texture

So one of my girls (idk which one) laid an unusually small egg, but not small enough to really be considered a fart egg. No idea if the size of it is the cause of this, but when I boiled it up, the yolk had the same [maybe a smidge rubberyer, snapped instead of crumbled when torn apart, shiny...

I’ve heard that, for example, Dorkings and Bresse have fine meat, while Cornish and Jersey Giants have coarse meat. I have only eaten store bought chicken and self-slaughtered Buff Orpingtons. Can someone explain the texture (and if applicable the taste) differences between Coarse and fine meat...