What about the thousands of animals killed to till a field of grain or vegetables?

Granted, this is done in part for animal feed, however in terms of humane practices I would argue that eating a pasture raised animal is more humane and killed less life than a veggie burger or loaf of bread.

I completely understand the reasons for going vegan, though when it comes to the environment, health, and humane practices it depends on the type of meat you are eating.

Rotational grazed animals are a benefit to the soil.

Unless you grow all of your food on a small scale, you cannot avoid killing animals in the process of agriculture. Massa scale agriculture is the bigger problem that effects all areas of farming.