Greenhouse gas inventory: estimated dairy emissions and their mitigation

Footnotes

1. Four groups of dairy cattle are used: DC1_DairyCalvesFemale; DC2_DairyReplacementsFemale; DC3_DairyInCalfHeifers'; DC4_DairyCows. Dairy progeny (i.e., male calves and surplus female calves) reared for beef are treated as beef cattle, but distinguished by breed of their dam. However, categorisation of animals as dairy-follower or dairy-beef is either by assumption or waiting until the animal is slaughtered.

2. see Moxey & Thomson (2021).

3. Dairy progeny reared for beef accounted for a further c.289kt CO_2e of emissions in 2018, and represented c.13% of Scottish-born animals slaughtered in Scotland. Dairy cull cows accounted for c.6% (others were slaughtered outwith Scotland), but their emissions are already accounted for.

4. A decline of c.28% in dairy cow numbers since 1990 has been offset by a c.40% increase in yield per cow to maintain Scottish milk production more-or-less constant.

5. e.g., see Del Prado et al., (2010), Adler et al., (2013), Sharma et al., (2018)

6. e.g., see Del Prado et al., (2010), Peterson (2018), Carroll & Daigneault (2019).

7. e.g., see Qiao et al., (2015), Lam et al., (2017), Tzemi & Breen (2019)

8. e.g., see Hawkins et al., (2015), Baldani et al., (2015), Styles et al., (2017)

9. e.g., see Beukes et al., (2010), Del Prado et al., (2010), Baldani et al., (2015)

10. e.g., see Shortall & Barnes (2013), Wettemann & Latacz-Lohmann (2017), Eory et al., (2020)

11. e.g., see Baldani et al., (2015), Sharma et al., (2018), York et al., (2018)

12. Indeed, this is likely to happen with supermarkets increasingly obliging farms to not cull male calves

13. e.g., see Webb et al., (2014), Styles et al., (2017), CIEL (2020)