Beef Cattle Research Council

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Beef Cattle Research Council - Environmental Footprint of Beef Production

Retrieved: November 20, 2017 - 07:24 PM

Grazing cattle are an integral part of the grassland ecosystem and play an important role in nutrient recycling. Pasture lands are important stores of carbon and provide habitat to many species at risk as well as preservation of wetlands that otherwise may be subject to cultivation. Production of cattle in feedlots lowers the carbon footprint of beef and increases the efficiency of beef production. As with any food production system, there is an environmental footprint associated with beef production. 


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Introduction/Video

The beef footprint has implications for greenhouse gas emissions, nutrient cycling, water and air quality, carbon stores, and preservation of grassland ecosystems. News related to the beef industry and its impact on the environment in the popular press is often about instances when production has not followed best management practices, however some components of the footprint such as the production of greenhouse gases are unavoidable.

Research shows that our industry has made significant improvements in efficiency over time. A 2015 Beef Science Cluster funded project found that Canada produced 32% more beef in 2011 than in 1981. Much of this was due to higher carcass weights. Producing the same amount of beef in 2011 required 29% less breeding stock, 27% fewer slaughter cattle and 24% less land, and produced 15% less greenhouse than in 1981. 

Reductions in the beef industry’s environmental footprint have largely come through technologies that improve production efficiencies. Optimizing nutrition has helped to improve growth and reproductive performance. When more females get pregnant and successfully wean a calf, fewer heifers need to be retained as replacements, so the breeding herd is smaller and there are less cows to produce greenhouse gas emissions. On the feedlot side, heifer carcass weight has increased due to growth promotants. Improvements in feed crop yields mean that a smaller land area is needed to produce the same amount of feed.

Many of the same things that improve productivity on the farm, ranch or feedlot also contribute to a smaller environmental footprint for the beef industry.

Carbon Sequestration in Seeded and Native Grasslands

Carbon sequestrationOver the last century, the majority of prairie grasslands were plowed for crop production with less than 20% of this ecosystem remaining intact. Native grasslands represent an important storage of carbon and may contain up to 200 tonnes of carbon per hectare. Much of this carbon is stored in the roots of grasses and shrubs, explaining why so much more carbon is released by plowing as compared to that released by natural fire.

Carbon storage can be increased if cropland is planted back to perennial pasture, with sequestration initially occurring rapidly and gradually plateauing over a 20 to 25 year period. In fact, models have shown that if beef cattle are switched from a grain- to perennial forages-based production system, and the forage associated from this transition is derived from newly seeded cropland, the entire beef production cycle becomes a net sink of carbon.

As with most biological systems, grasslands eventually revert to a steady state where if left undisturbed, carbon sequestration is
balanced with carbon emissions. Overgrazing or drought can increase carbon losses.

Amount of carbon stored in a hectare of native grassland is equivalent to the amount of emissions produced by approximately 150 cars over one year. 

The ability to further sequester additional carbon in properly managed grasslands is questionable, but levels may increase further as atmospheric levels of carbon dioxide continue to rise. However, it is clear that any increased sequestration as a result of increases in atmospheric carbon dioxide will not be sufficient to offset ongoing emissions related to the burning of fossil fuels.

Preservation of Grassland Ecosystems

Grazing ruminants are a natural component of grasslands and play a critical role in the recycling of nutrients within these ecosystems. Grasslands are richly biodiverse and harbor many of Canada’s most endangered or threatened species (e.g., burrowing owl, black footed ferret, swift fox, prairie chicken).

Plant communities depend on grazing for removal of aftermath, the distribution of seeds, and the provision of open niches that can increase sward biodiversity.

Establishment of perennial forages reduces the disturbance of prairie bird habitats of and, if near surface water, provides nesting sites for ducks and geese. In many instances, land owners control access to these rangelands, preventing the damage that is readily evident in areas where off road recreational vehicles and other activities have degraded grassland habitat.

Beef Cattle and Greenhouse Gas Emissions

In Canada, producing 1kg of beef now creates 15% less greenhouse gases than in 1981, due to improve production practices.

Nearly every living organism, including plants, produces greenhouse gases. Cattle generate more than other livestock because rumen bacteria produce methane as they digest feed. Additional greenhouse gases come from manure (methane and nitrous oxide) and fossil fuel use on farm (carbon dioxide).

In 2006, the United Nation’s Food and Agriculture Organization (FAO) released a report called “Livestock’s Long Shadow” which greatly misrepresented the amount of emissions produced in raising beef cattle.  A more balanced FAO report named “Tackling Climate Change Through Livestock” came out in 2013. This less publicized report found that producing a kilogram of beef in Latin America, India or China generates twice the methane as in North America, Europe or Australia.

A 2015 Beef Science Cluster funded project looked at the change in the Canadian beef industry environmental footprint between 1981 and 2011. Researchers reviewed many different Canadian research projects that studied how slight changes in reproductive rate, feed and forage crop yields, growth rates, carcass weights, etc. impact how much feed and land is needed to produce a kilogram of beef, and how much manure and greenhouse gases are produced as a consequence.

