As mentioned on page 29, desirable roosts may be made of 2 by 4's with edges beveled and laid flatwise but slightly titled up at about the angle of a quarter-pitch roof in the direction toward which the birds are likely to face. Roosts made of 2 by 4's or other sawed lumber may cause dents in the breastbones if they are laid perfectly flat. Smooth poles 2-1/2 to 5 inches in diameter also make good roosts. Material less than 2-1/2 inches wide is not recommended for turkeys half grown or older. Roosts should be placed preferably 20 to 24 inches apart (center to center), about 14 inches from the wall and lengthwise or the building. Those nearest the back wall of the shelter should be the highest, and each of the others should be about 6 inches lower than the one back of it. This arrangement insures an even distribution of the birds on the roosts without crowding. Allow about 1 foot of roost space per bird as they require as much space as this when approaching market age. The space beneath the roosts should be fenced off and covered with 1-1/2-inch, 18-gage wire mesh to prevent the birds from getting at the droppings. This wire should be placed either on the under side of the roost supports (fig. 17) or on special wire supports (fig. 21), and it should be 6 to 12 inches below the top of the roosts. When a wire-floored alleyway is used, removable vertical panels made of 1- by 4-inch boards covered with the 1-1/2-inch hexagonal, 18-gage wire mesh should be placed directly under the roosts which border the alleyways in such a way as to close the opening underneath the roosts (fig. 19). In very dry regions, it the space underneath the roosts and wire floors is entirely enclosed, the droppings may be allowed to accumulate throughout the entire growing season to save labor. In damp climates, however, the droppings should be removed frequently.