Evaluating on-farm methods for estimating gas emissions and quantifying risk of disease transmission for livestock barns

Abstract

The need for producers to demonstrate the environmental and economical sustainability of their operations is driven by several stakeholder and consumer groups, creating a call for methods to accurately estimate gas emissions and quantify risk of disease transmission. In this work, I first provide background on the mechanisms of gas emissions from deep-pit swine operations and a summary of current emission estimation strategies in the literature. Next, I present one thesis project demonstrating the opportunities and limitations to applying a mass balance approach to estimate methane and ammonia emissions from deep-pit swine barns. Through this project, different mass balance approaches are evaluated against each other and typical emission modeling approaches. Findings from this project show that there are limitations to the application of a mass balance approach in swine barns, particularly related to in-barn sample collection and dataavailability. Then, I present a second thesis project identifying opportunities and limitations to using a fluorescent gel as a proxy for disease transfer in biosecurity research. In this project, I present a method to quantify the luminance of the fluorescent gel and investigate the factors important in measuring the transfer of gel from one surface to another. Findings from these two projects provide a framework for the methods needed to conduct research in gas emissions and biosecurity in livestock operations. Understanding the current state and limitations of these methods is important to consider when applying them to future research, and the current limitations presented provide an outline for future work needed in these fields.