Do human beings have any obligations to other animals, in terms of their treatment? If it is wrong to treat animals cruelly, why is it not wrong to eat them? Explain if, and how, you think humans can find a balance between treating animals ethically while also raising them for food and for other reasons, such as the testing of pharmaceuticals.
You may get some ideas from these sites.
http://en.wikipedia.org/wiki/Factory_farming
http://www.sustainabletable.org/issues/factoryfarming/