Old baby formula that babies like me were raised on in the 1950's and 60's:

20 oz water 13 oz evaporated milk 2 level tablespoons Karo syrup

Heat all and then pour into 4 - 6oz bottles. Recipe can be doubled, tripled, etc.

Those not comfortable with Karo (corn syrup) can use Cane Syrup, sugar/water (1 cup granulated sugar dissolved in ¼ cup warm water), or maple syrup.

I have a friend who was a neonatal nurse and she told me if a baby was not feeding, they used to give them the above recipe. If a baby had bad colic, they'd add a pinch of sugar to the bottle.