This is all very interesting indeed. I think the major issue here is the assumption that we are trying to answer this question with ONE UPB for all living organisms that is biased toward humans.
Syllogistically, this is:
All organisms require universally preferred behavior to live. Man is a living organism. Therefore all living men are alive due to the practice of universally preferred behavior. Therefore any argument against universally preferable behavior requires an acceptance and practice of universally preferred behavior. Therefore no argument against the existence of universally preferable behavior can be valid.
Organisms succeed by acting upon universally preferable behaviour. Man is the most successful organism. Therefore man must have acted most successfully on the basis of universally preferable behaviour. Man’s mind is his most distinctive organ. Therefore man’s mind must have acted most successfully on the basis of universally preferable behaviour. Therefore universally preferable behaviour must be valid.
SO, what if we zoom out?
This says to me that to be able to employ UPB you need an organism, one living entity. This can go from groups of the smallest organisms (such as mycoplasma, or viruses, depending on what you consider to be alive) to the world and contents itself. The Earth itself being a null argument since we have no understanding as to it's participation in the solar system or the universe; I just wanted to make a point that the rules for UPB lends its principals to that of what is preferable to an organism rather than the personal desires of that organism, opening the general UPB postulation to more than just the human forum.
UPB does not say that in order to exercise UPB the organism has to also exercise or understand UPB. UPB appears to me to be based on or developed from instinct. We regard it generally wrong to kill people to serve the instinct to retain a thriving population, people generally feel bad when people die because it is a real life example of the fact that you are going to die, the world is coming to an end, anything can happen and that you fear the unknown. Why do people fear the unknown? This is an instinct to evade again a primal fear of death. So, organisms prefer what they instinctively think will keep them alive. We humans gum the simplicity of this all up with our abilities for abstract thinking. Suggesting that UPBs arise from basic black or white instincts, the vast gray areas created by our ability to cognate and communicate these cognitions, kind of like how a computer takes binary signals and turns it into webs of informaiton.
The way I see it, is that it is kind of set up like governmental bodies and maybe that is why we tend not to gravitate toward anarchism. Anyhow, in the US and most other countries we have everything from the neighborhood watch group to groups that discern what is right on international levels. These groups do not follow all of the same rules, they follow a set of similar rules considering the universal laws of societies, which in most cases fall under human UPB and adapt their own individual rules based on their situation. So, in the realm of all organisms there are a set of UPB rules that apply to everything. Basically speaking our actions/behaviors are directed by our instinct to remain alive (omitting suicidal personalities for the moment), our morals are developed through reinforcement of the fact that we continue to thrive. This makes the smallest of organisms or even organisms we cannot communicate hard to put in this category for us. Everything has memory to some extent, even rocks, no matter how minuscule and because we have not learned to identify/quantify an actionable response does not mean it does not happen. This creates a basis for what is good and what is bad. Therefore, morals and UPBs are built from the fact that behaviors can cause life or death, I guess this could be thought of as primary, secondary, etc UPBs. If all organisms in some way strive to remain alive, what drives that? It has to be simpler than cognitive ability.
Cow to human is similar to one prehistoric tribe running into another. Say one tribe has survived by roaming the land looking for other tribes to pillage and eat and the other tribe has remained stationary for generations thriving off the land. What happens, both tribes follow their own UPB principles, the peaceful tribe tries to peacefully interact, the killers eat the other tribe, this behavior is further imprinted on the killers moral functioning as necessary for survival and they move on. Let me just say that this in no way reflects my personal opinions of right or wrong, but I am outlining what I see UPB rules to encapsulate. Each tribe has individual paths to the reinforcement and solidification of each UPB, making each UPB moral to its specific grouping of people. That said, cows have their own UPBs, we know that they instinctively prefer to stay alive as do we. As hunter gatherers back in the day, it was necessary for humans to kill prey to survive and have deemed it morally right to do so since it once allowed us to thrive. I will admit, I do not know much about the behavior of cows and don't really care to learn, but I would assume that they have some capacity for learning. SO again each species have individual UPBs with some similar aspects. While eating meat is no longer a necessity, we have more or less been programmed by our history to do so it now remains a matter of opinion and is no longer subject to mortality, so far. Before this statement sets anyone off, you are violating the UPB of living organisms by killing, but on the other hand you violate the UPB of nature as a whole without death. If nothing died nature would not be efficient and have an ever increasing entropy, which is the opposite of what the behavior of matter strives for. To kind of make this make sense a perfect circle is made up of an infinite number of lines, there is no defined beginning or end, yet it contains an infinite number of things concerning what it is around.
SO every organism has it's own set of UPBs, when you get to organisms that interact socially you bring complexities into the situation. Animal rights for example are not a product of human UBP thought before we consider empathy, since the establishment of the morals creating the UBPs followed do not include eating animals. But, if you use the UPB of all organisms and the basic instinct to stay alive then yes you are in violation of that way of thinking, which in turn puts you in potential violation of nature UPB. When it comes right down to it, again I am not saying I personally feel this is right, the question as to whether or not animals deserve rights, or if they should be eaten at all, human UPB principles thus far cannot answer.
That said, organisms with the ability to articulate sensory data to one another have additional ways to imprint, produce morals and UPBs through communication that discern good from bad. The only rules for the UPBs of other organisms that we have any real concept of are ones that are in plain site and that we can experience. Pain at its root produces a reaction to that which may kill someone. When one experiences an others pain an empathetic response is produced through the mirroring of the others experience and influences us to react to protect the other from the cause of their instinctual reaction. This can fall under human UPB or organism UPB depending on how you define the universe to which you prefer and that is why someone can be an ethical vegan and yet say if I or someone lived in Antarctica with no means of creating plant life to consume, I would eat fish or penguins. So I guess that since causing animals unnecessary pain is no longer important for the larger portions of our species existence and our ability to mirror and communicate pain caused to animals by humans that nullifies my argument that eating animals unless absolutely necessary to continue living is no longer a matter of morality and the creation of UPBs? And human UPB now includes organisms that we can empathize with.
Animal testing is a bit different, in that once a population is considered to be genetically inbred enough that genetic variance no longer matters in experimental results, it is no longer categorized as an animal population according to the government. Testing protocols still have to be approved by an ethics committee within each institution, but these animals do not have the rights of "natural" animals. BUT, genetically speaking a rat is a rat is a rat regardless of its genetic differences from population to population, it just so happens that populations of rats used for testing have less genetic variance than "natural" populations. So, according to what I said above, this would be in violation of human UPB. What about cell cultures, since we cannot empathize with their innate drive to stay alive you are not in violation of human UPB but are with organism UPB.
Overall, it is to our existential advantage to keep other species thriving as well as our own, what if we need to eat them to survive. Is the hierarchy to be implemented from the top to the bottom or from the bottom to the top or randomly? How do we effectively go about defining interspecies UPB beyond what we currently know? We are and have always been so commonly concerned with ourselves that to perfect human to animal UPB, UPBs must further be reinforced for it to stick.
So in a nutshell animal cruelty is in violation of human UPB, when the human has the ability to be empathetic. The same goes for the treatment of the mentally ill and when trying to change the behavior of the mentally ill in accordance with human UPB we address only symptoms and not the problem.
Thought I would toss out another way to consider the topic.