What is a cattle pack, primal and subprimal?

Years ago, meat packers used to sell beef by the whole carcass called "hanging beef" (now called cattle pack).  Over the years, customers wanted to be able to buy certain parts of the beef carcass without buying the whole thing.  To make things simple, the meat packers divided the carcass into 8 sections:  Rib, Loin, Chuck, Sirloin, Round, Shank, Brisket, Plate, and Flank.  These are also known as the “Primals”. 

Once meat is cut into these large pieces (primals), it can be further cut into smaller, more usable pieces called Subprimals.   Many of the items that foodservice distributors buy are subprimal cuts. 

An example of this would be a Beef Tenderloin. 

The primal is the Loin, and within the Loin contains the subprimal, which in this case is the tenderloin.  A distributor who wants to sell tenderloins to his restaurant customers doesn’t want the whole loin (primal), but rather just the tenderloin (subprimal).  The meat packers will extract the tenderloin from the whole loin and vacuum package it.  They will put 5 individually vacuum packaged tenderloins in a box, creating “Boxed Beef”!