Pure makes good points... as always LOL. I just have to make a stronger point about the mess factor... I have used egg yolk to feed fry and it is HORRIBLY messy, with an oscar, the way they spew things from their gills, they'd be horribly messy with it. I would really avoid feeding egg, unless as a treat shortly before a water change.
My oscars get a staple of Hikari Cichlid Bio-Gold+, New Life Spectrum large/jumbo cichlid pellets, and they theive the spirulina and other sinking foods I put in for the plecs too. I give treats of mealworms, red wiggler worms, the occasional cricket, frozen foods such as krill, plankton, bloodworms, and they catch the occasional fly too LOL. Then again, I tend to spoil my fish LOL. I also throw in a small fish or two once in a while, but I never buy feeder fish, just overpopulation of young fish, bullies that pick on my favorites, or old fish who seem to be suffering from old age alone.
My point, they're not real picky, LOL. What is the reasoning for planning on feeding egg? Just curious...