Notwithstanding, the adequate dietary P content in rations fed to transition cows remains an issue of controversy. Dry cow nutritionEstimating the P requirements of dry cows presents a variety of challenges. The main difficulty arises from the lack of a suitable parameter to identify dry cows in negative P balance. Current recommendations for dietary P supply for dry cows’ range between 0.20 to 0.25% in dry matter (DM) in different countries (National Academies of Sciences and Medicine, 2021). Dry cow rations with 0.30 to 0.40% P and even higher are widely used in the field and can be considered as oversupply.