Wise to hatch/raise from current flock in the same location? Safe to eat if culling makes more sense?

[Imissmyducks]

I would not eat the meat. If any of those chickens were to wind up at a processing plant, they would dispose of them.

OK, so the state lab vet called me yesterday and was very educational. She is a chicken enthusiast herself, but the job doesn't allow her to currently own chickens of her own, although she does get to help with her mother's flock when visiting.
Anyway, she said that these tests only indicate that the hen had been exposed at some point in time to each disease and generated antibodies in response. But this could also include having been vaccinated against the disease as well as having had an actual bout of it. She interpreted the titers to be such that it had been at least 3 weeks, and more likely 6 months or more since the hen had some kind of exposure. Meaning that the titers were not high enough to indicate an active infection with any of these diseases at the time she was presented for scrutiny. So it is possible that non of my birds have an active case of any of these. Beginning in 2020, I bought started chickens from 3 different sources. The first group was a batch of 4 to 6 week olds purchased through McMurray but grown and shipped from Texas. They were sold as vaccinated against Mereks. When 2 of those "pullets" turned out to be roosters, I wound up dealing with Heritage Pullets in Montana who I believe said their stock came from McMurrays and were vaccinated against Mereks. The Montana pullets were 15 to 20 week olds. I have purchased several times from them because all their birds arrived in great shape and all were super comfortable around humans. Two years ago, I discovered a young teenager 30 minutes from my house selling 12 to 16 week olds and purchased 4 Buff Orps and 3 EEs from him because he also said his stock came from McMurrays and had been vaccinated for Mereks. This hen was one of that most recent additions. The state lab vet said that she had at some point in the past, spoken directly to McMurrays about their Mereks vaccine and discovered that in THAT year, they had actually been using a vaccine that covered multiple diseases just like our dogs get distemper shots that now cover 5 or 6 diseases. Apparently, McMurrays had chosen that version of the vaccine because it was the most economical one available THAT year, but they were not advertising it as anything other than for Mereks. I presume that was because they didn't expect to be able to continue getting that broad coverage in coming years. So it is possible that any of these could have brought in something and/or been exposed via vaccine rather than actual disease. Even so, if she had lived through IBD, she could well had come out the other side handicapped with a poor immune system as a result and so was more likely to succumb to something a healthier bird could have easily fended off.
Finally, I asked my 2 questions again. The state lab vet said, based on the limited information she has from this hen and my Zinc positive goose from a couple years ago, she does not believe that my premises pose a uniquely high risk of disease and would not hesitate to aquire more chickens, even day olds. As for whether or not the birds that are questionable currently in my flock would be safe to eat, she said none of these diseases pose a risk to humans. We actually specifically discussed each of the 3 or 4 I am contemplating culling due to their particular health issues. Of course, her assessment might be different if she had each of those in hand, but based on the various things the necropsied hen was negative for, she didn't see any red flags to eating any of them, although she surmised that a bird that had dropped significant weight simply might not have enough meat on it to be worth the effort of butchering. I also specifically asked about eating a bird believed to have cancer since I have a hen accumulating fluid in her abdomen after having been a wrinkly egg layer a couple years ago. I took a similarly suffering hen to my local bird specialist vet a few years ago and her best guess as to the source of that hens fluid buildup was a belly full of tumors with a side order of Mereks since she says it's safe to assume ALL chickens have been exposed to Mereks one way or another. The state lab vet said that the thought of knowingly eating an animal with cancer personally gives her the "heebee geebees" but that she didn't think there was any scientific reason that it would be unsafe. Adding that the USDA would NOT approve of it. I think that about covers it.
So my 5 year old rooster is now in my refrigerator and the others are still on the contemplation list.
Thank you ALL for your kind words and helpful insights. I will continue to consider all of it as each bird's needs require hard decisions...

 

[Eggcessive]

You could enjoy your chickens as long as they live. But I would close the flock to any new birds. Have any had vaccines that wouls have caused them to test positive on a necropsy?

 

[Imissmyducks]

I guess my mile long report on what the state lab vet said wasn't as clear as I had hoped. She clarified that the titers tests cannot identify the cause of the hens antibodies, but only that she mounted an immune response at some point. So, YES, the positive results could have come from a vaccine. But I bought all my current chickens as partially grown out pullets, so I was not the one who requested their vaccines. Nor do I know what variety of vaccines might have been given. Apparently, some of the Mereks vaccines actually cover multiple diseases which McMurrays has used at one time despite not advertising the vaccine as such.