|Brown brandl, Tami|
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 9/16/2013
Publication Date: 9/20/2013
Citation: Spiehs, M.J., Brown-Brandl, T.M., Jaderborg, J.P., DiCostanzo, A., Purswell, J.L., Davis, J.D. 2013. Water holding capacity and evaporative loss from organic bedding materials used in livestock facilities. In: Proceedings of the American Society of Agricultural and Biological Engineers Annual International Meeting, July 21-24, 2013, Kansas City, MO. ASABE Paper No. 131595738. Interpretive Summary: Producers have been bedding livestock and poultry for centuries with locally available crop- and wood-based bedding materials. The choice of bedding material can affect animal health and behavior, pen and animal cleanliness, and air quality in the facility, which are determined by the physical properties of the bedding materials. Unfortunately, bedding materials are most often selected based only on availability of supply and cost, without consideration for other factors. This may be due to a lack of understanding regarding how these factors influence profitability or simply a lack of information available about the physical properties of a particular bedding material. A study was conducted to determine the amount of water that bedding could absorb (water holding capacity), how quickly the water would be absorbed by the bedding materials (rate of saturation), and how quickly the bedding would release the water into the atmosphere (rate of evaporative water loss). Corn stover, soybean stover, wheat straw, switch grass, paper, corn cobs, pine, dry cedar, and green cedar were evaluated; each bedding material was evaluated at a coarse, medium, and finely ground particle size. Finely ground particles of all bedding materials absorbed more water that medium or coarse ground particles. Corn stover and wheat straw had the highest water holding capacity, while switch grass and corn cobs absorbed the least amount of water. Among the five crop-based bedding materials, pelleted corn cobs and soybean stover became saturated almost immediately. Corn stover, wheat straw, and switch grass had a slower rate of absorption and took 20+ hours to reach saturation. Among the wood-based bedding materials, pine and cedar had a similar rate of absorption, while paper was immediately saturated. Of the crop-based bedding materials, corn cobs retained water the longest, with switch grass and corn stover having the fastest rate of evaporative loss. Both cedar bedding materials and paper had a faster rate of evaporative water loss than pine. Producers seeking a bedding material that has a high water holding capacity, does not become saturated immediately and can quickly release water back into the atmosphere may find corn stover the most attractive bedding material. Wheat straw, pine, and cedar products may also be a good option based on the high water holding capacity and slow rate of saturation.
Technical Abstract: Physical and chemical characteristics of organic bedding materials determine how well they will absorb and retain moisture and may influence the environment in livestock facilities where bedding is used. The objective of this study was to determine water holding capacity (WHC) and rate of evaporative water loss (EWL) of organic materials used as bedding in livestock facilities. Corn stover, soybean stover, wheat straw, switch grass, paper, corn cobs, and wood (pine and cedar) were evaluated; coarse, medium, and fine particle sizes of each bedding material were measured. The WHC was determined by submerging bedding materials in permeable nylon containers for 1, 3, 5, 10, 20, and 30 min, and 1, 3, 6, 9, 12, 24, 48, and 72 hours. The evaporative loss was determined by saturating the bedding materials in water for 72 hr and recording the mass at 0, 4, 8, 12, 16, 24, 32, 40, 48, 60, and 72 hr after drying in a 100°C forced-air oven. With the exception of paper, the finely ground particles had higher WHC (P < 0.05) than the medium or coarsely ground particles of the same material. Among the bedding materials, corn stover (3.6 g g-1) and wheat straw (3.6 g g-1) had the highest WHC, followed by green cedar (3.2 g g-1) dry cedar (3.0 g g-1) and pine (3.0 g g-1). Switch grass and corn cobs absorbed the least amount of water (1.6 and 2.2. g g-1, respectively). After 72 hr of drying, all bedding materials except corn cobs contained > 98% dry matter. Producers seeking a bedding material that has a high water holding capacity, does not become saturated immediately and can quickly release water back into the atmosphere may find corn stover the most attractive bedding material. Wheat straw, pine, and cedar products may also be a good option based on the high water holding capacity and slow rate of saturation.