Feeding Fermented Grain

We are new to pigs. I got my first two American guinea hogs earlier this spring. The breeders kept them exclusively on pasture. We live in Maine and have mostly rocky woods. I've been feeding the pigs a mix of whole barley, cracked corn, while pays and pig grower fermented in leftover whey from the goat creamery where I work. I notice a lot of grain coming out the back end even though it's fermented. And I think I'm feeding them too much. Should I be using cracked/rolled grain? I want to get away from using pelleted feed entirely but our pigs live in confinement. How much should they be getting? I wish I could get my hands on organic feed but it is hard to come by in Maine workout spending three times as much.

I would have the barley cracked or milled. Barley is the one grain they can digest whole but not in large quantities. The other thing you can do with barley is to soak it and then place in moist trays until it sprouts to about 6" tall.
I have 70 pigs on the farm at the moment, we are a small commercial free range farm, and they are fed with malted barley (Brewery waste) and pig pellets, the pellets contain nutrients that the pigs cannot get naturally from our soil.
And best to soak the corn overnight too.

Malting the barley will give a wider range of nutrient value. Hobby Distillers are good people to get to know, they create lots of wonderful pig food that they usually need a way to dispose of. The mash leavings (mast) make great food for pigs and is/ was a traditional way of moonshiners disposing of their mashes so they didn't draw attention to their activities. I'd malt (sprout) all the whole grains; barley, oats, rye, corn, wheat. Mash is made with a portion of corn, usually cracked or even meal which is cooked for 1-2 hours to bring out the starches through gelatinization, the malt contains enzymes that covert these starches to sugar, the yeast converts the sugars to ethanol. YOU can use the ethanol for fuel by getting the proper licenses from the state to be an alternative fuel producer, this would allow you to make lots of pig food, legally and run some equipment as a bonus. vegetable left overs are also good, find the farmers stand and see if they have "throw outs" and if you can dispose of these materials for them. These are just some of the things I do to keep feed costs down and more natural and healthy.