About half the emissions from dairy production is from methane produced in the cattle's stomach [1]. Manure accounts for about a quarter of the emissions, while feed contributes about 15-20%. Energy consumption and postfarm emissions represent less than 10% of the emissions in total.

[1] Opio, C., Gerber, P., Mottet, A., Falcucci, A., Tempio, G., MacLeod, M., ... & Steinfeld, H. (2013). Greenhouse gas emissions from ruminant supply chains–A global life cycle assessment. Food and agriculture organization of the United Nations. https://www.fao.org/3/i3461e/i3461e.pdf (Figure 5)