The bible didn't mention the cruelty of animals in full extent. There are some provisions mentioned about taking care of animals. As said in the creation, God created man to take care of all the living creatures thus giving him (the man) the full authority over them (Genesis 1:28). But this should not confuse the fact that during the Old Testament days, animals were used (killed) as an offering to different kinds of occasions and cleansing requirements. We can say that animals can be killed for the purpose written in the bible (some parts in Exodus and Leviticus). However in the New Testament animal offering is not anymore necessary but doesn't talk much about the rights of animals.
As a whole we can take this verse for the point of argument regarding animal rights.
Proverbs 12:10 : "A righteous man cares for the needs of his animal, but the kindest acts of the wicked are cruel."