Fattening Using Fruit Scraps

My food forest is finally getting big enough to produce more than we can eat reasonably.  I've been playing with the idea of using fruit scraps (apricot, peach, apple, pear, berries) mixed with fodder for final fattening of livestock before butchering.  I run chickens, ducks, geese, and goats.  I'd gone back and forth on the morality of fattening but I feel like it is fine as long as the welfare of the animal is respected and confinement is not used.  The animals sure like it.  The calories should be there.  I've even heard of successful foie gras without force feeding.

Any one tried anything like that?  How would you store scraps for later use?  Fermenting/silage?

You'll need to check each animal type, to see which fruits are safe for which critters. I know peaches and other stone fruits are toxic to goats, but apples, bananas, berries, and pears are fine, as *occasional* treats.

The thing to keep in mind is all fruits are high in sugars, and a high sugar diet is rarely healthy for livestock. Sugar can set them up for serious digestive issues, and rumens can die (very painfully, and within hours) from the bloat it causes - and no - that doesn't mean they'll stop.

I'm not sure about the birds, though I know veggies are better for them.