Sadly, the owners will be the first to tell you the deer are not genetically engineered or hormone infused, they prefer to use terms like selective breeding and supplemental feeding.
Some years back I was told that a straw of frozen sperm from a buck of that caliber would sell for upwards of $10,000..
Seeing whitetails raised like that is very sad to me. I gave up hunting big whitetails for that reason, I hunted far and wide to harvest a fair chase 140". It was quite an accomplishment at the time. Now these farms make 150" 2 year olds and call them "management deer".