Adjusting for the declination angle of the shot can be a significant yardage at very steel angles....45* down means about a 30% reduction in the yardage you hold for....40 yards line of sight is shot for 28 yards in my example. You may get even steeper angles in sheep and goat country.
But, besides the shot angle yardage that is calculated by most rangefinders these days, I find it much more difficult to shoot accurately on a steep down hill shot....reducing my effective yardage significantly. Practice some steep angle shots and you will see what I'm talking about.
