Approximately, 98% of chickens in the United States are produced by large corporations, the other 2% are made up of local farmers free ranging their chickens. My husband and I are in that 2%.
As I write this, we have 67 Cornish cross chickens on grass. When we moved to our farm, we designated part of the lawn as pasture just so I would feel better about putting chickens on it. I still mow it, but the chickens are happy to roam the area in their chicken tractor.
This spring has been especially challenging. We had to keep the chicks in their brooder longer than expected, which meant keeping them in the garage. Normally, it wouldn't have been an issue, but they got too big too fast. This caused overcrowding and when we did get them outside, I saw some red in their feces. To combat that, I gave them garlic, honey, and apple cider vinegar in their water. The red was gone within a week, we didn't loose any chicks, and we didn't have to resort to medication.
However, the real trouble started when the temperature started dipping into the 30's and 40's at night. When I was growing up, we had to worry about heat stress, so I knew nothing about cold stress. When we started loosing birds, we would find one in the morning, then two in the morning. I was loath to do an autopsy on one, but when I saw one that wasn't going to recover I had no qualms about butchering it. We found a very healthy bird, but a low body temperature. Then when we butchered another one after a cold night, we found an enlarged heart and fluid in the abdominal cavity.
In fast growing meat birds, too much stress can easily be put on their hearts. In this case, the heart failure or hypertension caused the liver to stop working leaving fluid to build up in their abdominal cavity, which was evident in our chicken. This is known as “water belly” or Ascites Syndrome. This is caused when the chicken experiences cold temperatures. The good news is that the weather will get warmer, which carries hope for the rest of our chickens.
My husband and I don't have a chicken CAFO (concentrated animal feeding operation), but after pasture raising meat birds for a couple of years I have come to realize that the Cornish Cross was bred for a CAFO. Their chicken instincts have been nearly bred out of them, so grass foraging is minimal. They grow so fast that any environmental stress on them will likely be fatal. Their legs have to carry such massive bodies and huge breasts that walking and even moving becomes difficult. However, even with the knowledge that they were bred for a CAFO, I still wouldn't put them in one.