The world's animal genetic resources
Characteristics of indigenous African and Asian sheep breeds
Production and its improvement
References
H. Newton Turner
The author is with the Commonwealth Scientific and Industrial Research Organization (CSIRO), PO Box 184, North Ryde 21113, Australia. She gratefully acknowledges the assistance given by staff at CSIRO's Division of Molecular Biology.This article is intended to draw attention to the aims of the Joint FAO/UNEP Expert Panel on Animal Genetic Resources, to highlight the now-recognized value of small ruminants in developing countries, and the research that has been done there, as well as to encourage optimal use of indigenous sheep and goat breeds that are adapted to the often harsh environments of these countries.
Sheep have always been of value to Australia, the country with the world's highest sheep population and the largest fine wool production. Sheep are also important elsewhere, particularly in the developing countries of Africa and Asia, which have many adapted indigenous breeds. Each of these continents, in fact, has a greater number of sheep than Australia and produces more sheep meat annually, in spite of lower production per head (see Table). Furthermore, numbers there are increasing, by 17.1 percent in Africa and 6.5 percent in Asia over the last decade, with even greater increases in some individual countries.
These rises indicate a change in focus. When former colonies became independent after the Second World War and began developing their economies, mistakes were made, both by the newly formed governments themselves and by advisers from industrialized countries, the implications of which are now becoming clear. It was assumed that industrialization was the key to development; new factories drew the rural population into towns, and small food-producing farms were replaced by wide areas of cash crops. For animal production, large-scale government cattle farms were encouraged to earn export income for funding infrastructure. To improve livestock, temperate breeds, high-producing in their own countries, were imported either at the request of the developing countries or on advice from international consultants. At the same time, easily stored grain was considered to be the solution to the world's food problems.
By the early 1970s, the fallacy of many propositions was being realized. Diversion of rural workers into factories and cash crops often reduced food production. Stored grain may be the answer to emergency shortages, but it ignores the value of more than half the world's area that cannot grow crops but instead grows plants that can be converted by animals into human food. Exotic livestock will often not survive in environments where adapted indigenous breeds are able to produce, even if at a low level. Furthermore, enterprises such as large cattle farms may provide money for infrastructure but they are not a direct help to rural families who benefit from small flocks of sheep or herds of goats. Without refrigeration, a family cannot afford to slaughter a large beast for food, nor can it sell one that is needed for draught; a smaller sheep or goat can be slaughtered or sold more easily.
Production data for African and Asian countries with 0.5 million or more sheep
Données de production des pays d'Afrique et d'Asie ayant au moins 0,5 million d'ovins
Datos de producción de países de Africa y Asia con una cabaña de ovinos de 500 000 cabezas o más
|
Area
|
Total sheep |
Annual production numbers (1000 tonnes) |
||
|
(m) |
Meat 1 |
Milk |
||
|
1974-6 |
1985 |
1985 |
1985 |
|
|
World |
1054.5 |
1122.0 |
