A study conducted in Teagasc Grange earlier this year examined mitigating greenhouse gas (GHG) emissions in Irish beef production systems.
Speaking to Agriland, Mark Kearney, the PhD student who conducted the study at Teagasc Grange, said: “Agriculture and food systems contribute significantly to climate change with the greenhouse gas emissions intensity from beef production systems being relatively high when compared to other livestock production systems.
“If Ireland is to reach its climate action targets, mitigating GHG emissions from beef production systems is very important.”
Ireland has set an ambitious target of a 25% reduction in GHG emissions from the agricultural sector by 2025 in its National Climate Action Plan.
“With the continued expansion of the national dairy herd and concerns for the future of live exports of young calves, the number of dairy-beef cattle in the country is forecasted to rise and therefore reducing emissions from these dairy-beef systems will be key to meeting national climate ambitions,” Kearney said.
This study, Mitigation of greenhouse gas emissions in pasture-based dairy-beef production systems, looked to evaluate a range of management practices to reduce GHG emissions in a dairy-beef production systems.
It also aimed to identify any trade-offs between GHG emissions mitigation, farm profitability, food security and land use.
“If any of these mitigation strategies are to affect farm profitability, it would act as a major barrier to adopting the mitigation strategy,” Kearney said.
The study looked at dairy-beef steer systems slaughtered at:
- The end of the second grazing season;
- During the second winter;
- During the third grazing season.
These systems were examined at both a high and national average stocking rate which, according to Kearney, “makes the study more applicable to commercial practices”.
The mitigation strategies examined in the study were as follows:
- Reduced age at slaughter;
- Low emission slurry spreading (LESS);
- Protected urea;
- Replacing cereal ingredients in concentrate rations with by-products;
- Clover incorporation in the perennial ryegrass sward;
- Combining all the above mitigation strategies.
The results from the study showed that a combined mitigation strategy was the best way to reduce GHG emissions in a beef production system.
Findings from the Teagasc research
The combined mitigation strategy decreased emissions intensity by an average of 21%.
Incorporating clover in grassland swards was found to be the most profitable standalone mitigation strategy increasing net margins by an average of 18%.
Kearney said that he sees feed-food competition (the amount of human-edible protein a beef system produces versus the amount it consumes ) is going to be “a vital metric in evaluating beef systems contribution to food security moving forward”.
“Beef cattle have the ability to convert large amounts of forages, that are inedible to humans, into nutritious animal protein for human consumption,” he said.
“Substituting by-products for barley in a concentrate ration converted all systems into net producers of human edible protein.”
Steer systems finishing off grass during the third grazing season were the only net producers of human-edible protein as they had a low amount of concentrates in their feed budget. However, finishing at pasture during the third grazing season increased GHG emissions per animal and per kilogram of beef carcass.
Kearney said “all the mitigation strategies investigated are based on farm management practices that can be implemented quickly and easily without the farmer having to make substantial changes to their system”.
“While it would be great if all the listed mitigation strategies could be implemented by the farmer, in the immediate future, if farmers could focus on incorporating more clover into grass swards, it has the potential to reduce their farm GHG emissions and also improve their farm profitability levels,” he added.