Yesterday, in our continued quest to consider the future of a family dairy farm, we visited what must be the largest such farm in central Costa Rica. At 7,545 feet above sea level overlooking the valley from the northern slope, it may also be the highest.
It has eight times the land and double the cows compared to where we are based, 10 miles north and about 1,000 feet lower in altitude. That farm also has dairy goats. More on other implications of the visit later. Here, a quick note on feed. We had noticed on the dairy where we live that pineapple is part of the diet of the cows.
The dairy manager had explained that this is an important part of the nutritional mix. Despite our surprise we had not asked more about it. Yesterday we did, and the answer was another surprise. Milk production rises 10% or more with the pineapple added to the feed. The animals are healthier because of the fiber content of the fruit, compared to cows eating grains such as corn or soy. Plus, the methane bi-product is significantly decreased. Food produced in a dairy making this dietary change represents one small step toward reducing greenhouse gas emissions.
In the type of coincidence I never expect, but always enjoy, this article was near the top of my news feed today. Thanks to Judith Lewis Mernit and colleagues at the Yale School of Forestry & Environmental Studies for take my yesterday’s lesson and adding some important detail:
Emissions from the nearly 1.5 billion cattle on earth are a major source of methane, a powerful greenhouse gas. Now, researchers in California and elsewhere are experimenting with seaweed as a dietary additive for cows that can dramatically cut their methane production.
The spring morning temperature in landlocked northern California warns of an incipient scorcher, but the small herd of piebald dairy cows that live here are too curious to care. Upon the approach of an unfamiliar human, they canter out of their barn into the already punishing sun, nosing each other aside to angle their heads over the fence. Some are black-and-white, others brown; all sport a pair of numbered yellow ear tags. Some are more assertive than others. One manages to stretch her long neck out far enough to lick the entire length of my forearm.
“That’s Ginger,” explains their keeper, 27-year-old Breanna Roque. A graduate student in animal science at the University of California, Davis, Roque monitors everything from the animals’ food rations to the somatic cells in their milk — indicators of inflammation or stress. “The interns named her. She’s our superstar.”
Ginger is one of 12 Holstein cows participating in an experiment being conducted by Roque’s animal science professor, Ermias Kebreab, into reducing methane emissions from livestock by supplementing their diets with a specific type of seaweed. Methane is a potent greenhouse gas, with roughly 30 times more short-term, heat-trapping power than carbon dioxide. In California alone, 1.8 million dairy cows, together with a smaller number of beef cattle, emit 11.5 million metric tons of carbon dioxide equivalent every year — as much as 2.5 million cars.
The enormity of those numbers, in part, motivated California lawmakers to pass a law to reduce methane emissions and other short-lived “climate pollutants” by 40 percent below 2013 levels by 2030. The California Air Resources Board subsequently ordered a majority of the reductions in the new law to come from the dairy industry. Other cuts will come from diverting organic waste from landfills and eliminating fugitive emissions associated with oil and gas operations.
The UC Davis study will contribute to a global store of knowledge on how to limit the methane produced by “enteric fermentation” — the digestive process in a ruminant’s upper stomach chamber, or rumen, where microbes predigest fiber and starch, releasing gases when they belch and exhale. It’s “one of a handful of options in various stages of development that seem to have the potential to reduce [enteric] methane by 30 percent or more,” says Ryan McCarthy, science advisor to the Air Resources Board.
Kebreab’s experiments with seaweed additives to cattle feed have now surpassed that 30-percent figure, with one type of seaweed slashing enteric methane by more than 50 percent. In the fight to slow climate change, such reductions are no small matter: In the United States alone, domestic livestock — including cattle, sheep, goats, and buffalo — contribute 36 percent of the methane humans cause to be put into the atmosphere, according to the U.S. Environmental Protection Agency…
Read the whole article here.