My son shot a mature 7 pt. buck last weekend, and after being field dressed, hung overnight then weighed the next day, he weighed 125 lbs. I'm guessing he probably weighed 190 or so " on the hoof", does that sound close?

It varies but typically people say the deer will loss about 25% of the live weight after it is gutted. So if he was 125 gutted live weight would be about 165 or so. (127/.75 = 166.6)

we were on an mld III place an the manager asked us to weigh our deer "live weight" and then "field dressed" for the 4 years we were on this place in the hill country and what we found; was bucks usualy lost 30-40 pounds. Depended on age and pre-post rut and range quality. Does would loose 20-30 depending. the heaviest buck shot on the place was pre-rut and weighed 175# on the hoof and dressed weighed 140. This was western hill country Sutton county.