>
> It's true that modern domestic beef cattle, descendents of the
> pleistocene auroch, get up to full size and fully marbled fattiness in
> record-breaking time in the feedlot. However, grass-only farmers get
> them there as well. It just takes an extra year or two. The feedlot diet
> throws off the n6:n3 ratio somewhat, but there is plenty of saturated
> fat either way.


marbling is a pathological process and occur only when the animals are
eating unatural foods for the species .

fat deposits in a wild animal or domestic raised naturally are under the
skins around the organs and between muscles never inside the muscles .
Genetic have certainly also a role to play as i eat highland cattles and
their meat is absolutelly lean even when they are fat animals ( more
grasses here than in their homeland ), other more modern breed might deposit
more fats .

sheeps are a good ex of a domestic animal who makes easelly lot of fats even
when raised only on grasses ( not even hay ) the reason is , i think,
because wild sheeps are mountain animals living on sparse short  grasses
and where winters  are harsh.

jean-claude