Create a detailed 3D model of an Nguni bull cow for Unity 3D. The cow should have a brown and white spotted coat, distinct black and white facial markings, and large curved horns. The body should be robust with well-defined muscles. The cow should be in a standing position, facing forward with a slight angle to the left, legs evenly spaced. Ensure the model includes textures for realistic fur and skin, and optimize it for game performance in Unity 3D., #realistic#