Power supply with multiple ground points

Hi,

I've designed an SMPS with the ADP5050 IC and I want to know something: which way is better, to have each power rail with it's own ground connection (5 power rails and 5 ground connection) or all the power rails with one ground connection (5 power rails and one ground connection)?

PS: This SMPS is used to power up an KINTEX-7 FPGA and the FPGA board and SMPS board are 2 boards independently.

Thank you,

Vlad