6244 |
8621 |
|
Africa |
164.7 |
192.8 |
801 |
1213 |
|
Asia |
292.3 |
311.2 |
1798 |
3698 |
|
Australia |
148.5 |
149.72 |
475 |
- |
1 Includes only animals slaughtered in the country
2 In 1986, 156 m
|
|
Total sheep numbers |
Annual production |
||
|
(m)
|
(1000 tonnes) |
|||
|
Meat |
Milk |
|||
|
1974-6 |
1985 |
1985 |
1985 |
|
|
Country (Africa) |
||||
|
Algeria |
9.3 |
18.0 |
87 |
195 |
|
Benin |
0.8 |
1.1 |
3 |
- |
|
Burkina Faso |
1.5 |
2.0 |
4 |
- |
|
Cameroon |
2.0 |
1.9 |
7 |
- |
|
Chad |
2.3 |
2.2 |
9 |
7 |
|
Côte d'Ivoire |
1.0 |
1.4 |
6 |
- |
|
Egypt |
1.9 |
2.5 |
33 |
22 |
|
Ethiopia |
23.2 |
23.5 |
86 |
63 |
|
Ghana |
1.7 |
2.0 |
6 |
- |
|
Kenya |
3.1 |
7.0 |
25 |
28 |
|
Lesotho |
1.4 |
1.4 |
4 |
- |
|
Libya |
4.0 |
5.5 |
53 |
43 |
|
Madagascar |
0.6 |
0.6 |
2 |
- |
|
Mali |
4.9 |
6.5 |
22 |
32 |
|
Mauritania |
3.8 |
5.2 |
7 |
68 |
|
Morocco |
15.0 |
12.0 |
50 |
25 |
|
Namibia |
5.0 |
6.0 |
21 |
- |
|
Niger |
2.2 |
3.5 |
15 |
13 |
|
Nigeria |
10.1 |
12.8 |
44 |
- |
|
Senegal |
1.7 |
2.2 |
7 |
9 |
|
Somalia |
9.2 |
9.7 |
12 |
100 |
|
South Africa |
30.8 |
30.2 |
135 |
- |
|
Sudan |
13.9 |
19.0 |
96 |
590 |
|
Tanzania |
3.4 |
4.1 |
11 |
- |
|
Togo |
0.8 |
0.8 |
2 |
- |
|
Tunisia |
5.7 |
5.2 |
29 |
14 |
|
Uganda |
1.0 |
1.5 |
7 |
- |
|
Zaire |
0.7 |
0.8 |
3 |
- |
|
Country (Asia) |
||||
|
Afghanistan |
19.9 |
20.0 |
133 |
245 |
|
Bangladesh |
1.1 |
1.1 |
1 |
17 |
|
China |
94.4 |
95.2 |
320 |
532 |
|
Cyprus |
0.4 |
0.5 |
6 |
26 |
|
India |
40.0 |
41.3 |
135 |
- |
|
Indonesia |
3.2 |
5.0 |
24 |
- |
|
Iran |
34.8 |
34.5 |
234 |
715 |
|
Iraq |
11.1 |
8.5 |
50 |
168 |
|
Jordan |
0.7 |
1.0 |
8 |
26 |
|
Kuwait |
0.1 |
0.6 |
36 |
7 |
|
Mongolia |
14.3 |
13.4 |
96 |
12 |
|
Nepal |
2.3 |
2.6 |
13 |
- |
|
Pakistan |
17.5 |
25.0 |
190 |
37 |
|
Saudi Arabia |
2.1 |
3.6 |
95 |
94 |
|
Syrian Arab Rep. |
5.9 |
13.7 |
81 |
525 |
|
Turkey |
40.7 |
40.4 |
315 |
1200 |
|
Yemen |
1.6 |
1.8 |
21 |
38 |
|
Yemen (Dem.) |
0.8 |
0.9 |
7 |
12 |
Source: FAO Production Yearbook, Vol. 39, 1985
Some governments, of course, have long been aware of the value of small ruminants to their rural populations: India has had plans for upgrading sheep production since 1951, and has done considerable research on its native breeds. Pakistan was the first country to sell its carpet wool with data on measured quality, and in 1982 the Pakistan Agricultural Research Council organized an International Seminar on Sheep and Wool. Over the last few years, however, there has been a more general upsurge of interest in sheep and goats in African and Asian countries, and with it, increased investigation of native breeds adapted to a range of harsh environments.
Range of breeds and environments
Australia, New Zealand and the Americas had no native domestic sheep, flocks being derived largely from European breeds, although one African and one Asian breed made early contributions in Australia (Turner, 1983). Europe, Asia and Africa, on the other hand, have, over millennia, developed numerous breeds adapted to different environments and with a wide range of products.
Sheep are reared from sea level to altitudes of over 5 000 m; from above 50° latitude, north and south, to the equator; from deserts to the humid tropics. They are run under a variety of management conditions, from grazing without shepherding in fenced paddocks, to constant shepherding or to migration on a fixed route. Flock sizes range from fewer than ten to thousands, while mating systems vary from leaving the rams continually with the ewes, with or without service checks, to joining for specified periods, by natural or hand-mating, or AI.
