Modeling greenhouse gas emissions from stored manure:

Phase 1 - evaluation of dietary manipulation effects


Team:

Project Leader:  Dr. Ermias Kebreab, Dept. Animal Science, University of California Email: ekebreab@ucdavis.edu
Co-Investigators:
Mario Tenuta (U of M), Martin Nyachoti (U of M), P Loro (MAFRI) and Dr. E Salvano (MAFRI)

Funding:

MSAPP

Phase I Goal:

Develop a facility, MANGAS-RF, to measure greenhouse gas (GHG) emissions from stored manures and use the facility to evaluate engineered manures

Objectives:

The initial phase of the project was set to meet 5 objectives:

1) construct and test manure digesters
2) build animal holding pens and manure separation, collection, and processing facilities
3) formulate three different diets fed to a total of 15 pigs
4) collect manure from each group separately and incubate in the digesters, and
5) measure greenhouse gas emissions from digesters and recorded data.

Design:

This study focused on the effect of swine diet manipulation on GHG emission from liquid manure storage. Ten 25 L anaerobic digesters were constructed for this study. Each group of 5 pigs, three in total, were fed diets that were either low, medium or high in fibre. Liquid manure collected from the treatmetns over the coarse of the 20 week study was stored in the anaerobic digestors.

Under manure storage conditions, manure from the high fibre diet produced significantly higher total amount of CH4 and had higher emission rates than manures from low and medium fibre diets, related to the initial dietary fibre content. There were no significant differences in fibre content and therefore in CH4 productions between manures from medium and low fibre diets.

In terms of CO2 emissions during manure storage conditions, manure from the high fibre diet produced significantly higher cumulative CO2 production and emission rate than the manures from low and medium fibre diets. There was no significant differences in both cumulative CO2 production and emission rate between manures from low and medium fibre diets.

Learn more about TGAS MAN Site

Download Final Report here (pdf)