5. CONCLUSIONS AND RECOMMENDATIONS

5.1 General Conclusions

1. Among Asian countries, China, India and Iran have the largest populations of sheep and goats, and have the highest production levels. Information on the performance of Asian breeds is highly inadequate and largely unsatisfactory. While some of the breeds have not even been fully described, others are being indiscriminately crossed. Their improvement, even today, is entirely based on ram/buck exchange between breeders and distribution of rams/bucks from Government farms, with no provision for monitoring their performance and impact. Wherever improvement programmes are underway, the participation of farmers is virtually non-existent.
2. Most breeds of sheep are available in adequate numbers and there is no danger of extinction for any breed population. In goats, except for two breeds (Jamnapari and Barbari of India), whose numbers have declined to 5000 and 30 000, numbers are fairly adequate.
3. Most countries have been crossbreeding indigenous breeds with imported exotic rams/bucks/semen, in order to introduce gains in body weight and wool quality. Except for two cases (Turkey and India), these programmes have not been able to create any impact.
4. No system of recording performance in producers' flocks exists in the entire region except in Turkey. Crossbreeding is being extensively used under the impression that dramatic changes in the performance of these breeds will be obtained, without considering the realities of the environments in which these crossbreds are to survive and produce. It can be safely concluded that all these goals can be achieved if indigenous breeds are given proper nutrition and adequate health cover, combined with within-breed selection based on performance recording in farmers' flocks.

5.2 Gaps in Information

The information available from these countries on various aspects is scanty, and data need to be collected. Some aspects are detailed below:

5.2.1 Reproductive cycle

It has been observed that most breeds in the region breed round the year, while some breeds show considerable variations in breeding season and frequency of lambing. This inconsistency needs to be examined.

5.2.2 Lifetime performance

Data on sheep maintained in the experimental stations which have been reported in the literature refer to performance early in life. There are no data on lifetime performance. This vital aspect is not realized when comparing native breeds with crossbreds or new introductions. While some figures are available on lamb survival, the mortality figures over the years are not available. Changes in lambing percentage and wool production for native breeds with age are also not available.

5.2.3 Performance under village conditions

Lifetime performance needs to be compared in villages as well as on experimental farms. This information is not available.

5.2.4 Artificial management of crossbred and native

In most village conditions in Asia, whenever a crossbred is produced it is given special care, consequently the cost of production increases. The question which needs to be examined is whether a cost/benefit ratio on management would give this new crossbred introduction an advantage over the native if the special care did not exist. This information is vital for making any general recommendation on crossbreeding as a method of improvement.

5.2.5 Comparisons from available information

From the presently reported information, it is not always possible to decide whether the comparisons are contemporary or not. This is a basic defect with most of the data presented. Efforts need to be made to rectify this.

In most experiments native and crossbred have to be run concurrently, in the initial years of experiments. This comparison is available when crossbreds are being generated. Data on the natives are reduced as the crossbred groups are increased and the natives are eliminated, whatever the reasons, with the result that concurrent information on the natives is lost. This kind of design needs to be avoided if meaningful comparisons are to be made from which recommendations can be made to farmers.

5.2.6 Valuable traits of native breeds

Lists of genetic traits which are available from the point of view of conservation are difficult to make, but a few can be identified:

Adaptation: Most native breeds are adapted to harsh environments. When purebred exotics are introduced into these environments they generally do not survive. Halfbreds with exotics have shown increased production, but when concurrently left under village conditions the marginal increase is not large enough to justify the costs under the harsh environment. The crossbred survival is also difficult without proportionate input, which is generally not forthcoming.

High ovulation rate: A number of breeds from the Asian regions show high ovulation rate; particularly Javanese thin tailed sheep (JTT) and Bengal goats.

5.3 Recommendations

1. Evaluation of indigenous breeds needs to be undertaken, starting with those that are numerically more important and in keeping with local product needs, such as meat, milk and wool.
2. Evaluation of breeds for crossing with local breeds for increased meat, milk or wool production (quality and quantity) should be undertaken. This should include breeds from within and outside the region.
3. Most of the sheep and goat breeds in the region have long breeding seasons. In fact, some of the ewes continue to cycle even during the "non-breeding season". In some breeds, two peaks of breeding activity have been reported. This trait of sheep is not being fully exploited. There is now sufficient evidence under experiment station conditions that it is technically feasible to breed every eight months or three times in two years, but this concept has yet to be field-tested to identify practical problems under nomadic and transhumant situations.
4. There is interest in the use of hormones for synchronization of oestrus, superovulation and induction of early maturity. The physiology of reproduction and its modification through hormonal intervention is not sufficiently understood, however, to warrant immediate studies in the region. Instead, efforts are needed to understand the reproductive behaviour of the indigenous breeds in the regional environment. Hormonal interventions may be called for after the seasonal and lactational anoestrus are well understood.
5. It is necessary to develop JTT strains homozygous for the "prolificacy" gene. These sheep show considerable variability in litter size, but on an average, to have a high litter size it is necessary to develop strains which have a uniform litter size.
6. It is also desirable to develop strains of JTT sheep which do not carry the "prolificacy" gene. Such ewes will have mostly singles and twins. This will be an adequate level of prolificacy for most currently existing management situations.
7. Most of the indigenous breeds have poor body weight gains and efficiency of feed conversion. Improvement through selection in body weight gain, which is highly heritable, is possible.
8. A critical evaluation of the current crossbreeding programmes must precede any recommendation for the future.
9. Most of the breeds in the region produce fleeces which have high average fibre diameter and medullation percentage. These are suitable for various grades of carpets. Some of the breeds have coarser and more hairy fleeces which are not usable even for low quality carpets. Selection against medulallation results in improvement in fleece quality.
10. Selection for the first six-monthly fleece weight and against medullation percentage in extremely coarse and hairy breeds improves greasy wool production and quality towards better carpet wool. Such a selection needs also to be undertaken in better carpet wool breeds.
11. It is recommended that for improving apparel wool production, crossing of better carpet wool breeds with exotic fine wool breeds can be attempted, stabilizing exotic inheritance at 50%. Further improvement may be brought about through selection in crossbred populations for greasy fleece weight and against medullation percentage.
12. It is recommended that for improving mutton production, especially under intensive feed management, crossbreeding of extremely coarse and hairy wool breeds with exotic mutton breeds be undertaken.
13. Improvement of milk production in goats can be brought about through selection for first lactation milk yield and age at first kidding.
14. The important goat breeds of India whose number have declined seriously are the Barbari and Jamnapari. It is reported that only 5000 animals of Jamnapari and 30 000 heads of Barbari exist at present. They need to be conserved.

REFERENCES