The whole basis for this kind of thinking is flawed. The flaw lies in the fact that man is not of the animal kingdom, although people are similar to animals.

God spoke the animals into existence. God didn't make man in this simple fashion. God formed man out of the dust of the ground (chemicals of the earth) and breathed into him the breath of life. Man is different than the animals, though of similar physical structure in many ways.

At first, before there were mistakes made in this world, people were instructed to eat of the plants (except for the fruit of one particular tree, that they were instructed not to eat).

Then later, long after mistakes came into the world (the original perpetual nature of the universe was destroyed), God gave the animals to man for food along with the plants. However, after it was shown that man misused the animals in ways that were unfair, God, also, instructed people to use their animals fairly. This would include a quick, painless death for the animals that man is going to consume as food.

If you don't include the things that God has done with man, you will miss the truth.