Ontogeny of calcium preference in the parathyroidectomized rat

The ontogeny of calcium ingestion and preference was examined in parathyroidectomized (PTX) rats. Sucklings were tested by means of oral infusion. Four-day-old neonatal rats increased ingestion of CaCl2 after PTX but the effect was not specific to calcium because intake of MgCl2 was also increased. After 6 days of age the increase was more specific to calcium. The response increased in potency until 20 days of age. Weanlings were tested by measuring intakes from two burets, one with CaCl2 and one with MgCl2. Twenty-six-day-old weanlings showed a mild preference for CaCl2, but by 30 days of age the preference for calcium was similar to that reported for adult rats.