PRINCIPLES FOR PRESERVATION OF ENDANGERED
SPECIES AND BREEDS IN THE TROPICS

CONSERVATION OF ANIMAL GENETIC RESOURCES:
BRAZIL NATIONAL PROGRAMME

Armando Teixeira Primo 1/

The Brazilian Agricultural Research Corporation (EMBRAPA) through the National Research Centre for Genetic Resources (CENARGEN), is concerned with a programme for the conservation and evaluation of livestock populations belonging to the "naturalized breeds" (genetic groups originated within animals introduced to the Americas by the colonists). These populations have been submitted to a long process of natural selection, having thus acquired adaptive and/or productive traits for the diverse ecological conditions found in Brazil. Most of these populations are in an advanced state of genetic dilution and/or in danger of extinction, as is the case for some groups of bovines of the Criollo type. These animals are being studied with the objective of conservation of the germplasm. Conservation is done either in situ (breeding units) or ex situ (cryopreservation of semen and embryos).

It should be pointed out that EMBRAPA was one of the first research institutions in Latin America which, following FAO/UNEP recommendations, established a programme for the conservation of animal genetic resources which was in an advanced state of disappearance (Table 1).

Table 1

In Brasilia, CENARGEN maintains a sperm and embryo bank with the objective of avoiding genetic dilution and irreplaceable gene losses of the valuable "naturalized breeds" germplasm. At present the gene bank stores frozen embryos and semen of Caracu, Crioulo Lageano and Mocho national cattle.

Techniques in cryopreservation, thawing and embryo transfer to recipient cows are wholly dominated. Through adaptation of foreign technology, freezing of bovine embryos for long-term storage became a reality in 1983. Together with the preservation and breeding in special reserves, the preservation of frozen semen or embryos is presently an alternative which permits formation of a gene bank to supply future research and breeding programmes. Biological stability, given by cold storage will also help in preventing genetic drift.

Micromanipulation has permitted the production of identical twins from a single embryo. Embryo halves can be frozen and stored for a long time, thus allowing evaluation of zootechnical traits of an individual or its progeny while maintaining a genocopy of the same in the embryo bank.

Genotype-environment interactions can be evaluated over time by allowing identical twins to develop in different years.

EMBRAPA/CENARGEN presently has the infrastructure and trained personnel required to begin research on embryo splitting.

The National Programme for Research on Genetic Resources includes, amongst its many components, both plant and animal projects in identification, characterization, evaluation and preservation of animal germplasm in danger of extinction belonging to naturalized breeds or types. Among the bovines, Caracu, Mocho Nacional, Pantaneiro, Crioulo Lageano or Franqueiro and Curraleiro or Pé-Duro merit special attention.

In collaboration with other research institutions cooperative conservation projects are being carried out with donkeys and Brazilian breeds of pigs and sheep.

1. ANIMAL GENETIC RESOURCES - BRAZILIAN NATIONAL PLAN

In 1980, a "Coordination of Animal Genetic Resources" was established at EMBRAPA/CENARGEN with the following duties:

-	to implement activities to develop animal genetic resource conservation in Brazil;
-	to consider the conclusions of the FAO/UNEP "Technical Consultation on Animal Genetic Resources Conservation and Management", held in Rome in 1980.

EMBRAPA, through CENARGEN, assumed the responsibility for the conservation of endangered Brazilian breeds through binding contracts with the remaining enthusiastic private owners.

With this contract, EMBRAPA/CENARGEN keeps 70 percent of the frozen embryos or calves produced, and the owner of the endangered stock will get 30 percent of the germplasm. It is expensive to conserve minority breeds, which are not economically profitable. Government financial assistance must always be given to ensure the breed's survival in the original environment or by means of genecryobanks in order to revive the vanishing and endangered animals in the future.

Before it was too late, EMBRAPA/CENARGEN began a nationwide programme to maintain locally adapted breeds. In certain regions of Brazil, these old breeds fit best in the given ecosystem (Table 2).

The conservation of animal breeds, having irreplaceable hereditary traits, is necessary for research education, general natural protection, and history, apart from breed improvement and economical and social reasons. With some breeds the problem was not so urgent, and the objective of EMBRAPA/CENARGEN was to arrest the decline of the breed before it reached serious proportions. At the same time, it was necessary for CENARGEN to plan a long-term strategy, and, in this respect, the creation of the Semen and Embryo Bank was a most significant development. It will ensure that genes from the minor breeds can be stored against emergency or changing requirements in the future. At this time, semen and embryos are available from four breeds of cattle that are included on EMBRAPA'S priority lists, namely, Caracu, Mocho Nacional, Crioulo Lageano and Pantaneiro. With some breeds, which appear to have little relevance in current commercial systems, the role of the gene bank is limited mainly to preservation, but the Caracu is successfully establishing a relevant position within the cattle industry. The Caracu is demonstrating qualities unsuspected in the past. More recently, this breed has updated its image and it is noted now for its performance in feeding tests (Table 3 and (Table 4) and the high growth rate of its crossbred progeny (Table 5).

Table 2

BRAZILIAN ENDANGERED CATTLE BREEDS

Table 3 SUMMARY OF FOUR YEARS' PERFORMANCE FOR FOUR BREEDS
OF CATTLE AT SERTAOZINHO-SAO PAULO, BRAZIL

^1/ Corrected final weight (w 392)

^2/ Gain in 112 days of test (G 112)

Source: Estacão Experimental de Zootecnia-Sertãozinho - SP.

Table 4 SUMMARY OF FOUR YEARS' PERFORMANCE FOR FOUR BREEDS
OF CATTLE AT SERTAOZINHO-SAO PAULO, BRAZIL

^1/ Corrected final weight (W 378).

^2/ Gain in 112 days of test (G 112)

Source: Estacão Experimental de Zootecnia-Sertãozinho - SP.

Table 5 PRODUCTION EFFICIENCY (P.E.) FOR WEIGHT AT 18 MONTHS (W18)
IN AN EVALUATION OF NELLOR (N), CHANCHIM (C), SANTA
GERTRUDIS (G), HOLSTEIN (H), BROWN SWISS (S) AND
CARACU (K) AS SIRE BREEDS IN MATINGS WITH NELLORE COWS

^1/ F = (Fertility) = calving rate corrected for mortality.

^2/ P.E. = Beef production at 18 months of the calves per cow exposed = F x W18.

^3/ I = Index in relation to control group NN = 100.

^4/ Class = Classification

Source: Instituto de Zootecnia-São Paulo, 1985.

1.1 Characterization

CENARGEN is carrying out studies in the area of characterization of germplasm in order to describe the genetic attributes of animal species or breeds covering the phenotypic and genetic parameters.

1.1.1 Morphological characterization

Body measurements were taken in three Criollo cattle populations to characterize the germplasm in respect to conformation and size. Simple correlations between morphological measurements, in the Caracu breed, showed positive values ranging between 0.324 for height in the hindquarter and rump width and 0.825 for height in the hindquarter and height at withers (Trovo and Primo, 1984). Height at withers is shown in Table 6.

Table 6 CRIOLLO CATTLE HEIGHT AT WITHERS (cm)

1.1.2 Cytogenetic characterization

Systematic cytogenetic studies are being done in all the animals involved in the production of semen and embryos for long-term storage. No chromosomic abnormalities were found. The Y chromosome is submetacentric in some of the animals and acrocentric in the majority of the Criollo cattle studied, suggesting influence of zebu blood. The Caracu and Curraleiro showed approximately 90 percent of acrocentrics while this percentage is 43 in the Crioulo Lageano cattle (Tambasco et al. 1985).

