Animals eating pray is different; we humans however can choose and we do not need to. Even if I think if you (or someone else but not some bio factory) get up in the morning and chase your own boar, hang it and slaughter it then it is ok but buying some packet in the shop should at least give you pause.
Let me know how the dogfood works out that would be good.
The word originates from the Latin verb sentire, "to feel". Plants feel their environment. The Venus Fly Trap feels when an insect is on it, for example.
>Plants are sessile, highly sensitive organisms that actively compete for environmental resources both above and below the ground. They assess their surroundings, estimate how much energy they need for particular goals, and then realise the optimum variant. They take measures to control certain environmental resources. They perceive themselves and can distinguish between ‘self’ and ‘non-self’. They process and evaluate information and then modify their behaviour accordingly.
[1]Biocommunication of Plants, http://www.springer.com/us/book/9783642235238
[2] https://en.m.wikipedia.org/wiki/Plant_perception_(physiology...
A more valid argument is that the sound or sight of killing an animal is more off-putting than killing a plant, which is of course a purely subjective sentiment, hence the deeming of "right vs wrong" which is itself a purely subjective sentiment.
Sentience is defined as the capacity to feel, perceive, or experience subjectively. Since we have very little understanding of how consciousness works and how to test discern whether an entity is conscious or not, I realize this is a sticking point for a lot of people. But I think you'll agree that there's a very real difference between killing a plant and killing a member of your family. And that distinction applies to many animals as well.