Tips for responsible agriculture
According to a 2008 study, the entire process of raising an animal from birth to dinner table is responsible for 14 percent of total global warming in the European Union.
While farmers work to “go green,” Dr. John Hermansen of Aarhus University (Denmark) has found that there are several steps livestock producers can take to reduce their carbon footprints even further. Hermansen’s paper, co-authored by Aarhus University scientist Dr. Troels Kristensen, was published in the July issue of the animal agriculture magazine Animal Frontiers.
To measure carbon footprint, Hermansen and Kristensen looked at life cycle assessment (LCA) studies, which tracked carbon output through meat and dairy production. The LCA includes analyses of livestock management steps like feed transportation, manure handling, and protein production.
In meat production, Hermansen found, farmers should try to use less feed to raise livestock. “In order to reduce the carbon foot print of the livestock products, farmers should draw very much attention to the overall feed efficiency,” said Hermansen in an interview. This viewpoint is backed-up by studies showing that in pig farms where the ratio of feed to kilogram body weight gain was less, carbon footprint was reduced by 10 percent. Increased feed efficiency was also important in dairy farming, where increased milk production per cow markedly reduced carbon footprint.
Hermansen also looked at the ways farmers handle manure. Current manure handling practices often lead to an increased carbon footprint, due to the production of methane. But studies showed that when waste was stored at lower temperatures, methane emissions decreased. Instead of storing waste as slurry, Hermansen suggests using manure as a replacement for artificial fertilizers. Both low-temperature storage and use as manure can reduce carbon footprint.
Perhaps the most innovative use for manure is as a source of biogas before it is used as fertilizer. “Livestock has a huge potential to contribute to the production of ‘non-fossil based’ energy,” Hermansen said. “In addition to energy production, this allows for a better utilization of the nitrogen in the manure, thus reducing the requirements for artificial fertilizer.”
Another piece of advice: keep animals healthy. Hermansen reviewed a 2011 study from the Netherlands that showed that reducing dairy herd replacement rates also reduced greenhouse gases.
For more information on reducing the carbon footprint of farming, read the paper in full at animalfrontiers.org.
Scientific Communications Associate