ENHANCING REPRODUCTIVE EFFICIENCY OF POULTRY (S285)

Reproduction in birds is enabled (and adversely affected) by environ-mental stimuli that affect specific groups of central nervous system neurons. These neurons, in turn, control the pituitary gland and gonads. Hormones secreted from these organs enable the development and function of reproductive tracts and affect sexual behavior. Reproductive success is determined by the following environmental variables: photoperiod, diet, ambient temperature, pathogens, toxins, as well as social interaction among birds within a flock. Furthermore, the quality of an egg has a pronounced effect upon the performance of her offspring during incubation as well as post-hatch. Finally, poultry reproduction is profoundly affected by genetic selection. In summary, poultry reproduction constitutes a field of study with depth and breadth that has ready application within a major U.S. agribusiness. The U.S. poultry industry depends upon intense genetic selection. Even though this assertion was true throughout the latter half of the 20th century, the technology that enables genetic selection at present either did not exist then. Furthermore, the emergence of systems biology affords a means of explaining biological processes in terms of gene networks. In this regard, the proposed work constitutes a point of application. Whereas the environmental factors affecting poultry reproduction were by and large outlined within the 20th century, the gene networks affecting reproduction will be outlined in the 21st century. However, where this advance occurs is another matter altogether. Historically, federal funding has empowered Land Grant and ARS scientists to study poultry reproduction. This project will enable such scientists to build upon their accomplishments and collaborate towards a new goal: defining gene networks that enable poultry reproduction. The proposed research addresses poultry reproduction, which is a critical challenge to a major U.S. agribusiness that depends upon intense genetic selection and multi-generational amplification of breeding stock. Reproduction is a physiological process, and any physiological process can be explained in terms of cellular networks. Research performed during the 20th century served to outline these networks as well as the molecular mechanisms upon which they depend. By the turn of the century, advances in the discipline of genetics changed the practice of poultry breeding. For example, the first and second assemblies of the chicken genome were released in 2004 and 2006, respectively. The third assembly is anticipated in 2010. In addition, the release of the first assembly of the turkey genome is imminent. Such advancements change the nature of animal breeding, e.g. SNPlotype-based selection. In summary, the ultimate goal of the proposed multi-state project is a paradigm that links the reproductive process with the information inherent to DNA. This advancement will strengthen the U.S. poultry industry in a fundamental and long-term manner.