JTN sounds very knowledgeable about the questions here too but heres my two cents LOL
As stated before, geese chicken and ducks are different animals. Geese and ducks have different needs especially for the first 10 to 12 weeks of life than chickens. Chickens have multiple choices for feed usually medicated chick feed when small however I feed my geese NON medicated chick feed when small, they do not need the medication that's in chick feed. Also GEESE NEED GRASS throughout their entire lives. They are grazing animals, grass is their main source of food and the feeds should be secondary at about 10 weeks you will see they prefer grass to any other feeds. I know ducks like grass too but usually picking and looking for bugs. Chickens will look for bugs too but not the grass. It is inhumane to put geese in an area where there is no grass to forage. In the winter if all grass is covered they still need the greens is essential for their health. I live in southern CA there is always grass for my geese. I no longer have the chickens or the ducks. Geese are the BEST I think. Smart funny and interactive. For ducks and geese I use MAZURI WATERFOWL feed to supplement their grass, at night when I pen them (we have coyotes and raccoons who go after the geese) I feed them the feed I do mix it with chicken scratch they really like that too but as babies they have different needs. WATER WATER CLEAN water ALL THE TIME for geese and ducks essential. I have several cheap plastic cement mixing pans that I empty two times a day morning and evening. 4 geese 4 plastic mixing pans and they do just fine but remember they drink bathe clean out their eyes and sinuses all in the same water so essential to keep water clean to avoid any diseases.
chicks= chick feed medicated as adult chicken scratch
ducklings=non medicated chick feed or specific waterfowl starter feed as adults waterfowl feed
goslings=non medicated chick feed with access to grass as adults waterfowl feed and absolutely access to grass.
CLEAN WATER ALL THE TIME ESSENTIAL FOR GOOD HEALTH FOR ALL MORESO FOR ADULT GEESE AND DUCKS.
I don't really promote one brand over the other as different brands are available in different parts of the country.
These guys are the three I kept from my clutch of 7 that hatched on Easter Day this year 2015. The one on the right is an overly friendly male the other two his sisters. They are Mom is purebred Cottonpatch and dad is a Toulouse. Such good babies and very friendly (not imprinted just friendly).
This is momma Miss Ruby with the three little ones at about two days. She is a great momma watches after them even to this day.
Beautiful geese, love those babies