As far as meat goes in America and possibly the entire world, the "chicken" by far is the most consumed, most GMO creature on 2 legs and by far the most toxic as they are so highly modified and fed highly GMO grains/chemicals/hormones....and often the egg producing chicken is so highly GMO that even the government won't permit them to be sold as food for a human......
A chicken loves grass and bugs, but they are carnivores more than anything else, they will eat any type of meat, including any chicken near them if the opportunity arrises.......
So in comparison, the COW is by far the more GREEN creature--it can actually grow to maturity eating nothing but green grass/weeds and also will eat grains and also can be highly GMO and fed GMO for commercial markets.....but as far as NATURE GOES, a cow can be all GREEN raised........................
Same goes for the rabbit, they prefer green grass/weeds and will eat grains when those are not available, so they prefer to be all GREEN and have been slect bred to the point today you can get a 20# + rabbit on all green grass and surely that would have to be better than the chicken, but I have never tasted a rabbit in all my days......
The reason I bring up the subject is that the Amish are getting into rabbits and having meetings on education on how to mass produce and market..............so who knows, maybe the rabbit will 1 day replace the chicken............since the rabbit is food for every predator from the sky and land, you seldom see the open range raised, but it is possible..............owls and weasles/mink are by far the most destructive/worthless creatures in the predator world, they will mass slaughter every living creature and prefer to only suck the brains out and leave the meat to the flies/buzzards..
At least the eagle eats what it kills and hawks at least eats part of the animal and this is why settlers did their best to slaughter all the predators, while government "today" restocks predators like rattle snakes, wolves, predator birds and have basically destroyed most of the hunting and trapping of nusience animals such as coon, coyotes, muskrats, fox, groundhogs etc....and this has lead to spread of disease such as rabbies, etc. Nature keeps the balance by way of parasites when Man seeks to obtain an imbalance by man created laws...
One of the most beneficial birds God ever made is the buzzard, the janitor of death and the chicken is its flightless cousin for sure.....a chicken will pick the meat off your bones no different than a buzzard does..
Rabbits, when out of balance, over populated can also eat their babies, but when left to nature they get along well as GREEN creatures.