Calcium is one of the most abundant elements in the body and is often the major cation in the diet. More than 90% of the body’s calcium is located in the skeleton; bones and teeth. Calcium is also important in cellular metabolism, blood clotting, enzyme activation and neuromuscular action. Ionic calcium in blood plasma is maintained precisely by a large number of regulatory processes, centering around the calcium homeostatic hormones. Calcium is very important for eggshell formation and milk secretion.

Main sources

Calcium carbonate Oyster shells

Quality and selection parameters
Particle size and solubility are important parameters. The optimal size and solubility depend on the type of feed (poultry, pigs, ruminants, compound feed, premix, complementary feed). Limestone is available in various particle sizes from fine flour to coarse granules.
The particle shape of oyster shells is flaky and is available in various grades as well. The colours white, grey and yellowish can also be taken into consideration for several feed products, especially premixes and mineral supplements.
The main inorganic calcium sources have a relative biological availability of 95 to 100%. Calcium in plant raw materials instead often occur as a complex with oxalate, which has a relatively low bioavailability.
Analytical methods
Acid / base titration
Moisture:H2O - Scan - P 39:80

Insoluble in HCl:  DIN 65918 Conversion factors
CaCO3 X 0,4004 = Ca
Ca X 2,497 = CaCO3 (lime)