Precision Tools for Forage Assessment and Nutritional Decision Support in Grazing-Ruminant Systems: A Narrative Review

Spatial and temporal heterogeneity in pasture quantity and nutritive value remains a major constraint to efficient nutritional management in grazing-ruminant systems. This critical narrative review was based on targeted searches of peer-reviewed literature on pasture heterogeneity, forage quality assessment, grazing management, animal monitoring, and data integration in grazing-ruminant systems, with emphasis on both recent studies and conceptually foundational work. Precision technologies have emerged as complementary tools that can improve the characterization of pasture resources, animal responses, and grazing dynamics, but their value depends on whether they support nutritionally relevant decisions under field conditions. This review examines current precision approaches, such as portable near-infrared spectroscopy, proximal and remote sensing, geospatial tools, animal-mounted sensors, and grazing-control technologies, and their capacity to improve decisions related to supplementation, stocking rate, grazing rotation, and pasture allocation. Across technologies, performance and applicability vary substantially with observational scale, calibration requirements, and validation context. This review also highlights persistent constraints, including calibration robustness, transferability across systems, field validation, interoperability, economic feasibility, and barriers to routine adoption. Precision tools can improve pasture-based nutritional management, but their practical contribution depends on how effectively they are validated, integrated, and translated into decision-support logic under commercial grazing conditions.