This study was conducted to investigate four different Dicalciumphosphate's (DCP) produced in Turkey and two different imported DCP's and their effects on egg production and egg shell quality of two different strain laying hens.

In order to investigate the effects of P sources on egg productivity and the quality of egg shell, 480 white and 480 brown laying hence were used. The experiment took 180 days to finish and feed consumption, egg yield, egg weight, feed conversion, shell thickness, shell weight, proportion of egg shell, and abnormal eggs were determined and evaluated.

Daily feed consumption was found 130,4 g as the highest level in (-) control group showing the significant differences from other groups (P<0.05) and the differences between the groups with additional P were found as non significant (P>0.05). Related to egg yield and egg weight, the groups did not show significant differences (P>0.05). The lowest and the highest feed conversion value were found as 3.38 and 2.88 ■ the (-) control and imported DCP II. respectively.

Specific gravity (SG), which is used to determine the quality of egg shell, have not been affected by rations (P> 0.05). The best SG value was obtained as 1.086 in the (■) control group. The values of SG for the other ration groups were found 1.084 in the imported DCP' s and 1.082, 1.084. 1.084 and 1.084 in the domestic DCP. The ratio of shell weight / egg weight is an other criteria to determine the quality of egg shell. These proportions were calculated 9.11 and 9.14 for the imported DCP's. 8.87. 9.04, 9.07 and 9.05 for the domestic DCP's, respectively. The differences between the rations were not significant (P> 0.05).

As a result, the effects of different P sources on egg yield and egg shell quality were not significant.