26 Complementary Roles for Genetic Selection and Population Dynamics in Enhancing Livestock Sustainability

Abstract

Abstract Over the past several years, there has been considerable international dialog surrounding the importance of enhancing the sustainability of global food production systems to meet the demands of the growing global population. Internationally, sustainable food production systems are defined as those which contribute to food and nutrition security while safeguarding the economic, social, cultural, and environmental bases of food production for future generations. Although animal agriculture often has strong cultural roots around the world, there are challenges related to the environmental impacts of animal products, the social acceptability of production practices, and the affordability of animal-source foods which present opportunities for improvement. Historical advancements in the affordability and environmental footprints of animal-source foods highlight the tremendous impacts of genetic selection for enhanced productivity on animal-source food sustainability metrics. Continued emphasis on genetic selection as a tool to address sustainability objectives may be an essential strategy to continue enhancing the role of animal source foods in contributing to a sustainable and secure global food system. However, systems dynamics modeling demonstrates trade-offs between the rate of genetic progress and aspects of sustainability like environmental impact and social acceptance. These trade-offs are largely driven by the generation interval and assumptions surrounding the fate of animals culled either early in life or during mid-career due to undesirable genetics. Exploring alternative production systems which make better use of cull animal populations presents a strategy to address some of these trade-offs. To better explore these factors in tandem, the objectives of this work are to review the historical improvements in animal genetic merit and the impact on sustainability of animal-source foods; to explore future selection strategies and how they may support continued sustainability enhancement; and to highlight the complementary roles of population dynamics and genetic selection in enhancing livestock sustainability.