Raising Pigs on Spent Brewers Gains & Beer

Hi everyone. I'm a small regenerative farmer who raises heritage pig in pasture. I recently acquired a local small brewery to partner with. Each week I get 2,000 pounds of spent brewers gains. I have been fermenting then to get some additional health benefits & some fantastic flavor.
This has cut down on my imput cost Immensely & my pigs thrive. I Fulfill my goals of sustainability by utilizing this local waste product.
However here a question for anyone who has finished hogs on actual BEER.
What benefits have you seen?
Taste?
Digestibility?
If a farmer profit?
And what age or at how many weeks do you begin to finish on beer.
Last but not least has anyone found a Beer waste source. I'm in Wisconsin the capital of beer making but have yet to find outdated beer for sale.

Hi Stacy,
I don't have any experience with pigs on beer, but I wanted to say Welcome to Permies.

Welcome!

They may have to destroy it due to alcohol tax laws.  Or they may distill it into liquor.  

Just curious what your ration mix is with the spent grains?  My pigs have never seemed too interested in the spent grains from my friend’s homebrews, but I only raise one at a time so they are not competing for food.  The current one will barely eat apples. 🤷

Also, what are you doing with the manure from your pigs?

Thanks guys.
To the second question, what is my feed ration.
My feeders get about 3 pounds daily of GMO free 17% Hog grower the rest is spent gains and pasture.
The heritage breeds happily eat spent grains more then your production pigs.
But the key is to make them hungry. If they have a choice they will always chose Corn base grower ver barely oat gains. So make them want it. Each spent brewer mesh will have a slightly diff protein %  but in general that is about 19% to 25%. Some claim its higher but ??
So they will fain weight because it High in Carbs. So play with it. You want a good growing pig but you want meat and nice fat not far and some meat. In the winter months if in a cold climate let them eat as many spent gains as they want. They will not have a problem gaining too much fat. They will stay warm with all that Metabolic heat from digestion.