I believe that fundamentally, animals were created in order to serve human purposes; however, from my comprehension of Genesis 1:26, we have a responsibility to care for those animals and to treat them well lest commit an immoral act. Though I do not believe that animals are conscious of their own being (as I've expressed before and as is argued by Buddhists and Descartes), I do believe that we have a level of moral obligation towards them as they remain living, feeling beings. Furthermore, similar to the animal inferiority argument, I feel that we are superior to animals in that we are more intelligent, abstract, developed, and have more elaborate talents and characteristics than what our animal companions appear to possess. This only further supports my belief that as we are more mentally capable than animals, we are required to take care of them and treat them with dignity and respect as fellow creations.
Simply put, we owe them kindness and consideration because we have the capability to treat them that way. In order to prove our superiority to ourselves, we must first overcome the egotism of being thought as superior in the first place, regardless evidence that supports it. This can be said of other things as well, such as in the case of Bill Gates who dresses middle-class and treats everyone with respect regardless civil stature. Although he is rich, he does not use it as an excuse to flaunt his wealth or waste money; rather, he funds global operations such as the Red Cross and AIDS Research in order to help the less fortunate. The same can be said for humans in relation to animals in that though we are of superior intellect, that does not mean we owe animals any less consideration than we would give our own species.
Kant best explains my perception of animals. Lacking a conscious, they are creations based on instincts rather than rationalism. They lack the capability to understand the consequences of an action as well as the ability to understand what is socially acceptable and what is not. Because they lack the ability to rationalize their behaviour, the actions of an animal cannot be considered bad or good, moral or immoral. Animals simply act as nature intended, whether it is killing other animals, attacking one another, etc. I do believe, however, that animals have souls (contrary to Buddhist beliefs), and I do believe that animals are capable of acting, unintentionally or intentionally, in good faith whether they understand their actions or not. For example, an animal that appears to be comforting another animal or a human, or an animal that "adopts" a baby animal of the same or another species. There's an interesting video on YouTube of a lion that adopts and protects a baby sheep; though the lion might not understand that this act is "good" (in human perspective, anyway), it behaves this way outside of instinctual norms. Animals are then not restricted by instincts at all given moments and may be able to understand some ideas.
What I find interesting is that once an animal infringes on a human's right or property, they suddenly become part of the moral society in limited terms. A pack of wolves that kills and eats a farmer's cow in order to stay alive during winter is suddenly prone to being "punished" by either being trapped or displaced, or by being poisoned by the farmer himself. They become subjected to the human concept of punishment and consequence regardless the animals' inability to understand that what they did was considered "bad" or "stealing" in human society. Is this not then a double-standard where animals can be punished for acting "immorally" as per human standards, but do not have the right to be treated morally or with consideration in general? Though the animal's behaviour was both natural and instinctual, humans refuse to consider this once their own property has been violated in some way. Is that not wrong of us, to hold animals to our moral standards but not include them in our moral community in all circumstances? In our own societies, double-standards are discouraged i.e. the use of the "N" word between black individuals is OK but it is wrong for other ethnicities to address them as such – so why would it be acceptable to propose a double-standard on animals?
In conclusion, it is in my belief that yes, animals may be used to serve human purposes as long as they are treated properly and do not suffer unduly in the process; however, this is based on a combination of a softened version of the Divine Command Theory, Kantian Ethics, and the idea that to behave cruelly to animals is, in itself, an immoral act that is thus ethically unacceptable. I also agree that in some cases, as with an infestation of rats which may cause illness amongst humans, it is morally acceptable to kill animals of any sort, as per Peter Singer's utilitarian hierarchy concept. I do not believe, as per the Buddhist's, that animals lack a soul, or that our intellectual superiority denies moral rights to animals, as per the Animal Inferiority theory. We have an obligation to treat animals with a respect; it is our duty to care for them and to not improperly benefit from their existence. All measures must be taken in order to assure that the welfare of the animals which are used or will be used for human purposes will be taken into consideration as to not cause unneeded suffering. Whether they have a conscious or method of reason is irrelevant; they ultimately feel, and that is the deciding factor in whether or not they deserve to be treated well.