Same Milk Same Cow?

I went to the supermarket and was for the first time overwhelmed by the sheer size of it all. All the information and advertising and branding were so overwhelming that I felt that nauseaustic feel. I felt faint and all I wanted was to buy milk.

My housemate came along for the ride.

"So which one?" he said.

I was bored and tired from uni that day and all I could muster was a laconic
"Anyone"

"This one?" He went on.
"Look dude, it's just milk."
"How about this one? It'e the cheapest!"

He started it all and so came my reply:

"It doesnt matter. It's all milk.
Why does it matter? Does it matter that it comes from the same cow?
How do you know that even if it was from the same brand, can they ensure its from the same cow so that the quality is the same?"

Silence (5 secs)

" This whole quality thing is dodgy dude.. It's the same with eggs."

So we settled the issue with a pick from the home brand ones. And laughed thinking about it.