Are all the RIRs you are talking about Hatchery stock?
Has anyone had experiences with Heritage RIR stock from breeders? If so, have you had more than one line?
I have not had RIRs at all. But I have had related breeds - Production Reds (PRs - hatchery stock & hens only), Rhodebars (RBs) & Rhodebar/RIR crosses (to improve the RBs). I want to say I've had another breed bred from RIRs but I sure can't remember what it is at the moment...
So far, from different lines (but all imported by Green Fire Farms) of RBs from a couple of different breeders - most of the roos have turned dangerously mean, aggressive and sneaky about doing their attacks. I'm not sure why, it doesn't seem to matter if they are contained in a coop/run or if they are allowed to free range. Doesn't seem to matter if they have been handled from "baby-hood" or not. Not all of the ones I've had have "changed" - but enough that it is definitely noticeable.
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I want to get some non-industrial, heritage RIR breeding stock to put in with some of our RBs. We will see how that goes in the future.
None of our RBs are as noisy as the FBCMs. Geeze, now those are some NOISY birds! and when I had hatchery stock hens, it was only the Cuckoo Marans that were noisy, the Production Reds were some of the quietest birds I've ever owned.