Conservation of animal genetic resources
The many breeds of sheep are part of the world's rich animal genetic resources (AGR), in which interest is increasing, with concern about their erosion. This interest parallels concern about conservation of plant genetic resources (PGR), which culminated in the establishment of the International Board for Plant Genetic Resources (IBPGR) in 1974, and the FAO Commission for PGR in 1984. FAO has been interested in both PGR and AGR since its inception in 1945, and has done much to foster documentation of livestock breeds, including sheep and goats (FAO, 1978; 1980a; 1982a; 1985a, b).
FAO has also held a series of technical consultations on AGR since 1966, culminating in 1980 with the appointment of an Expert Panel with worldwide representation to work in association with an AGR officer in Rome, who publishes a periodic newsletter. The Panel is charged with encouraging the "conservation" of AGR, considered to cover documentation, evaluation, optimal use and, where necessary, preservation (FAO, 1980b; 1981). Documentation would include establishing regional (compatible) computerized data banks, the first step toward which are descriptor lists to encourage standardized recording (FAO, 1986). Preservation of threatened breeds in specific flocks is to be encouraged, as well as establishment of regional gene banks with cryogenic storage of semen or embryos.
In the 1970s, developing countries increased their interest in their own resources; the Inter-African Bureau for Animal Resources (IBAR) setup an Expert Committee on AGR in Africa which met in 1981, one of its recommendations being the establishment of a data bank to document African breeds and strains, in cooperation with FAO and the International Livestock Centre for Africa (ILCA). Reviews of indigenous breeds were presented at a 1983 meeting (OAU/STRC/IBAR, 1985).
Other organizations have also been active in the field of documentation and evaluation, including the Commonwealth Agricultural Bureaux, the European Association for Animal Production (EAAP), and the Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO, 1980). India now has a Bureau of Animal Genetic Resources, and reviews of Indian sheep breeds have been published (e.g. Acharya and Bhat, 1984).
Establishment of sheep and goat networks
All these many conservation activities have dealt with every livestock species. In addition, networks are being established to keep research and development workers with sheep and goats in touch with each other, and to make their work more widely known.
ILCA has established a Sheep and Goat Unit, which publishes a periodic newsletter, and has cooperated with IBAR in organizing a Sheep and Goat Network for Africa. Other similar networks are being established by FAO, one for Asia and the Pacific (FAO, 1985c; 1986), one for Latin America and the Caribbean and another for the Near East.
Although some features of indigenous breeds are still to be recorded, enough data are available to show that they have outstanding characteristics, the most important being adaptation to often harsh environmental conditions, demonstrated by their survival.
Reproduction rate
Figures on reproduction rate indicate ability to survive; they are available more often from experimental stations than from the field, but Wilson (1985) gave data for lambs born/ewe/year in farmers' flocks in some sub-Saharan countries. These ranged from 1.05 to 1.51, with lambing intervals from 365 to 275 days, and pre-weaning death rates from 13 to 30 percent, resulting in valuable figures of 0.91 to 1.06 lambs weaned/ewe/year.
Lahlou-Kassi (19873 gave figures from experimental stations for adapted breeds in North Africa. Age at first lambing ranges from 12 to 22 months, lambings per year from 1.0 to 1.7, and average litter size from 1.0 to as high as 2.65 for some flocks of D'man.
The ability to lamb more than once a year, with high litter size, is demonstrated also by the Java thin-tailed and fat-tailed sheep (FAO, 1980a), as well as the Chios (Sakis) from Greece and Turkey, and hair sheep of tropical America (e.g. the Barbados Blackbelly), originally from West Africa (FAO, 1980a).
Other prolific Asian breeds are the large-tail Han of China (FAO, 1985a) and the wera (local) breed of Bangladesh, suggested by Turner (1983) as possibly descended from the otherwise unidentified prolific Bengal sheep, which made a major contribution to the early sheep industry in Australia.
Lahlou-Kassi (1987) stressed the need for increased reproduction rate in indigenous North African sheep to overcome the meat shortage, and Mason (FAO, 1980a) suggested it would be more profitable to use adapted local prolific sheep for crossing instead of imported breeds from very different environments, such as the Finn and Romanov.
