Unmodified Rimworld isn't a human farm simulator. Even with Biotech DLC, which would allow your colonists to have children, it would be much more practical to farm real farm animals like cows and chickens. It is very realistic, and will not allow you to have new children every day like in Monster Black Market. And you'll have to deal with realistic consequences of keeping humans like livestock.
Maybe with some cheat mods and 18+ mods it will be more practical.
This may be straying off topic, but unmodded Rimworld can be a human farm simulator if played a certain way.
I mean, you can capture raiders/visitors and then surgically remove parts based on the pawn doing the harvesting. With enough medicine skill you can remove 1 leg, 2 arms, 1 kidney, 1 lung, and 1 eye of the prisoner. You could remove both legs and replace them with pegs, but that takes extra time and surgery. When you 'release the prisoner' they will slowly hop off the map and the faction they belong to will get a positive reputation modifier for releasing a captive. Those body parts can be sold to traders for silver. Rinse and repeat for profit.
What's funny is if that faction raids (negative rep) or visits (positive or neutral rep) you there is a chance they will return to your base as one of the pawns generated for the encounter. Any weapon they are randomly assigned will immediately drop to the floor when they spawn on the map as they have no arms and they will then hop slowly towards your base as part of the raid/visit.
With enough time and luck you could have a massive raid of armless space pirates dropping assault rifles at the edge of your map. Those items could also be sold for profit and as they can easily be taken captive before fleeing you can sell their clothes and armor before releasing them. That gear won't have the 'removed from a corpse' debuff and everything can be sold for profit to traders.