Yeah, it's always corporate talk, so it's hard to tell, BUT it says
|Our chickens are fed only the finest grain produced in America's Heartland,
Quite frankly, they a) look way way too big to be pastured chickens and b) they would no way have the first thing on their page be about the grain the chickens are fed. Take a look at pastured meat websites. They go on and on and on about their method, their farming, their land, they have pictures of the chickens on pasture, and often the farmers out there with them. They are small, almost always family farms. They rarely sell chicken parts much less boneless skinless. And they are never a big corporation.
From their info, I would guess the chicken's ENTIRE diet is grain based feed, the chickens probably don't actually spend much time outside, and if they do, it's in a small, muddy, chicken crap filled pen, which has no grass, bugs, veggies etc for the chicken to eat, and that they are hybrid birds, hybridized to have grow freakishly fast and have freakishly large breasts, not for taste, or growing at a good pace (for the chicken's quality of life or for the slow time needed to get nutrient dense).
I could be wrong. I think it's unlike that they're high quality pastured chickens though.