Actually on here you will get VERY different answers--It depends on personal preference..which brands you use...what stage you are feeding...etc..etc..Me personally I have only fed Purina Crumbles...I did research for almost one year before getting chicks and felt that was what was best for my brood. Since I have had my brood I have watched, observed and talked to other chicken lovers to get other opinions and compare my hens to others--still sol on Purina..But that is up to you--do your research and decide what is best for you--for me I am staying with Purina--unless I find another brand or typ becomes better suited for them and that is what they need--just like you would do for your children...Hope this helps...
Mine stayed on crumbles until they were about 1 1/2 years old. I changed to pellets because it seemed that the crumbles just seemed to be more and more full of dust and fines. The girls actually seemed happy to make the switch and be able to get the larger pieces.
typically you will get less waste with pellets, so they're a little more cost-effective. i use crumbles until the birds are big enough for pellets (and i supplement with table scraps, garden weeds, etc).
I do want to add-that I do supplement my girls with good scraps from my family dinner table--vegs--fruit--oats, left over scrambled eggs...lol...ect..but the main source is their feed.. I have considered once older maybe they need pellets--but they all are still young (all under year old)..So I still reseach (just like I would do for my human family) and change and fix when needed for my brood...I do not have much experience this is just my experience with my own "family". And they are doing "MARVELIS" LOL