We allow all of our chickens to free range all day every day, since the beginning. I did purchase 6 chicks this year and they went into the house brooder for 3 weeks. Then I stayed away from the chick dept of the stores, purchased feed and walked an aisle over, though know the virus could still be on me.
I like the green tea idea in water for the chickens.
We take EGCG, found in green tea, and Quercetin for our immune system. We began this early 2020 to boost immune during SAR CoV2, as we were not going to take a shot that was mostly not tested much. No offense to those who did. I was ill Jan 2, 2021 and tested positive. I began hydroxy that night and continued it for that week. Fever 102.5-101 for 2 days, then 101-100 and day 4 was tested. Positive. I say Yea! as I now have natural antibodies.
I write this as I believe the EGCG and Quercetin helped my immune system and then, of course, the Hydroxy on day 1. If it could boost my immune system and is safe for poultry, I would like to give this green tea water to our birds.
I need to read more about it for dosage. Maybe half day only water and second half tea water? Unsure, but I will read more.
Another thought, okay, I'm weird. We have wild birds but have not had a bird bath. I wonder if putting green tea water in the bath, might help with their immune system. Just my random thoughts.