Table 3.

Summary of biophysical reduction potential (proportion of an animal's enteric methane production) for enteric methane emissions due to (i) improved feeding practices, (ii) specific agents and dietary additives and (iii) longer term structural/management change and animal breeding.^a

AEZ regions	improved feeding practicesb					specific agents and dietary additivesc					longer term structural/management change and animal breedingd
	dairy cows	beef cattle	sheep	dairy buffalo	non-dairy buffalo	dairy cows	beef cattle	sheep	dairy buffalo	non-dairy buffalo	dairy cows	beef cattle	sheep	dairy buffalo	non-dairy buffalo
North Europe	0.18	0.12	0.04			0.08	0.04	0.004			0.04	0.03	0.003
South Europe	0.18	0.12	0.04			0.08	0.04	0.004			0.04	0.03	0.003
West Europe	0.18	0.12	0.04			0.08	0.04	0.004			0.04	0.03	0.003
East Europe	0.11	0.06	0.03			0.04	0.01	0.002			0.03	0.07	0.003
Russian Federation	0.10	0.05	0.03			0.03	0.04	0.002			0.03	0.06	0.003
Japan	0.17	0.11	0.04			0.08	0.09	0.004			0.03	0.03	0.003
South Asia	0.04	0.02	0.02	0.04	0.02	0.01	0.01	0.0005	0.01	0.002	0.01	0.01	0.001	0.01	0.02
East Asia	0.10	0.05	0.03	0.10	0.05	0.03	0.05	0.002	0.03	0.012	0.03	0.06	0.003	0.03	0.07
West Asia	0.06	0.03	0.02	0.06	0.03	0.01	0.02	0.001	0.01	0.004	0.01	0.02	0.001	0.02	0.03
Southeast Asia	0.06	0.03	0.02	0.06	0.03	0.01	0.02	0.001	0.01	0.004	0.01	0.02	0.001	0.02	0.03
Central Asia	0.06	0.03	0.02	0.06	0.03	0.01	0.02	0.001	0.01	0.004	0.01	0.02	0.001	0.02	0.03
Oceania	0.22	0.14	0.06			0.08	0.08	0.004			0.05	0.03	0.004
North America	0.16	0.11	0.04			0.11	0.09	0.004			0.03	0.03	0.003
South America	0.06	0.03	0.02			0.03	0.02	0.001			0.02	0.03	0.002
Central America	0.03	0.02	0.02			0.02	0.01	0.001			0.01	0.02	0.002
East Africa	0.01	0.01	0.01			0.003	0.004	0.0002			0.004	0.006	0.0004
West Africa	0.01	0.01	0.01			0.003	0.004	0.0002			0.004	0.006	0.0004
North Africa	0.01	0.01	0.01			0.003	0.004	0.0002			0.004	0.006	0.0004
South Africa	0.01	0.01	0.01			0.003	0.004	0.0002			0.004	0.006	0.0004
Middle Africa	0.01	0.01	0.01			0.003	0.004	0.0002			0.004	0.006	0.0004

^aValues have been adjusted for non-additivity of individual practices.

^bIncludes replacing roughage with concentrate (Blaxter & Clapperton 1965; Moe & Tyrrell 1979; Johnson & Johnson 1995; Yan et al. 2000; Mills et al. 2003; Beauchemin & McGinn 2005; Lovett et al. 2006), improving forages/inclusion of legumes (Leng 1991; McCrabb et al. 1998; McCaughney et al. 1999; Woodward et al. 2001; Waghorn et al. 2002; Pinares-Patino et al. 2003; Alcock & Hegarty 2005) and feeding extra dietary oil (Dohme et al. 2000; Machmülller et al. 2000, 2003, Lovett et al. 2003; McGinn et al. 2004; Beauchemin & McGinn 2005; Jordan et al. 2006a,b).

^cIncludes bST (Johnson et al. 1991; Bauman 1992), growth hormones (McCrabb 2001), ionophores (Benz & Johnson 1982; Rumpler et al. 1986; Van Nevel & Demeyer 1996; McGinn et al. 2004), propionate precursors (McGinn et al. 2004; Beauchemin & McGinn 2005; Newbold et al. 2005; Wallace et al. 2005).

^dIncludes lifetime management of beef cattle (Johnson et al. 2002; Lovett & O'Mara 2002) and improved productivity through animal breeding (Ferris et al. 1999; Hansen 2000; Robertson & Waghorn 2002; Miglior et al. 2005).