So in my world the human empire have lived together with humanoid beastfolk: think werewolf/lycanth, minotaur, big feline like tiger/lionfolk or humanoid jungle cat, etc.
They are relatively smart or sentient, almost like human-level inteligent/sentient; the thing is they consider humans as their equal or part of their pack, whereas humans think of them as nothing more than just as pets or slave workforce. I am struggling to find a way for these humans to trick their fellow beastfolk into selective breeding so as to dumb them down or make them more loyal to human: think of werewolf/lycanth into dogfolk, minotaur into dairy minotaur, orc into pigfolk, the feline into catfolk.
The dogfolk is to turn into the army or guards, or a plaything pet for humans; the feline to guard the farmland from pests, hunters or forest rangers; the minotaur to produce meat and milk; and also the pigfolk for food and pig related products. Yes, my humans will eat both of them.
They have to manage to selectively breed them into those docile versions, without the rest, the pure beastfolk, finding out that they are being tricked by the humans.
Before this happened, the beastfolk could do whatever job they want; although they still have savage tendencies or lack of self control: especially since they have sharp teeth, claws, and horns/tusks, which is also one of the reason human want to tone them down.
The political scene is dominated by humans, so the beastfolk is currently just citizen; they don't care much regarding human politics outside of taxation.
Concentration camps or similar like is out of the question, as is any use of force, I want a more civil way without making dissent or provoking suspicion/fear in the remaining beastfolk, because despite how mighty the human race is with their advanced technology, you still don't want wild beasts wreak havoc or run amok in your country.
Religions or religion-related mechanisms are out of the question, because the beastfolk religion is almost nonexistent or at best shamanistic: ancestor spirit or food chain type of religions (you know the life and death recycle thing). Human religions are pretty speciesist: like, only human will gain salvation or go to heaven. They dont condemn the nonbeliever though, because it is exclusive to humans, so beastfolk cannot join nor care about it. Also, the humans are not fanatic to their religion so they don't hate beastfolk, they just think of them as lesser beings than them and enjoy the beastfolk companion as their pets. The religions are also not influential in the politics outside of influencing the human mindset. They don't want to use force against beastfolk.
Law protecting beastfolk from cruelty exist, although turning them into consumable meat or other products is actually fine: it fits beastfolk religions/mindset as I mentioned with the food chain thing; they generally don't like to waste the dead (though they are fine to burn, bury or decompose it, if the corpse is beyond consumable or contain deadly disease), and they do share the medically checked meat of their dead fellows to be consumed. Still, killing or murdering the beastfolk is not fine (at least before they turn into meat petfolk). The problem is them realizing they are betrayed and bred to be killed as industrial meat or getting dumber or breed to be slave.
Machines, chemicals or drugs (including magic) as a brainwashing method to instantly turn them into petfolk without using selective breeding method is also out of the question.
I have thought about a dating agency, but I am not sure about the effectiveness, and it's not like all of them go to the dating agency to find their mate (since I don't want to enforce it). They are also quite proud and are disinclined to use something like that.
I have also thought about a way to make a trending/viral hype to attract this beastfolk to unconsciously follow the selective breeding (think of teenage viral/trending challenge like condom snorting, ice bucket challenge, etc.) to create something like: elephants start to breed with tuskless male, because tuskless elephant is the hot thing right now. The thing is I don't know what kind of trending would do it, and I am not sure about the effectiveness either. Besides, they don't have internet or television yet, although they do have paper or newspaper including book as the medium (privately owned) - but as I mentioned religion is out of the question.
The human civilization is the industrial civilization, or something like that I guess.... but the leader is not dictator or a tyrant (in a way like using an iron fist or enforcing their rule or law).
It's fine if the selective breeding happened before the empire founded, like during caveman times for example.
Also beastfolk cannot breed with humans, only with their own species or closely related species.
Feel free to correct my grammar and edit the tags, since I am not sure which tag is appropriate for my question.