Mathematical models of nutritional requirements for all species of livestock and poultry are widely accepted and used in managing feeding systems. These models hold the promise of continued increases in efficiency of feed utilization and reductions in nutrient excretion into the environment. More highly-aggregated models, such as the National Research Council model for nutrient requirements of beef cattle, provide end-users ready access to an extensive body of knowledge pertinent to the feeding of domestic animals. More mechanistic models may provide a deeper understanding of animal requirements, performance, and feed utilization.1-10-1
Production of ruminant livestock by grazing indigenous grasslands is thought to be one of the most sustainable of all agricultural production systems. Relative to the calculation of nutrient requirements and prediction of performance in confinement, models for grazing are complicated by abiotic and spatial factors affecting primary production and by foraging behavior. The increased breadth of domain opens an opportunity to address more varied questions relevant to livestock production systems, but potentially at some sacrifice in resolution.
Was this article helpful?