Using polyhalite as an acidogenic ingredient in close-up diets
Ishaya U. Gadzama & Fernando Díaz
At calving, calcium requirements are quadrupled, which results in cows experiencing variable degrees of subclinical to clinical hypocalcemia. To improve calcium mobilization, Goff and Horst (1997) suggested to generate a light metabolic acidosis by modifying the equilibrium between anions and cations (Na+K)-(Cl+S) in the diet. Feeding polyhalite mineral as an acidogenic ingredient has been proposed to reduce urine pH in close-up dairy cows.
Polyhalite is a natural mineral formed where sea water has been concentrated and exposed to prolonged evaporation. Polyhalite in Greek means “many salts”, and is a hydrated sulfate of potassium, calcium, and magnesium. Polyhalite contains four important minerals:
- 48% SO3
- 17% CaO
- 14% K2O
- 6% MgO