There are other considerations about these prolific breeds. Since it has been demonstrated that the high performance of the Australian Booroola Merino is controlled by a single gene, or group of genes (Piper, Bindon and Davis, 1985), other fecund breeds have been examined. Lahlou-Kassi and Marie (1985) consider the large variation between individual sheep in reproduction rate in the D'man indicative of single-gene control, while Bradford et al. (1986) suggested similar control for the Javanese breeds.
Identifying single genes is still time-consuming, though techniques are advancing rapidly. The prospect of being able to transfer a gene without associated disadvantages of a hair coat or small body size, yet retaining characteristics of adaptation, is attractive, if distant.
Other characteristics
A satisfactory reproduction rate is one indication that a breed is adapted, but research is needed to determine why, particularly if genetic engineering is to be used in future to increase adaptation. What relevant characteristics govern (i) ability to survive on limited amounts of coarse feed; (ii) drought resistance; (iii) disease resistance; and (iv) walking ability?
Studies on rumen flora and gut length may be important for (i), and on the fat-tailed sheep for (ii), although other factors must also play a part. Fundamental work on trypanotolerance indicates why some breeds are resistant (Murray and Trail, 1-98-2) but other diseases await investigation.
Aims
In the developed world, sheep, goats and cattle are kept for economic return from their products; provision of food, clothing or shelter for the owners is a minor consideration. In less developed countries, direct economic return from products may still be important, but use by the owner family or tribe is sometimes more so. In addition, animals may be a sign of wealth or prestige; they may be kept for work, sport or religious reasons, or for bride price. These reasons can lead to changes in flock structure, which have to be considered in improvement plans.
The main economic sheep products at which improvement is aimed are fibre (apparel, cross-bred or carpet wool, hair), food (meat, milk) and skins (leather, woolled skins, fur). By-products such as dung for fuel or fertilizer are useful, but not - usually objectives for improvement.
Any animal enterprise involves not only production, but the whole post-production chain from producer to consumer - collection, preparation, marketing, processing and consumption - which can often influence production as much as breed or environment. For example, wool is produced in the interior-of Australia as the product does not deteriorate on the long journey to international mills.
Several questions need consideration in relation to this post-production phase:
· Is there a market and, if so, what is its capacity?· Where is the market, and what does it require? Hand-processing of wool, for example, calls for different attributes from sale on world markets for factory processing (a higher fibre diameter, sometimes with a preference for pigmented rather than white wool).
· What are the facilities for slaughtering animals and transporting meat? Are the abattoirs strategically placed so that animals do not have to walk long distances, and are they equipped for the ready collection of by-products (blood, offal, skins, etc.)?
· Will milk be consumed locally or converted to other products such as cheese? If the latter, on-farm or in a factory? What transport facilities are available?
In developing countries, this part of the chain often favours the go-between rather than the farmer. Australia has recently been released from overclassing of wool as soon as it is shorn. In Pakistan fleeces are usually bundled together immediately after shearing, with no sorting, even for colour, and a travelling merchant will buy the mixture and reap benefit from sorting. Even a preliminary separation of colour and length would benefit the farmer.
Initiation of improvements in these post-production phases is as much part of breeding plans as the calculation of elaborate selection-indices, and is sometimes even more important. In Australia, sale of wool on measurement gave an impetus to the incorporation of measurement in Merino sire selection, and it was the animal breeders and those associated with them who first began to plead for measurement to replace visual appraisal in dealing with wool.
Photo/Foto: B.M. Bindon
Photo/Foto: C. W. Fox
The need to consider post-production as well as production of course applies to avenues of improvement in management as well as breeding, and is especially important in developing countries.
Documentation and evaluation of breeds
Having decided on a product, what breed or strain will be chosen? For this choice, production records are needed. The work of various organizations on documentation has already been mentioned, but the records are far from complete. Some points for consideration are listed below.
Source of data. Most, though not all, figures are collected on experimental farms or government stations, but not in commercial flocks where conditions are likely to be different. Also, the environment in which the data are collected is not always described.
To overcome these problems, the FAO data banks are asking that more field data be collected, and the source always entered, with a description of the environment in standard terms (FAO, 1986).
