Suitability of oral administration of monosodium phosphate, disodium phosphate, and magnesium phosphate for the rapid correction of hypophosphatemia in cattle.

BACKGROUND

Hypophosphatemia is commonly associated with disease and decreased productivity in dairy cows particularly in early lactation. Oral supplementation with phosphate salts is recognized as suitable for the rapid correction of hypophosphatemia. Little information is available about the differences in efficacy between salts used for oral phosphorus supplementation.

OBJECTIVES

Comparison of efficacy of oral administration of NaH PO , Na HPO , and MgHPO in treating hypophosphatemia in cattle.

ANIMALS

12 healthy dairy cows in the fourth week of lactation in their second to fifth lactation.

METHODS

Randomized clinical study. Phosphorus deficient, hypophosphatemic cows underwent a sham treatment and were afterwards assigned to 1 of 3 treatments-NaH PO , Na HPO , or MgHPO (each provided the equivalent of 60 g of phosphorus). Blood samples were obtained immediately before and repeatedly after treatment.

RESULTS

Treatment with NaH PO and Na HPO resulted in rapid and sustained increases of plasma phosphate concentrations ([Pi]). Significant effects were apparent within 1 hour (NaH PO : P = .0044; Na HPO : P = .0077). Peak increments of plasma [Pi] of 5.33 mg/dL [5.26-5.36] and 4.30 mg/dL [3.59-4.68] (median and interquartile range) were reached after 7 and 6 hours in animals treated with NaPH PO and Na HPO , respectively, whereas treatment with MgHPO led to peak increments 14 hours after treatment (3.19 mg/dL [2.11-4.04]).

CONCLUSIONS AND CLINICAL IMPORTANCE

NaH PO and Na HPO are suitable to rapidly correct hypophosphatemia in cattle. Because of the protracted and weaker effect, MgHPO cannot be recommended for this purpose. Despite important differences in solubility of NaH PO and Na HPO only small plasma [Pi] differences were observed after treatment.