The egg yolk contains several substances of potential therapeutic value, some of which are already used in commercial products. A number of scientific papers dealing with their properties and applications have been published. In this review we present some current and possible applications for egg yolk lipids, lipoprotein, phosvitin, sialic acid and antibodies (IgY). Moreover, we discuss the possibilities of increasing the yield of yolk and simultaneously the yield of these substances by both management and breeding approaches.
