My BA Mamma did show some distress when I slid the 2 CWhites under her...BAs don't come in yellow, and she knew it. But, they peeped and scratched, so she decided to love them, anyway, within the first day.I had a Silkie broody hen that sat on eggs of various vintages, one of them hatched but she stayed broody on about 2 more eggs. Meanwhile I had an incubator hatch of 13 chicks so after a couple days or less I put them under the broody hen at night. She accepted all of them except the 2 partridge and continued to sit. It took a few more days for her to accept those 2 but eventually she did and her 2 eggs did not seem viable so I removed them and she was a good mother for all the chicks. Chicks just seem to do so much better raised by a hen even though the mother takes them out in very cool weather (40s and 50s) when they are only a couple days old. I don't think the breed matters but the color may at first.