Graduate Student Literature Review: Rethinking concentrate feeding strategies for precision nutrition in lactating...

The dairy industry in the United States has undergone significant intensification over the past several decades, resulting in improved nutrient use efficiency and economic gains, largely driven by genetic selection, improved nutrition, and better management practices. However, environmental concerns such as GHG emissions and N excretion by dairy farms remain. Concurrently, the industry faces structural changes marked by farm consolidation, particularly affecting small farms, leading industry professionals to seek strategies aimed at increasing nutrient use efficiency and farm profitability. These are all timely issues where nutrition can have a positive effect. In the present review, we discuss historical and current feeding strategies and explore opportunities for precision nutrition in dairy systems. We investigate how feed and feeding management strategies may be refined for modern dairy farming using advanced knowledge, equipment, and technology. Traditional TMR feeding, although effective at reducing digestive issues and standardizing nutrient intake, often fails to account for individual cow variation in nutrient demands and use efficiency. Nutritional grouping has emerged as a practical step toward more precise feeding, improving both nutrient delivery and income-over-feed costs. Furthermore, in a hypothetical scenario, precision nutrition could be achieved through individualized feeding, particularly in systems using robotic milking or out-of-parlor feeders, as well as component feeding approaches. Whereas individualized concentrate feeding has demonstrated potential to reduce nutrient waste and environmental effect (e.g., 10% reduction in enteric CH₄ emissions and up to 40% decrease in urinary N excretion), evidence for consistent improvements in overall lactational performance remains limited. Moreover, its adoption is often constrained by practical and economic challenges, including changes of cow feeding behavior and investments in equipment and technology. The future of precision feeding will depend on improved real-time data collection, automated systems, refined models for predicting individual cow response to nutrients, and real-time data integration-innovations that are emerging but not yet fully realized. Looking ahead, advances in dairy farming efficiency are likely to come from integrating individualized feeding strategies with broader understanding of biological variability in nutrient use efficiency among cows, thereby linking precision nutrition to both environmental sustainability and profitability in dairy production.