1.1.3 Characterization by blood typing

Up to the present, blood factors belonging to 10 genetic systems were analysed, and the number of factors per animal in the cattle populations of Pantaneiro, Curraleiro, Crioulo Lageano, Mocho Nacional and Caracu were studied.

Pantaneiro presented the highest genetic variability (12.61 factors per animal) and Caracu the lowest (10.91).

This preliminary analysis suggests a close relationship between two breeding populations (Mocho Nacional - Caracu) and (Pantaneiro - Crioulo Lageano). Curraleiro is associated with this last group at an intermediate genetic distance.

These preliminary results must be confirmed with the study of other genetic loci such as transferrins, haemoglobins, carbonic anhydrase and others (Mario Poli, Pers. Comm.).

1.2 Evaluation

Too often, breeds, strains and genetic types have been discarded for no valid reason. The evaluation of the existing genetic material in a number of environments and production systems is in the process of being implemented by EMBRAPA. This evaluation will involve pure breeding as well as crossbreeding. Frequently the superiority of the F, offspring in crosses has been ascribed solely to the introduced breed although it has later been shown to be due to heterosis. The expansion of the zebu at the expense of Criollos in Brazil is a clear example of such confounding interpretation of heterosis.

The adaptive and productive potential of Crioulo Lageano cattle, as purebred or in crossbreeding with Nellore and Charolais cows, is being studied through a cooperative project between EMBRAPA and the Federal University of the State of Santa Catarina. Based on these studies involving fertility, maternal ability, growth rate, milk production, resistance to parasites and carcass characteristics, it is expected to obtain indications on the rational use of this cattle as a source of genes, mainly associated with adaptive characteristics or traits.

A similar project is under way in the "Pantanal" region (a seasonally flooded area in the states of Mato Grosso and Mato Grosso do Sul) utilizing Pantaneiro cattle as purebred or in crossbreeding with zebu. These two projects have financial help from the Bank of Brazil.

1.3 Conservation of Animal Genetic Resources

EMBRAPA/CENARGEN utilizes three methods for the conservation of animal genetic resources:

-	reproducing populations;
-	freezing semen; and
-	freezing embryos.

1.3.1 Reproducing populations

Until five years ago, animal germplasm was maintained in herds of a few individual breeders on the basis of expected economic returns or due to family tradition or personal interest. Just one herd (Caracu) was maintained, at the time, by a public institution (Instituto de Zootecnia - Sao Paulo) besides the private owners.

Nowadays, EMBRAPA/CENARGEN maintains small herds of animal germplasm which were on the verge of disappearing, or provides a small subsidy and technical assistance to encourage adequate population size in the remaining herds.

EMBRAPA is taking care of three endangered groups of bovines, namely, Mocho Nacional, Curraleiro or Pé-Duro and Pantaneiro in special conservation units.

1.3.2 Frozen semen

Storing germplasm in the form of frozen semen or frozen embryos could become a practical approach to conserving genetic stock whose survival is at risk.

FAO/UNEP (1983) provided information on methods and estimated costs of preserving gametes and embryos.

Smith (1984b) examined the efficiency of alternative methods for minimizing the loss of genetic variablility. For periods of over five years, semen storage became the cheapest form of conservation (Smith, 1984a).

When possible, EMBRAPA/CENARGEN store 100 units of semen from each of 10 slightly related males. At present, CENARGEN has 10 000 doses of semen of one breed (Caracu) and of three local strains (Crioulo Lageano, Mocho Nacional and Pantaneiro), for long-term storage. As an urgent safeguard to protect endangered stock, semen was collected from some sires lacking performance data. Further testing and gradual substitution will be needed.

The rotational use of frozen semen from unrelated sires on each other's daughters would help to reduce inbreeding and drift in gene frequencies (Smith, 1977).

1.3.3 Frozen embryos

Storage of frozen embryos would be desirable where it is important to preserve the capability of reconstituting a breed or strain and maintaining it with low inbreeding. On the other hand, the genotype is intact in embryos, whereas at least three backcrosses are required to reconstitute the approximate genotype from semen. For frozen embryos, collection of 25 embryos each from 25 donors, would be sufficient for conservation purposes (Smith, 1984a).

Costs of frozen embryos are very high, but as for frozen semen the annual storage costs are low.

At present, CENARGEN, in Brasilia, maintains a gene bank with storage of embryos from Caracu, Crioulo Lageano and Mocho Nacional cattle. Through adaptation of foreign technology, freezing of bovine embryos for long-time storage became a reality in 1983.

1.4 Data Bank

It is necessary to obtain a comprehensive description of the characteristics of local breeds, together with a characterization of the environments to which they are adapted (Hodges, 1984).

EMBRAPA/CENARGEN just started work storing in a microcomputer the distinguishing physical features of local breeds in addition to reproductive traits. Semen and embryo collection data are already stored in a readable format. Changes in numbers and structure of the Crioulo Lageano cattle population is followed by close monitoring by CENARGEN data bank.

It is essential to have well defined Animal Descriptors.

1.5 Inter-country Cooperation

Many of the indigenous breeds are spread across many countries, so that genetic resource management requires cooperation between countries.

FAO/UNEP recommended that inter-country cooperation in the exchange of germplasm should be encouraged with due regard to quarantine precautions.

In Brazil, the Crioulo Lageano cattle are in danger of extinction (herd of 250) with a high inbreeding level and few bulls of related ancestry.

There are similarities between the Brazilian Crioulo Lageano and the Argentinian Criollo, possibly explained by the Iberic origin. Sal Paz (1977) demonstrated that the pure Criollo, in the Chaco ecosystem in Argentina, produces a greater weight of weaner calf per hectare per year than zebu, British beef breeds or zebu crosses.

In an effort to widen the genetic base and to arrest genetic dilution in the breeding unit of Crioulo Lageano cattle in Brazil, three Criollo bulls were imported from Argentina in 1985.

This exchange of germplasm was a donation from the Argentinian Instituto Nacional de Tecnologia Agropecuaria (INTA) to EMBRAPA.

The conservation of naturalized breeds is a matter of paramount importance in Brazil, not only for sentimental reasons, but to ensure the maintenance of genetic variability to meet future yet unforeseen requirements.

REFERENCES

INDIA'S EFFORT IN CONSERVATION AND MANAGEMENT OF INDIGENOUS
LIVESTOCK AND POULTRY GENETIC RESOURCES AND
CREATION OF DATA BASE

R.M. Acharya 1/

PART I: ANIMAL GENETIC RESOURCES

The Indian sub-continent is known for the size and divesity of animal genetic resources and has been recognized as the home for many important breeds of livestock especially draught cattle, milch buffaloes, carpet wool sheep and highly prolific goat breeds. The Indian breeds are adapted to tropical heat and diseases and poor quality feeds. There are 26 breeds of cattle, 7 of buffaloes, 40 of sheep, 20 of goats, 4 of camels, 6 of horses, 3 of pigs and 18 of poultry. Due to the lack of any geographical barriers and little controlled breeding by Government/breed societies, there has been large inter-mixing of breeds contiguous to each other over the centuries resulting in dilution of breed characteristics making more than 75 percent of the populations nondescript. Added to this is the introduction of crossbreeding programmes involving superior exotic breeds, mostly from temperate ecologies to meet the economic needs of the changing society, which is further hastening the dilution and possibly extinction processes of the well established breeds. This in spite of the breeding policy which requires that the descript breeds be not involved in crossbreeding programmes.

