Donkey cooked but sheep discarded

[m4tm4t]

Hello,
I can't find the rule explaning this in the rulebook. After animal breeding, I had one donkey and one sheep too many.
The game showed me only one button: "cook the donkey and discard the sheep".
What's the rule? I can't cook more than one animal at that time and the game choosed the best one to cook for me?
Thanks in advance!

* love that game and that adaptation!

[Tisaac]

You can't cook babies. So if you have 4 donkeys and you have new baby you cant fit, you can always say you are going to cook on of the 4 donkeys and put the baby at his place.
However, if you have only 2 sheeps and cant fit their baby sheep, you cannot cook any of the sheep so you must discard the baby.

[m4tm4t]

Ok, that makes sense!
Thanks!