This thesis moves beyond the traditional approaches of how we ought to treat animals, and instead concentrates on the best strategy for preventing animal suffering in the farming industry. Chapter 1 considers the question of how we can know that animals feel pain, and concludes not only that it is rational to believe that they can, but also that this is a significant fact. Chapter 2 then analyses one possible strategy for helping to prevent animal suffering, namely demi-vegetarianism. For a number of reasons, however, this strategy is found to be flawed, therefore Chapter 3 analyses a second possible strategy, namely vegetarianism, and concludes that this is, in fact, the best strategy for helping to prevent animal suffering in the farming industry