@Spiritus Arcane
 

 
Actually, not a lot of people seem to know this, but lactation in both horses and humans (and presumably other animals as well) can take place without any pregnancy at all.
 
Basically all that needs to happen is the teats be suckled on at least once a day, over a period ranging from a week to more, and the body will start lactating.
 
Heightened hormone production pregnancy certainly helps so milk flow is unlikely to be as good without either that, or hormone supplements, but those things certainly arent necessary.

One heck of a milker, since it seems to have gotten milk out of a non-lactating mare. …Unless Pinkie’s not telling us something.