Introduction to Ranching?

[badimo]

I've been ignoring ranching since it came out because it never struct as something particularly interesting and I found it a little clumsy.  However, I am currently very many cycles in and am exploring it.  Per usual, I'm doing something (maybe) peculiar and I am trying to build a zoo.  I'm trying to keep 3 of each animal type alive simultaneously.  There are a few basics I am struggling with and I am sure the experts in this community have some solutions.  I've searched various posts, but there is a lot of complexity out there and I am hoping for simplicity.  Here are a few questions I have:

1. How do automatically move the "oldest" critters out of each habitat?  I understand that you can auto-wrangle the surplus, but I don't see how to ensure your colony doesn't die out from old age.
2. How do you remove eggs that don't match the type of critter you are trying to raise in that habitat?
3. Does anybody have a guide on the most logical things to feed each critter?  I have thoughts on this but maybe someone has done extensive thinking on this subject.
4. Does anyone have an interesting looking kill machine?

[Saturnus]

I strongly suggest you start here

 

[kolyapedal]

I avoid ranching saving my CPU power for more interesting things.  And that's  the reason why I have this in my colony ( for your 4th quest):

 

[Gnarmaw]

1. You can't, the colony doesn't die out from old age because you will have a room where you keep all the babies

2. The best way to remove eggs is to use Auto-Sweepers to move the eggs out of the Stables and drop them in the room you will use to store eggs and babies, let's call it the "Hatching Room"

3. You pretty much feed them whichever resource you have the most, note that they poop based on the mass that they eat, so if you want coal from Sage Hatches, feeding them food items is a bad option

4.

This only works on critters that can't fly and can't stick to walls. So pretty much only Hatches, the buttons are just to make sure that the doors are closed when they die because due to a bug you won't get 2 Meat from Hatches if there's already a meat on the ground and there's an open space above, weird bug I know

Now, on how to maintain the population:

Upper left corner is the Egg Dropper Room, this is where all the eggs come with the Shipping system, the Sweepers drop the eggs to the room below that I call the Hatching Room. In the Hatching room, all my critters hatch and when they grow up (5 Cycles) Dupes will auto wrangle them (the Critter Drop Off point is set to zero critters and enabled Auto Wrangle). The priority of the Drop Off Points in stables is set such that it's higher than the Drop Off Point in the Drowning room (room on the right), so dupes will first fill the stables then put any extra critters in the Drowning Room where the automation makes sure to drown the critters where their meat is collected and shipped to the food storage.

[badimo]

44 minutes ago, Gnarmaw said:

how to maintain the population

Alright.  This makes a lot of sense.  Let me try to set this up for my various types of hatches and see how far I get.

I guess I was thinking too hard on how to manage the population inside the room instead of external to the room.