Oh wow, I had never heard of this. The daycare centers that I've been to have a cook and their own kitchen and our Head Start and Jump Start programs are all on public school grounds so they get their meals from the school cafeteria (they are brought to the classroom on a cart). The idea that some places got their meals catered just never occurred to me as an option.
I googled catering for daycare in my area and didn't find anything.