Childhood indoctrination

[Forbinator]

Well, do instincts constitute enought argumental power to make a case for legal rights?

This is status-quo bias. The real question is what differences exist that justify denying them legal rights? Back when slavery of African-Americans was allowed, your question could have been rephrased to "does walking on two legs and being able to talk constitute enough argumental power to make a case for legal rights?" The real question is why should they be denied?

And besides, animals already have some legal rights, from the absolute blatant acts of cruelty. The authorities seem to turn the other way or create loopholes if the cruelty is in the name of business though.

A animal with only "fundermental" level of intelligence (basic instincts) sees it`s only purpose in reproduction.

If you had ever owned a cat, you would notice how they aggressively drive away their kittens once they have grown up. A behavioral pattern seen in many animals.

Yes, different species have different interests, and have evolved different means of propagating their genes. This is why I believe that it is a horrible crime to kidnap a ten-year-old human child from their parents, but would not hold that same belief for other species. It is a horrible injustice that the dairy industry kidnaps and kills calves on their first day of life, however if a calf is separated from his/her mother (without being killed) at a year old, once there is no longer a biological urge to suckle, I would not carry the same objection.