Local researchers explore more sustainable ways to raise cattle

By Adrienne Perron

The green feed machine at UNH’s Organic Dairy Research Farm dispenses grain for the cows that reside there. But when the machine distributes food, the cows are getting more than a snack: The machine is measuring the amount of methane on each cow’s breath as it eats grain.

This is one way UNH researchers are investigating how to reduce the amount of methane gas released into the atmosphere when cows digest their food.

Ryan Courtright, the farm manager at UNH’s Organic Dairy Research Farm, said that it is believed that methane production in cows decreases their efficiency of milk production. In addition to using the green feed machine, he said that the farm has also recently completed one year of a two-year study that looks at the canola plant and how it affects methane gas production in cows.

“It is believed that canola has some benefits to reducing methane in the rumen,” Courtright said. “Canola prefers to be grown in cooler temperatures, so we planted canola on the farm in the early part of August and sixty days later we were able to pasture it. One of the great benefits of planting canola is that it extends the grazing season for the organic industry, so we had our cows out for a total of 160 days this year. The organic requirement is 120.”

Adrienne Photo

Cows are considered to be a ruminant mammal. Ruminants have extra stomachs that are full of microbes, so they can eat food that has a very high fiber content. The microbes in their rumen break down that fiber into sugars that the cow can use to make energy and protein, and as a result, produce the byproduct of methane, a greenhouse gas.

Since greenhouse gasses are a major contributor to climate change, farmers and researchers from the University of New Hampshire have been trying to find ways to improve the efficiency of cows’ digestion so that methane production may be reduced in cattle raised for dairy and beef. By decreasing levels of methane emitted by cows, researchers could improve the sustainability of local dairy and beef farms and decrease their contributions to global warming.

According to Tess Stahl, a second-year agricultural science master’s student, cows will always have to produce methane because it is a byproduct of how they digest feed. However, she thinks that if more efficient nutrition allowed cows to produce less methane, without killing the methanogens in their rumen, it would be a good thing.

Even though researchers like those at the Organic Dairy Research Farm are trying to improve the diets of cows to cut back on methane gas emissions, many have said that cows do not produce the exaggeratedly high amount of the gas that some think they do.

The debate about the negative effects of methane gas produced by cows, and that gases contribution to global warming, has led to activism against dairy farming, but, as indicated by University of New Hampshire Dairy Club president Jessica Sexton, this countermovement may be based on misinformation.

According to Sexton, many people’s thoughts about methane gas production by cattle are misconceptions. She said that a lot of movies use outdated statistics from before people knew what they were doing and knew how to farm in the most efficient way possible.

“Now animal agriculture in the United States only contributes to [a low percentage] of greenhouse gases, so when people are trying to blame agriculture, it’s just not what’s causing a lot of these issues.”

According to the original study published in 2013 by the Food and Agriculture Organization, the sources of emissions that were considered in order to get the percentages of greenhouse gas emissions produced by livestock included feed production and processing in addition to enteric fermentation from ruminants, which are the two main sources of emissions from livestock. These sources represent 45 and 39 percent of sector emissions, respectively according to the organization. The other sources include manure storage and processing which represents 10 percent, and the remainder comes from the processing and transportation of animal products.

Peter Erickson, professor of dairy management and extension dairy specialist at UNH, agrees with Sexton that cattle are getting a bad rap for their production of methane gas.

“The contribution of livestock to [greenhouse gasses] in the US, the correct number, is about 4.2%, not 14%,” Erickson said. “The [Food and Agriculture Organization] went back and changed it because they had been proven wrong, a majority of greenhouse gases come from transportation, vehicles, not livestock. But it’s an easy thing to pick on.”

In addition to the methane produced in the rumen, manure also contributes to greenhouse gas emissions, as it contributes to about ten percent of total emissions by livestock. The Food and Agriculture Organization said that methane is released from the anaerobic decomposition of organic material. Also, during storage and processing of manure, nitrogen is mostly released in the atmosphere as ammonia that can be later transformed into nitrous oxide, a major greenhouse gas.

