PURPOSE: To provide the subject composition containing a calcium source, viscous polysaccharide and a silicate respectively in a specified amount, forming a thixotropic gel in the presence of water, free from precipitation and separation of the calcium source, excellent in palatability and suitable for prevention of milk fever.

CONSTITUTION: An objective composition containing a viscous polysaccharide, preferably sodium alginate, etc., and a silicate such as calcium silicate respectively in an amount of 0.06-2wt.% and 0.02-6wt.% based on a calcium source (preferably ≤3μm), preferably tribasic calcium phosphate and further containing water in an amount of 30-90wt.% based on the whole composition.