Mine are the opposite of a lot of people's. They prefer the pellets over the crumbles, the chunks over the powder. They will pick out the pellets and larger chunks and leave the powder. But about once a week, I don't refill the pellets until they clean up the powder. I don't want the leftover feed they won't eat to get moldy. They don't starve. They will clean up the powder. When I have a mixed aged flock, I feed Grower or Starter in Crumbles form. If that is all they have, they all eat that. They may pick the larger chunks out and leave the powder until last, but they will eat it. You'd think that preference would change with the different generations, yet mine have been pretty consistent in preference.
Chicken feed is made into pellet form. Crumbles are crushed pellets. Mash is ground pellets. It's all the same stuff. It really doesn't matter which form they eat. The nutrition is the same. I think I get less wastage with pellets since mine clean it off the ground under the outside feeder. And they can find the pellets easier in the litter under the inside feeder.
If I take the same feed and put it in a new feeder, they think that is a great treat. If I spill some on the ground while filling the feeder, they think that is extra special. It is the same exact feed, yet they go nuts over it. Birdbrains!
The chicken feed is formulated to keep them healthy and provide what they need to lay efficiently if that is all they eat. It has the right mix of vitamins, minerals, proteins, fats, fiber, and all that to get the highest number of right sized eggs eggs at the least cost per egg. But like Sunny Side Up, I believe the eggs are better for us if they get some treats or, even better, free range over decent forage. You may not get quite as many eggs or the eggs may be a little bit smaller, but studies have proven they contain a wider variety of vitamins and minerals. I think the chickens are happier and healthier too. They get more exercise chasing those grasshoppers so they probably have less body fat and stronger hearts.
I don't worry about their protein content or them getting the perfect balance of nutrients if they free range. They will pretty much balance out the nutrients themselves, eating grass and weeds, grass and weed seeds, and the various creepy crawlies they can catch if the forage is decent. If you cannot free range but give them treats instead, I think you do need to be careful about upsetting that balance too much. It's not an exact science for us. If your treats are a pretty varied diet of greens, kitchem scraps, grains, and creepy crawlies, then you can give them more than if their only treat day in and day out is cabbage. I think they have a fairly wide tolerance for that balance as far as staying healthy and even laying eggs, but too much of a good thing is often not a good thing.
