I got my info from Merck Manual of Diagnosis and Therapy. I'm skeptical of this peafowl website. Seems kinda random. Merck is essentially the Vet bible.
Also I now speak from experience. I took back the sick chickens i had and just bought some newly hatched chicks. I sanitized my coop well...
So my Barred rocks are laying below average size eggs and from what I understand they are supposed to be prolific layers of above average eggs. I bought them as 11 month old hens from a Lady who ordered 25 (minimum order) from a breeder and decided to sell the barred rocks when they grew up. So...