Ah yes. MSA is short for Meat Standards Australia. Grade 0 means no significant intra-muscular fat, Grade 9+ means extremely fine marbling (almost speckled)
There are other axis for tenderness and flavour, but marbliing score is the one most people look at.
Right on, and indeed - Choice and Select are what most of us grocery-store shoppers see, in the U.S. In Canada, AAA is like Prime, AA is Choice, and A is akin to Select.
This discussion has:
The forum can’t help me get a good steak, so I’ll just address the curious bit 
This is the US Grading System:
This is the Australian Grading System
From my eyeballing, and anyone can feel free to disagree, USDA prime seems to be around grade 5 or 6, and choice seems to be around grade 1-2.
Around here, supermarkets would bulk package anything up to Grade 2 meat. Individually packaged premium steaks in a super market could get up to grade 4. Speciality butchers could get to 6 or so. Coincidentally, 6+ is called export grade, and anything over 6+ is almost impossible to get unless you go to a high end steak house. The kind of place where you not only choose the cut, but the breed, the number of days it has been grass or grain fed, and the number of days it has been aged. Yes, I have been to a place where the menu is not sorted by course (entree, main, dessert, etc), but the breed of cattle the steak came from.
Anyway, I am now tempted to get a bone in, standing rib roast, bones 6-9 (four serves), fat caps left on, of as close to grade 6 as I can get, aged in my special low humidity fridge for 5 weeks. Then dried fat trimmed off, in the sous vide for 16 hours, barded with bacon, and flash grilled to give it a charred taste. No marinade except salt and pepper. (You shall not defile my meat with that marinade!!!)
Of course, I don’t have the patience to do that, but it’s Friday night, so I’m going to check to see if the wife wants to go to a steak house…
Not sure about the rest of Canada, but as an American carnivore temporarily living in Manitoba, My observation is that in the local market AAA is closer to Choice, AA is closer to Select. I don’t see much locally rated A. I’m not sure if there is a special designation for better than AAA, but I rarely see anything in the Manitoba markets that compares to the Prime they sell south of the border.
I’m not saying that there isn’t good beef in Canada, for the most part, it is very good quality, likely better than US beef in general. I’m just saying that my experience is that from a visual marbling perspective, not much offered for sale up here is visually similar to Prime in the US.
Chris, you are exactly right. I had read some incorrect information back a while, and today I see this:
The four high quality grades (A, AA, AAA, Prime) represent 98% of all youthful graded Canadian beef carcasses. The grade criteria for these four grades are identical, with the only exception being degree of marbling.
