Is this an oxymoron, a term that contains the meanings of two conflicting words?
The definition of “humane” is “having or showing compassion or benevolence”. (Oxford dictionary)
The definition of “compassion” is “feeling or showing sympathy and concern for others”. (Oxford dictionary)
The definition of “benevolence” is “kindness”. (Oxford dictionary)
The definition of “slaughter” is “the killing of animals for food”. (Oxford dictionary)
So to kill an animal for food when it is unnecessary for survival and is against the animals will, cannot be an act of sympathy, concern, and kindness. More of an act of selfishness, cruelty, and greed.