the chef at my work asked me this question and i could not really answer it. i told him i would start a discussion and let him know what other vegans think:
what do you say about soil with manuer (did i spell that right, you know cow poopies) being used to grow veggies, etc? because it is an animal by-product, one type of animal parts we decline in consuming.
now you cannot make the argument that only factory farmed veggies use poops because my place has their own local farm to grow our produce and they sometimes use bone char to give the soil nutrients. i am sure they also use manuer.
so...what do you say?