You have to offer the peas and sooner or later the geese will eat them. I usually start them on peas when little sure do eat them then. Geese will eat as gosling what you offer them because they do not know what all to eat. Now this is what I do. I cook the peas and mine seem to like them better. Spoiled I guess. My geese do not eat carrots and other people say their geese love them. But it is a good practice to start your little ones on peas a about a week old.
