Drivers of grazing livestock efficiency: how physiology, metabolism, experience and adaptability influence productivity

• Published in: Journal of animal science 2016-11, Vol.94, p.111-119
• Main Authors: Mulliniks, J T, Cope, E R, McFarlane, Z D, Hobbs, J D, Waterman, R C
• Format: Article
• Language: English
• Subjects: Adaptability; Beef; Beef cattle; Cattle; Cattle production; Diet; Economics; Energy efficiency; Energy utilization; Environmental changes; Environmental conditions; Genetic diversity; Lactation; Livestock; Maintenance; Metabolism; Nutrient utilization; Optimization; Physiology; Pregnancy; Productivity; Profitability; Range management; Rangelands; Reproduction; Sustainability; Utilization; Viability
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas2015-0711

Beef cow efficiency is a century's old debate on what the criteria, certain phenotypic traits, and definition of an "efficient" cow. However, we do know that energy utilization by the cow herd is proportionally large compared to the rest of the sector, which accounts up to 70 to 75% of dietary energy for maintenance with the residual used for pregnancy, lactation, activity and adaptation to the environment. Therefore, leveraging genetic variation in cow energy efficiency by selecting cows that require less energy for maintenance potentially reduces total energy utilization for beef cattle production, which will ultimately improve production efficiency and profitability. For livestock producers, optimizing both economic and biological efficiency is critical. The continued viability of production systems utilizing rangelands requires more rapid adoption of innovative management practices and selection tools that lend to increased profitability through optimization of nutrient utilization and increased reproductive performance. However, the implementation of a gold standard to identify energy efficient beef cows has not yet been fully realized for the beef industry. Rangeland beef cow herds are required to be biologically and reproductively efficient in an array of ever changing environmental conditions. The most efficient cows are those that easily adapt to environmental changes and have the ability to conserve or reset their maintenance requirements to match current environmental conditions. To achieve this metabolic adaptability or flexibility, beef cows need to be suited to their environment and have the ability to acclimate to environmental changes. The purpose of this proceedings paper is to identify and describe factors that influence range cow efficiency and ultimately contributes to the sustainability (both from a productivity and economic view point) of range cows in extensive enterprises.