OK, so you got one

[Sam McMichael]

I go get my son. After all, if I wanted to do all the heavy lifting, I would have had all girl children. Or I could just go crank up the tractor and roll him unto the front end lift.

[pdk25]

Not necessarily the easiest thing, but tie a rope around the  deers neck near a tree with a someone stout branch.  Throw the rope over and take up the slack.  Grab the deer under the front arms and lift, taking the slack out as you go. ( you will get bloody)  Do this until the deer is verticle and tie the rope off at the base of the tree.  Then back the truck up with the tailgate down and the deer will be in the bed and you just need to untie the rope at the base of the tree.  Not necessarily the best solution, but it will work.  Don't bother trying this with a whole elk, lol.