I mean, I like animals too, but in context it does make sense. The context was to treat them as "obtainable yet ultimately killable entities you keep as a group, not individuals", which cattle pretty much is. Unless you consider keeping cattle as draft animals, but I think that stopped being the main purpose a long time ago.

It got the point across, at a time where most people basically acquired servers, kept them until they died, and he was trying to push a development workflow where you constantly close("kill")/bring up new servers.