It took my son from the 10th percentile weight at birth to the 70th percentile weight at 9 months, and he's a champ in the walker now...so there must be something to it.
(Incidentally, it really is interesting to see linear progression at its most basic level with babies...they can't even lift their heads when they first come out, then you see them lift their heads, then scoot, then crawl, then pull themselves, up, then walk. Not something you normally think about when you think of Seyle's adaptation principle, but it's definitely there.)
Racist.
Which is outweighed by the fact that it's human breast milk. Seriously, stick to the bovine stuff if you're over two years old...
But to the original question...I would be shocked if you could take down a gallon of (nonalcoholic) egg nog in a day unless that's all you eat. I enjoy me a good egg nog pretty much every winter season, but I can only drink it as an after-dinner dessert...
Egg nog is like Rack Pulls (not really): unnecessary for a novice, but excellent at the right dose and the right time. You wouldn't replace deadlifts with rack pulls during NLP, would you? Similarly (thought it's completely different), don't replace the milk in GOMAD with egg nog. Here's how intermediate and advanced trainees can incorporate eggnog into their supplementation*:
Fill your normal protein shake container halfway with milk.
Add a couple large scoops of protein. Shake until well mixed, making sure to switch arms halfway through the shaking to maintain Feng Shui in your forearms.
You should have 1/4-1/3 of the space left (I'm just guessing, I don't really pay attention to these details). Fill it the rest of the way with egg nog*, and sprinkle some cinnamon on top.
Shake again for a few seconds.
* Don't argue with me, I'm experienced at this. I've had at least 5 of these shakes over the last 2 years.
**Hood Golden Egg Nog is the only commercially available brand I've found that's worth my time. I'm willing to fight over this. Insert Hurling-esque pseudo-poetic violent language, including an obligatory reference to the red mist and the wodka.