I have no access to grass-fed dairy (but I'm not going to cry over grain-fed spilled milk). We consume a lot of cream and and butter, two big sources of SFAs around here. Knowledge is power, and I love heavy cream, it's my paleo go-to source for fats (ok it's not strictly paleo, but if it is good enough for Kurt Harris, it is good enough for me). I have about a cup (238 grams) of heavy cream with my coffee which serves as breakfast, and when I'm dieting I will have a glass of heavy cream as a light meal.
Here's a screen shot (with my added notes) of the lipid breakdown of 100 grams of heavy cream from the USDA database.
Now this is supposedly the breakdown of typical off-the-shelf heavy cream. I've no idea how accurate or typical this really is or how it compares to grass-fed cream because I can't find a lipid breakdown for grass-fed. Note that the fats in the table add up to 35% which is heavier than many creams (ours is 31%).
But the good news is that, assuming this is accurate, the n-3/n-6 ratio is very good and the total n-3 is excellent. A cup of heavy cream has around 1.3 grams of n-3 with about 2 grams of n-6. This is something one can feel good about, at least as far as getting a healthy dose of ω-3 is concerned. Well, not too good because cream doesn't supply any DHA or EPA ω-3s. For that one still needs to eat something fishy. Whether or not DHA and EPA are really as important as they are cracked up to be since the body can form them from α-linolenic acid is still an open topic but it probably doesn't hurt to get plenty of them.
And, since that was such a short and boring post, here's a picture of a monkey playing cymbals: