To adequately answer these questions, we should first intuitively understand what the words "respect" and "dignity" mean. I do not say these words lightly with casual meaning and I do not equate them with concepts of morality and ethics. These terms are often confused with one another, either through ignorance or by intentional obfuscation. Therefore let us unlink the associations and refine their meanings first. The terms respect and dignity denote that there is something inherently noble in a thing rather than something that is bestowed upon by externalities. It is a recognition that the subject/object must be viewed not merely as a thing for a particular task or a circumstance but must be considered as having value in a broader context. This value is not contingent upon passing an exercise in reason or decreed by an authority. It is about humbling ourselves in recognizing that we are equals and we can relate at some level that is innately common between us. The attitude bestowed upon the other is a reciprocation of our expectation that hopefully others have on us. When this condition is satisfied, it is referred to as mutual respect. But what can we say about respect and dignity in the context of food? Doesn't the fact that you're eating a living thing constitute a lack of respect? Well, not quite.
It is true that it's not "nice" to kill a thing to eat it. Herbivores eat plants but only because they're hungry. They eat the leaves and fruits, but those grow back in time and do not necessarily kill the plants. Carnivores on the other hand eat other animals, but again they do so out of hunger. The relationship between hunter and prey is innately respectful because they each are allowed to be free to be themselves and to be true to their natures. It can be cruel and horrific but the prey is dignified in its death as it gives its life to the hunter, and in turn the hunter is thankful for the flesh that is given. Omnivores however are not as specially equipped as Herbivores and Carnivores but the same respect still exists as they live in nature and depend on the bounties she offers. Although humans are omnivores, for the most part they are no longer part of nature and do not fit into the ecosystem as it chooses not to be bound by its laws. But does that mean that respect and dignity cannot exist in the psyche of man in relation to nature and her children? After all, why abide by rules when one no longer finds it necessary to be bound by them? Why not exploit nature as we see fit?
This mode of thinking can be summed up as hubris and an excuse to be reckless, cruel, and without shame. A closed loop system will go unstable given a series of stimuli that pushes it outside of its operating range. Since man relies on this system for survival, wrecking it is an act of war on future generations and living beings who are particularly sensitive to it. Some may say that their motives are not as insidious and that they have no choice given their circumstances. Perhaps so. Then it's a matter of changing those circumstances but the mode thinking also needs to change if it is to be meaningful and lasting. If man is no longer a part of ecology, then he must remove himself from it so as to minimize his influence. We must grow our food for our needs but do not take the existing food away from others. To do so is to be the negative stimuli that nudges the system towards instability. This is respect for nature and all she needs is for us to just to let her be as she should be. But that's a separate topic of ecological conservation, which detracts from the current subject. It is enough for now that we understand the concept of respect and dignity in a larger setting so that we can apply it effectively in our context.
Now that we understand one another (as able as I can bridge), let us go back to discussing our foods. Do we have respect for those who give us their lives to sustain us? Do we let them be true to their natures and allow them to be valued in our communities? Can we really say that we respect something when we refer to them as "commodities" and "resources"? If dehumanization of man is a tool to excuse atrocities, what then is commercialization of life? To say that we must be compassionate is hopelessly inadequate, as compassion is an overused term, which does not capture the full scope of the sentiment. Rather we must view the problem with genuine love and affection for living creatures and their shared existence on this planet of ours as neighbors.
Judge the tree by its fruits. But remember to...
Wash the beam out of your eye with soap.