Methods for Animal Production Systems
Effective beginning 5/20/2025: Please note this site is under review and content may change.
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- Recommended Citations
Leytem, A.B., S. Archibeque, N.A. Cole, S. Gunter, A. Hristov, K. Johnson, E. Kebreab, R. Kohn, W. Liao, C. Toureene, J. Tricarico. 2024. Chapter 4: Quantifying greenhouse gas sources and sinks in animal production systems. In Hanson, W.L., C. Itle, K. Edquist. (eds.). Quantifying greenhouse gas fluxes in agriculture and forestry: Methods for entity-scale inventory. Technical Bulletin Number 1939, 2nd edition. Washington, DC: U.S. Department of Agriculture, Office of the Chief Economist.
Chapter 4: Quantifying Greenhouse Gas Sources and Sinks for Animal Production Systems
Animal production systems include agricultural practices that involve breeding and raising animals for meat, eggs, milk, and other animal products such as leather, wool, fur, and industrial products like glue or oils. Animals considered in this sector include cattle, swine, and poultry, along with other animals such as sheep, goats, American bison, llamas, alpacas, deer, horses, mules and asses, rabbits, and fur-bearing animals.
This chapter provides methodologies and guidance for reporting greenhouse gas (GHG) emissions associated with entity-level fluxes from animal production systems. It summarizes animal management practices and their associated GHG emissions, then describes the methods for estimating GHG emissions from enteric fermentation, housing, and manure management.
Enteric fermentation:
- Dairy cattle
- Beef cattle
- Sheep
- Swine
- Other animals
Housing:
- Methane (CH4) and nitrous oxide (N2O) dairy production systems
- CH4 and N2O beef production systems
- CH4 and N2O swine production systems
- CH4 and N2O poultry production systems
- CH4 and N2O other animal production systems
Manure management:
- CH4 and N2O for solid manure storage (stacked)
- CH4 and N2O for composting
- CH4 and N2O for aerobic lagoons
- CH4 and N2O for anaerobic lagoons
- CH4 anaerobic digesters
The magnitude of GHG emissions from animal management depends primarily on the quality of the diet, the animals' physiological status and nutrient requirements (e.g., grazing, pregnant, lactating, doing work), feed intake, and the systems in place to house animals and manage manure.
