Chicken IgY antibodies are the predominant serum immunoglobulins in birds, reptiles and amphibians. In the female, transfer of IgY from serum to egg yolk confers passive immunity to embryos and neonates similarly to placental IgG transfer in mammals which also confers passive immunity to the fetus.
http://www.creative-biolabs.com/De-Novo-Chicken-IgYs-Sequencing-Service.html