Uniformity of recording. It is hoped that animal production workers everywhere will be encouraged to use these standard descriptors. One record which particularly calls for standardization is reproduction rate; "Lambing percentage", for instance, can mean a number of things. The FAO descriptors list uniform terms that are unequivocal.
Gaps in records. Existing reviews show many gaps. In particular, there are few estimates of total lifetime performance (in Australia, as elsewhere), while reproduction data are often missing. Statements about the length of the breeding season are often based on the incidence of lambing, unsupported by observations on oestrous activity.
Evaluation. Production data on different breeds are usually gathered in different places at different times, with no comparison on contemporary animals run together. Some work to remedy this has been done, but mainly at experimental stations, not in the field.
Various techniques are available for broadening the conclusions from such comparisons. The same "reference" breed can be used in a number of centres, as in the FAO dairy cattle comparisons; the Animal Breeding Research Institute at Katanning, Western Australia, has a similar project in its Sire Reference Scheme, which allows comparisons between Merino studs.
Flock productivity. In investigating village flocks in Africa, various workers have developed indices for comparing the productivity of different flocks or species. One of their comments is that emphasis on the productivity of individuals omits the importance of flock structure, including the proportion of non-breeding animals. Peacock (1985) stressed the need to emphasize the cumulative effect of individual traits on whole flock productivity, and suggested the following:
The author tested sensitivity by varying the levels of the inputs, and was able to isolate the proportion of breeding females giving birth each year that had the greatest influence on productivity. She was careful to say that one index alone cannot provide a definitive account of production; indices designed for special circumstances are more likely to be useful in revealing areas for research. The study dealt with the Masai in Kenya, where the flock itself must be considered as the resource requiring improvement; in areas of communal pasture, the flock is the unit that can be manipulated by its owner. With fixed grazing areas (as in Australia) it might be more appropriate to consider production per unit of land.
Peacock's index is, of course, developed for a flock where meat is important; she mentions the need to include wool or other products where appropriate.
Improvement techniques
The first step in any improvement programme is a clear definition of what is required in the product. Improvement techniques can then be classified under breeding plans and management. Each requires some measurement of production; for breeding plans involving selection, measurement of individuals is required, but in many other cases only measurement of flock performance is necessary.
Defining production
Fibre: As a preliminary to the sale of wool in Australia on a measured sample, the Australian Objective Measurement Project undertook years of research to define the characteristics of greatest importance to manufacturers of apparel wool (AWC, 1973). Work is continuing in association with sale on description only. Average fibre diameter stands as the main characteristic of importance; this and clean weight per head are included in the Australian Woolplan scheme launched for breeders in 1987, to provide a service for selection on measurement.
The requirements for carpet wool or hair have not been so clearly defined. Burns, Johnson and Chen (1940) recommended some limits for average fibre diameter and percentages and types of medullation for carpet wool, but these were based on measurements of wools in current use; there were no experiments to determine whether these were optimal, or what effect variations would have on the quality and durability of the final carpet. Work at the Wool Research Organization in New Zealand may lead to a reassessment of requirements.
Meat: Quality characteristics for meat will vary from country to country. In Australia, for example, emphasis is now laid on lean meat, but some countries show a preference for the fat tail.
Milk: About 9 percent of the-world's total sheep milk production comes from Africa, with about 45 percent each from Asia and Europe. The greatest amount of research on sheep milk has been done in France, which has well-developed breeding plans for sheep milk, similar to those used for dairy cattle (Flamant, 1970); these include selection criteria for milk produced for cheese-making.
Skins: Little work has been done on precise definition of the characteristics required of skins, though traditionally those of various breeds are used for specific purposes.
Measuring production. Refined measurement techniques and the necessary infrastructure have been developed for western countries; in Australia their acceptance for selection for wool production in the field was initially slow, but has gained momentum since the advent of sale of wool on measurement instead of eye appraisal.
The transfer of these techniques to developing countries has not always been practicable (FAO, 1982b). For example, when individuals have to be identified, it is not possible in some countries to use eartags, either for religious reasons or because many shepherds in field flocks are not yet literate. The timing and amount of recording will have to be established for each country according to the type of management, the product, and the infrastructure available.
