The role of existing and emerging biotechnologies for livestock production: toward holism
Wheeler, Matthew BMonaco, ElisaBionaz, MassimoTanaka, Tetsuya
Animal biotechnology has been practiced in one form or another since the beginning of the domestication of animals. Many of the previously used tools of animal breeding, genetics and nutrition have played an important role in the selection, propagation and management of desirable and economically important characteristics in livestock. Modern livestock production has been dependent on biotechnology for development of improved feedstuffs, feed ingredients, vaccines, biologicals, enzymes, high quality genetics, genetic markers and assisted reproduction. Recently, new technologies including genomics, transcriptomics, proteomics, metabolomics have been applied to livestock production. The term "omics" refers to a broad field of study in biology and stems from ''Omes'', the Greek for 'all' or 'complete'. Therefore, these technologies offer a holistic instead of a reductionist view of the biological phenomena. Several "omics" technologies are readily available for scientists or industry today and in this section we will provide a brief overview of their availability in livestock science. Other "omics" technologies have developed quickly and are available for research or industry in livestock field. The microarray technology for microRNA is available today for bovine, pigs, and chickens. Combined with the use of appropriate bioinformatics tools, they have been of great help in understanding livestock genomics. Large-scale SNP arrays are also available today, but only for bovine among the livestock species. Epigenomics, the study of the non-DNA hereditable factors affecting the phenotype, has been used for large-scale studies, but data have not been generated using this technology in livestock. Systems biology has emerged to investigate "interrelationships of all of the elements in a functioning system in order to understand how the system works". A systems biology approach is only possible by combining a single or multiple "omics" technique(s) along with bioinformatics for a broad purpose such as to study the whole system, organism or comparison between organisms. In order to take full advantage of the breakthroughs from "omics" techniques efficient animal breeding and reproduction of these rare genetic individuals needs to take place. For decades assisted reproductive technologies (ART), such as artificial insemination (AI), superovulation (SOV), embryo transfer (ET), and in vitro embryo production (IVEP), have contributed to animal breeding programs allowing faster transmission of desirable traits in livestock populations in a shorter period of time compared to classical approaches. The use of transgenic technologies along with ART's to introduce single or multiple genes into existing genomes of livestock has played an increasingly larger role in the genetic development of our production livestock. Addition of appropriate stem cell technologies to the genetic "toolbox" has further increased our capabilities to enhance and modify livestock genomes and physiology. In the future, livestock production will rely even more heavily on existing and emerging biotechnological advances to produce our food. However, improvements are still needed in product composition and production efficiency, especially in growth, disease resistance, and reproduction. The attainment of such improvements will depend heavily on our ability to quantify desirable traits, to identify markers linked to gene(s) responsible for those traits, to select or redesign populations of superior individuals, and to propagate those animals efficiently, practically and economically.
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