Use of wood-based materials in beef bedded manure packs: 1. Effect on ammonia, total reduced sulfide, and greenhouse gas concentrations.

facilities are increasing in popu-larity among cattle producers in the quad-state region of Iowa, Minnesota, South Dakota, and Nebraska. In these facilities, cattle are raised in complete confinement, sometimes on concrete floors, with bedding added once or twice weekly. Producers may maintain a bedded pack of manure and bedding through one or more groups of cattle, or they may remove the bedded pack on a weekly basis. Most producers use locally avail-able by-products of cereal grain production for bedding, such as corn stover, soybean stover, wheat straw, or corn cobs (Doran et al., 2010). Corn stover is the most common bedding material used in beef confinement facilities (Doran et al., 2010). As the number of local confinement facilities increases, the demand for corn stover may surpass local availability. Selection of an alterna-tive bedding material will likely be based on availability and price of the material and on animal comfort, with little consideration for the effects of bedding material on air quality of the confine-ment facility.Previous research has shown that bedding material can greatly influence the air quality of livestock facilities (Jeppsson, 2000; van Vliet et al., 2004; Misselbrook and Powell, 2005; Powell et al., 2008; Garlipp et al., 2011). The chemical and physical properties of chopped wheat straw, sand, kiln-dried pine wood shavings, chopped newspaper, chopped corn stover, and recycled manure solids were evaluated as bedding materials in dairy barns (Misselbrook and Powell, 2005). Ammonia (NH