La gallina de los huevos de oro

[ROBINDESBOIS]

we use this sentence when something or someone provides money, food etcc for everybody, for example in my case my gallina de los huevos de oro could be my father because he makes a lot of money and he is very generous, if one day he dies, my gallina de los huevos de oro will be gone too. People tend to say you have to take care of the gallina de los huevos de oro, when sb provides you good food or all the necessary things to leave on, or other things.
How can we say that in English?

[Perikles]

In England, it's a goose that lays golden eggs, not a chicken.

[JPablo]

That's right, "la oca" o "la gansa"...

To kill the goose that lays the golden eggs = Matar a la gallina de los huevos de oro