|Rotz, Clarence - Al|
|THOMA, GREG - University Of Arkansas|
Submitted to: Dairy Herd Management Symposium Proceedings
Publication Type: Book / Chapter
Publication Acceptance Date: 5/27/2016
Publication Date: 7/1/2017
Citation: Rotz, C.A., Thoma, G. 2017. Assessing carbon footprints of dairy production systems. In: Beede, D.K., editor. Large Dairy Herd Management. 3rd edition. Champaign, Illinois: American Dairy Society Association. p.19-31.
Technical Abstract: The farm-gate carbon footprint of milk quantifies the net greenhouse gas emissions of a dairy production system. Published values vary widely depending upon farm management practices and the calculation method used. Standard procedures for calculating the carbon footprint of milk are now established, which is improving the accuracy and comparability of published values. The major greenhouse gas emission source on dairy farms is enteric methane from the animals, which makes up 30-60% of the farm-gate carbon footprint of milk. Other important sources are emissions from manure (10 – 30% of the footprint) and those associated with the production of resources used on the farm (10 – 25% of the footprint). Other smaller sources include emissions from cropland (1 – 10% of the footprint), the combustion of fossil fuels and decomposition of lime (4 – 6% of the footprint), and indirect emissions occurring beyond the farm from ammonia and nitrates leaving the farm (0.5 – 12% of the footprint). The carbon footprint of milk produced on well-managed farms typically ranges from 0.8 to 1.2 kg CO2 equivalent/kg of fat and protein corrected milk produced, but lower and higher values are found. Methods for reducing the carbon footprint include increasing the milk production per cow, reducing the herd replacement rate, feeding less forage in the diet, and optimizing total protein intake. Manure emissions can be reduced by using a covered or enclosed manure storage or using an anaerobic digester to produce gas and electricity used on the farm. With appropriate mitigation strategies employed, the farm-gate carbon footprint of milk may be reduced by 20 – 30%. Finding cost effective strategies for reducing the carbon footprint of milk is both challenging and necessary as we work to improve the sustainability of our production systems.