Hi lappilahja, at the moment no but there is a shortcut, it’s not clean but it could work.
Create a custom theme page for this content type:
https://codex.www.ads-software.com/Post_Type_Templates
(just copy the single page that it’s been displayed now, somewhere in your theme, you don’t need to code all the page).
Now you have two options:
a)When creating a litter in the body create a tag, something like [dateb]X-X-X[dateb] and with php filter it and display it as you like.
https://stackoverflow.com/questions/9253027/get-everything-between-tag-and-tag-with-php
b)Change the publishing date of the post (so it would be the same day of birth of the litter) and display it as you like
https://codex.www.ads-software.com/Template_Tags/the_date
Now To change the order of the litters in the Laika content type it will be more difficult. I would start uncheking “Show on Laika” on felicette settings and theming it yourself looping the litters.