Drinking Trough

Fig. 1 . 1 is a front, top and right side perspective view of an ornamental design for a drinking trough showing our new design; fig. 1 . 2 is a rear, bottom and left side perspective view thereof; fig. 1 . 3 is a front view thereof; fig. 1 . 4 is a rear view thereof; fig. 1 . 5 is a left side view thereof; fig. 1 . 6 is a right side view thereof; fig. 1 . 7 is a top plan view thereof; fig. 1 . 8 is a bottom plan view thereof.