Thank you so much for responding to my question. Was kinda curious about the outcome. As for my girls, I took them off Purina foods, put them on a local farmers co ops feed and they all started laying again. And just for s&g, I put them back on the food I'd pulled. They stopped laying again. Both tests took just a week each, and only say that my girls perform better on the co op feed. Off to read those threads you listed for me now. Thanks again!Here are two threads that discuss some testing results:
https://www.backyardchickens.com/th...en-feed-craze-posted-testing-results.1564737/
https://www.backyardchickens.com/threads/feed-tests-more-results.1565804/
As for whether it was "debunked," I suppose that depends on what you mean by debunked.
--There are no test results showing anything wrong with any feed (at least, none that I saw.)
--Many flocks began laying again as the days got long in the spring, regardless of whether their feed was changed or not. I do not know if ALL flocks began laying again.
--For the feeds that were thought to cause the problem, quite a few people shared that they were feeding those same feeds and their flocks were laying just fine. So not EVERY flock eating those feeds was having issues.
--There was speculation about what might be causing the trouble, and many points were disproven for specific flocks (this one had enough light, that one had no parasites, another one had feed that was fine for a neighboring flock, etc.) There was no point that could be proven for ALL flocks.
My personal opinion: I think many flocks did stop laying, but for many different reasons. Some quit because of the short days of winter, some quit because they were molting, some quit because they were getting older (old hens tend to take more time off than younger hens.) Probably a few people did get bad bags of feed (maybe a mixing error at the mill, or maybe feed that was stored too long or stored improperly). Some flocks might have had parasites, or diseases, or stress from weather or predators.
With all the different causes, I think it's pretty clear that "bad feed" did not cause ALL the problems that people were complaining of. I did read at least one story of hens that showed ill health over multiple months, including no eggs, and a change in food did improve their health and then they did start laying again-- so that one probably was a feed issue, even if many others were not.