Pastured or free ranged chickens are healthier. The eggs from them are healthier for you to eat. They have more of the better type of fatty acid in them and also more vitamins. The difference is that chickens should also be eating what you would normally feed them, including some grain. Chickens have different dietary needs than cattle. Yes, pastured chicken is a good idea, but it's a part of what they eat, not all of what they eat. If you live in a tropical climate, with lots of insects, tender foliage, seeds and fruits, plus a lot of acreage, they could do well year round if they're free to eat whatever they want. I would still provide additional food for the highest production. The original chicken wasn't designed to lay an egg a day, which takes a lot of additional food and nutrients every day to produce. Farmsteads with free ranging chickens have also traditionally had other livestock around. The chickens eat spilled grain and alfalfa leaves, along with all the other foods, scraps and even gleaning some crops in the field. They also had a large and rich environment to forage in. You could create a diet that substituted other foods for the grain, but it would be a lot more expensive and a hassle. You would need to substitute other foods for the carbs and all of the nutrients in the grains. You can already get eggs that are good for you, without doing that, so I wouldn't do it. I don't think grains are a bad food, I think excessive grains are bad, especially when you feed them as a major part of a diet to a species that wouldn't normally be eating them or wouldn't be eating them as such a high percentage of the diet. Feeding nothing but pasture to confined chickens would be just as bad, just in a different way. Their bodies were designed to be eating other foods along with it. You can look up the information on the testing Mother Earth News did on free range eggs. Those chickens laid very nutritious eggs, while still eating grain. If you want to, you could work on planting more items for your chickens to forage on. You could also look at the different foods you could add in the winter, when the foraging is poor. Check out some of the threads on sprouting and feeding wheat grass. They are good foods, even if they start as grain. There are lots of ways to provide non-soy protein. There are lots of different fruits, vegetables, dark leafy greens and seeds that are good for chickens. Quite a few people are also mixing their own feed. You could read some of those threads, too. Just make sure you're providing adequate protein that's balanced and has enough methionine in it. Plus the other nutrients. It's often easier to feed a base diet and add supplements to it at first, rather than start out mixing your own and needing to know everything all at once.