[QUOTE=Hillside H Ranch;5533470]
I think that information is outdated, personally. I think the worst thing you can do for a post-foaling mare is change her diet like that. There is nothing magic about bran-mash preventing colic. The big thing is that it increases water intake, which is, of course, helpful for preventing impactions. Bran is high in fiber, which is also helpful, but so is hay 
Post foaling colic has a lot of causes, impactions, torsions, displacements, so there is no one preventive/cure.[/QUOTE]
I also believe the use of high starch feeds contributes to the cause. After foaling, the mare has an open void in her body cavity until things get “back into shape.” If you “meal” feed enough of a high NSC feed (usually for milk production and to maintain body weight) you’ll run the risk of “starch bypass” into the hind gut. Gas is one of the byproducts of the fermentation of starches and sugars in the hind gut. The gas produced may or may not be enough to cause a gas colic, but why chance it? IMO, lactating mares should be fed concentrates multiple times a day vs 2 or 3.