It is a fallacy to say there are alternatives that ensure the animals are happy and taken care of. That is simply not true from an ethical point of view, which isn't really concerned with your subjective measure of another individual's "happiness."
There is no ethical way to create an individual with the preformed intention of forcing that individual into a state of life-long dependence, where you are its only means of survival. That on its face is already profoundly unethical, it's a truly monstrous and selfish thing to do to another individual.
The animals we create are morally equivalent to our own children. They are entitled to the exact same unconditional love and protection.