We noticed our 6 month old rooster acting more lethargic than hens and not eating as much. I'm sad to say it was going on for a bit before we realized it was a problem. These are our first chickens and we thought the rooster was just normally behaving differently. Well we noticed green diarrhea and upon further inspection noticed he feels pretty skinny. When I did some researching I realized I was giving them way too much cracked corn and we think that'd all he's really been eating so poor nutrition. Well we stopped the corn but now for the 4th day in a row he has a small (slightly smaller than golfball) bunch of something hard/gritty in his crop. We tried making him regurgitate the other day and mostly corn and the water came out so we think it's corn in his crop. His poop is still watery but is getting more consistency to it and he is acting better (we have also been tube feeding him with albon and formula with pedialyte to help perk him up) but that darn bunch is still there. We have been massaging it and it doesn't seem to bother him after he drinks some water it feels like one of those rubber stress balls so not hard and not huge. We were hopeful last night that his crop was full of food and felt like the other chickens tgat it would feel better this morning but it doesn't. I'm going to keep him inside today (I live in Massachusetts where it is currently a high of 10 degrees so it's probably best he stays in anyways where he's skinny) with only water and plan to make him vomit this afternoon and then feed formula for a day then feed food made into a mash. He is such a sweet beautiful rooster and we feel so bad it's probably our fault he is like this.. any input would be much appreciated.