The indigenous breeds have mostly evolved through natural selection primarily involving adaptation to ecological conditions of their home tract, management system and to a limited extent to meet the economic needs. However, in more recent years, improvement through selection, primarily based on physical conformation and to a very limited extent on production, has been emphasized.

On Indian breeds of livestock, a number of small and disjointed studies have been conducted by the Indian Council of Agricultural Research, Agricultural Universites, Animal Husbandry Department of the State and Central Governments.

Attempts have been made to compile information on indigenous breeds of livestock and poultry, more recently, by Acharya (1982) on breeds of sheep and goat, and by Acharya and Bhat (1984) for all species including poultry. These compilations stress the need for conservation of a number of breeds where numbers are seriously declining.

It is increasingly being realized that the indigenous breeds especially draught and dual purpose breeds of cattle, carpet wool breeds of sheep, more prolific breeds of goats and species like yak, mithun and camel need to be evaluated, conserved and further improved. This attempt should be preceded by a breedwise study covering their production, reproduction, adaptation and disease resistance characteristics especially in their native habitats and under existing management. Litte emphasis on description of the existing breeds and their differentiation based on gene markers has been meaningfully laid.

1. SETTING UP THE NATIONAL BUREAU OF ANIMAL GENETIC RESOURCES

To undertake studies on indigenous livestock genetic resources and to build a data bank, the Government of India (Indian Council of Agricultural Research) has set up a National Bureau of Animal Genetic Resources (Bureau) at Karnal (Haryana). The brief objectives of the Bureau are:

-	To undertake systematic surveys for description, evaluation and cataloguing of livestock and poultry genetic resources and to establish a data bank and information service on these resources and to determine the need of and recommend steps for the conservation and management of these resources.

1.1 The Bureau's Activities

The first phase of the Bureau's activities will be directed at collecting and collating as much published and unpublished information as possible on the descript breeds and to conduct surveys to augment information on them in areas where there are deficiencies. Identification and description of a breed is to be approached in a multi-disciplinary manner and should involve the topography, soil and water resources, physical environment, feed resources and management systems. So far, largely the descriptions of breeds were on the bases of body conformation, coat colour and a few body measurements. Information on production and reproduction parameters was given on only a few breeds and that too based on limited data on animals maintained on Government farms. In a breed itself, sometimes subtypes have been delineated on the basis of physical conformation and performance characteristics. Modern scientific tools especially gene marker traits, e.g. blood groups, biochemically polymorphic traits and variations in chromosomal structure and number would be applied in establishing breed identities and studying their evolution. Studies related to major histocompatibility complexes and DNA sequencing have not been evolved to the extent of applying to description of and differentation among breeds but developments in these areas do hold tremendous promises for the future and would be ultimately employed.

Since breeds of domesticated livestock have been evolved to meet specific requirments and they have adapted well to their native environment and managment it will be necessary that a description of a breed involves description of environment and managment practices. The environmental factors such as monthly average temperature and range, relative humidity, rainfall, wind velocity, hours of daylight and possibly solar radiation and the managment aspects covering feed resources and feeding, common disease problems, breed improvment programmes, breeding procedures etc. will give a meaningful description of a breed in its breeding tract. Above all, the interaction with man should be given due consideration especially so with the nomads, tribal and certain livestock breeding communities who seem to have provided a type of isolation for their livestock resulting in the emergence of recognizable breed characteristics.

The Bureau will advise the Government and possibly through cooperation with other agencies, undertake conservation of indigenous genetic resources (threatened with extinction) through both by in situ and ex situ methods, the former through maintenance of purebreds on the organized farms - in their home tract and the latter through cryopreservation of semen and fertilized embryos.

2. OTHER RESEARCH ACTIVITIES RELATED TO BREED EVALUATION AND IMPROVEMENT BEING UNDERTAKEN BY ICAR

In the recent past, livestock improvement in India has been attempted through the introduction of exotic breeds of different livestock for replacement of indigenous populations as in the case of poultry and fur animals and for evolving new breeds through crossbreeding, combining productivity of the exotic and adaptability of the native breeds in most other species. However, more recently the importance of indigenous breeds and need for their conservation through management have been realized.

The first task should, therefore, be to identify the existing genetic variants (breeds/strains) with respect to physical conformation, coat colour, size, performance and their adaptation to the physical environment and managment practices in their home tract. The Indian Council of Agricultural Research is conducting extensive research work on the performance of important breeds of livestock and their genetic improvment through its species research institutions. It is planned to include in the network 79 farms for indigenous cattle and 56 for buffaloes belong to the animal husbandry departments of the central and state governments and also farms belonging to the Defence Organization maintaining Holstein x Sahiwal crossbred cattle and Murrah buffaloes, in addtion to those in ICAR Research Institutes and State Agricultural Universites.

India was one of the first few countries to take up a Herd Registration Scheme. Herdbooks are being maintained for 8 breeds of cattle, viz. Sahiwal, Red Sindhi, Tharparkar, Hariana, Gir, Kanvary, Ongole and Kangayam and Murrah breeds of buffalo. These herdbooks serve as authoritative guides on the standard breeds. However, effective use of these herdbooks has not been made in genetic improvement of these breeds.

ICAR, in additon to the nine species institutes and National Research Centres, viz. National Dairy Research Institute for cattle, Central Institute for Research on Buffaloes for buffaloes,-Central Sheep and Wool Research Institute for sheep and fur animals, Central Institute for Research on Goats for goats, Central Avian Research Institute for avian species and the National Research Centres for yak, mithun, equine and camel for these respective species, has Directorates on cattle and poultry improvement and All India Coordinated Research Projects on buffalo, sheep, goat and pig breeding. All these Institutions and projects of the ICAR will cooperate with the Bureau in undertaking studies on the indigenous genetic resources. Also, the Bureau will enter into collaborative studies with the State Agricultural Universities through ad hoc research schemes funded by ICAR wherever required. The National"^ Institute of Animal Genetics, a sister institute and located on the same campus and sharing common facilities with the Bureau will conduct basic research studies on cytogenetic and immunogenetic aspects both as a guide to such studies to be conducted elsewhere and as a support to studies taken directly by the Bureau.

PART II: DATA MANAGEMENT SYSTEM FOR ANIMAL GENETIC RESOURCES BEING DEVELOPED AT THE NATIONAL BUREAU OF ANIMAL GENETIC RESOURCES

1.INTRODUCTION

The success of the management of a system depends mainly on the quick transformation of the available data into information helping in timely and right decisions. At the basic level, every organization generates and processes data to produce limited information. Usually, once an objective is met, the data serve no further purpose. Often, when some information is needed for the existing data, the information is obtained with delay which is proportional to the volume of data and the efficiency of storage and retrieval system. The problem becomes severe when inter-departmental or inter-organization data are concerned. But, whatever the cost may be, flow of the data to a central place is a necessity because information for managing an organization cannot be obtained without processing the data from the various sources. Managing a hugh data bank and deriving informa­tion from it is a stupendous task with the conventional system, but the arrival of computers and the database management software systems make it a realizable target.

