Humankind is known to use animals for their benefit (and, at times, the mutual benefit of humans and animals) over the course of possibly millions of years. Horses, pigeons, dogs, oxen, camels, birds of prey, dolphins, etc. have all been used for different purposes like transportation, hunting, and farming for as long as we have been civilized and perhaps before.
But with the apparent ease of training animals to do our will, why did we so often stop short of massive animal training and slavery? Great Apes can be trained to build and farm, sea mammals can be trained to assist in naval transit and even combat, birds trained to communicate and hunt and perhaps even participate in battle as well, and so on.
Assuming that we developed more animal training and then widespread animal slavery early on, what are the effects?
And what would be the result of mankind's eventual dispute on their freedom and humane treatment? When could such an argument have taken place?
Not really going anywhere with this, just beginning a discussion. Any thoughts?