Nice, spent brewers grains have great value in fermentation :) I dug this up for reference..
http://articles.extension.org/pages/68860/feeding-brewers-grains-to-poultry#.VklE1iPn_qA
The high fiber content in it will need to be offset if you don't want the extra poo from it, but other than that...
I mix my own feed too ;)
The only thing I really do different in winter is I increase the molasses, and this year I'm fermenting, and I've decreased my feed consumption by 30% just with the fermenting.
I'm also experimenting with replacing most if the corn with sorghum, so here's the recipe...