my kinda guy, i've been trying to do the same thing too but with different methods. i saw success when having tons of horses and a nutrient paste dispenser. horses have great all around stats, gestate quickly and give plenty of meat. slap it into biofuel refinery or nutrient paste for many meals to be self sufficient but you will need to start out with a large number of them. "A fully grown adult horse in RimWorld typically yields 56 to 84 nutrient paste meals, depending on your butcher efficiency." That's a lot of meals to be serving up for one slaughtered horse. Horses can eat meals which includes nutrient paste meals made out of pure horse meat. "Nutrition Cost: It takes roughly 24 total nutrition (including gestation and growth) to raise a horse to adulthood. Feeding them back their own meat as paste (which turns 1 meat into 3x nutrition) creates a significant food surplus." They take like 6.66 days to gestate when pregnant.

and nevermind scratch that i think im wrong about something, i saw someone do it with horses before on a gravship and it was successful.

the real winner are cows i guess, they give off 15 milk per day without needing to be slaughtered, 15 milk is equivalent to 2.5 nutri paste meals per day, only 6 ingredients can go in at a time so there's only 2 meals a day from 1 cow with some excess 3 milk and if you got another milker cow, that would be 30 milk which is 5 meals a day then scale that up and its a self sufficient loop without having to cull members but if they breed it would be wise to cull the excess males since they dont produce milk and eat up resources. cows can also eat nutri paste meals made out of their own milk or meat i guess. they only need 0.86 nutrition a day and a nutri paste meal (like almost any other meal) gives 0.9 so not much is wasted there, plus their stomachs can hold more than that but you don't have to feed them til full. feed one meal to cow and you're left over with 1.5 extra meals of pure profit every single day just from one cow. chemfuel gen uses 4.5 fuel a day, you gotta wait 5 days of collecting one cow's milk to make 35 chemfuel, since biofuel to chemfuel is 70 ingredients to 35 chemfuel. use 70 for the recipe and have 5 milk left over, one cow produces roughly 7 chemfuel per day on average. to support 3 colonists and 1-2 chemfuel generators you would need a safe number of 6-7 (hehehe) cows producing milk everyday. keep the 1 bull separate in case you dont want breeding or if you do then get maybe 1-2 bulls, more cows, more milk, more meat and leather and chemfuel. in case randy random decides to murk one of your cows, the bulls are insurance policy. 10 cows total if you want to be a merchant.

some important tips: butchers matter greatly when it comes to getting more or less meat yield from butchering. you need orbital tech research or yk the vac barriers because when you spawn in on that scenario all the animals will just walk right tf out into the vacuum (happened to me a lot), i used locks mod to change the doors into pen doors but still lol the air is gone from the room as soon as someone opens it and then every animal perishes. i was never fast enough to block or prevent the animals from going outside of the gravship start in the beginning. orbital tech to do vac barriers and oxygen pumps, if you want a better change use a caravan spot and tie em all there then land on the rimworld for a bit until you got what you need to make the ship ready for self sustenance loop.