2.NATIONAL BUREAU OF ANIMAL GENETIC RESOURCES

The data on the livestock resources of India are not currently available in a central place, but scattered in different departments of the State and Central Government, Autonomous organizations and universities. Little has been done to bring such data or information on the genetic resources that can be compiled into a publication except on sheep and goat breeds by Acharya (1982) and subsequently on all species, though in much less detail, by Acharya and Bhat (1984). The National Bureau of Animal Genetic Resources (Bureau, Karnal, Haryana has been set up by the Government of India/Indian Council of Agricultural Research (ICAR) to collect, compile and computerize the Animal Genetic Resource data currently available and to be collected through surveys. The following tasks are inter alia to be taken up by the Bureau in a phased manner in creating and maintaining a computer-oriented database for the generation of information on genetic resources of livestock in India:

1. Identification of data sources and collection of existing data.
2. Designing data and information formats for easy storage retrieval of data in a computer.
3. Design of a rational database and development of support software.
4. Routine updating, report generation and monitoring.

3 DATA SOURCE, COLLECTION AND COMPILATION

Table 1 gives the source of data required for a model proforma given in Appendix 1.

More than 75 percent of the Indian livestock are nondescript. But within the remaining 25 percent, 26 cattle, 7 buffalo, 40 sheep, 20 goat, 4 camel, 6 horse, 3 pig and 18 poultry breeds have been well defined and established. Therefore, the data relevant to these breeds will be initially collected and compiled. In most of the cases, adequate informa­tion covering all the aspects may not be available and survey work will have to be undertaken to bridge the gap.

Table 1 DATA SOURCE FOR LIVESTOCK GENETIC RESOURCES AND
THEIR ENVIRONMENT

In the available census, data information on breed-wise population is not available and as such it is not possible to monitor the population changes in the different breeds. However, this aspect will be taken up for inclusion in the ensuing National Survey to be undertaken by the Bureau through the cooperation of different agencies.

4. COMPUTER FACILITY

As the first phase of developing the data bank, a microcomputer, with Motorolla 68000 processor, UNIX Operating System, 640 KB RAM, 72 MB Winchester disks, tape and floppy drives and a printer, has been procured by the Bureau. Along with the system, a rational Database Management System (DBMS) has also been obtained as it was felt that this would suit better than the other DBMS softwares. The system supports report generation and computer languages such as C, COBOL and FORTRAN. These languages will be used to develop support softwares for pre and post-processing of the data in the DBMS as well as in statistical computations.

All the data available for a breed will be collected from the individual records of the animals in various organized farms and population characteristics will be derived from them. Wherever survey data are available, they will be included. The data on environmental and manage-mental aspects will also be gathered from the available sources and Processed to incorporate in the database.

The processed data on various breeds will be stored in a rational DBMS. From the census data giving population of different species and a Prior knowledge of the home tract of the breed, population size of various breeds will be generated and added to the database. Once the database is fully implemented, it is expected to give the following information:

1. Population number and compositional (age and sex) trends and possible factors affecting such trends.

2. Whether the present population size in an area (home tract/new area where a breed has been introduced) can be supported by the available feed resources and what is the optimum population size in relation to the existing feed resources.
3. Conformation, physical measurements, performance (production and reproduction), cytological biochemical and serologically polymorphic traits and special characters especially related to the adaptation, disease resistance, prolificacy etc. of different breeds.
4. What are the prevalent diseases and other management problems related to individual breeds and what measures will be effective to tackle them.

6. FUTURE PROSPECTS

The National Herd registration scheme being carried out by the Government of India has done commendable work in identifying elite animals of 8 descript cattle and 11 buffalo breeds.

The information regarding the registered animals could be kept in a database for use in possible future development programmes of the breeds especially in selection of mothers and possibly for use in multiplication of elite stock and conservation through cryo-preservation of semen and fertilized embryos. The availability of bulls, facilities for collection, processing, freezing and storage of semen in various organizations throughout the country would be kept in the data bank along with the pedigree and progeny evaluation results of the bulls, wherever available, so that possible central coordination can be effected by the Bureau in identifying and recommending exploit of superior germplasm.

REFERENCES

PRINCIPLES FOR PRESERVATION OF ENDANGERED SPECIES AND
BREEDS IN THE TROPICS

Sheep and Goats

Helen Newton Turner 1/

1. INTRODUCTION

The reasons for preservation, frequently discussed, can be summarized in one sentence - the need to maintain genetic variation. This need will govern the principles of preservation, which are similar for all livestock, though their application will vary with species and type of husbandry.

The principles will be discussed under five main headings:

-	Which to preserve?
-	In what numbers?
-	By which technique?
-	By whom?
-	How to maintain a preserved group?

The characteristics of sheep and goat husbandry in the tropics which influence the application of principles for preservation are:

-	Flocks and herds are often small.
-	There are seldom flock or herdbooks laying down breed characteristics; the organization of breed societies is, however, being encouraged in some countries {e.g. OAU 1983 p.103).
-	Censuses by breed are rare.
-	Type of management varies (stationary, transhumant or nomadic).
-	Stud structures, with sires supplied from specialized breeding nuclei, are rare, though government farms frequently fulfil the role, distributing improved sires (indigenous, exotic or crossbred). This practice is more common with sheep than. goats.
-	In some countries there has already been indiscriminate crossing with exotic breeds.
-	Techniques using frozen semen or embryos are not yet as useful with sheep and goats as with cattle, though this position will undoubtedly change.

2. WHICH TO PRESERVE

Interest lies in genetically distinct groups. The FAO/UNEP Technical Consultation on Animal Genetic Resources which met in Rome in 1980, and which recommended the establishment of this Expert Panel, discussed work on breed documentation which had already been done, and urged that more was needed (FAO, 1981). Documentation of breeds in tropical countries had already started (e.g. Bhat et al, 1979), and there has been more since (Acharya, 1982; OAU, 1983; Cheng, 19S5; Hasnain, 1985).

Much more needs to be done, and in particular more detailed information is required on the degree of relationship between the breeds, and the genetic differentiation of strains within them, but the work is long-term; enough data are already available for urgent decisions. These decisions will be based on numbers (present and future, predicted through rates of decline) and on performance (which includes other things besides production). Circumstances will decide whether the observer should look first at breeds under threat and then decide which to preserve, or rank the breeds in order on performance, then see if any near the top of the list are threatened.

2.1 Declining Numbers

Wildlife conservationists use five "status" categories (IUCNN Red Data Book, Brooke and Ryder, 1978), based on current numbers and rates of decline, and have suggested the same should be used for domestic species. The categories are:

1. Endangered
2. Vulnerable
3. Rare
4. Not threatened at present
5. Indeterminate (insufficient data)

Where should the borderlines for sheep and goats be drawn? It is a simple matter to calculate what a population will be in year y if it is decreasing at x percent per annum (Figure 1). Figures of 500 breeding females for the vulnerable category, and 300 for the endangered, were suggested, but the meeting reached no conclusion.

What is not so simple is to obtain the necessary estimates of current populations and rates of decline. Census data in many countries do not differentiate breeds; this lack was recognized in recommendation 5 of the Second OAU Expert Committee Meeting on Animal Genetic Resources in Africa (OAU, 1983), which read that national governments should be encouraged by the Organization of African Unity and the Interafrican Bureau for Animal Resources "to conduct a regular census of their livestock and poultry population classfied according to the various breeds, types and strains, and in terms of sex, age, distribution and location".

