Where does the milk go?

I am not sure if my boss was joking when he asked me that question last week. He wants me to find out why there is so much milk in the office refrigerator. There is always at least 24 cartons each of 2%, Half-n-half, and skim in the fridge. It really is a lot. And they're never expired. So his question is "What do they do with the milk after it expires? Do they just throw it all away?" I felt like I was telling a 7-year-old the truth about the Animal Humane Society (euthenasia) when I said "Yes, I think they do." He asked me if there wasn't something I could do about that. I said I would get right on it.
Apparently he was quite serious. Because today he "followed up" with me on the "milk issue." Where do I begin? The cows?
Back to the animal euthenasia topic: I have a vivid memory of a movie they accidentally showed us when I was in 1st grade. The title was something like "Save the Animals" and some idiot teacher assumed it was about rainforests or something. Without viewing it first, they played it for six classes of 1st graders. It was two hours straight of Humane Society employees carrying unwanted puppies and kittens and sweet old animals into a room where they either held them down or supported their heads as they gave them lethal injection after lethal injection. With horror we watched as dozens of sweet furry animals went limp and slowly closed their eyes. When the other teachers received their classes after the movie, they were surprised to find not a dry eye amongst us. They had to spend the rest of the day sitting and hugging kids and having meetings about our feelings. At the end of the day they sent letters home to all the parents explaining why their child might be weeping all through dinner.