Gilt Developer Please take a look at some gilt developer units we have built. This is the penning in a GDU. This GDU was on a Nedap electronic feeding station and they had one way gates the pigs were trained to walk through so they would be used to the Nedap gating when they got to that stage. Here is a standard GDU with SDI feeders. Floor Plans for GDU A complex overview of a GDU all the components that will be in a GDU. Another complex overview of a GDU.