Use setTag to as identifier for the UICollectionView objects, which can then be used by delegate and datasource methods.

gistfile1.m

for (int i = 0; i < 5; i++) {
    UICollectionView *currentCollectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, maxWidth, collectionViewHeight) collectionViewLayout:layout];
    // Trick to let the delegate and data source functions deal with the multiple UICollectionView's
    [currentCollectionView setTag:i];
}