The first good conduct the Buddha asks us to do is to avoid harming sentient beings

[There are] basic conditions for us to be a basic Buddhist person. One of these basic conditions are like to take commitment do not harm any being, do not cut off others’ life. It’s important as basic condition for anyone to practice the Buddhist tradition because the Buddha does not allow anyone to practice dharma while being harmful to somebody or killing others. The Buddha doesn’t allow for anyone to do both together, but only one who is to be able to avoid any harmful actions. Of course, people understand that it’s not good to harm others, not only people, but do not harm any being, any sentient being, which means including small insects, birds, chicken, fish. We should not harm them, attack them but we should protect them. That’s very basic conditions for us to be able to receive and practice teachings of the Buddha.

Hungkar Dorje Rinpoche, “Three Qualities a Dharma Master Should Have (Part II)”