This study was designed to investigate the effect of feeding two different (oystershell and limestone) sources of calcium to layer hens (Bovan) on performance and egg shell quality. The experiment extended for 4 weeks during which 24 Bovan layers at 24 weeks were used. Birds were divided into two groups (12 bird/ treatment) with four replicates in each battery cage. Traits measured were egg production, feed intake, feed conversion ratio,, body weight change, egg weight, egg height, egg diameter, albumen weight, albumen height, yolk weight, shell weight, and shell thickness. Results showed that the source of calcium (oystershell versus limestone) significantly affected (P
Albumen, ash, limestone, oystershell, yolk.