Breeding plans. The classic tools are selection and crossbreeding, the latter being used for replacing a breed, developing a new one, or exploiting heterosis.
Selection: Recent years have seen emphasis in the western world on distinguishing between breeding objectives and selection criteria and, with the rapid expansion of computer technology, increasingly sophisticated selection indices. This work may be useful in squeezing the last drop of efficiency from breeding plans in developed countries, but it is difficult to see its value to shepherds with small flocks, particularly those that are transhumant or migratory. More thought should be given to techniques for improving village flocks, though it is likely that solutions will differ from country to country.
In Australia, sires are distributed from ram-breeding flocks (studs in the classic hierarchy or central nuclei in group-breeding schemes), or are home-bred where flocks are large enough to form a nucleus. Flocks in the developing countries of Africa and Asia are frequently too small for selection to be of-any value, and a stud structure seldom exists.
The latter is usually replaced by government farms that produce and distribute rams, either of indigenous or exotic breeds. Often even these government flocks are too small for effective selection; both Acharya (FAO, 1982a) and Bhat (1987) have commented that selection of indigenous breeds in India has been branded as a failure when in fact-the techniques, not the-principles, were at fault.
If such a scheme is to be of value, the ram-breeding flock should be large enough for selection to be effective, with a minimum of 500 breeding ewes. Further, distribution of rams should not be haphazard but made to a predetermined pattern (Turner, 1982).
Group-breeding schemes have been successful in New Zealand and Australia (Parker and Rae, 1982), and a modification of them might be useful in some cases for small flocks elsewhere. In a group-breeding scheme a central nucleus receives ewes from contributors to which rams go out, in contrast to a classic "closed" stud from which rams move out but nothing moves in. The pool for selection is thus widened.
Cross-breeding: Exploitation of heterosis in crossbreeding requires maintenance of pure-bred flocks of different breeds, and constant production of first-cross ewes. Such a structure does not seem appropriate in the current types of African and Asian sheep flocks; furthermore, the amount of heterosis so far recorded for most sheep traits is not sufficiently high to reward complex breeding plans. This was demonstrated by Farid, Makarechian and Sefidbakht (1977) with crosses between Iranian breeds. A self-replacing flock is more likely to be acceptable.
This leaves replacement, or development of a new breed, as the avenues for cross-breeding, and many so-called "improved" breeds from temperate areas have been introduced into Africa and Asia. Sometimes central nuclei of the exotic breed have been established, with rams distributed in the field. An example of this is in the North West Frontier Province of Pakistan, where rams have been distributed to migratory flocks in the hill areas from a flock of American Rambouillet established some years ago. Body weight, fleece weight and quality showed improvement in areas receiving the-rams (Atkinson, FAO consultant, Personal Communication, 1982) but, without a set distribution pattern and field monitoring, the full impact cannot be assessed. Furthermore, although the nucleus is in the cooler hills, it has deteriorated. The NWFP Government has plans for improving the farm, bringing in new exotic sheep, and instituting better field monitoring.
In many other cases exotic introductions have performed poorly or failed to survive, and attempts have been made to produce new breeds by selection among crosses. These have been successful in China with the Xinjiang (Chinese Merino), the Northeast Finewool and the Gansu Alpine Finewool (FAO, 1985a) and with the Kashmir Merino in India (FAO, 1987).
Two Turkish Merino breeds developed in this way over the last 50 years account for only 3 percent of the total sheep population, while other new breeds such as the Avastara (finewool) and Avakalin (improved carpet wool) in India, and the Baghdale (semi-fine) and Pak Karakul (fur) in Pakistan do not yet seem to have spread far from their experimental flocks.
Crossing of the highly prolific Javanese thin-tailed sheep with temperate breeds at Ciawi, in Indonesia, has shown that the pure-bred produces a-greater weight of lamb weaned than the crosses, in spite of its lower individual lamb weights (Fletcher et al., 1985).
