safe vaccines against the parasites.

Likewise, ICIPE cannot guarantee vaccines against ticks in the near future.

Of immediate application are the procedures developed by ILRAD which permit the use of monoclonal antibody techniques along with the Enzyme-linked Immunosorbent Assay (ELISA) for the rapid serodiagnosis of trypanosomiasis, theileriosis and reproductive diseases such as IBR-IPV and brucellosis. Also of immediate application is the technique developed in Zimbabwe for a rapid diagnosis of Salmonella using DNA hybridation (Chigaru

13

etal., 1989). Within 12 hours instead of many days when conventional methods are used, this technique can detect the presence of the pathogen and could be a breakthrough for the early diagnosis of salmonellosis which is known to affect man and animal health.

There is no doubt that most African NARS now have the above diagnostic tools or know of them. However, how much impact is produced so far in terms of parasite control, increased productivity and net financial return due their use is unknown. It is likely that this impact, at least for now, is negligible as heavy uses of conventional insecticides, acaricides, trypanocides continue to prevail where Theileria and Trypanosoma are causing considerable losses. In fact, a survey by Elcovet (1991), showed that the decades old Diminazene-di-aceturate is still the most efficient base of trypanocides and that trading these trypanocides is the most lucrative of the veterinary drug sale businesses in Central and West Africa. Further, chances are that nothing has changed at the family sector levei where Brucella go undiagnosed and continue to represent a major constraint to increased reproductive efficiency particularly in Ndama which is loved for its trypanotolerance but hated for being probably the most susceptible among African cattle breeds to brucellosis.

Certainly, it is a disillusion to believe that the fact that powerful diagnostic kits are

developed in Africa and for Africa means that these kits will be used extensively and rapidly change the health image of the continent's herds. Policy and economic constraints are overwhelming and suffice to totally undermine any livestock development effort (see section on policy issues).

2. Impact on Reproduction and Milk Production

Successful adoption and use of Al are spotty or a rare event in Africa. As seen earlier,

in Sub-Saharan Africa, only Zimbabwe, Botswana, Malawi, Tanzania, Cameroon and Nigeria are said to have adopted the technology for upgrading purposes in dairy development programmes. The reality is that Al may not have contributed much in having a positive

impact on dairy cattle reproduction and milk production in the majority of these countries.

Table 5 indicates that in 1989-91, 62.5 per cent of these countries were unable to reach the level of their total caput milk production ten years before. It is, thus, doubtful that Al technology has produced any measurable global impact in livestock development in Africa.

The situation is likely to be worst when impact of embryo transfer is contemplated as the

technology virtually does not exist in the continent.

3. Impact on Nutrition

Nutrition of farm animals in Africa is essentially based on rain-fed natural pastures. With

the exception of research stations and a few government farms, ruminants are grazed in the bushes and often scavenge. Improved pastures or cultivation of forage plants for animal nutrition do not exist in the traditional system of production under which almost all the livestock raised in the continent is found. Rhizobium research and production can be said to be almost if not entirely directed to food crop production that is destined for human consumption. Further, the ILCA's endeavour with respect to in vitro plant culture and distribution of Brachiaria species is not any near to produce an impact in the traditionally managed livestock sector. To effect production, Brachiaria in form of improved pasture must be extensively adopted by stockholders and/or owners first. This, unfortunately, is not the case. Overall, it can therefore be concluded that no tangible impact of plant culture and biological nitrogen fixation is occurring as a result of biotechnological research or

adoption. -

14

Potential Impacts

We have seen earlier in this monograph that African NARS make virtually no contribution to biotechnology research. This means that the main stream of development has to come from the developed countries or their funded agencies operating in Africa. As a result, fear of uncertainty about possible inadaptation to the continent conditions of the technologies developed in the West has emerged. Question about the West imposing its technology to Africa has also been raised. We will see in subsequent sections to what extent this negative perception is valid. For now, it is our view that, at least in the area of livestock development, no biotechnology is completely useless. It can give a hint to find solutions to local problems, can be adapted or modified. Based on this fact, we consider that all the world technologies reviewed earlier are important in producing direct or indirect impacts on livestock sector in Africa.

