Phosphorus Homeostasis in Dairy Cattle: Some Answers, More Questions

Phosphorus homeostasis in dairy cattle has received increased attention in the last decades because of the possible association between hypophosphatemia and the downer cow syndrome, as well as because of increasing concerns about the environmental impact of excessive amounts of phosphorus (P) in manure. Assessing the P homeostasis in animals is difficult since the concentration of this predominantly intracellular ion in serum or plasma does not reliably represent the total body P pool. The plasma P concentration in dairy cows can drop considerably following a sudden loss of P as it occurs at the onset of lactation through the mammary gland, but hypophospahtemi