i'm from italy

can i get a free opinion about cornflakes (link below) as food for swan and similar aquatic bird?

is ok food for swan, or it have too much protein and/or carboidrat and/or sucre?

it's better than white bread?
it's better than brown bread?
it's better than cracked corn?

..i'm looking for some fast and sane food for swan goose and duck, different than (suspected dangerous) white bread...

best regards

marco.