It is said about Lord Buddha sadaya-hrdaya darsita-pasu-ghatam. He saw the whole human race going to hell by this animal killing. So he appeared to teach ahimsa, nonviolence, being compassionate on the animals and human beings. In the Christian religion also, it is clearly stated, 'Thou shall not kill'. So everywhere animal killing is restricted. In no religion the unnecessary killing of animals is allowed. But nobody is caring. The killing process is increasing, and so are the reactions. Every ten years you will find a war. These are the reactions. - A. C. Bhaktivedanta Swami Prabhupada