1. Potential Impact in the Area of Genetic Improvement and Preservation of Genetic Resources

Africa has many hardy breeds that are relatively well adapted to the prevailing harsh environmental conditions. These breeds are unimproved, have poor to mediocre growth and reproductive performances and the prospects for their improvement are one of the greatest. This is the area where Al, MOET, embryo splitting and cloning, recombinant DNA technologies can all converge to produce, multiply and rapidly propagate animals that grow faster, give more milk and have better fertility than the actual ones.

Ndama breed which, because of its trypanotolerant attribute, is the best adapted cattle breed to humid zones, has too small a size. This is generally a major constraint to its use for animal traction. The breed also produces only 1 to 2 litres of milk per day that are hardly enough for the young calf, and reaches slaughter or marketable weight at relatively late age.

West African Dwarf (WAD) goats, also adapted to humid zones of Africa is listed among the most prolific small ruminants of the word but like Ndama, they are very small and can be taken for tiny kids even at the adult stage; they are poor milk producers as well and cannot provide their new-born with an adequate feeding, a situation that is responsible for heavy neonatal mortalities and mediocre preweaning survival.

Zebu breeds which are much more numerous and more important cattle in Africa, also have poorer reproductive capability than taurine breeds and, because they lack genes that encode protection against trypanosoma species, are banned from the humid zones where feed resources are more abundant.

The local breeds of chicken found in every rural household and very much appreciated for the good meat flavour and low fat content, have a strong hatching ability which prevent the females not only from having high reproductive rate but also from being used as laying hen. They also have a very poor growth to slaughter age which is three to four time less than that of modern broilers.

The current emphasis on breed substitution in Africa is another problem. It may rapidly leads to loss of genetic diversity and of some genotypes of animals particularly cattle.

Moreover, some less favoured breeds are now in the verge of disappearing. For example, the Mpwapwa cattle in Tanzania has been declared an "endangered species" by FAO. The Dwarf Shorthorn cattle found along the west coast of Ghana also faces the same fate.

Many other endangered cattle species which exist in the continent are provided by IBAR (see Adeniji, 1983).

15

The above are some of the many breeding and genetic problem areas that are specific to Africa and that are awaiting contributions from gene manipulatioti and other novel technologies. Less favoured and endangered breeds, however, cannot afford to wait much longer and must urgently benefit from gametes and embryos cryoconservation technique which will permit their in vitro preservation and their regeneration in the future. By the same token, there may be long time before the West provides kits to detect the proteins responsible for performance problems mentioned above or to find genes and the corrections needed. .The bottom line is that impact can be expected in a foreseeable future only if Africa seizes without any delay the opportunities which are already there.

2. Potential Impact in Reproduction and Milk Production

Reproductive inefficiency is one of the major constraints preventing the African livestock

sector from being highly productive and economically viable (see ECA, 1992). Zebu cattle, in particular, do not always show behaviourial oestrus as manifestations of the heat are not shown by the females. Breeding thus does not take place and a lot of potential calves

are lost as a result of fertilization failure of viable ova.

Also lost are many embryos and foetuses from pregnant females which are slaughtered every day in Africa. Experts now estimate that this is one of the highest reproductive

losses ever found in African livestock sector and point out that this is due, among other

things, to the lack of diagnostic tools capable of early detection of pregnancies. Mono- clonals now offer Africa an opportunity to design sensitive detection systems (i.e.. Kits) or to use those already available in the world market (see Table 4). Every thing being equal, the financial and social gains from saving the great number of calves, kids and rams which otherwise might have been lost, is expected to be considerable. They could include a rise in farm income, a decrease in meat export and/or an increase in animal proteins consump tion.

There may also be more consumption of animal proteins at cheaper price in Africa if more milk is produced and if more people now suffering from lactose intolerance consume it. Total cow, buffalo, sheep and goat milk produced by the continent is estimated at 21.45 kg per inhabitant in 1991. This corresponds to 58.8 g per day and per caput and represent only 23 per cent of corresponding value (225.8 g per caput and per day) for Latin America.

The use of recombinant growth hormones are of particular importance in the African context and more so if the milk produced is proven to be hazard-free. That twin beef embryos can now be implanted into dairy cows to promote simultaneously both beef and low-lactose milk production, adds more to the continent new opportunity to change the actually gloomy image of its livestock sector and to become self-sufficient in beef and good quality milk.