Anita Klein, faculty fellow for the NH Agricultural Experiment Station, says that although improving efficiencies in diet and reducing methane production is one big area of research, the farm is also working to turn cow manure and the bedding that cows sleep on, which contains urine and manure, into compost through aerobic composting. Composting with oxygen produces less methane.

According to Klein, this type of composting is implemented to make the organic dairy production more of a “closed circle.” By composting material aerobically, farmworkers can capture the heat produced to warm water to clean cows before milking.

“All agriculture disrupts ecosystems,” she said. “It’s [about] trying to find the best balance that you can, and there is plenty of room for optimizing.”

Ben Patterson, a senior sustainable agriculture and food systems major at UNH was raised on and is now financially responsible for his family’s beef farm. Patterson says raising cows for meat utilizes land that is otherwise unusable to grow food for humans. It also avoids certain environmental problems that stem from tilled land.

“An important part of cows is their ability to eat grass and turn it into food for us, because we can’t eat grass,” Patterson said. “On my family’s farm, 90 percent of the land is not arable land. It’s clay, hilly. There’s no way you could ever plow it and plant vegetables, so the only thing you could ever do is have something that eats grass to be able to produce food off of it. On top of that… tilled land actually releases a lot of carbon in the atmosphere.”

Grasslands, including those which cows graze from, have been found in certain areas to be a more effective carbon sink than even forested, areas according to Patterson. A study done by the University of California, Davis found that grasslands are more resilient carbon sinks than forests in places such as California, because they are less impacted by droughts and wildfires. When fire burns grasslands, carbon tends to stay in the roots and soil as opposed to being released back into the atmosphere as it does when trees combust. This makes grasslands more adaptive to climate change.

As for land tilling, according to a study conducted in 2016 by Biogeosciences, a scientific journal about earth sciences, the practice “changes the balance between organic carbon put into the soil by plants and carbon output as greenhouse gases due to organic matter decomposition.” Soil tillage may also lead to leaching and erosion.

Because cows in the Organic Dairy Farm herd forage on the farm, Courtright said the farm is working on new strategies for tilling land that will benefit and aid in the sustainability of the farm for both “today and tomorrow.”

“We are able to implement new technologies on the cow side as well as on a forage production side including different tillage practices that we try to implement so we prevent erosion and things like that,” he said. “I just believe in taking care of the soil and providing for future generations but also improving the soil for today.”

Unlike the Organic Dairy Research Farm, Fairchild Dairy, located at UNH in Durham, has a conventional herd, meaning it is not organic because the cows are treated with antibiotics. According to Erickson, who helps out with the Cooperative Real Education in Agricultural Management (CREAM) program for students at the farm, Fairchild Dairy is also a very sustainable facility.

According to Erickson, Fairchild Dairy is more sustainable than other farms because the animals are fed more grain and less forage. Erickson said that for years it has been proven that high-forage diets increase the production of methane in a cow’s rumen.

“If you do your nutrition right, and I am a nutritionist, you can optimize production and simultaneously reduce the effect of methane,” he said.

The average dairy farm in New Hampshire has a herd of about 150 cows, according to Erickson. He said that this is environmentally friendly because there are regulations to control effluent manure and nutrients on those operations. He also said there are federal laws to protect water and the environment from contamination.

Other efforts of sustainability done by Fairchild Dairy, according to Erickson, include utilizing a manure spreader that handles liquid manure. The spreader injects the nutrients into the ground to decrease air pollution and puts nutrients at the roots where plants need it. The process also decreases manure odor. In this kind of system, Erickson said, “the manure is now benefitting farmers more than if it was spread on the land.”

Erickson said that although sustainable strides are being made and methane emissions are not as high as many may believe, there is still more progress to be made.

“Just because it’s low doesn’t mean that we aren’t addressing it,” Erickson said about methane emissions made by cows. “They get a bad rap but that doesn’t mean that there isn’t room for improvement.”

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