Advances and Challenges in Breeding Forages with Improved Quality.

Nearly 50 years have passed since the initial efforts to select and breed forage grasses with increased digestibility at the Welsh Plant Breeding Station, Aberystwyth, Wales and the USDA-ARS, Tifton, Georgia.  Early efforts to improve forage quality were viewed with extreme skepticism by many breeders, who felt that increased quality would lead to huge fitness problems, a fear that has not yet been realized.  Improved digestibility, translated to increased animal performance, has been documented in many species.  Genetic gains in digestibility are stable across environments, managements, and from research plots to working farms.  Early challenges included sampling methodology, experimental design, laboratory methodology, and verification with livestock analyses. Current challenges include fitness problems and measurement problems associated within traits meant to predict intake, understanding the limits to selection and effects on plant fitness, and trait-trait interactions with potential negative effects on livestock performance.  Biotechnology offers great potential for improving forage quality, but it is not a panacea.  Sociological and political impediments have slowed the development of forage crops with increased digestibility associated with modified lignin pathways.  In addition, research and development costs, anticipated royalty payments on patent-protected technology, and extremely small profit margins for many forage species will prevent use of these advanced technologies.  Genetic improvements in digestibility and intake potential will continue to result from forage breeding efforts, but breeding programs are increasingly dependent on partnerships and collaborations from agronomists, pathologists, physiologists, molecular biologists, and ruminant nutritionists to understand the complexities of some trait-trait interactions and to document the effects on agronomic and nutritional performance.