A method for culturing avian embryonic stem (ES) cells that comprises the steps: (a) Suspending ES cells originating from the blastoderm disk of fertilised un-incubated avian egg(s) in a basal culture medium supplemented with animal serum and insulin-like growth factor-1 (IGF-1) and ciliary neurotropic factor (CNTF) as the sole growth factors and (b) Seeding the suspension of ES cells obtained in (a) on a layer of feeder cells and further culturing the ES cells between 2-10 passages. The cells obtained in the method can further be used in methods of genetic modification and subsequently used to generate a genetically modified bird. The bird can be a chicken or a duck.
