When I think of UPF and being "addictive" I think of potato chips and peanut m & m's. They have that 'you can't eat just one' quality. So, given a choice between unlimited peanut M&Ms vs carrots and celery, I'm goin to keep eating the peanut M&Ms. However, maybe it's just my chickens, but they'll turn down chicken feed pretty quickly for an opportunity to rummage in the garden or eat a small helping of table scraps."The simplest way of classifying UPFs is that they are made up of complex mixtures of chemicals and food extracts which don't resemble the original parts of whole foods" Spector op.cit. p. 34.
"UPF labels usually list over 10 [additives]...UPFs are designed to be highly profitable (with low cost ingredients and long shelf lives), convenient (ready to consume), hyper-palatable (addictive) products" p.35.
Sounds to me like a pretty good fit with pelleted feed.
Personally, I think it would be great to give my chickens a more whole-food option that provides them with complete nutrition. But, I know I don't have the time or resources to make that happen - certainly not consistently.
I'm planning on putting a bug zapper above their run this summer. We'll see how that does for providing a supply of scrumptious morsels.