Such censuses do not always exist, and though some assumptions about breed numbers can be made from regional numbers, these are by no means accurate, as pointed out by Acharya (1982). A conscious effort must therefore often be made to estimate present numbers and rates of decline, the most common causes of the latter being crossing (leading sometimes to complete breed replacement) and alienation of land (expansion of cities, roads etc.). A full survey such as that by Brooke and Ryder (1978) is expensive, but information can be obtained through extension officers, working to a planned questionnaire, and making records with an interval of (say) 3 years of the numbers and breeds (including crosses) of:

-	Mature females and males (noting which of the latter are to be used for mating).
-	Female and male lambs (or kids) and young animals prior to mating.

This information could be collected from a number of flocks in a number of regions. Where the animals are transhumant or nomadic, check points can be established at points through which they normally pass.

Figure 1 Populations with different rates of annual decrease.

At the first such census, crossbred animals could in many cases be identified visually and planned matings with different males recorded. Information on likely declines through crossing would then be immediately available.

In dealing with crossing, a decision has to be made about the level of "foreign" genes which will be permitted before an animal is rejected as a "purebred". Britain's Rare Breeds Survival Trust accepts animals with up to 20 percent of "foreign" genes. It is suggested that 25 percent might be taken as a limit. This would permit the progeny of first-cross males (between breed A and breed B) and A females to be classed as A. They are 75 percent A, and two back-crosses to pure A males would give 93.75 percent A.

If males of breed B are mated to females of breed A, all offspring are 50 percent A and would be disqualified. The rate at which the A breeding females are replaced by AB, however, depends on the number of age groups of breeding females. Figure 2 shows the decline in percent of A ewes after 5 years when different percentages of A females are mated to other than A males, for 5 and 8 age groups of females.

Figure 2 Reduction in purebreds with crossing.

When males which are half A are used, the decline in pure A is slower if 25 percent A is accepted. Figure 3 shows the decline in "acceptable" A females after 5 and after 10 years when half A males are used on various percentages of the A females (5 age-groups of females assumed).

The assumptions used in calculating these figures are:

1. Annual mating.
2. Females enter the breeding flock 2 years after the mating which produced them.
3. If there are 5 age groups of breeding females, one-fifth are replaced annually (no death rates allowed for).

Figure 3. Reduction in purebreds with crossing.

Figure 2 and Figure 3 can be used in conjunction with the type of spot census suggested above. If a count of 1500 breeding females of Breed A has been made, of which 80 percent are to be mated to males with no A genes, then after 5 years the number of A females will be only just above the 500 level if there are 5 female age groups, and down to 900 with 8 age groups (Figure 2). If half-A males are to be used, the number of ewes with at least 75 percent A genes will be 1350 after 5 years, but only 450 after lo years. Somewhere in that period preservation action would need to be takers.

2.2 Performance

What makes a breed worth preserving? More features than production have to be considered, and questions to be asked include:

-	What are the main sheep (or goat) products required, in different parts of the country?
-	Are any existing breeds outstanding for production of that commodity?
-	How do the breeds rank for other traits such as reproduction rate, age at puberty, lambing frequency, mothering ability, resistance to disease, adaptation?
-	Has any breed an outstanding single feature, such as high prolificacy, short post-partum anoestrus, etc?

Decisions will be helped by FAO/UNEP's proposed data banks, which will cover records of all aspects of performance as well as descriptions of the environment. The need for more breed identification and performance figures must always be stressed, but in the meantime much data are already available, even though not always uniformly recorded, usually collected on experiment stations rather than in the field, and without direct breed comparisons. The figures are nevertheless a guide when urgent decisions are needed.

3. IN WHAT NUMBERS?

In an emergency, the only action possible may be to preserve all members of a single flock or herd, but ideally a preserved group should be a sample drawn from a number of flocks (or herds) of the breed, and be large enough to minimize inbreeding.

Technique will influence the number stored. One of the recommendations of the" Joint FAO/UNEP Expert Panel meeting in 1983 (FAG, 1984) ws that "the preferred preservation techniques will usually be the cryogenic storage of sperm and/or embryos, because most developing countries would not be willing to preserve live animals without utilization". The recommendation, vent on to urge that FAO/UNEP should set up an /?/International Cryogenic Animal Gene Bank.

Since freezing of sperm means continued back-crossing to recover a breed, embryos rather than sperm seem a more profitable source for storage. Eventually the frozen embryos will have to be retrieved as live animals, so in deciding on numbers to be stored, allowance has to be made for losses between storage and animals-on-the-ground. This loss will depend on when and where storage is made. The following discussion refers to the final count of animals-on-the-ground, and to the numbers required for maintenance; larger groups may be preferable if there is to be selection for genetic improvement.

3.1 Representative Sample

This is formed by collecting both males and females from a number of flocks and herds.

3.2 Size of Preserved Flock or Herd

One of the main problems is to limit inbreeding. Smith (1984) chose to limit the annual rise (F) to 0.2 percent. If we accept this, we can use the following approximate formula (Turner and Young, 1969) to estimate sire numbers:

where Δ F	=	annual rise in inbreeding %
M	=	number of sires added per year
L	=	generation length

The L value will depend on age at first mating and numbers of age groups of males and females. For first mating age 1 1/2 years, with 2 age groups of males and 5 of females, we arrive at M = 6, or a total of 12 males. With 10 females per male, the number of breeding females becomes 120.

At 10 females per male Formula (1) gives an underestimate of F, the discrepancy decreasing as the sex ratio increases. The formula can be used, however, to give approximate numbers. As a working figure, 150 breeding females with 20 breeding males is suggested, the males being unrelated as far as possible.

4. BY WHICH TECHNIQUE

The available techniques are:

-	Breeding flocks of live animals
-	Frozen embryos
-	Frozen semen

Smith (1984) discussed the relative costs, and concluded that, although initial costs were far higher for cryogenic storage than for animals, maintenance costs were lower. His maintenance costs for animals were based on British conditions, and in countries where animals can be continually grazed, with low shepherding costs, it is likely that collection of a breeding flock might be the initial choice of techniques, at least until the International Cryogenic Gene Bank has been established. This point will be discussed more fully by other speakers.

The recommendation from the OAU Expert Committee, discussed above, was directed to national governments, and it is clear that in all countries, tropical or otherwise, the task of identifying the threatened livestock breeds is likely to fall on governments or their agencies. Most tropical countries have government farms or research institutes which maintain breeding flocks of sheep, though goats have been somewhat neglected. Such institutions are obvious starting-points for undertaking the collection and maintenance of preserved groups; some, in fact, already have indigenous breeds, though there needs to be a planned effort to ensure that all required breeds are included, and that more attention is paid to goats.

There are alternative ways of spending the money needed to maintain preserved groups:

-	Extending existing facilities on government farms and research institutes, particularly to include goats as well as sheep.
-	Helping universities with animal husbandry faculties to establish or expand farm facilities; the preserved groups would be valuable student training material.
-	Paying private owners to retain a flock/herd; the necessary negotiations between extension officers and owners would help to strengthen links between them.

