Was the animal genocide of Noah?s day justified?

Was the animal genocide of Noah?s day justified?

Many Christian and Catholics justify the killing of the human population of Noah?s day, including the innocent children and babies as a judgment against an evil population.

I recognize that the genocide of man has been argued forever and believers have no problem with that particular genocide and I do not want to rehash that particular issue. All one need do is recognize that the notion of free will did not exist back then for the population and move on.

Having killed many animals, even by hand, and not being bothered by it, I can tell you that at a certain number, even my hard stomach and heart begins to be upset and I have to take a break from the slaughter of these food animals.

I just cannot find any justification for the slaughter of the earths animal population at the time of Noah. Some say that animals have souls the same as humans but frankly I cannot see God putting souls into what He has said is meat to us.

It cannot be said then that animals are evil because they cannot discern good and evil. Only man and God can do such.

The only reason I can think of for the slaughter and genocide of the animals is then cruelty. God could have easily spared all of them and did not.

Deuteronomy 32:4
He is the Rock, his work is perfect: for all his ways are judgment: a God of truth and without iniquity, just and right is he.

Was He just being cruel to His perfectly created animals or is there some other motivator that I am missing?

Regards
DL