One of my earliest memories as a child was when my father and grandmother would boil up big coppers full of potatoes for the hens and ducks. These would be surplus or lower grade potatoes. We'd light the fire, cook them and when they were cool enough mash them down somewhat and often mix them with some laying mash or wheat.
The hens and ducks loved it and invariably thrived. These days I still do it for the hens when we have spare or damaged potatoes. Make sure you do not use any green potatoes and remove any green skin or green pieces from the potatoes. If in doubt throw them out!
If you have spare or damaged potatoes it's a great way to use them up. If you're short of money but have some spare ground on which you could plant some more potatoes, it would probably be worth growing potatoes especially for any hens or ducks you might keep.
In recent times I've also used the pulp from the centre of pumpkins and lightly cooked them for the hens as well. Once cooled, the hens enjoy the pumpkin pulp too. They'll also readily eat cooked pumpkin skins. When peeling pumpkin pieces to make pumpkin soup I mix the cooked skins into the bucket which contains any other household scraps for the hens.
One of my little red hens, Matilda. Is she asking when the next batch of mashed potatoes will be ready?