About 4 weeks ago, my local feed store ran out of the chicken feed I had been using so I bought a different brand. It had the same protein content, etc. I didn’t realize I was supposed to change food slowly so I just loaded their feeders with the new feed. Well…long story short, three hens died. 
Seems like they have gotten on top of it now and are doing well except for one hen. She sometimes acts off and looks way off. Her craw is enlarged and sometimes she looks sulky. I isolated her for a few days but she did not think that was proper. She continued to eat and drink and was very anxious to get back with the others. I put her back and she is still acting fine but her craw never goes down. Is this normal?

Seems like they have gotten on top of it now and are doing well except for one hen. She sometimes acts off and looks way off. Her craw is enlarged and sometimes she looks sulky. I isolated her for a few days but she did not think that was proper. She continued to eat and drink and was very anxious to get back with the others. I put her back and she is still acting fine but her craw never goes down. Is this normal?