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We constantly hear statements about how cows are the new SUVs and that livestock farming is detrimental to the environment, but what are the facts?
In 2011 Teagasc and UCD published an academic paper in the Journal of Agriculture (Foley et al., 2011) in response to pressure on Ireland to reduce its agricultural share of greenhouse gas emissions and meet its commitments to the Kyoto Protocol.
Five suckler-to-beef production systems were modelled on a carbon footprint basis. The analysis included both direct (emissions associated with farm activities) and indirect (emissions associated with inputs brought on to the farm, eg arising from the manufacture of feed and fertiliser) greenhouse gas emissions. Leached and volatilised ammonia-N were also included as indirect emissions. Greenhouse gas sinks associated with land use were not considered and the final figure was based on total pre-slaughter emissions.
The five farming systems are outlined in Table 1. The base scenario was designed to represent average farming conditions in Ireland and so data from 100 suitable farms in the National Farm Survey (NFS) was used. In the NFS scenario, males are slaughtered at 30 months and heifers at 26 months. A seven-month grazing season (31 March to 1 November) is assumed, during which grass utilisation is 60%.
The four alternative scenarios were designed to reflect more intensive farming, with figures based on data generated at Teagasc Grange. Two of the systems produced steers at 24 months and two produced bull beef at 16 months. Moderate (2.2LU/ha) and intensive (2.9LU/ha) stocking rates were modelled. In these alternative systems, the grazing season was assumed to be one month longer (15 March to 15 November) than NFS and grass utilisation was set at 80%. In the bull systems, calves were weaned in November and remained indoors until slaughter the following June.
Physical performance is also presented in Table 1. Younger age at slaughter on the alternative farms versus the NFS freed up winter accommodation space and allowed for an increase in cow numbers. As expected, the intensive systems were able to carry more cows than the moderately stocked systems, but also required much bigger inputs of chemical nitrogen fertiliser. Grass consumption increased on the four alternative farms versus the NFS, likely a function of improved grassland management
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Table 2 outlines the emissions and financial results from the five farm types for one year’s production. Per kg of beef produced, the NFS scenario was the most carbon-inefficient system, requiring 23.1kg of CO2 equivalent. On the flipside, bull beef produced at a moderate stocking rate (2.2LU/ha) had the lowest carbon footprint at 18.9kg CO2 equivalent/kg of beef, an 18% reduction.
In financial terms, the NFS was the least profitable system on a per hectare basis (-€67), while the intensive bull beef system produced a net margin of €687/ha. The system with the lowest carbon footprint (Bull – mod) yielded a net margin of €477/ha – the second most-profitable.
What is a carbon dioxide equivalent?
A carbon dioxide (CO2) equivalent is the unit used to measure and compare emissions from various greenhouse gasses based on their global warming potential. Methane (CH4) and nitrous oxide (N2O) are the main greenhouses gasses in beef cattle production.
What are the sources of greenhouse gas in beef farming?
Taking the bull – mod scenario as an example, the various greenhouse gas sources and their proportionate contributions to the overall figure are outlined in Table 3.
What is carbon sequestration?
Carbon sequestration is the process of transferring carbon from the atmosphere to the soil or vegetation. Soils store more carbon globally than the atmospheric and living vegetation pools combined. Temperate grasslands have shown strong potential to store carbon below ground in roots and soil. However, there remains uncertainty surrounding baseline soil carbon concentrations, the extent to which different fractions of the soil can sequester carbon and the permanence of this carbon in the soil.
A 2015 study carried out found that the capacity for carbon storage was generally higher in Irish soils than reported for comparable grassland regions elsewhere in the world. Interestingly, the same study also suggested that intensive management systems practising frequent reseeding could lend themselves to more favourable conditions for soil carbon storage.
In terms of actual carbon sequestrations, a 2010 American study found that sequestration could potentially offset 43% of the greenhouse gas emissions from the pastoral systems modelled.
Work to define sequestration rates in an Irish setting is ongoing at Johnstown Castle.
Defending the suckler cow
It’s easy to take aim at the suckler cow in the climate change debate. Though initiatives like BETTER farm have shown that she can be profitable in a sustainable manner, her viability is questioned because the average suckler farm is loss-making. Why not hammer another nail into the coffin and say that she’s too inefficient from a carbon point of view?
Granted, this best-case scenario figure of 18.9kg of CO2 equivalent/kg of carcase beef is high compared with the average for other proteins like chicken at less than 2kg CO2 e/kg meat. However, in beef and indeed lamb production, we have a rumen to contend with. This rumen can digest and utilise feed that monogastric animals such as poultry, pigs or humans cannot. In our low carbon footprint suckler beef production system (18.9kg CO2 e), 90% of the feed required comes from forage.
