Age and Calcium Sources in Laying Hen Feed Affect Calcium Digestibility

The apparent calcium (Ca) digestibility coefficient (ADC) and true (TDC) of different inorganic sources were determined in laying hens ages. Three Ca tests carried out, each assessing 240 Lohmann Brown lineage distributed a completely randomized design. Nine dietary treatments arranged 3 × factorial design consisting three ages (40, 50 70 weeks) (dicalcium phosphate (DCP) sources, fine (FL) coarse (CL)) limestone, comprising eight replicates per treatment six birds experimental unit. Regarding the DCP, ADC was higher (P as 0.889, 0.613 0.712, respectively. No effect > 0.05) age on noted for either FL or CL. Comparing DCP exhibited 0.05). Endogenous loss values 790, 860 930 mg·kg-1 consumed dry matter observed at 40, weeks, For TDC, no interaction between bird age. highest TDC value found fed (0.786) followed by (0.637) CL (0.534). In addition, 40 weeks (0.714)