6. MAINTENANCE OF PRESERVED GROUP

With cryogenic storage, genes are maintained without change, except for the possible risk of mutations induced by the technique. With live animals, the question arises - should an attempt be made to preserve the status quo, or should the preserved group be subjected to a genetic improvement programme?

The apparent conflict between these options was discussed at the FAO/UNEP Technical Consultation in 1980, and Professor King produced the outline given in Table 1 (FAO, 1980, p.17).

The general opinion of the meeting was that the second option was more likely to be adopted, though if and when International Cryogenic Gene Banks are established both methods may be possible.

Numbers required if genetic improvement is sought will depend on general breeding plans. The main aim of a central nucleus would be to distribute sires (or semen); available facilities, the size of the target population and reproduction rates would be influencing factors.

7. CONCLUSION

The aim of this paper is to outline suggestions and promote discussion, not to offer firm recommendations. Those will come later in the light of circumstances in different countries.

Table 1 CONSERVATION VERSUS GENETIC IMPROVEMENT PROS AND CONS

REFERENCES

PRINCIPLES IN USE OF LIVE ANIMALS

I. Bodó 1/

1. INTRODUCTION

There are two basic methods to preserve pure breeds or pure animal genetic material:

1. in situ methods;
2. ex situ methods.

The first one is the preservation of live animals mostly under the original environmental conditions (jn situ) .

The second is the conservation by several cryogenic methods.

The topic of this short paper cover some aspects of only preservation in living herds.

2. ADVANTAGES AND DISADVANTAGES OF KEEPING LIVE ANIMALS IN A PRESERVATION POLICY

The goal of a preservation policy is to preserve the animal popula­tion for future use, so that the structure of genes of the population in question remains unchanged as far as possible.

In this sense the efficiency of keeping live animals, i.e. the pre­servation by management, is very difficult.

To breed a domestic animal herd for many generations in the same gene structure is nearly impossible, because of several reasons:

-	we do not know or see the genes but only some effects of them;
-	the selection made by nature is sometimes very effective even against our wish;
-	the sex ratio used in domestic animals requires selection, there� fore many males are eliminated, according to the breeder's decision every year;
-	the number of animals is mostly limited. When culling a cow or bull it is impossible to substitute it by another with the same gene structure even when this second animal is his son or her daughter.

Considering these aspects, the cryogenic method is advantageous when deep-frozen embryos are stored. In this case the next generation, the embryos, can be preserved for the future and remain nearly unchanged compared with the preserved stock which will show more genetic changes in all new generations.

If cryogenic storage is carried out using deep frozen semen (as is usual today), one can restore the breed in the future only by upgrading. In this case the advantage of unchanged genetic material does not exist.

There are other aspects as well. The conditions in some countries make it impossible to organize the cryogenic storage of genetic material. There are some domestic animal species whose semen cannot yet be deep-frozen without lethal damage (horse, pig).

Thus, a preservation policy cannot be planned without the management of live animals.

Another theoretical danger can be presumed when restoring a cryogenic stored breed or population in the future. In such a long period of many hundred years a considerable change of bacteria or other pathogens cannot be ignored. The live animals can accommodate to the small changes from one generation to the other but this is quite impossible for the cryogenically stored animals, because the change is very brutal for them. This is a theory but by accident there can also be other important changes in the environment conditions, when one considers a period of many hundred years.

An advantage of living herds compared to the cryogenic method is observation, because of two important reasons:

-	from an aesthetic point of view the cryogenic storage affords nothing, while generations of men are highly delighted at the sight of living herds of unusual, pleasant-looking animals;
-	the preserved genetic material has also a professional value; because it possesses important characteristics for possible future use. When the embryos are preserved in containers, nobody will think of the ancient breed and after a long period all the valuable traits of a breed in question can be forgotten.

This is also an argument in favour of living herds.

Domestic animals portray our culture as do buildings and other products of men's creative activity. Therefore it is desirable for future generations to see also the product of their ancestors in this field. Good cooperation is possible with National Parks, because the rare old breeds and the ancient method of keeping animals belong to the protected regions as well.

Nowadays there are many domestic animal breeds the characteristics of which are not yet evaluated. Thus, for evaluation live animals are essential (Maijala, 1984).

Cryogenic storage is expensive, while costs of maintenance of living herds can be more or less compensated by their products under given economic conditions.

As a conclusion one can state that both cryogenic storage and management of live animals are necessary for a" complete system.

3. PROBLEM OF INBREEDING

When preserving valuable genetic material sometimes effective preservation starts only at the last moment when the number of animals is very small. On the other hand it is very difficult to verify the minimum number for such a breeding goal, when the costs of maintenance of a non-commercial herd have also to be taken into consideration.

Because of the ambition to minimize the number of animals preserved, the danger of inbreeding is a very important point in preservation policy.

May I mention here two opinions on the minimum number of several species which is necessary to avoid the endangered status (i.e. the breed in question is in danger of extinction):

Species	Number of breeding females
Cattle	750	1000
Sheep	1500	500
Pigs	150	200
Horses	1000	-
Goats	500	200

Regarding livestock size the critical status of the populations is under that of the endangered ones and is estimated to lie in the range of 10-15.

Smith (1984) calculated small numbers and narrow sex ratio which can only be kept in research conditions:

Species	Male	Female	Number of breeding animals entering/year
Cattle	10	26	10	5
Sheep	22	60	22	12
Pigs	44	44	44	18
Poultry	72	72	72	72

We can speak about a "natural" preservation strategy in conventional herds and about an "artificial" one which is carried out in a laboratory yard or cages, under scientific control.

For the latter, a better and proven example is the Cornell Control White Leghorn population. They have a breeding scheme designed to minimize inbreeding and to maintain genetic variability. Fifty sires and 250 dams constitute the breeding population in each generation. Parents are chosen so that only one male and one female parent originate from each sire and dam of the previous generation (Bodó et al., 1984).

Spanish workers keep 50-400 females and 10-100 males in poultry stocks that are conserved (Campo and Orozco, 1982).

The damage by inbreeding can be grouped according to the traits in question:

1. Qualitative traits.
2. Quantitative traits.

1. The problem is the diminishing variation of the characteristics of qualitative inheritance, the most spectacular of which is the colour.

   It is very important to prevent this diminishing variation when the breed decreases in number and loses its territory.

   More important are however the defects caused by major genes. The frequency of noxious genes can increase and some genetic defects appear (lack of hair, lack of tail, atresia ani, shortened legs etc.)

   One has to use a special mating system to discover the carriers and a very severe elimination of them is necessary.

   These are very obvious signs of inbreeding, but not as dangerous as they might appear. The elimination of such disadvantageous characteristics is relatively easy, in spite of the fact that they may last sometimes for many years.

   Inbreeding can be considered in this sense as an advantageous method for discovering the hidden genetic defects of populations.

2. The situation is certainly more dangerous if the signs of inbreeding appear in quantitative traits. These characteristics are fertility, calving difficulties, increased mortality of young animals, decrease of mothering ability of dams, degeneration of constitution, lack of growth etc.

   These problems appear only slowly and not easily because of the considerable influence of environment and the human factor.

   It is true that the effect of inbreeding is exaggerated because it is a well known danger in small populations, also in relation to human life, and is a subject pursued by many.

   In an investigation in a Hungarian Grey Cattle herd the correlation between Wright's coefficient and the reproductive ability of cows was r = 0.134.

