The obvious solution is to start a cult that worships the baby. Once the baby has Divine rank 0 it doesn't need to eat anymore.

Other ideas include:

Sell the babies soul to the abyss in exchange for a succubus to nurse the baby.
Cast "Bite of the Wolf" on the baby so it has teeth and can eat.
PAO/shapechange/wildshape yourself into a cow/nursing woman.
Magic fang the baby (probably won't actually work)
Shadow conjure a cow.
Use miracle to make the baby take care of itself (using the "very powerful request" form)
Lesser planar ally/binding something that can feed it.
Gate in a Balor and use it's wish ability to feed it.
Kill it and use reincarnate so it stops being a baby
Cast "Awaken" on the baby so it becomes a magical beast able to feed itself with 3d6 int.
Have the baby drink the "nectar like beverage" from heroes' feast.
Create food and water specifies "The food that this spell creates is simple fare of your choice—highly nourishing, if rather bland." That seems to imply that if you want baby food style food, you get it.

Put it in a stasis of some sort until you find someone who can feed it. Ways to deal with it later include:
Killing it and rezzing it.
Covering the baby in quintessence.
Casting "Temporal Stasis" on the baby.
Flesh to Stone.
Casting "Imprisonment"
Leaving it on the NE plane for a bit.