You can register a sow/gilt through the path: 

Management> Breeding Herd> Data entry>  Females> Purchase  > Add

There are three categories of female purchase:

  1. Gilts

Click on the "Add Gilt Purchase" icone And the following screen will open

Click on this icone for an open sow, and this icone  for a pregnant sow purchase.

After filling all the data just click on the "save and close (if there is no other entry to add) or Save and continue (to add another entry).