Emissions from cars driving in Dublin but produced in Germany come under the Irish emissions umbrella. In political circles, so too do emissions from suckler cows in Galway producing beef for consumption in London
While these figures surrounding suckler cow carbon emissions in Ireland come from the most recent peer-reviewed research available, it must be noted that our cattle herd has made big genetic improvements in the interim. The blueprint for young bull production now aims for a carcase weight of 395kg at 15 months of age (versus 352kg at 16 months of age in the cited research). Our animal is now spending less time on farm and producing an extra 40kg+ of beef with similar resource inputs, further diluting the emissions/kg beef produced. In simple terms, if we can hit a 395kg carcase with the same input requirement (improvement largely genetic based), emissions per kg of beef produced reduce by 11%.
While agriculture is by far Ireland’s biggest source of carbon emissions (32%), remember that we are an exporting nation. Taking beef as the example, 90% of our production is consumed abroad. Emissions from cars driving in Dublin but produced in Germany come under the Irish emissions umbrella. In political circles, so too do emissions from suckler cows in Galway producing beef for consumption in London. Granted, it’s an unorthodox way of looking at the issue, but in an increasingly globalised world, different countries specialise in producing different products.
A 2015 study carried found that the capacity for carbon storage was generally higher in Irish soils than reported for comparable grassland regions elsewhere in the world.
Indeed, when we look at the overall EU picture, agriculture accounts for just 10% of the EU’s greenhouse gas emissions according to Eurostat. Ireland’s small, family-farm model where much of the animal’s lifetime weight gain comes outdoors on pasture ticks a lot of boxes for the consumer. At the end of the day, something is produced because a consumer is deciding to buy it. Consumer decisions drive emissions – why should those who produce the products, and not the consumer, be penalised?
Dairy beef
There is an argument for dairy beef systems and, indeed, Teagasc research shows that when the same model is applied to a 24-month Holstein-Friesian steer system, CO2 e/kg of carcase beef are 14.4kg. However, this figure applies to a 285kg carcase which is on the lighter side of what processors are looking for, in part due to issues around processing efficiency. While these types of carcasses tick boxes for processors, heavier, better-conformed carcasses have a huge role to play in our national beef supply.
The average European citizen consumes 11kg of beef annually (average Irish person eats 18.6kg). If we apply our Irish suckler model results to this, adding 3% for post-slaughter emissions, it costs 262kg of CO2 e to produce a European’s total beef for the year when farming at average standards and 214kg CO2 e – an 18% reduction in emissions – when we adopt low carbon footprint standards (Bull – mod).
If we were to import the beef from Brazil, an individual’s requirement would cost 880kg of CO2 e. The latter value includes emissions caused by land use changes, which have been estimated based on increases in pasture area in Legal Amazon. Without these included, the figure is 528kg – still over double that of home-produced beef.
The reality is that the emissions from a person’s annual beef consumption (using average production standards) pale into insignificance when compared with the carbon cost of running a relatively fuel-efficient car at a modest rate of yearly mileage (20,000km per annum). The latter requires eight times the carbon of the beef (x10 using low carbon beef standards). If we move to a higher powered vehicle, we use over 16 times the carbon (x20 low carbon beef) to run it for a year than we do to produce a single person’s beef.
In a society where many don’t bat an eyelid at the prospect of jumping on a long-haul flight, economy class return flights for one person between Dublin and JFK airport New York cost the same in carbon terms as 5.3 European citizens’ beef for a year (average production standards). If we apply our best production system standards, we can get 6.5 EU citizen’s beef from our trip to the US.
The most recent figures from the Central Statistics Office show that a European’s average greenhouse gas emissions per capita stood at 8.8tCO2e in 2015. The same person’s annual beef consumption accounts for less than 3% of this figure (using average production standards).
The modelling trial also demonstrated how the most profitable systems are also generally more carbon efficient, so there is a two-pronged gain for producer who decide to adopt technically efficient farming practices.
Of course, carbon emissions aside, the suckler cow is a vital component of rural Ireland and this role of hers is often overlooked. To cite a recent IFA study, every €1 invested in her generates €4 in the local economy.
For me, one of the biggest problems with the Irish suckler cow today is variation - the national cow herd is too much of a mixed bag from an efficiency point of view. However, as more and more farmers look toward better genetics and performance measuring, ripplings of positive change are becoming evident.
The ICBF’s new weaning efficiency metric is a definite step in the right direction – an excellent tool for helping farmers to pick out their most efficient cows when it comes to producing live weight. As our recent BETTER farm analysis showed, improving this figure by six percentage points, from 42% to 48%, in turn reduced emissions by 6% per kg of beef.
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