We have a 2.5 year old Redstar that slowed down then quit laying eggs over the last month. We have also noted that her crop is massive, we had noticed a bulge from the front a few weeks ago but today I caught her and several other chickens to compare. Her crop is probably just under the size of a tennis ball. Last week it felt soft but enlarged(Sour crop?), this week it is firm which makes me wonder if it is sour crop(soft?) vs impacted crop(hard?) I have isolated her from food and given her access to plenty of fresh clean water. I attempted to lightly massage the crop but it feels too firm to have that be of any benefit. Is there anything else I should do for her? Should I try giving her vegetable oil to help clear it? Should I keep her away from food until the crop has returned to a normal size?