Pay Attention to the Source of Limestone and its Calcium Content in Poultry Feed by: Dr. Mohammad Al Zawkari and Dr. Jihad Al Jouaifari 

In summary, limestone is used in poultry feed as a source of calcium (Ca). The formulation of the feed often depends on estimating the calcium content of limestone, but unfortunately, the results of the analysis of ready-made sources are relied upon, while there are differences in the actual content of limestone.

Calcium (Ca) is an essential nutrient important for bone growth and mineralization, eggshell formation, and muscular and nervous function. Also, calcium metabolism is closely linked to and affected by the availability of phosphorus (P) and vitamin D, so that any deficiency or excess of one may greatly affect the metabolism of the other. The utilization of Ca and P depends on their concentration and availability or abundance in the feed formulation and is modified by gut, renal and skeletal mechanisms.