   The difference between the reproductive results of inbred and non-inbred cows was 5 percent in favour of the non-inbred. The whole herd was under blood group control and the difference was not significant. Such a difference in reproductive performance of inbred and non-inbred bulls could not be observed (Bodó et al. , 1982).

   For measuring the degrees of inbreeding Wright's coefficient is used. It is very good to judge the individual inbreeding rate when pedigree data are available.

   The simple average of Wright's coefficient of individuals cannot characterize the degree of inbreeding of a population because it is possible that not all the inbred animals have the same common ancestor in their pedigree and the number of common ancestors can vary in several herds.

   Therefore when using the coefficient of Wright for characterizing the inbreeding rate of a population the number of common ancestors should also be given.

   Instead of Wright's coefficient the blood groups and other blood polymorphisms can be used to characterize the level of inbreeding in a given breed. Pedigree data are not necessary and from the frequency and the existence of possible factors and alleles one can conclude the degree of inbreeding in the given population (Bodó et al., 1982; Bodó, 1984).

How can we avoid the damage affected by inbreeding? There are many well known methods.

1. First of all increasing the number of animals is the way to stabilize the preservation strategy, because the loss of heterozygosity is proportional to the decreasing effective population size.

   The increasing number of breeding animals can be the only basis for all possible manipulations. It is the simplest and most important action but in some cases realization is very difficult.

2. Rotational mating system. It needs pedigree data. It can be carried out by keeping the population as one unit or forming several subpopulations which will be crossed only after some generations.

   It was believed that division of a population into several sublines and using a circular group mating system reduces the inbreeding rate more than the simple rotational mating in one random population (Yamada, 1981). However, more recent studies by Yamda and Kimura (1984) have shown both the probability of fiation of a rare gene, and the chances get dangerous enhancement of inbreeding rate within sublines are greater when using subpopulations in the mating system.

   It can be concluded, that in the "natural" preservation form with an endangered population size, e.g. 500 cows, the division into subpopulations is very useful in discovering noxious genes in accordance with Yamada's first opinion. On the other hand under artificial conditions the small popultion can only be treated as a single random unit.

3. Keep the sex ratio as narrow as possible. The best effective population size can be obtained by a ratio of 1:1. Such management cannot be used under natural circumstances, but in laboratory yards. Often changing the males instead of using the best ones for a long period is a possible solution.

4. If some possibilities exist to control the blood of groups or other polymorphisms, these data can be used as an aid for mating and culling the dams and for selection of the future sires.

5. To introduce an extraneous/similar breed is a very dangerous method and is only admissible in the last resort of evident genetic degeneration, because this intervention threatens with extreme peril all the genetic merit of the population in question.

4. REMARKS ON MANAGEMENT SYSTEMS IN A PRESERVATION POLICY

In a preservation strategy it is also very important to preserve the original environmental conditions for the animals. This ensures the effect of natural selection in the same way as it was before. On the other hand it is sometimes even more difficult to preserve the original conditions for a breed is than the preservation of the breed itself.

In the course of history natural and artificial selection kept the balance against degeneration of the population (and selection for improving production was not effective). For this reason in situ preservation seems to be the most authentic form for preservation. The other solutions can lead to falsification to some extent, because their goal is to obtain some genetic equilibrium which was never the situation in practice.

A real danger exists, that a population can lose its valuable traits when no selection is made over more generations even when it is theoretically attempted by scientific methods to keep the frequency of genes on the same unchanged level.

The "natural" and "artificial" system of management has already been mentioned. It is important to acknowledge that these two methods can also be used together.

When one wants to establish the technology for maintenance of a threatened herd, the first task is to choose the system of mating and to subordinate all the other elements of technology used to this system.

When speaking of management systems, some disease problems must also be mentioned.

A very important threat exists for endangered breeds, namely infectious diseases. The usual method adopted for commercial populations is to eradicate the population infected with a contagious disease and replace it with a new set of animals after a period of time. This is not possible when rare non-commerical breeds or populations are affected. In this case it is necessary to find other veterinary solutions to guarantee the survival of the animals (for example, by separation of the offspring from the dam or even by embryo transfer).

Another veterinary aspect in management is the presence of facultative pathogenic organisms. They can afflict animals when their natural resistance is reduced by underfeeding, poor management etc. Usually the local endangered breeds are kept under harsh conditions and therefore run a greater risk of breakdown in resistance. To change these conditions would be not only expensive but also undesirable if preservation strategy is involved. Therefore a compromise is necessary. The environment should be constantly monitored to ensure that it does not pose a threat to maintenance of good health in the animals (Bodó et al., 1984).

Thus the most authentic method is the in situ maintenance of the threatened rare breed's or populations under the original unchanged harsh environmental conditions and it can be complemented by scientific solutions in. order to conserve the unchanged status of the genes. In some cases one of these methods can/must substitute the other.

5. IMPORTANCE OF TYPE WITHIN BREEDS IN CONSERVATION AND PRESERVATION

Essentially animal traits represent a great value for mankind and the gene structure of a population or breed is the basis for these traits.

When we are speaking about preservation we always think of endangered breeds or the diminishing variability in single purpose breeds etc. Thus, the category for the population which has the merit to be preserved is the breed

In so doing, breed variation is neglected for some traits in the interest, of high production. For example, in British breeds body size is acre and more increased using American and Canadian sires. In North America it is very difficult to distinguish among such different breeds as Hereford and Charolais and Simmental on the basis of body form.

The Hannoverian horse breed was a relatively heavy draught horse, and now it is a real sport horse because of the use of Thoroughbred stallions without changing the name of the breed.

When breeders' associations wanted to develop their breed in a modern direction (which is quite understandable), they increasingly eliminated the rare and commercially non-valuable traits and genes from the breed. The breed thus changes drastically and valuable genes are being lost for the future use of humanity.

If it is desired to establish a crossbred suckler cow herd of medium size out of dairy cows of big size (Holstein) it is possible by using original British beef breeds (e.g. Aberdeen Angus), but it is impossible when one has to use the modernized type of these breeds (e.g. Wye Angus with bulls of 1 200 kg).

In reality the value for mankind is represented by the genes and by traits based upon them and not by the breeds!

In this sense the activity and ambitions of breeders' associations and efforts of FAO are in contrary directions.

The topic of this short paper is preservation therefore the possible role of types in conservation of animal genetic resources, i.e. the profit heterosis, is only mentioned here.

In the future the different types within breeds must increasingly be taken into consideration.

REFERENCES

EXPERIENCE IN APPLICATION OF EMBRYO AND SEMEN FREEZING
TO ESTABLISH A RESERVE OF GENETIC MATERIAL

Stefan Wierzbowski 1/

Practical work started in 1984 at the Institute of Zootechnics, Department of Animal Reproduction and covered one cattle and two sheep breeds.

Red Polish cattle are diminishing rapidly due to crossbreeding. As a result only a limited number of purebred animals exist. Red Polish cattle are a dual purpose animal previously also used for draught. This breed now exists only in the hilly area of southern Poland numbering about 300 000 animals. Although the number of animals is still quite convincing, the policy of crossbreeding is diminishing the number of pure bred animals. The programme to establish a gene bank reserve executed is in two parallel activities: one by establishing three government farms with 300 cows, and the second by collecting semen and embryos from selected animals.

