The absorption of phosphate from the digestive tract of ruminant animals

Under normal dietary conditions in which the phosphorus (P) intake of ruminant animals is adequate, the absorption of phosphate (Pi) ions takes place from both the fore-stomachs and the small intestine. The rate of Pi absorption from the latter appears to be at least three times greater than that from the former. When absorption of Pi ions from the reticulorumen is severely reduced, as in dietary P deficiency, the absorption of both calcium and magnesium ions from the reticulorumen becomes impaired. Thus, dietary P deficiency may play a role in the aetiology of acute grass tetany.