First of all, Parmigiano Reggiano and Grana Padano differ in their origin. Both varieties can refer to a “Protected Designation of Origin (PDO)” of the EU. This means that a product is manufactured in a specific geographical area using a specific process.
Parmigiano Reggiano is produced exclusively in the provinces of Parma, Reggio Emilia, Modena, Bologna (left bank of the Reno) and Mantua (right bank of the Po). This is where the breeding and dairy farms are located, where the cows are fed exclusively on the grass or hay grown in the area.
The area of origin of the Grana Padano, on the other hand, is much larger with large parts of the Po Valley, which stretches from the western Alps to the Adriatic coast. The producing dairies are located in different regions of Italy – starting from Piedmont via Lombardy, Emilia Romagna, Trentino-South Tyrol to Veneto. In addition, so-called “silo feed” (fermented feed; silage) is permitted as feed for the dairy cows.