Feathers are a great source of protein, as long as they're getting them off the ground and not each other, you're probably fine. In terms of yolk color it comes from a word I can't spell (begins with a C), which is generally found while free ranging but can also be incorporated into the feed. Adding marigolds to the feed will deepen the yolk color. Birds that are able to free range on pasture will get a mix of grasses, legumes, worms and bugs into their diet. Those eggs will be higher in Omega 3 & 6's, have firmer whites and dark orange yolks, but that's generally only spring, summer and fall. In terms of quantity of feed (again based upon maximum production, with minimum cost) field studies of pasture raised birds average out at 4.5 oz of feed per bird per day during spring, summer and fall. It goes up in winter (but was too sporadic to come up with a viable average). Following about three days behind cattle on pasture would reduce the feed consumption, but again no really good measurements to speak of. Too many variables in the test populations.
