Almost everywhere in Europe, injunctions to reduce cattle herds are making breeders shudder. “What if it’s our turn soon?” », French breeders cannot help but think. But after the outcry caused by the announcements of massive slaughter in Ireland, the sector gradually seems to be structured around technical organizations to try to reconcile breeding and methane emissions.
THE Irish breeders have ringing ears. Last June, a leak from the Ministry of Agriculture recommended massive cattle slaughters – around 200,000 dairy cows over 3 years – to limit greenhouse gas emissions of the sector. This bleeding of the Irish herd would lead to a reduction in the national herd of around 13%. The objective: to offer breeders voluntary slaughter in exchange for compensation. And for good reason, agriculture is the Source of more than a third of the country’s GHG emissions.
But faced with the outcry, it is difficult for the government to maintain its posture. The minister in charge of agriculture quickly described the report as a “scenario”, specifying that the final decision had not yet been made. Not to mention the cost of the measure. To make things easier, the report envisaged compensation of around 600 million euros!
If the perspective of massive slaughters seems behind the Irish, the methane question remains relevant. In accordance with the Paris Agreement, Ireland is committed to achieving carbon neutrality by 2050. On an island which has more cows than inhabitants, suffice to say that the country will not succeed without involving the breeders.
To meet these challenges, the Irish agency responsible for research and development in agriculture (Teagasc) is doubling its inventiveness. And among its tracks, the reduction in the slaughter age of beef cattle holds a good place.
Control the slaughter age?
“Currently the average age at slaughter of Irish cattle is 26 months. The aim is to reduce this time to 22-23 months by 2030. It is estimated that for each month of reduction in the national average age at slaughter, the reduction is equivalent to the emissions of around 100,000 cows,” estimates Dr Peter Lawrence on the Technical Institute website.
The slaughter at 26 months may surprise French breeders, who are accustomed to finishing young cattle at 16 or 18 months, but it can be explained by the fact that the Irish give more in the production of cattle over two years old.
Opting for slaughter at 24 months, rather than 27, makes it possible to reduce methane emissions per animal of the order of 19 kg. Because food is the main precursor of methane. In short, the larger the animal, the more it eats, and the greater the ruminal fermentation. “A project led by Teagasc established that for an indoor finishing ration, beef cattle produce on average 230 g of methane per day, the equivalent of 22 g of methane for each kilo of dry matter ingested,” continues the institute in a summary note.
For Peter Lawrence, this constraint can even be an opportunity for productivity gains. Work to establish precocity indexes is underway. “The recent revision of the cattle selection indexes now includes a “finishing age” as a new evaluation criterion.” A way of selecting the best performing animals over a given time to reduce the slaughter age, while limiting potential losses in carcass weight.
The Ministry of AgricultureNorth Ireland has also embarked on this path. Since January 1, 2024, breeders slaughtering their beef cattle before a age limit benefit from a prime. The program runs for four years, with a target age of 30 months for the first year. “From April 2024, the payment rate will be £75 per eligible animal,” says the Department of Agriculture and Rural Affairs. At the end of four years, the premium will only be granted to cattle slaughtered before 26 months.
But this injunction is coldly received by farmers. Some criticize him for favoring the use of concentrates for finishing animals, to the detriment of grass. Others see it as a sneaky way of encouraging breeders to reduce their stocking.
Focus on additives
More difficult to supervise, thefood nevertheless appears among the levers proposed by Teagasc. If Ireland is the country of pasture, controlling it makes it possible to limit methane emissions. The higher the grass, the less digestible it is, and the more enteric methane emissions increase. Grazing management, coupled with the introduction of more digestible plants, such as Clovercan be a way.
Because even if the clover is the emblem of Ireland, it is not very present in the meadows. In addition to meeting part of the nitrogen needs of meadows, “clover, plantain and chicory contain plant compounds which potentially have negative impacts on the activity of ruminal microbes involved in the production of methane”, details the technical institute.
Algae, fats and others additives are also being closely studied to benefit from enteric methane production inhibitors.
Towards the selection of clean cows
Teagasc has also undertaken toidentify individuals who emit more or less methane, by comparing food consumption with animal emissions. And the data seems to offer some room for maneuver to breeders. The most efficient animals produce 30% less methane than the highest emitters, for equal performance! “There is significant potential to exploit variation genetic methane emissions within the national herd, in order to bring about permanent and cumulative reductions in methane production from future generations of livestock,” the institute continues. Work is also underway to understand the biology of methane production.
If we are not yet at the stage of selecting cattle according to their emissions, genetics already allows gains in zootechnical performance, which are a path towards reducing methane emissions.
