Enteral administration of sodium phosphate, potassium phosphate and calcium phosphate as treatment for hypophosphatemia in lactating dairy cattle

Abstract

Onset of lactation and various periparturient diseases can result in hypophosphatemia in dairy cattle. For treatment of hypophosphatemia, oral supplementation is assumed to be the best method. Sodium phosphate salts are frequently used for oral treatment, but other phosphate salts might be equally effective and therefore interesting alternatives. Debate exists about the role of the reticular groove reflex after oral administration of NaH2PO4 containing solutions. Six healthy lactating cows were fed a phosphorus deficient diet in order to induce a hypophosphatemia in study animals. Each animal received four different treatments in randomized order, phosphate absorption was studied after treatment with either NaH2PO4, KH2PO4 or Ca(H2PO4)2. Activation of the reticular groove reflex was evaluated with the acetaminophen absorption test. Oral and intraruminal administration of NaH2PO4, as well as intraruminal administration of KH2PO4 resulted in similar increases in plasma Pi concentrations. Intraruminal administration of Ca(H2PO4)2 resulted in a numerically lower increment in plasma phosphate concentration than intraruminal administration of NaH2PO4 and KH2PO4. It is concluded that intraruminal administration of KH2PO4 is equally effective as oral and intraruminal administration of NaH2PO4, intraruminal administration of Ca(H2PO4)2 however is less effective. No indication was found that oral administration of a 3.2 M NaH2PO4 solution induced closure of the reticular groove.