 Consider factory farming, the most common method used to convert animal bodies into relatively inexpensive food in industrialized societies today. An estimated 8 billion animals in the United States are born, confined, biologically manipulated, transported and ultimately slaughtered each year so that humans can consume them. The conditions in which these animals are raised and the method of slaughter causes vast amounts of suffering (see, for example, Mason &amp; Singer 1980 [1990]). Given that animals suffer under such conditions and assuming that suffering is not in their interests, then the practice of factory farming would only be morally justifiable if its abolition were to cause greater suffering or a greater amount of interest frustration. Certainly humans who take pleasure in eating animals will find it harder to satisfy these interests in the absence of factory farms; it may cost more and require more effort to obtain animal products. The factory farmers, and the industries that support factory farming, will also have certain interests frustrated if factory farming were to be abolished. How much interest frustration and interest satisfaction would be associated with the end to factory farming is largely an empirical question. But utilitarians are not making unreasonable predictions when they argue that on balance the suffering and interest frustration that animals experience in modern day meat production is greater than the suffering that humans would endure if they had to alter their current practices.