Chemical, physical, and environmental properties of pelleted newspaper compared to wheat straw and wood shavings as bedding for horses.

Two experiments were conducted comparing pelleted recycled newspaper (PN) to wheat straw (S) and kiln-dried pine wood shavings (WS) as an animal bedding material. Adult horses housed 20 to 21 h/d in boxstalls served as the animal model for comparisons. In Exp. 1 eight boxstalls, each housing one horse, were each bedded with two types of PN (0.32 and 0.64 x 2.54 cm), S, and WS over four 5-d periods (replicated 4 x 4 Latin square). Initial amounts of bedding materials surpassed most commercial conditions, but stalls were cleaned daily of feces only and additional clean bedding was added as needed to maintain animal cleanliness, thus challenging the bedding properties of each material. In Exp. 2 nine boxstalls were bedded with PN (0.32 x 2.54 cm), S, and WS over three 14-d periods (three 3 x 3 Latin squares) during summer and autumn. Feces and wet spots were removed daily and clean bedding was added to reestablish working volume and simulate commercial conditions. In Exp. 1 and 2 daily additions of clean bedding varied (P < 0.05) with material (S > WS > PN). The higher water-holding capacity of PN and WS contributed to fewer bedding replacements. Usage of each material was greater (P < 0.05) during the autumn; PN had the greatest increase. Type of material and season also influenced bedding environment. Bedding pH increased (P < 0.05) with use and was highest in PN and lowest in S. Higher concentrations of breathable NH3 N were present in stalls bedded with PN and during autumn. Higher pH of used PN and decreased ventilation due to closed doors and windows during autumn were contributing factors. Season, type of bedding, and duration of its use affected (P < 0.05) numbers as well as species of microorganisms present in the breathing zone, nasal cavity, and on the leg of the horse. Clean and used WS contained greater (P < 0.05) quantities of particle fines, but with 5 d of use, particle fines in PN also increased. Quantities of breathable dust during cleaning of stalls varied (P < 0.05) with material and duration of its use; dust peaked at d 7 with PN but continued to decrease with S and to increase with WS through d 14. These data indicate that management of bedding materials varies with type of material and season of year. Use of PN as a bedding material has high potential.