What SD said on brow-tine.
I think (my reference book is 600 miles south), what a bull has for brow tines in it's 3rd year is it is mentioned in "Ecology and Management of North American Moose".
I have watched two different bulls from yearlings to 5 years old. What they had in 3rd year was what they had in 4th and 5th year (both 2X2). Both were marginal 50" legal in year 5 and I didn't dare shoot. (50 inch or 3 brow tines on one side regs. I hunted the same two roughly one square miles - 5 miles apart - every year for 25+ years. I had a pretty good handle on the moose there)
On one, I didn't moose hunt the 6th year at all, and never saw him again. On the other, I also never saw him again, having shot a different bull year 6. Some other basted shot them both!!!! I think. And they were named, dammit!!!....