As humans we can imagine
what is wrong about withholding freedom from other people.
When a child is born, birth is the first step on the
way to freedom. His upbringing will hopefully prepare
him to function freely as an adult later in life. Freedom
is a means and an end to a meaningful life. But every
individual has to determine for himself what is meaningful.
Is this wrong: having an animal grow up disabled, so to speak, for meat consumption? Is condemning them to boredom reprehensible towards the animals and harmful to their well-being? Is it a form of abuse when you do not optimize their welfare? Is an animal's life meaningful when it only lives to be eaten and not for itself?
Is there an answer that can convince a person who is indifferent to the rights of an animal?
When we see other people suffer, we can try to place
ourselves in that other person's shoes and try to imagine
how this would feel. Most of us will then try to help
this other person and to relieve their suffering.