Do animals have a basic right to life and a right not to be subjected to brutal or painful treatment?

Animal Rights & Vegetarianism

1. Do animals have a basic right to life and a right not to be subjected to brutal or painful treatment? Why or why not? If animals do have these rights, then is it then immoral to slaughter and eat animals? Why or why not?

2. If it could be shown that vegetarian diets are ecologically preferable to meat-based diets or demonstrated that meat-based diets contributed to American Dependency on foreign oil products or contributed to global famine, would that mean that a vegetarian diet is necessarily morally preferable?