Policy changes at both national and European Union level will require a “greater focus” on a wide range of sustainability metrics for dairy farmers, attendees heard today (Tuesday, July 7) at Moorepark 2023.
Total livestock numbers are around 6.2 million, which is 5% below the national peak of 7 million in 1998 and according to Teagasc, 8,000 dairy farmers milk 1.55 million dairy cows.
Dairy cows on average have access to grazed grass for 71% of the year, with an average milk yield of 450kg of milk solids – which is well below the European average.
Current situation
For Irish dairy farms the key welfare indicators are somatic cell count (SCC) and lameness.
The average SCC levels in dairy herds have declined during the last decade, and the average SCC is now close to 180,000 cells/ml.
In terms of lameness, a recent analysis reported that 6% of cows on a sample of commercial farms had moderate suboptimal mobility, and less than 1% of cows had severe suboptimal mobility.
Also important to note is that herd age profile continues to increase, with the average number of calvings/cow increasing from 3.3 in 2014 to 3.6 in 2022.
The target is for the average parity within the herd to increase to 4.5.
Calf welfare
There are approximately 48% more dairy cows in Ireland now compared with the period from 2007-2009 – but dairy cow numbers are approximately the same now as they were in 1984.
These additional cows are resulting in increased numbers of dairy origin calves entering the beef industry.
In Ireland, the additional calves provide a significant opportunity for the beef industry to reduce greenhouse gas (GHG) emissions/unit of product and production costs associated with beef production.
The dairy industry is now embracing the use of sexed semen to generate replacement heifers and selecting bulls from the Dairy Beef Index (DBI) to generate non-replacement calves.
The continuation of the live export of calves is important to satisfy a market demand while helping Ireland meet its policy targets.
Maintaining calf welfare during transport is crucial to the integrity of the calf transport process and requires robust monitoring as well as the development of solutions to increase welfare during transport.
Carbon footprint
The carbon footprint of Irish milk is one of the lowest in the world; based on national activity data from 2017-2019, the average dairy carbon footprint was 0.97kg carbon dioxide equivalent (CO2e)/kg of fat and protein corrected milk yield (FPCM).
When the carbon sequestration is included in the calculation this figure is closer to 0.86kg CO2e/kg FPCM.
Analysis based on 2022 data suggests the footprint has reduced to 0.93kg CO2/kg FPCM and “with more representative Irish emission factors is 0.86kg CO2e/kg FPCM” according to analysis from Teagasc.
When sequestration is included, this figure will be closer to 0.61kg CO2e/kg FPCM.
There is a scientific understanding that relatively small reductions in biogenic methane across a prolonged period of time will prevent any additional warming from methane and further reductions in methane will result in a reduced warming effect.
Ammonia
Ammonia (NH3) emissions are associated with the acidic deposition onto ecosystems and the formation of secondary particulate matter.
Agriculture accounts for 99.4% of the NH3 emissions in Ireland.
Total NH3 emissions are above the national ceiling target since 2016, with a substantial increase in NH3 emissions in 2018 to 135,200t.
Ireland’s national NH3 emissions ceiling is 116,000t, set as part of the NEC (National Emissions Reduction Directive).
Emissions in 2019 declined by 9,800t relative to 2018, driven by decreases in livestock numbers, reductions in fertiliser nitrogen (N) use, as well as increased use of low-emission slurry spreading technologies.
This was followed by another decline in emissions in 2020, and subsequently a slight increase in 2021.
Water quality
The Environment Protection Agency (EPA) published detailed reports describing the changes in biological quality and nutrient concentrations in water on an ongoing basis.
The most recent report on water quality was published in 2022 – this report, entitled ‘Water quality in Ireland 2016-2021’, covers the periods from 1987-1990 through to 2018-2021.
The report indicated a consistent and steady reduction in river water bodies described as ‘bad’ (3.92% in 1987-1990 period and 0.04% in the 2019-2021 period).
Just over 60% of rivers were described as having high or good biological status in the 1987-1990 period with the corresponding figures for the 2019- 2021 period being 56% (the same as the period 2016-2018).
Over the period 2019-2021, the number of rivers classified as moderate increased from 26% to 28% while at the same time the number of rivers classified as poor declined from 18%-17%.
Technologies
There are many currently available technologies that can be immediately implemented by farmers that will have positive impacts on sustainability.
In most cases, they will not increase costs at farm level and in some cases these measures could help reduce costs and increase profitability.
Achieving continued improvements in cow welfare requires a focus on farm management, infrastructure and breeding.
Adopting correct calf management practices are critical to ensuring healthy, well-grown calves.
Management during the pre-weaning period has implications for subsequent animal health and welfare, and also for subsequent productivity and longevity.
When weaning, calves should be weaned gradually to minimise post-weaning reductions in growth rate and to maintain good health and welfare.
In addition, the housing environment should allow calves perform to their maximum ability with minimum disease risk, and positively influence the health, growth, development and general welfare of the calf.
The Marginal Abatement Cost Curve (MACC) has identified the most cost-effective pathway to reduce sectoral emissions.
The adoption of measures such as reducing our reliance on chemical nitrogen fertiliser, a change of nitrogen fertiliser type to protected urea, using high EBI and high DBI genetics, use of sexed semen, improved animal health, extending the grazing season, and use of white clover are critical to reducing sectoral emissions.
Reducing emissions
There are a range of options to reduce ammonia emissions on dairy farms.
These include reduced crude protein in concentrate feed, use of protected urea instead of ordinary urea or CAN, as well as the use of LESS technology for the application of animal manures.
At dairy farm level, the two measures responsible for the vast majority (circa 80%) of the
ammonia emission reductions are using protected urea and LESS:
The Teagasc Agricultural Sustainability Support and Advisory Programme (ASSAP) programme is designed to enable landowners to engage positively in seeking solutions to local problems in relation to water quality through the support of a confidential sustainability advisory service focused on water quality improvement.
Biodiversity management on-farm involves retaining, enhancing and creating habitats.
It is important to optimise the biodiversity value of existing farmland habitats before new biodiversity measures are established.
Increase sustainability
The focus of much of Teagasc’s current research is on increasing the sustainability of the Irish dairy sector with increased focus placed on key areas including:
- Cow health and welfare;
- GHG;
- Grass quality and seasonal profile;
- Feed additives;
- Carbon sequestration;
- Warming effect associasted with GHG emissions;
- Water quality.
Since the removal of milk quotas, there has been significant expansion due to the pent up capacity in the industry.
The next phase of development will need to be based on the principle of decoupling GHG and NO3 emissions and N loss from production, while advancing the quality and quantity of enriched areas on-farm.
All of this is possible and will be the focus of technologies that are introduced onto farms in the coming years.
This will all occur at a time when there is increasing investment in research for new solutions and will provide the platform for even greater ambition around sustainability at farm level.
It is also clear, however, that grass-based systems of milk production have an important role in sustainable ruminant production globally, and could play an even greater role in the provision of ruminant products in the future.
Therefore is necessary to improve the metrics used to evaluate the sustainability of the farms, and to ensure that a robust and balanced assessment of farm sustainability is completed during the process.
Additional metrics for water use, feed/food competition, and international emissions comparisons are required.