As long as the animal doesn't understand its situation — it's about to die or is being kept alive to be eaten — I don't think it matters. It's also important that other animals aren't affected by its death.
This would even apply to humans. For example, imagine you're having a nice day, walking down the street and then... nothing. A car coming from behind hits you, instantly killing you, you have absolutely no concept of your impending death and therefore it's meaningless to you — not your family and loved ones. And therefore no harm is done to the person.
This would seem to imply that if you unknowingly get killed by a car but have no loved ones or family then nothing wrong was done. Further most meat comes as a result of factory farming in which the conditions the animals are kept in it terrible.
At this point, they are still in our diet and without extraordinary means are a requirement for us. There seems to be no other point in trying to deny that the world does operate as a food chain, and therefore no reason to exclude one's self from it.
Actually we go to extraordinary means in order to supply meat products to everyone. It would require less effort, less resources, less land, less water, less just about everything if we all stopped eating meat.
The intellectual capacities of humans make them equipped to extend the lifetimes of animals on a large scale, via:
1. Arranging favourable living conditions.
2. Controlling the environment.
3. In the long-term, colonising other worlds.
Thus, killing animals indirectly furthers their species, by furthering humanity.
Really? You are proposing that us breeding, raising, and slaughtering large numbers of animals furthers their species?
We don't arrange favourable living conditions. Again, most animals for consumption are raised under factory farm conditions, which are usually extremely poor. Please read up on factory farming chickens.
They certainly continue to live and reproduce in large numbers, but only for our own purposes. That is less like life and more like a resource than anything. We use them as a resource, and we find ways to breed them or genetically modify them or shoot them full of various substances soley for the purpose of increasing their yield. This is not what a reasonable person would consider furthering a species. Would you consider pumping all women full of fertility drugs, and increasing the output of their breast milk as furthering the women species?
There is no reason or justification for the way we treat other animals aside from 'Might equals right" and while that is certainly a reality of the world I dream that intelligent species would find better justification for their actions or not do it at all.
Despite this I eat meat, which makes me a hypocrit. Like most people I've grown up with eating meat and it has become a habit, a preference based on taste, and dare I say an addiction.
Now if we cut back on our overall meat consumption and allowed animals to live good full lives before finally using them for food that would be much better.