Ahimsa parmo Dharma! Non violence is the only duty! So whatever you decide should revolve around this... Veganism is logical extension of this. Be vegan. Killing a plant is cruel too.. but it's minimal violence compared to killing or exploiting an animal.. Mahabharat war was violence.... but if it wasn't done there would have been more violence and exploitation due to a evil king. So the rule is practiced as one with minimal violence!