I wanted to present a fairly uncommon practice of animal husbandry that is perhaps the best suited for a healthy planet. If we are to keep domestic animals (let's face it, humans almost always have) the biodynamic agriculture school of thought believes in respecting and ultizing the innate character of these beings, for the improvement of the soil and their own lives.
Although biodynamic farming isn't inherently tied with meat-production, that is obviously a possible by-product, as reflected by Polyface Farms (owned by Joel Salatin, check out the extra features on Food, Inc where he discusses the exact roles each animal's animal-ness plays on the farm as a whole). For those seeking factory farm alternatives, finding a biodynamic farmer in your area would be ideal. These people are doing it right! They first and foremost focus on the health of the soil, since all else springs from there--The idea is to create a closed agricultural system where nothing from outside is brought in (fertilizer, antibiotics, feed, etc). As Joel Salatin says, the farmer is the conductor, and the animals do all the work; for example they fertilize in synergy (the cows, chickens and pigs all have a place in the process). In farms where vegetable crops are grown, it is also highly important to recognize what minerals are extracted and replenished into the soil by each type of plant so that rotating selected crops leads to the best possible soil composition.
Please read more in this fairly short article here. It's a very interesting practice, and is worth seeking a farmer of this discipline if you want ethically-raised (not humane) meat or if you think of yourself as an omnivorous environmental steward.
I accept this form of animal husbandry to be the best, since the system respects and values the health of the soil, the air, the water, the crops and the animals; and I understand and accept the fact that veganism is not for everyone, but I do believe that the current level of consumption of meat is completely out of proportion to our natural diet and that cutting back and embracing alternative, responsible husbandry practices could heal the soil, the air, the water and most importantly make better use of the land we've already destroyed for these industries rather than continue exploiting and annihilating ancient ecosystems for such a meager reason.
Okay, I lost my breath!
I hope this bit of information helps you in your own quest to be conscious of your food choices and how they affect our world at large.
May all be loved, healed and fed and Mr. Robbins says!