Please allow me to make a small correction. There is no commandment “not to kill”. Rather, the commandment is “not to murder”, and it is referring to human beings and not to the animal world. However, there is a different prohibition against causing unnecessary pain to animals. For this reason many Jewish authorities frown upon hunting for sport. There is, however, no prohibition against killing animals and fish to eat if so desired. I hope this answer is clear and helpful and please feel free to write again with any other question about Judaism.
