Precision feeding is commonly framed as increasingly accurate diet formulation and delivery, yet this framing can reverse the decision sequence. Nutrient requirements arise from the animal’s changing physiological state, while the feasibility of meeting those requirements depends on disease status, voluntary intake, digestive capacity, feeding behavior, feed form, and environmental conditions. This article develops an original non-empirical nutritional decision model that begins with the animal phenotype and treats diet selection as a conditional response rather than the starting point. Evidence across dairy cattle, pigs, poultry, and small ruminants is used to distinguish metabolic demand from intake capacity, formulated nutrient concentration from realized nutrient availability, and intrinsic animal state from behavior expressed under management constraints. The proposed model organizes feeding decisions around sequential characterization of physiological demand, disease-associated modification, intake feasibility, digestive and behavioral constraints, environmental context, and only then diet selection, followed by reassessment when the animal state changes. This architecture does not imply that phenotype can be measured without error, that individualized feeding is always superior to group feeding, or that one set of thresholds can transfer across species and production systems. Its principal value is analytical: it makes explicit where calculated nutrient targets may become biologically or practically infeasible and where apparently adequate diets may fail to match the animal receiving them. Prospective testing, external validation, species-specific calibration, and evaluation of decision utility are required before the model can support implementation claims.
