What about raising cows or chickens, then consuming their milk and eggs?
What do you do with the cow when its milk yield drops after several pregnancies? what do you do with the male calves? Just keep them all as pets?
I think there are situations I could contrive where I'd say yeah its fine ethically to eat these things, but the general case still has victims.
And again, since maybe the first week without them, I truly haven't missed milk or eggs or anything else after eliminating them from my diet. Plant options are pretty good too and there are plenty of plants.
Why is okay to kill a tree to build a home, kill a plant to eat, but not okay to kill an animal to eat?
Is it okay to kill a cockroach or a rat in your home?
Does the biological complexity of the organism make it more or less okay to kill it?
The ability to suffer is the distinguishing/relevant factor. We all know what suffering feels like and we know that animals have the capacity to suffer. We don't really know that trees do. I want to reduce the suffering I am responsible for.
> Is it okay to kill a cockroach or a rat in your home?
I probably would get rid of infestations in my home and feel bad about it.
It's not about having a 100% perfect record with not killing animals. It's about striving to minimize animal suffering as much as practicable. You're never going to reduce this to 0 animals. But you can get to 95% better than the average human pretty easily if you want.
Sheep get castrated, ears notched and tail docked. Then they get set out to pasture.
A bull is selected to be your herd bull and any cows either get milked as you described or pastured to be mama cows for building a herd. Any bull calves either get sold off to be someone else's herd bulls if the genetics are good enough or they get castrated, notched ears and in at least one herd I have seen, their tails are docked.
As the old ag teacher in high school explained, you castrate them to keep their minds off of the ass and put 'em on the grass.