Methods for enhancing embryonic and post-hatch growth and performance of poultry by administration of a probiotic composition, such as a composition containing a mixture of one or more bacterial cultures, to the surface of the shells of fertilized eggs prior to setting. Optionally, the method further includes administration of the same probiotic composition at the same concentration to chicks hatched from the eggs that had received the topical in ovo administration to the shell. The probiotic composition is administered to the chicks orally, such as in feed.