sapient beings

Frankly, this is the most difficult question to ask what makes a sapient being? Or should it be a rational being or a clever being or, or, or...
Over the centuries many people who were much better educated to answer this question have tried it. Searching for some form of metric, some criteria in order to define it. The question was simply what is a human, subhuman is a specific race more human than another human race? Quite often the intent was neither benevolent nor scientific gain. The "research" was done to justify the own behaviour, to cement a form of superiority so that dubious actions could be justified.

On Turian's World this question, this problem is even more complicated. With species, quite some species obviously not even related to humans, using tools, building structures, having societies capable of speech. Which have all been used to define a species "sapient being".

A single being within a species, a whole species, a magical construct and all those engineering marvels conjured entities, all those could be sapient beings. But many are not, some birds use tools and are capable of problem-solving. Some others are self-aware to a degree. A sheepdog can learn and take action of its own motivation.
So the question is still not simple. Was Lassie an intelligent, maybe even a sapient being?

However, is that really the question in Turian's World? Or is the question more along the lines of "Did I kill something or someone?" and that question is of moral weight because we value someone more than something? And there lies the rub, Turian's World is NOT our world, almost all of our modern earthly values are either unknown, useless or dangerous in that world.
Slavery is not an organized business as it was until the 19th century on Earth. It is mostly a consequence of lost wars, a bad business deal, honour debt and other circumstances. It also is by no means non-existant or super rare in Turian.
There are cultures and species in Turian that practice extreme sexism. There are some arthropod groups that are known to slaughter, even eat the male after copulation. Another example are some Felidae that basically "enslave" all males for just procreation and domestic service. On the other spectrum, there are Felidae races where the males are the protectors, warriors and maintain a harem but they are not capable of owning land.

The question of morality in behaviourisms is generally only applied within the own community and its allies. As soon as behaviour affects something or someone outside of that, it is mostly considered irrelevant.