In France, to the east of a line going from Rethel to Toulouse, around a hundred cooperatives have united to create a dairy industry, located in Charolais, close to major transport routes. The production of 20,000 cows belonging to farmers grouped in a dairy cooperative arrives every day in the Régilait factory in Saint Martin Belle Roche, built and equipped thanks to funds from the Marshall Plan. Through the voice of comedian Jean Rigaud, a liter of milk tells its journey, from a stable in Rethel in the Ardennes to the factory in Saint Martin Belle Roche, where it is transformed into powdered milk. resulting from numerous treatments and controls.