Biotechnology applications for the sustainable management of goat genetic resources

Abstract

Goats are usually raised under harsh environmental conditions and have a unique ability to take advantage of marginal areas. The diversity of goat genetic resources throughout the world reflects their adaptation to very different production systems, with a predominance of native breeds, often in danger of extinction, very well adapted to local conditions. There is an urgent need to establish programs aimed at the characterization, conservation and sustainable utilization of those genetic resources, and recent developments in the different branches of biotechnology may provide the opportunity for new approaches to achieve those goals. Biotechnologies can further enhance genetic improvement programs, provide tools to ensure the integrity of procedures in goat production, foster opportunities for new products to be developed and support animal health control. Of the biotechnologies currently available, genetic markers, genetic modifications and reproductive technologies are the ones with more potential for the sustainable management of goat genetic resources. For example, artificial insemination and embryo transfer/cryopreservation are essential in conservation and very useful in selection programs, while genetic modifications are primarily applied to obtain recombinant proteins with pharmaceutical or nutraceutical properties. Genetic markers, including neutral, sex-specific and non-neutral markers, as well as single nucleotide polymorphisms (SNPs), are essential for the appropriate management of goat genetic resources, especially in activities related to their characterization and conservation, and specific genetic markers, such as polymorphisms in the αs1-casein locus or in the PrP gene, can be used to strengthen selection programs. Recently, the availability of high-density marker panels which allow the simultaneous detection of thousands of SNPs, opened the possibility of practicing genomic selection, which could increase tremendously the rates of genetic progress currently achieved. Nevertheless, the costs involved are high, and the appropriate definition of breeding objectives, including fitness-related traits, remains a crucial issue, especially for goats. The integration of biotechnologies in goat breeding programs in extensive systems is challenging, as it requires an appropriate organization of the breeding and production systems, which could be based on a simplification of performance recording and the adoption of a flexible open nucleus breeding system.