Associations between digestibility, feed efficiency, nitrogen efficiency, and nitrogen partitioning in dairy cows on Dutch commercial farms

ratio, with lower ratios associated with more efficient use of digestible N and reduced urinary N excretion. The frequent interactions between variables and sampling session demonstrate that efficiency and N partitioning metrics are context-dependent, emphasizing the need to account for farm- and time-specific conditions when developing strategies to improve nutrient use efficiency and reduce the environmental impact of dairy production.