The strength is dictated by the shear limits of the screw heads. Use the correct screws and it will hold a tremendous amount of weight. Sheet rock screws are not the answere...Good looking bracket.
Do you make different length arms to accommodate the placement of the animal mount in the available wall space?
Depending on the weight of the taxidermy and the length of the bracket arm, you can get some pretty good torque on the screws holding the bracket to the wall. The farther those screws are vertically apart, the better the bracket will hold.