Emu egg

The inside of an emu egg looks about like the inside of any other egg, with a yolk that is yellow (sometimes a little paler yellow than chicken egg yolk) and a normal, translucent egg-white - again, like chicken egg, but slightly more viscous because it contains less water - 67% versus 75%. One noticeable difference between emu eggs and chicken eggs is that in the emu egg, the yolk is huge. Chicken eggs (excluding shell) contain about 65% white, 35% yolk. Emu eggs, by comparison, contain 55% white, 44% yolk. This is not surprising, considering that an emu egg is designed to feed a developing chick for a 50 - 56 day incubation period (versus only 21 days for the chicken) and considering the fact that most of an egg's nutrients - fats, vitamins, minerals and proteins - are concentrated in the yolk.