Crossing with temperate exotic breeds thus holds doubtful promise, except in special areas; the successful breeds mentioned in Asia are in the mountains, where animals are less exposed to heat and humidity.
An alternative that has been successful in some countries is to choose local superior breeds to upgrade inferior ones. This route to improved production will become more valuable as further breeds are fully documented, with information available through data banks.
Management
As in the case of breeding plans, each country must develop its own strategies for improved management, the main building blocks for which are nutrition, disease control and flock structure.
Countries in Africa and Asia face problems not encountered in Australia. For example, Australia has overgrazed soil-eroded areas in many districts and the land is subject to a complex pattern of grazing rights. While in Africa and Asia the degraded rangelands, tramped over for centuries by nomadic flocks, have no private owners who can be held responsible for introducing improvements. All Australian sheep have their own grazing areas; they are not forced to go out daily in small bands with shepherds to scavenge along road verges or canal banks.
Nutrition and disease control are two of the main avenues for improved management. One of the problems in all such strategies is the order of importance of these two items. In Australia, advice on improvement of animal production was initially in the hands of veterinarians trained in - diseases. Later, when many major scourges had been brought under control, animal husbandry (management of healthy animals) appeared as a discipline in its own right. The new discipline was regarded suspiciously at first by veterinarians, but is now thoroughly accepted; animal husbandry technicians work side by side with veterinarians.
The same course is being followed elsewhere. In India and Pakistan, for example, the basic university training for anyone associated with animal production is in veterinary science. With so many diseases still to be controlled, a continuing supply of veterinarians is essential, but there is room also for extended training in animal production. Animal husbandry courses have been introduced in many universities, but in Pakistan as recently as 1984 it was still difficult to place graduates who had specialized in production.
Australia has a well-integrated system of research and extension for the sheep industry, extension officers being distributed in the country and given transport. Radio and television can be widely used as English is the universal language.
Many countries of Africa and Asia now have well-established research institutes, and in some, but not all, cases, trained extension officers. These officers encounter language problems with a variety of tongues in the country; furthermore, they are often allotted neither money nor vehicles for transport, while anyone watching television reports on the delivery of famine relief supplies in Africa will be familiar with the problem of poor roads.
Peacock (1985) isolated the proportion of females producing lambs, plus the proportion of castrates, as main contributors to flock productivity in parts of Kenya. Sociologists, as well as animal production extension officers, will need to work with owners if flock structures are to change.
Not all African and Asian sheep, of course, are nomadic, and in some places there are good pastures. However, poor nutrition is a constant problem for livestock. To help overcome this, sheep are brought from the rangelands to lot feeding in some countries, while much research is devoted to making agricultural byproducts suitable for livestock.
Other techniques
No comment on animal improvement would be complete without reference to other techniques and their likely value to developing countries. Many could be useful on government farms, though they are of doubtful value at present in the field.
Artificial insemination (AI) can be valuable for spreading genes from superior sires, and is widely employed with dairy cattle, using frozen semen. For sheep and goats, selection can be based on the sire's own body weight or wool production without progeny-testing; further, frozen semen is not as successful as with cattle, unless a surgical technique is used. Chilled semen was used in the field in Rajasthan, but was abandoned because owners failed to bring their ewes singly to the centre when on heat; in Gujerat couriers were paid to do this. On government farms these difficulties are not present, and AI with fresh semen is widely used, as for example in China.
Oestrous synchronization, multiple ovulation, embryo transfer and laparoscopy all have their uses for increasing numbers of superior animals and can be used on government farms; some countries have already established embryo transfer laboratories. It is to be hoped these will be used for multiplying superior animals of indigenous breeds, and not only for exotic imports. Again there are at present practical difficulties, including cost, about their use in field flocks.
Genetic engineering offers exciting, though distant, visions for the future of animal production. Hodges (1986) discussed the possibilities, pointing out that the first major success will be in diagnosis of disease and preparation of vaccines, through manipulation of bacteria. Remodelling of animals by gene transfer requires much more work in costly highly specialized laboratories, which will be done initially by the newly established International Centre for Genetic Engineering and Biotechnology (located in New Delhi, India and Trieste, Italy) rather than by individual countries.
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