Where can you find herbivore egg in Monster hunter freedom 2

i presume you mean CARNIVORE eggs not HERBIVORE eggs.

you can get some on nests. there's only one nest on every map and some actually don't have it. it's a great source of pokke points if you brought it to the red box at base camps.

note: those maps that has a "thing" to carry (crystals and ores) does not has carnivore eggs.
Mountain, jungle, great jungle, great forest, has some carnivore eggs.

note: you can't bring it home.