One of the TV hunting shows discussed this and inlisted the advice of some type of "scientist, or biologist" he said that chemically there is not a significant difference between the make up of human urine compared to most animals urine. Other then female's in heat type stuff our urine wont smell a lot different then all the other critters that piss in the woods. It is different but a deer couldn't pick it out as being human and not that of an animal He suggested that deer are used to smelling urine and human urine would act as more of a cover scent to cover other odors you might have emitted in the woods that will spook a deer.
On a side note in a biology class I took in college I was taught that chemically sweat and urine are identical and under a microscope you can't tell the difference. They are both the bodies way of elimnating liquid waste. He said this is why the old white shirts of a person that sweats heavily will get yellow stains in the arm pits. Think about that the next time there is some sweat running down your face.