I just spoke to my feed store. They are saying that because it is all-purpose mash, it is a grower feed.
I also contacted Miller Hatcheries, who I order my day old chicks from. After hearing all the symptoms they confirmed it is probably Ascites. Which is irriversible and untreatable. And, they too recommended to start processing them. Unfortunately, I need to wait 3 more days to ensure the antibiotic is out of them. But, I will begin the processing this weekend.
The hatchery had mixed opinions about eating the infected birds. I think, to be on the safe side, since I am feeding my family, I will discard any birds that are showing symptoms /or that are fluid filled.
Thank you all.
I'll let you know how my first time processing, turns out...I'd appreciate any further advise for that, as well. Maybe I'll start a new thread in the "meat bird" section.