Cow's milk is allowed to have feces in it. This is a major source for bacteria. Milk is typically pasteurized more than once before it gets to your table... each time for only 15 seconds at 162 degrees Fahrenheit.
To sanitize water one is told to boil it (212 degrees F) for several minutes.
Keep in mind that at room temperature the number of bacteria in milk DOUBLE around every 20 minutes. No wonder milk turns rotten very quickly!
ONE cubic centimeter (cc) of commercial cow's milk is allowed to have up to 750,000 somatic cells (unscientific name is PUS) and 20,000 live bacteria... before it is kept off the market.
That amounts to a whopping 20 million live bacteria and up to 750 MILLION pus cells per liter (slightly more than a quart).
1 cup = 236.5882cc 177,441,150 pus cells ~ 4,731,600 bacteria
24 oz (3 glasses) = 532,323,450 pus cells ~ 14,220,000 bacteria
(the "recommended" daily intake)
The EU and the Canadians allow for a less "tasty" 400,000,000 pus cells per liter.
The Truth About Milk