Some hatcheries even listed the birds as "Delaware/Columbian Rock" in their brochures. I can't recall which ones, but I saw it with my own eyes. seriousbill can tell you more about it than I can. One of our members showed me a picture of his Delaware rooster...with many solid black feathers rather than barred ones in the tail, an indicator of that outcrossing. I would say that most would not admit to it, but the proof is in the birds.
Found this older breeder/hatchery listing page and that is the way Welp has their birds listed, however, this year, on the actual Welp site, that isn't listed "Columbian Rock/Delaware" any longer, which tells me that they did the outcrossing, but no longer admit to it.
Welp, Inc.
PO Box 77
Bancroft, IA 50517
Phone: (800) 458-4473
Fax: (515) 885-2346
http://www.welphatchery.com/ Chickens - Bantams:
Clean-Legged:
.Ameraucana-Araucana, BB Red Old English, Black & Brown Belgium Quail, Black Japanese, Black Old English Game, Black Rose Comb, Black Tailed Buff Japanese, Black Tailed White Japanese, Croele Old English, Dark Cornish, Golden Sebright, Gray Japanee, Red Pyle Old English, Rhode Island Red, Silver Duckwing Old English, Silver Sebright, Spangled Old English, White Cornish, White Crested Black Polish, White Faced Black Spanish, White Japanese, White Laced Red Cornish.
Feather-Legged:
Barred Cochin, Birchen Cochin, Black Cochin, Black Silkie, Blue Cochin, Blue Silkie, Buff Brahma, Buff Cochin, Buff Silkie, Dark Brahma, Golden Laced Cochin, Light Brahma, Mottled Cochin, Mille Fleur, Partrdge Cochin, Porcelain, Red Cochin, Red Frizzle, Cochin, Red Silkie, Sultan, White Cochin, White Frizzle Cochin, White Silkie.
Chickens - Standard:
Meat Type:
Cornish Rock
White Egg Layers:
California White & White Leghorn.
Brown Egg Layers:
Rhode Island Red, Barred Rock, Black Australorp, Red Sex-Link, Black Sex-Link, White Rock.
Cochin:
Black, Blue, Buff, Partridge, White.
Polish:
Buff Laced, Golden Laced, Silver Laced, White Crested Black.
Other:
Ancona, Ameraucana (Araucana), Black Giant, Black Sumatra, Blue Andalusian, Black Minorca, Buff Minorca, Brahma-Dark, Brahma-Light, Red Broiler, Black Broiler, Brown Leghorn, Buff Orpington, Buff Rock, Buttercup, California Gray, Golden Campine, Silver Campine,
Columbian Rock/Delaware, Cornish Dark, Dominiques, Egyptian Fayomi, Golden Lakenvelder, Silver Lakenvelder, New Hampshire Red, Partridge Rock, Production Black, Salmon Favorelle, Silver Spangled Hamburg, Speckled Sussex, Turken, White Laced Red Cornish, Golden Laced Wyandotte, Silver Laced Wyandotte.
