I'm not going to feed black oil sunflower seed to my chickens because it's *not chicken food*. I don't feed the dog cat food, and I don't let the rabbit eat the dog food (and he tries). Also, I'm trying to keep them away from the bird feeders so they don't get avian flu. That was the initial point...
As far as trusting what I'm seeing in my chickens behavior? I'm seeing they're pretty persistent beggars. Worse than the dog, who is def not starving. And I would hope that food specifically formulated for chickens is not rubbish! They ARE eating it, they just go nuts for the birdseed- now that other people have described that as junk food, it makes more sense. They would also love to eat everything in my vegetable garden... and my roses, apparently, too... I'm not going to let them just run rampant and eat *everything*.