J.E.O. Rege

Animal genetic resources and economic development: issues in relation to economic valuation

Abstract The worlds domestic animal breeds represent an important resource for economic development and livelihood security. Extensive genetic diversity in these breeds allows the existence of livestock in all but the most extreme environments globally, providing a range of products and functions. Unfortunately, a large number of breeds have been lost and many more are at risk of loss. An important research and development goal is the systematic evaluation of breeds in production systems where they arc typically found, quantitative assessment of the genetic diversity they possess, the definition of relationships amongst breeds and the implementation of programmes for their effective management, including development of policies and strategies for conservation and sustainable utilisation. The key issues of threats to livestock genetic resources, justification for conservation, conservation strategies, priority-setting for conservation are summarised. The potential contribution of economic valuation in ensuring equitable sharing of benefits derived from domestic animal genetic resources (AnGR) is also discussed. Decisions will be required about which breeds are of highest priority, and which conservation or management options represent optimal use of resources for diversity conservation. There is urgent need for the development and application of economic and policy analysis tools to aid rational decision-making in the management of the global domestic AnGR.

An approach to the optimal allocation of conservation funds to minimize loss of genetic diversity between livestock breeds

About 30% of all farm animal breeds worldwide are at risk of extinction. To prevent this irreversible erosion of genetic diversity, the limited funds available for conservation need to be allocated in the most efficient way. Applying the diversity concept of Weitzman [Quart. J. Econ. CVII (1992) 363; Quart. J. Econ. CVIII (1993) 157] this paper presents a framework for the allocation of a given budget among a set of breeds such that the expected amount of between-breed diversity conserved is maximized. As a novel methodological contribution, a functional relationship between conservation funds spent in one population and the conservation effect in terms of reduced extinction probability is suggested. Based on arguments from population genetics, three different functions are derived, which may reflect the range of possible functions in typical conservation situations. The methodology is illustrated with an example of 23 African zebu and zenga cattle breeds. The results indicate that conservation funds should be spent on only three to nine of the 23 breeds, depending on the model used. Highest priority is given to breeds, for which the ‘conservation potential’, that is, the product of extinction probability and marginal diversity is maximum, and these are not necessarily the most endangered breeds. The methodology can be extended to the maximization of total utility, which incorporates diversity, as well as other direct use, and special value, characteristics. However, a number of essential input parameters such as extinction probabilities and economic values are lacking and realistic models for developing cost-efficient conservation strategies have to be derived. Given these lacking bits of information become available, the methodology suggested provides a breakthrough towards applicability of diversity-based approaches for decision taking in conservation programs. # 2003 Elsevier Science B.V. All rights reserved.

Hybridization of banteng (Bos javanicus) and zebu (Bos indicus) revealed by mitochondrial DNA, satellite DNA, AFLP and microsatellites

Hybridization between wild and domestic bovine species occurs worldwide either spontaneously or by organized crossing. We have analysed hybridization of banteng (Bos javanicus) and zebu (Bos indicus) in south-east Asian cattle using mitochondrial DNA (PCR-RFLP and sequencing), AFLP, satellite fragment length polymorphisms (SFLP or PCR-RFLP of satellite DNA) and microsatellite genotyping. The Indonesian Madura zebu breed is reputed to be of hybrid zebu–banteng origin, but this has never been documented and Bali cattle are considered to be a domesticated form of banteng. The banteng mitochondrial type was found in all animals sampled on the isle of Bali, Indonesia, but only in 35% of the animals from a Malaysian Bali-cattle population. The Madura animals also carried mitochondrial DNA of either zebu and banteng origin. In both populations, zebu introgression was confirmed by AFLP and SFLP. Microsatellite analysis of the Malaysian Bali population revealed for 12 out of 15 loci screened, Bali-cattle-specific alleles, several of which were also found in wild banteng animals. The tools we have described are suitable for the detection of species in introgression studies, which are essential for the genetic description of local breeds and the preservation of their economic and cultural value.

Assessment of cattle genetic introgression into domestic yak populations using mitochondrial and microsatellite DNA markers

Hybridization between yak Poephagus grunniens and taurine Bos taurus or indicine B. indicus cattle has been widely practiced throughout the yak geographical range, and gene flow is expected to have occurred between these species. To assess the impact of cattle admixture on domestic yak, we examined 1076 domestic yak from 29 populations collected in China, Bhutan, Nepal, India, Pakistan, Kyrgyzstan, Mongolia and Russia using mitochondrial DNA and 17 autosomal microsatellite loci. A cattle diagnostic marker-based analysis reveals cattle-specific mtDNA and/or autosomal microsatellite allele introgression in 127 yak individuals from 22 populations. The mean level of cattle admixture across the populations, calculated using allelic information at 17 autosomal microsatellite loci, remains relatively low (mYcattle = 2.66 ± 0.53% and Qcattle = 0.69 ± 2.58%), although it varies a lot across populations as well as among individuals within population. Although the level of cattle admixture shows a clear geographical structure, with higher levels of admixture in the Qinghai-Tibetan Plateau and Mongolian and Russian regions, and lower levels in the Himalayan and Pamir Plateau region, our results indicate that the level of cattle admixture is not significantly correlated with the altitude across geographical regions as well as within geographical region. Although yak-cattle hybridization is primarily driven to produce F1 hybrids, our results show that the subsequent gene flow between yak and cattle took place and has affected contemporary genetic make-up of domestic yak. To protect yak genetic integrity, hybridization between yak and cattle should be tightly controlled.

Economic Analysis of Crossbreeding Programmes in Sub-Saharan Africa: A Conceptual Framework and Kenyan Case Study

Conventional economic evaluations of crossbreeding programmes have overestimated their benefits by ignoring subsidies, the increased costs of management such as veterinary support services, and the higher levels of risk and socio-environmental costs associated with the loss of the indigenous genotypes. A conceptual evaluation framework is developed and applied to Kenyan dairy farmers. Results suggest that at the national level crossbreeding has had a positive impact on Kenyan societys welfare, although taking into account important social cost components substantially lowers the net benefits. Farm-level performance is, however, little improved under certain production systems by replacing the indigenous zebu with exotic breeds.