|VAN WEELDEN, MARK - Iowa State University|
|ANDERSEN, DANIEL - Iowa State University|
|ROSENTRATER, KURT - Iowa State University|
|PEPPLE, LAURA - University Of Illinois|
|SANTOS, TANIA - University Of Illinois|
Submitted to: Biological Engineering (ASABE)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2016
Publication Date: 9/1/2016
Citation: Van Weelden, M., Andersen, D., Kerr, B.J., Trabue, S.L., Rosentrater, K., Pepple, L., dos Santos, T. 2016. Impact of dietary carbohydrate and protein source and content on swine manure foaming properties. Biological Engineering (ASABE). 59(4):923-932. doi: 10.13031/trans.59.11470.
Interpretive Summary: The accumulation of foam on the surface of deep pit manure storages is a serious concern for pork producers for a number of reasons. On a practical level, foam accumulation can significantly reduce the amount of space available for manure storage, which may force farm managers to apply manure during untimely seasonal windows or seek other means of manure storage. Foam accumulation also impacts safety at swine facilities where foam has the capacity to trap gases (i.e., methane) produced by the anaerobic decomposition of swine manure, and when the foam layer is broken, release of methane may be rapid enough for explosive concentrations to occur in the barn. Results in this study suggest that the dietary ingredients tested were not directly responsible for foam formation during storage of feces and urine because none of the diets containing these ingredients exhibited all the required foaming properties. However, certain diet composition characteristics did exhibit enhancement of some of the properties related to foam formation and diets did impact the development of different microbial community structures. Even though no single diet stood out as one that exhibited enhanced methane production, physical characteristics similar to foaming manures, or enhanced foaming capacity and stability, in terms of gas production, manure produced from pigs fed soybean hulls and distillers dried grains with solubles tended to have highest rates of methane production and an enhanced potential for methane production. Research results described in this report provides scientists and swine producers information on dietary and physical factors that may be associated with foam generation in swine manure storage facilities.
Technical Abstract: Diet ingredients are thought to contribute to foaming problems associated with swine deep-pit systems. Two experiments explored the impact of protein and carbohydrate sources in swine diets on the physicochemical properties, methane production potential, and foaming characteristics of swine manure. Manure from the animals was tested for: 1) total and volatile solids; 2) methane production rate and biochemical methane potential: 3), surface tension, 4) foaming capacity, and stability. No single diet yielded manure with all of the anticipated qualities associated with foaming manure. However, manure collected from pigs fed diets containing soy hulls and DDGS exhibited higher methane production rates (0.95±0.20 and 0.96±0.20 L CH4/kg VS, respectively) and biochemical methane potential (322±25 and 269±22 mL CH4/g VS, respectively) when compared to manure obtained from pigs fed the other diets.