I don't know about the composition of the dropings. Just like humans, a deers dropings will vary from solid pellets to the runs depending on what they are eating and any viruses/ infections they may have. So just the just the composition of the dropings alone won't tell you much.

However you can make a very good guess as to the sex by how the poop is left on the ground. A doe or cow will tend to leave a single pile where as a buck or a bull will tend to leave a "trail" of poop. This also goes with the urine. A buck or bull will tend to "swing" when he urinates and a doe pees in a single spot. It helps to have snow on the ground for the urine... or dry dirt.