That is the kind of thing that made me doubt religion, as a child. How could "god" allow cruelty to animals? As a lover of parrots, you know what cruel fates are dealt to hundreds, perhaps thousands, of black market birds.
Talesin, Christians grapple with these kinds of questions all the time. It is an important question and one not easily answerable at first glance..... if for no other reason that its sheer scope.
When attempting to answer a question it is important to identity the presuppositions inherent in the question, otherwise a person can very easily find themselves in a round room looking for the corner. I'm not trying to give a lecture here, but I want to work through this question.
First your question, assumes there are laws that identify cruelty, and that implies a law-giver. This question cannot be asked unless an absolute moral law is assumed, otherwise the cruel person has just as much legitimacy as the loving person. And, an absolute law-giver - if anything proves gods existence rather than dislodges him. At the minimum, God is in the framework of the question.
Second, I think there would be widespread agreement that the supreme ethic is Love. Inherent in Love is the "will". Some wise poet once said love is something you do, not only something you feel. My point is that a necessary component of love is volition. You cannot have love without the freedom not to love, otherwise all you have is automation, conformity and compliance... all of which are in contradistinction to love. It may appear like it on the surface, but it is of vastly different texture and substance once you pop the hood and look at its mechanics.
So, if the supreme ethic in a world such as ours is love, and the freedom of will is indispensable to love, and if God must remain in the paradigm, then I would answer that God's greatest gift is the freedom of our will in order that we may love God.
But along with a "greatest gift" there must also be assumed a "greatest cost". Cruelty is the price of freedom of will.
God not only gave us the greatest gift that he could give in order for us to enjoy (not ever to fully understand) him, in all his limitless splendor, but he also suffered the greatest cruelty, in himself, to complete the possibility of the reconciliation of all things to himself, who is the personification of love.
Good is real and evil is real. We must ultimately come to some conclusion on the nature of our moral reality and make a choice. Otherwise we will live in a world where we can choose bad without consequences, or pose a show of love without heart, both of which is beneath our amazing engineering which alone in all creation was made in the image of God.