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United States Department of Agriculture

Agricultural Research Service

Title: Manure Composition As Affected by Dietary Protein and Cellulose Concentration

Authors
item Ziemer, Cherie
item Kerr, Brian
item Trabue, Steven
item Crouse, John
item Powers, Wendy - IOWA STATE UNIVERSITY

Submitted to: Air and Waste Management Annual Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 21, 2005
Publication Date: June 21, 2005
Citation: Ziemer, C.J., Kerr, B.J., Trabue, S.L., Crouse, J.D., Powers, W. 2005. Manure composition as affected by dietary protein and cellulose concentration. Meeting Proceedings.

Interpretive Summary: Animal manure is an excellent resource for amending soil through its ability to supply carbon and nitrogen, both components of soil organic matter. However, storing manure and land application can result in the release of carbon and nitrogen into the air environment resulting in less of these nutrients being applied to the soil. The objective of this study was to investigate the effects of feeding pigs diets containing different levels of crude protein and cellulose on subsequent nutrients (carbon, nitrogen, and sulfur) and malodorous chemicals (namely volatile fatty acids, indoles, and phenols) in manure. Experimentation utilized finishing pigs, 105 kg initial body weight, fed diets containing either 14.5% or 12.0% crude protein in combination with either 2.5% or 8.65% cellulose. Over the 56 day trial, urine and feces were collected and added to manure storage containers designed with similar surface area per animal as deep pit manure storage in finishing barns. Decreasing dietary crude protein reduced manure pH, NH4, isovaleric acid, phenol, and 4-ethyl phenol concentration. Increasing dietary cellulose decreased pH and NH4 concentration, but increased acetic acid, propionic acid, butyric acid, and cresol concentrations in the manure. Increasing dietary cellulose also increased manure carbon concentration and increased manure dry matter. The data can be utilized by manure action plan personnel and agronomists indicating that changes in levels of dietary crude protein and cellulose fed to finishing pigs can impact the concentration of malodorous compounds in stored swine manure which may have both positive and negative impact on odor emissions. In addition, this study demonstrates that these diets will significantly impact manure nutrient composition which will affect nutrients applied to the soil and ultimately available to crops for utilization.

Technical Abstract: The objective of this study was to investigate the effects of dietary crude protein and cellulose levels on manure nutrient composition and concentrations of volatile fatty acids, indole, and phenol. Twenty two pigs, 105 kg initial body weight, were fed diets containing either 14.5% or 12.0% crude protein in combination with either 2.5% or 8.65% cellulose. Pigs were fed twice daily over the 56 day trial. After each feeding, urine and feces were collected and added to manure storage containers; containers were designed with similar surface area per animal as deep pit manure storage in finishing barns. Manure was gently stirred prior to sampling. Decreasing dietary crude protein reduced manure pH, NH4, isovaleric acid, phenol, and 4-ethyl phenol concentration. Increasing dietary cellulose decreased pH and NH4 concentration but increased acetic acid, propionic acid, butyric acid and cresol concentrations in the manure. Increasing dietary cellulose also increased manure carbon concentration and increased manure dry matter, nitrogen and carbon content as a percent of nutrient intake. This study demonstrates that diets differing in crude protein and cellulose content can significantly impact manure nutrient and chemical composition which in turn affects nutrients available in soil amended with this manure, as well as the potential to generate malodors.

Last Modified: 12/21/2014