By Dr. Eleanor Murphy, Bord Bia Origin Green sustainability and data analytics manager
Bord Bia gathers a range of sustainability and productivity metrics on farm through the audit process for the Sustainable Dairy Assurance Scheme (SDAS) and the Sustainable Beef and Lamb Assurance Scheme (SBLAS).
By analysing the most recent full year audit data from 2022, and comparing it against previous years, we can see the areas in which farmers are making progress.
Dairy efficiency
Dairy carbon efficiency has been steadily improving since Bord Bia began carbon footprinting Irish dairy farms.
Preliminary results of audits conducted in 2023 indicated a dairy carbon footprint of 0.90. This figure will be finalised once all audits conducted in December 2023 have been fully certified following close out.
The average three-year carbon footprint of SDAS farms has fallen from 0.94 in 2018-2020 to 0.91 during 2020-2022 (the carbon footprint is reported as kg of CO2e (carbon dioxide equivalent) per kg of live weight gain (LWG) for beef, and per kg of fat and protein corrected milk (FPCM) for dairy).
We can also see a sustained improvement in output per cow in that period. Average milk solids (ms) per cow have risen from 424kg in 2020 to 443kg in 2022.
The average dairy herd size has increased from 92 cows in 2020 to 96 cows in 2022. This corresponds with an increase in total farm emissions due to the expansion of the dairy herd.
Farmer actions
However, farmers are taking important actions, as recommended by the Teagasc Marginal Abatement Cost Curve (MACC), to mitigate against greenhouse gas (GHG) emissions from dairy production.
Bord Bia began tracking protected urea usage in 2021. Its usage has risen from 10% of total chemical nitrogen (N) applied on SDAS farms in 2021 to 18% in 2022 (see figure 1).
The use of protected urea and low emission slurry spreading (LESS) on Irish dairy farms has increased significantly in recent years.
In 2022, 70% of SDAS farms reported using LESS, up from 35% in 2022 (see figure 2).
Beef carbon footprint
Preliminary results of audits conducted in 2023 indicated a beef carbon footprint of 9.38. This figure will be finalised once all audits conducted in December 2023 have been fully certified following close out.
The three-year average carbon footprint of member beef farms has been stable at 9.23 since 2018-2020, and again in 2020-2022.
This is an average figure for all beef systems audited under the scheme. The table below shows productivity by six types of beef enterprises as tracked by the audit.
Beef enterprise Carbon footprint (kg CO2e per kg liveweight gain) Total farm emissions (kg GHG) Kg GHG/ha Kg beef/ha Bull beef 8.92 339,390 7,654 858 Suckler to beef 9.88 202,524 4,843 490 Suckler to weanling/store 10.45 129,752 3,923 375 Weanling/store to beef 9.50 139,200 4,543 478 Dairy calf to beef 7.56 196,235 5,675 751 Dairy calf to weanling/store 7.02 121,206 4,269 608
Beef systems that produce the highest output (i.e, liveweight gain) relative to total emissions will have a lower carbon footprint.
Farmer progress
Beef members have made steady progress in the adoption of measures to reduce emissions, as recommended by the Teagasc MACC – usage of C.A.N has fallen from 92% of chemical N applied to 81% in 2022 (see figure 3 below).
Use of protected and straight urea continues to rise. Usage of the splash plate has fallen from 82% to 61% in 2022, as 39% of beef farmers report using LESS technology in 2022, e.g., trailing shoe or shallow injection (see figure 4 below).
Animal productivity has also improved; the average liveweight gain across SBLAS farms increased by nearly 7% in 2022 while output rose from 467kg of beef per hectare in 2021 to 475kg/ha in 2022.
About the Bord Bia data
The information reported is from four sources:
- Animal Identification and Movements (AIMS) database from the Department of Agriculture, Food and the Marine (DAFM);
- Daily liveweight gain information from the Irish Cattle Breeding Federation (ICBF) (for beef only);
- Milk production data from dairy processors (dairy only);
- The sustainability survey.
AIMS data is used in the carbon footprint calculation and to display livestock units and stocking rate.
The data gathered from the sustainability survey is provided by the farmer as part of their audit and is reliant on the accuracy of records provided by the farmer.
All milk data is provided by dairy co-ops and is used to calculate fat and protein corrected milk (FPCM) and milk solids. A minimum of nine months milk supply data is required to calculate the carbon footprint.
