In its September Livestock, Dairy and Poultry Outlook, the USDA notes an overall milk production reduction for 2012 based on a lower forecast for milk yield per cow.

FORBES: Dairy

While Holsteins tend to produce 8, 000 to 10, 000 litres of milk, each of the Sansaw herd is expected to yield about 4, 500 litres a year.

BBC: Cows