3. Potential Impact on Health Improvement

It is in the area of disease control that probably the greatest contribution is expected.

This must be so because the number of diseases plaguing livestock in Africa is frightening (see Table 3) and because none of these diseases is near eradication. Though some of them are more important than others, they all converge, helminthiasis included, to produce the heaviest part of the losses recorded. Trypanosomiasis, theileriosfs, brucellosis, food and mouth disease (FMD), 'peste des petits ruminants', rinderpest, avian coccidiosis, dermatophytosis, babesiosis are among the most devastating. FMD for example, severely curtails some African nation's international trade in livestock and livestock products. A well known case is that of Zimbabwe which lost an export opportunity of nearly US$ 42 million in 1980/90 (ECA, 1991) due to FMD infections. In Nigeria, babesia infections were said to have been causing a US$ 540 million loss in the cattle sub-sector every year.

16

Africa has further problems in relation to animal diseases. In the rural households which represent 80 to 90 per cent of African population, people live with their animals in close cohabitation. Many diseases (zoonoses) thus go freely from animal to man (e.g., brucellosis, rabies, salmonellosis, tuberculosis, ...). Further transmissions are made when raw meat and fresh milk are consumed (e.g., rift valley fever, taeniasis) or when vectors transmitting the disease to humans and animals are the same (e.g., trypanosomiasis or sleeping disease).

It shows from the above that the urgent need to reduce the number of or eradicate animal diseases in Africa is not only a matter of economics but also a matter of human health and welfare. There is no doubt that the continent will benefit a great deal if the technologies reviewed earlier with relation to animal health together with specific new others that are obtainable through the use of monoclonal, recombinant DNA and other well known tools are applied for the production of novel and safe vaccines along with curative products. In order words, better human health that is needed for better productivity, greater economic return and greater likelihood of achieving animal protein self-sufficiency are some components of the impact expected.

Let us recall that FMD encoding genes was copied into the DNA of Escherichia coli and the nucleotide sequence of viral protein expressed in this bacteria was immunogenic in animals more than a decade ago (Kleid etal., 1981). The loci responsible for trypanosomi asis tolerance properties are candidates for DNA probes. Genes coding for these properties can be transferred to other cattle particularly to the Bos indicus animals whose case was highlighted earlier. The genes can also be cloned and DNA transferred into bacteria for mass production of the disease causing antigen. The potential is thus there and certainly Africa knows it.

4. Potential Impact in the Area of Feed and Feeding

Some of the characteristics of animal feed and feeding in Africa has been highlighted earlier in the actual impact section. To these, it should be added that the continent has vast natural grazing fields but most plant forage species are unpalatable and poor in digestible nutrients. Grasses which form the bulk of these species have the capability to grow fast during the rainy season, mature rapidly and either dry out once the short rainy

period ends in semi-arid zone or remain green but with poor nutritive value almost during

the entire year in the humid zones. The major cause of the unpalatability and poor nutritive value is their lignin content which increases as the plant matures. The only time ruminants can get forage of high nutritive value is generally during the growing season (beginning to

mid rainy season) when plants are immature. It is also at this period, unfortunately, that

most animals suffer from mineral deficiencies particularly those regarding phosphorus.

They may also suffer heavily from diarrhoea due, among other things, to high water content of the forage, from insect bites and from heavy parasitism. Overall, the poor quality of the forage in these humid zones results in permanently unsatisfied condition of the animals.

In the semi-arid zone where the sahelian countries are found, forage feed shortages during the dry seasons are so pronounced that cattle are seen scavenging, chewing paper, consuming soil or dying all together. The grazing there causes one of the serious environmental problems in Africa.

Biotechnology can help solve the above problems be they related to phosphorus

deficiency and lignin in the forage or environmental degradation. However, two questions remain unanswered with respect to animal nutrition situation in Africa. These have to do with whether Africa will be, one day, serious about using biotechnology to achieve increased animal food production and what the continent's benefit from growth promoting and other novel agents wilt be if feeding of animals continues to be carried out the way it is done today? Certainly, the likelihood of an affirmative answer from the first question

17