Our chicks are in a playpen out on our breezeway, where we have a patio table. The other night I felt so terribly guilty because we were eating ....chicken....out there for dinner.
It wasn't anyone they knew, or could have been related to, but still...I felt awful.
Try to figure out how much salt is really on the popcorn and how many/size chickens you are feeding. chickens can digest small amounts less than 1 mg per day per hen without any problems. I must add that I too am very aware of how much salt are in my treats for them.