摘要
Developing countries from the southern hemisphere have similarities in terms of climatic and agricultural conditions and cattle are the most important livestock species in these countries ?which leads to many areas of similar interest and opportunities regarding beef cattle production. The increase in demand for meat in developing countries offers large market opportunities for livestock producers. If the productivity of beef farmers can be improved to commercial levels, it may have the potential to address poverty in these agriculturally based economies. Climate change is predicted to be highly dynamic and can have adverse effects on crop and livestock productivity. The cattle breed to be used and the production strategy to be followed in developing countries of the southern hemisphere will depend primarily on the environment and level of management. The availability of diverse cattle breed resources with adaptive and productive differences will allow breed types to be matched to different environments, management capabilities and markets. In the harsh and undeveloped areas or pastoralist systems, pure breeding with e.g. Sanga, Zebu or naturalized breeds may be the only production strategy that can be followed. In the more developed areas, crossbreeding with small indigenous cows may succeed in improving the output of beef cattle farming. It is believed that crossbreeding will gain importance in many developing counties in the southern hemisphere. It is therefore essential that crossbreeding studies be conducted where necessary, to supply information regarding heterosis and for the development of multi-breed genetic evaluations, breeding objectives and decision making. By describing production environments it may be possible to identify genotypes that are adapted to a specific environment. However, tools are needed to overlay geo-referenced data sets onto the different environments. Statistical science continues to support animal breeding and improvement, especially with respect to production traits. Traits linked to fertility and/or survival are still problematic and the appropriate quantitative breeding technology to properly handle these traits still needs to be developed. Gene or marker assisted selection may play an important role in selection for disease and parasite resistance or tolerance, since it is generally difficult to measure these traits directly. Strategies that utilize EBVs derived from genomic analyses (genomic EBVs), together with conventional mixed model methodology, may speed up the process of breeding animals with subsequent higher and more efficient production. The application of a landscape genetics approach offers the potential to greatly enhance the knowledge of how landscape heterogeneity influences the genetic population structure, gene flow, and adaptation. Results from these studies can be used to address questions related to species management and conservation.