With one important difference to the past:

Slaves have to volounteer, and with proven sane mind into this.

A M.D. will record this and mark the slave with a small tattoo on neck.

Also the papers (ID etc) will be changed to reflect the status. Legally a slave is treated as deceased.

the slave will then be brought into reeducation centers to break the mind and to ensure total sexual servitude regardless of slaves prior preferences. 

Than it will be sold. like cattle, into his or her new life.

 This is what I want!