Cutting livestock emissions via feed

Cutting livestock emissions via feed

Initiative's goal is to compile scientific data and develop best practices to help reduce greenhouse gas emissions from livestock.

AS greenhouse gas emissions from agriculture rise worldwide, Pennsylvania State University dairy nutrition professor Alexander Hristov is leading a new international project aimed at helping reduce such emissions from livestock production.

Formally titled the "Global Network for the Development of Nutrition-Related Strategies for Mitigation of Methane & Nitrous Oxide Emissions from Ruminant Livestock," the $1.65 million initiative involves a consortium of researchers from nine countries whose goal is to compile scientific data and develop practices that promise to address the problem.

The U.N. Food & Agriculture Organization estimates that animal production accounts for up to 18% of greenhouse gas emissions worldwide, Hristov said.

"In some countries, such as New Zealand, agriculture accounts for more than 45% of the total greenhouse gas emissions," Hristov explained. "In the U.S., however, livestock accounts for only about 3% of the total greenhouse gas emissions because the energy and transportation sectors are much larger contributors."

Globally, he warned, the problem is expected to get worse as personal incomes rise in developing countries, leading to more demand for animal-derived foods. He explained that developing countries may be home to many animals, but their productivity typically is much lower than in North America and Europe.

"A cow here may produce 20,000-30,000 lb. of milk annually, but in many parts of Africa and Southeast Asia, for example, production is a fraction of that," Hristov said. "By increasing production, we can supply the rising demand while maintaining or reducing the levels of greenhouse gas emissions per unit of meat or milk produced.

"We need to look at genetics, reproductive efficiency and scientific feeding," he noted. "The Global Network project is focused on nutritional strategies for reducing emissions through new feed formulations and by using different feed additives."

A major objective of the Global Network is to create a database of existing studies that can serve as a clearinghouse for the latest science addressing the issue. Hristov said the project will solicit research studies and data — both published and unpublished — from scientists around the world, not just from those involved in this consortium.

"There is a large body of existing nutrition-related greenhouse gas mitigation data that are not well organized," he said. "We hope scientists will share individual animal data, which will help in creating effective prediction models for greenhouse gas emissions."

Some collaborators in the consortium also will conduct new research designed to fill knowledge gaps in the database, said Hristov, who studies phytonutrients as methane mitigation agents in dairy cows. Compared to carbon dioxide, methane has 23 times the potential to influence global climate change, he noted.

Other Global Network objectives are to develop guidelines for conducting experiments that are designed to evaluate nutritional strategies for emission mitigation; to develop and evaluate models for predicting methane emissions and nitrogen excretions under various nutritional, animal and farm management scenarios, and to identify and recommend mitigation technologies that are both practical and feasible to implement in various ruminant livestock production systems.

The four-year project is funded through the Europe-based Joint Programming Initiative on Agriculture, Food Security & Climate Change. Funding also comes from government agencies in the researchers' respective home countries. The U.S. Department of Agriculture's National Institute of Food & Agriculture is supporting the U.S. portion of the project, which also includes scientists from The Ohio State University and the University of California-Davis.

Other Global Network researchers come from France, Spain, Finland, Ireland, the U.K., the Netherlands, Switzerland and New Zealand. Dairy Management Inc. will host the project's research database through its Innovation Center for U.S. Dairy.

 

Oil cake in feed

On a similar front, initial results of research carried out by the Basque research institute Neiker-Tecnalia suggest that the use of rapeseed cake in the production of livestock feed may cut methane and carbon dioxide emissions by as much as 13%.

Specifically, the incorporation of the oilseed plant Brassica napus — canola is one variety of rapeseed — into animal food reduces methane emissions by 6-13% and carbon dioxide emissions by 6.8-13.6%, an announcement said.

Introducing this oilseed preparation into the diet of ruminants also improves the animals' efficiency in the use of digestible organic matter by between 4.4% and 10.1% and cuts the fermentation of the diet by 6.2-11.8% without adversely affecting its digestibility. Rapeseed cake, also known as oil cake, is a byproduct obtained after pressing the rapeseed plant to extract its oil.

The research is part of the Life-Seed Capital project, funded by the European Union through its Life+ program.

The advantages of selecting this plant start from its use as a rotation crop, because it is capable of increasing cereal productivity and improving soil structure.

Once it has been harvested, rapeseed can be used as a biofuel and added to diesel in varying proportions after simple cold pressing. A waste product of this process is used to produce animal feed, with the result being cutting costs for farmers and greater efficiency that reduces the emission of greenhouse gases.

 

Strategies

An international team of academics led by the University of Bristol's School of Veterinary Sciences has outlined eight strategies to cut the environmental and economic costs of keeping livestock such as cows, goats and sheep while boosting the quantity and quality of the food produced.

The eight strategies include:

1. Feed animals less human food. Livestock consume an estimated one-third or more of the world's cereal grain, which some advocate would be better used to feed people directly. Some of this could indeed be avoided by capitalizing on ruminants' ability to digest food that humans cannot eat, such as hay, silage and high-fiber crop residues.

2. Raise regionally appropriate animals. Working to boost yields from local breeds makes more sense in the long term than importing poorly adapted breeds that are successful elsewhere.

European and North American Holstein dairy cows can produce 30 liters of milk a day. Thousands of these animals have been exported to Asia and Africa in an attempt to alleviate malnutrition. However, when exposed to hot climates, tropical diseases and suboptimal housing, the cows produce much less milk, and the costs of feed and husbandry far exceed those for native breeds.

3. Keep animals healthy. Human and livestock disease are generally treated as separate problems, but sick animals can make people sick. In low- and middle-income nations, 13 livestock-related zoonoses cause 2.4 billion cases of human illness and 2.2 million deaths each year.

Animal management should include measures to control transmissible diseases by improving hygiene, quarantining new arrivals on farms and establishing coordinated, sustained surveillance for diseases that cross the boundaries of species or countries.

4. Adopt smart supplements. Supplements can boost the productivity of ruminant animals by encouraging microbes in the rumen to grow quickly and provide the animals with better nutrition. Also, with some supplements, animals can produce more milk and meat for proportionally less greenhouse gas.

5. Eat for quality, not quantity. Raising animals for milk and meat is often considered to be at odds with the challenge of feeding a growing human population, but for undernourished communities, there are health benefits to consuming healthy animal products.

6. Tailor practices to local cultures. Close to 1 billion of the world's poorest people rely on livestock for their livelihoods. Traditional animal husbandry supplies not just food but wealth, status and even dowry payments.

However, the benefits of keeping animals are disrupted when conventional grazing and mixed-farming practices are replaced with industrial systems that prioritize short-term production.

Policies to encourage high-welfare, efficient management should consider cultural as well as natural factors.

7. Track costs and benefits. Despite ruminant livestock's poor image as major greenhouse gas emitters, sustainably managed grazing can increase biodiversity, maintain ecosystem services and improve carbon capture by plants and soil.

8. Study best practices. A global network of research farms — known as farm platforms — can evaluate the economic and environmental benefits of these and other farming practices, serve as examples for local farmers to follow and provide valuable information for policy-makers.

Professor Mark Eisler, chair of global farm animal health in the Bristol School of Veterinary Sciences and Cabot Institute, said, "With animal protein set to remain part of the food supply, we must pursue sustainable intensification and figure out how to keep livestock in ways that work best for individuals, communities and the planet."

Volume:86 Issue:12

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