When you eat meat do you feel guilty about the early death of the creature? You probably believe that because someone else killed it you are without guilt. Buddhists are careful not to step on a blade of grass - those who really follow the Faith. It must be remembered, however, that even plants are alive, so there is no way you can avoid taking a life to obtain food.
Recently, Australia temporarily stopped the export of live cattle to Indonesia. ABC television showed a documentary showing cruelty to animals during the slaughter process. Some people have pointed out that cruelty takes place at Australian abattoirs.
Humans need food. Meat has more energy than any other food product. It is no wonders we consume it in massive amounts. Perhaps we cover up the guilt by calling cattle "meat" very early on in the slaughter process. For example, dead unprocessed chickens are called "whole bird products".
Feeling guilty about taking a life is a religious value. When something is dead it is just that - dead. If you do not believed in a hereafter that is the end of it. When a lion takes down its prey the pain endured by the victim is not a consideration.
Perhaps this double standard is due to people keeping pets which become part of the family and owners think that they must have an afterlife too. In evolutionary terms we are only just out of the savage stage. Neanderthals are widely accepted as falling into this category, though evidence shows they were just as advanced as us. Spearing an animal must cause pain, but to survive we must do it.