As to the science, the main explanation is the effect of a high level of enzyme (lysozyme) activity. Compared to cow's milk, moose milk also has a higher fat (10%) and protein (8%) content, and much higher levels of aluminium, iron, selenium, and zinc.
You can hear all about it here, from NPR'sarchives. The guy who loves fresh moose milk sounds exactly like a guy who would love fresh moose milk.
It should also be noted that Moose Milk is often (well, not often) is made into one of the world's most expensive cheeses. As of a few years ago, there was apparently one dairy in the entire world that made moose cheese, so it is has not taken off yet, per se. The good news is that it sells for about $500/lb.
Hey American entrepreneurs, there is something that people in Europe have paid $500 a pound to acquire, and it apparently does not yet exist in America, home of people willing to pay a lot of money for anything. I smell business opportunity! Let's get some moose babies and start milking.