Not really. The level humans have already messed with ecosystems through animal breeding and care taking is far beyond any other activity that we’ve done so far.
As long as we are depending on animal products, the situation becomes more complicated because we are self managing a system that is largely unnatural– reproducing them more than they likely would otherwise, growth of numbers without natural predation, confined spaces that radically transform contained plant species and soil structure.
If we were to tear down our fences, and boundaries between homes, it might be a better way to raise animals… going with someone who herds them from place to place.. however in India that’s been done and it’s not been working for them, soils are degraded, plant species are few and many places are barren, so they end up feeding goats and cows trash. It’s also unnatural because we use species outside of their natural habitat. To me it boils down to, the unnaturalness of managing, breeding and living off of arbitrary species outside of their natural habitats in confined spaces– especially at the expense of our health, ecosystem health and unnecessary suffering to the animals. No matter how you slice it, over the long term, with our human population it doesn’t fit that well.
Animal sanctuaries are something that I do like to support, because these animal industries do leave behind many sentient victims. In these situations, the animals are not being bred, but allowed to live out their lives free from abuse. The number of animals in sanctuaries pales compares to animals on farms being bred. But these living situations are still largely unnatural, they compact the soil, eliminate plant species.. it’s the nature of the game. If you have a large enough plot of land, this can be minimized with something like rotational grazing that allows soils a rest from the constant packing. It’s a common feature that in animal fields, from the weight and movement of these large herbivores they often create hardpans under the soil. Trees are always a plus, but they also take away from ground space for easily accessible plants, which economically, may not give the same returns for the space in terms of food for the animals. Unless it’s a type of tree that animals are happy to eat, and managers are able to harvest leaves in unreachable places for the animals. The more space an animal has, the better off the system will be, however large tracts of land, can promote the issue of deforestation, which happens regularly in the US, because of ‘grass-fed’ cattlehttp://www.worldwatch.org/node/549, http://www.pnas.org/content/111/33/11996 . Some large herbivores instinctually won’t enter forests, since it’s harder for them to see and escape threat. Maybe if the animals have no where else to go, they could become accustomed to it. I think pigs are pretty good in forest settings however, they are notorious for digging up roots and overturning soil. Which can be a good thing if you are getting ready for planting, but again, the most natural thing is for them to have access to large tracts of land, enough land that the forest floor can rejuvenate, while they wander around. For 1 cow you need about 2.5 acres of land. It comes with the rest of the problems however, water supply– 2,000 gallons of water goes into a gallon of milk. Animals are taxing on the environment, they are because we are breeding them in exceedingly unnatural supply, which they wouldn’t have gotten to that point in the wild.
Of course the smaller the animal, the less impact they will have on vegetation and soil, per amount of space given.
Otherwise to most sustainably consume animal products, if humans could learn how to hunt the weak and the sick from abundant populations of local animals that would probably be the least taxing on the environment– or already dead like roadkill.
But why cause unnecessary suffering when you don’t need to? Or damage your health by consuming animal products when you don’t need to. There’s just no reason…. experiment more with vegan foods, arbitrary texture is not a good enough reason to sacrificing our health, the planet and other animals… and those textures can be found in plants!! It’s really only about texture because, meat is typically always prepared with plants for taste.. and minerals, like salt and pepper.