Bulls used for natural mating at the end of their breeding careers were selected as semen donors. Up to now 39 bulls have been chosen. Depending on the period of time available, condition of collection, transportation etc. 170 to 1200 doses of semen were produced from a semen donor. On the average 320 doses per bull are collected and kept in store. It is planned to select 15 more bulls and round off the number to 45 animals. Semen was frozen in pellets as this method is commonly used in Poland. For collection of embryos, so far 20 cows have been used. To qualify a cow as a donor the following conditions had to be fulfilled: over 3800 kg of milk per lactation, 4.2 percent fat, a calf per year for at least six years, easy calvings, complete recovery of genital organs after last calving, not yet served or inseminated after last calving. Uterus and ovaries in normal condition. Generally, good health (negative TBC, Bruc, EBL tests) and acceptable condition were also demanded.

Superovulation was induced by a single injection of 2000-3000 i.u. of PMSG on day 8 to 11 followed by administration of 500-750 μ g of cloprostenol (ICI) 2 days later. The donors were inseminated usually twice, starting 8-12 hours after oestrus onset. On day seven of post-oestrus, the uteri of donors were flushed non-surgically. A total of 52 attempts were made to induce superovulation. Treatments were repeated in 60.3 day intervals on the average. In 42 cases (80.7 percent) one or more embryos were recovered after flushing and in 10 (19.2 percent) cases the response for superovulatory treatment was missing (Table 1). Three cows did not respond at all although 9 treatments were applied.

Table 1 RESULTS OF EMBRYO COLLECTION IN SUPEROVULATED
POLISH RED COWS

On the average 4.3 embryos per treatment were obtained (Table 2). The best donor was a 12-year-old cow which in three flushings gave 23 embryos, with 12 of freezable quality. No age difference was found in efficiency of cows as embryo donors (Table 3). A total of 181 embryos were recovered and 92 were qualified for freezing. 2.1 embryos of freezable quality were obtained per induced superovulation. According to our experience 2 1/2-3 frozen embryos are needed to obtain one pregnancy.

Table 2 EFFECTIVENESS OF SUPEROVULATORY TREATMENT AND
EMBRYO RECOVERY RATE IN POLISH RED CATTLE

Table 3 EFFECTIVENESS OF SUPEROVULATORY TREATMENT IN POLISH
RED CATTLE DONORS ACCORDING TO AGE OF ANIMALS

Also natural heats were used for embryo recovery. In 7 donors 25 flushings were performed and 6 embryos of freezable quality were recovered.

In sheep two breeds, were selected to create a gene reserve. The Swiniarka breed no longer exists. It was only a flock of animals resembling more closely the original type of the breed. The Olkusz breed, or rather type, is a sheep still under consolidation as a breed. The idea behind the creation of a gene reserve was just to establish a basis for future comparison and evaluation of the breeding progress made in this sheep. However, the procedure of establishing a gene reserve is the same as in the case of endangered breeds.

Creation of a semen bank in sheep is much more difficult than in cattle. Of the Swiniarka breed only 5 and of the Olkusz breed 6 rams were available. Of the Swiniarka rams, 683 semen doses in 40 days were produced and in Olkusz sheep 1628 semen doses in 34 days were collected (Table 4).

Table 4 EFFECTIVENESS OF FROZEN SEMEN
PRODUCTION IN RAMS

Breed	Swiniarka	Olkusz
Number of rams	5	6
Collection period (days)	40	34
Produced semen doses	643	1628
Average per ram	136	271
	(84-168)	(151-411)

In Swiniarka sheep 37 ewes were used as donors. For superovulatory treatment 30 i.u. (kg) 800-100 i.u.(PMSG) on day 8 after oestrus was administrated, and 48 hours later 100 µg cloprostenol (ICI) was given. Nearly all ewes were used twice in one breeding season. On day 7 surgery was performed in midline and uterus was flushed applying retrograde technique. Ovulatory response was found in 65.2 percent of the cases and 1.9 embryos were flushed out on the average. Sixty-nine embryos were qualified for freezing with the average of 1.5 per induced superovulation (Table 5).

Table 5 EFFECTIVENESS OF SUPEROVULATORY TREATMENT
AND EMBRYO RECOVERY RATE IN SWINIARKA BREED

Donor ewes	37
Superovulatory treatments	72
Induced superovulation	47
Ovulatory response (CL+unovulated follicles)	255
Ovulatory response per successful treatment (CL+unovulated follicles)	5.4
Recovered embryos	91
Recovered embryos per superovulatory response	1.9
Embryos of freezable quality	69
Embryos of freezable quality per superovulatory response	1.5
Stored embryos	69

In Olkusz sheep 36 ewes were superovulated only once. Treatment and recovery procedure was the same as used in Swiniarka sheep. Seventy-five percent of donors responded to the stimulation and 2.6 embryos, on the average, were flushed out. Thirty-four embryos qualified for freezing, giving 1.3 per superovulation (Table 6).

Table 6 EFFECTIVENESS OF SUPEROVULATORY TREATMENT
AND EMBRYO RECOVERY RATE IN OLKUSZ BREED

Donor ewes	36
Superovulatory treatments	36
Induced superovulation	27
Ovulatory response (CL+unovulated follicles)	143
Ovulatory response per successful treatment (CL+unovulated follicles)	5.3
Recovered embryos	72
Recovered embryos per superovulatory response	2.6
Embryos of freezable quality	34
Embryos of freezable quality per superovulatory response	1.3

CONCLUSIONS

Collection, processing and storage of semen is a reasonably easy and inexpensive procedure in comparison with collection of embryos. In bulls planned bulk collection of 300 semen doses was usually established in 2 to 5 collections during one or two weeks. It may also be assumed, that out of 300 doses of semen nearly 200 calves may be produced.

Rams are less efficient due to the lower freezability of ram semen and higher number of sperm needed for one semen dose. It is also the reason why in rams a much lower number of semen doses per ram was collected. Rams were collected in 40 days (Swiniarka) and 34 days (Olkusz), but only on average, 210 semen doses per ram were acquired. to achieve one pregnancy 2.5 to 3 doses of frozen semen are needed. In this case it may be expected to produce some 30 to 40 lambs from each hundred semen doses only.

To establish cattle or sheep embryo reserves decidedly more efforts are needed. Females are less efficient producers of gametes which requires consideration in every plan to establish an embryo reserve. Some aspects which may have influenced the results received to be taken into consideration. Superovulatory effect of PMSG according to our experience may be irregular. Also it is possible to have very good results, as some PMSG products may have a limited effect. Also cows were selected for fertility since there was really no efficient donor available. In sheep there was no selection as records were unavailable.

It has also to be considered that all used breeds were of rather primitive type where also fertility is very satisfactory, expecially in Polish Red cattle, less in both sheep breeds, but the prolificacy is rather limited, and this may also be the reason for generally low susceptibility for superovulatory treatment.

REFERENCES

^1/ National Centre for Genetic Resources, EMBRAPA - CENARGEN, Cx. Postal 10.2372, 70770 Brasilia, DF - Brazil.

^1/ Indian Council of Agricultural Research, Krishi Bhawan, Dr. Rajendra Prasad Road, New Delhi-110001, India.

^1/ CSIRO, P.0. Box 184, North Ryde 2113, Australia.

^1/ Dept. of Animal Breeding, University of Veterinary Science, Budapest, Hungary.

^1/ Institute of Zootechnics, Dept. of Animal Reproduction and AI, 32-083 Balice/Kraków, Poland.