The results showed that producing the same amount of beef in 2011 produced 15% less greenhouse gases than in 1981. Over 78% of the methane emissions occurred in the cow-calf sector, because the breeding herd spends nearly its whole life consuming forage-based diets that produce more methane than grain-based diets do.

Reductions in the beef industry’s environmental footprint have largely come through technologies that improve production efficiencies.

Cattle production contributes to the emission of three greenhouse gases (GHG);

      • carbon dioxide
      • methane
      • nitrous oxide

Carbon Dioxide

Carbon dioxide accounts for a small portion of emissions (5%) from Canadian beef production and arises primarily from the burning of fossil fuels. In the beef industry, the use fossil fuels is primarily associated with crop production (fertilizer and fuel) and the transport of feed, cattle and beef to markets. Because beef is produced outdoors, emissions associated with the heating of production facilities are miniscule. Grasslands on which cattle graze contribute to carbon sequestration, or the capture of carbon dioxide.

Methane

A global research effort has identified technologies that can reduce methane emissions from cattle. Increasing the value of carbon would increase the use of these technologies in beef production. 

Methane is produced by methanogens under anaerobic conditions (without oxygen) in both the animal and manure. However, as beef manure is typically applied to the land fresh, the anaerobic conditions necessary for methane production are impaired. Therefore, beef manure only accounts for approximately 5% of emissions.

The largest source of GHG in beef production comes from the methane produced in the gastrointestinal tract, accounting for over 60% of total emissions.

Methane is a natural by-product of feed digestion in the intestinal tract and is produced by the reduction of carbon dioxide via the addition of hydrogen. If methane production is inhibited without an alternative hydrogen disposal, efficiency of beef production can be impaired. Identifying technologies that lower methane production without adverse impacts on efficiency has proven to be a significant challenge for the scientific community. However, enteric methane emissions can be reduced by the addition of certain feeds, including grain or oils, to the diet.

A global research effort has identified technologies that can reduce methane emissions from cattle.  Increasing the value of carbon would increase the use of these technologies in beef production.

Nitrous Oxide

Nitrous oxide has a much higher global warming potential than either methane or carbon dioxide. Nitrous oxide emissions arise from manure and cropland and account for approximately 25% of total GHG emissions from Canadian beef production.

Emissions of nitrous oxide are increased if the level of protein in the diet exceeds the animal’s nutritional requirements or if the amount of nitrogen applied to land exceeds what is required for the crop. Balancing of the diet to meet protein requirements and soil tests to ensure that manure application does not exceed crop nitrogen requirements, are two of the most effective methods of reducing nitrous oxide emissions from beef production systems.

Click here to learn how greenhouse gas emissions associated with Canadian beef production changed between 1981 and 2011.

Impact of Beef Cattle on Air Quality

Lethbridge Research CenterA common environmental footprint concern raised during beef production is the negative impact that intensive feedlot operations have on air quality through the generation of dust and odors. Issues often arise from acreages or towns that reside downwind of feedlots.

Dust can arise from pen surfaces, alleys and roads and is influenced by humidity, temperature and wind speed. Secondary emissions in the form of ammonia and odoriferous organic compounds such as amines, sufides, phenols and volatile fatty acids may also occur. Depending on the compound, they can be transported several kilometers from the feedlot.

Balanced feedlot diets that do not exceed animals' protein requirements reduce nitrous oxide and ammonia emissions. 

Long term health consequences associated with exposure to particulate matter from feedlots are largely unknown, but its impact on individuals suffering from chronic respiratory disease can be severe.

Deposition of ammonia and organics may adversely impact water quality. Ammonia can also contribute to indirect nitrous oxide emissions.

Mitigation

As with nitrous oxide, ammonia emissions from feedlots can be reduced by balancing diets so as not to exceed protein requirements of the animal. Urease inhibitors which inhibit the hydrolysis of urea in urine may also reduce ammonia voltalization, but are expensive and may only delay rather than reduce total ammonia emissions.

Provision of fresh bedding in pens, frequent cleaning of pens, planting of shelter belts and the construction of wind breaks may all reduce the movement of dust and odors associated with the feedlot. Proper drainage of pens can also prevent the development of the anaerobic conditions that promote such odors. Under arid conditions, sprinklers and water trucks can be used to reduce dust emissions from pen floors, alleys and roads. Many of these practices have the added benefit of improving animal health and housing conditions.

Proper manure management practices can also reduce nuisance odors by incorporating manure immediately after land application. This may also help conserve nutrients for crop growth and increase the organic matter content of soil.

Impact of Beef Cattle on Nutrient Cycles

On grassland

Cattle Nutrient Cycles

Nutrients are largely cycled within grassland ecosystems without reaching high concentrations or leaving the system. Nutrients in feces and urine are dispersed as cattle move throughout the pasture seeking new forage stands to graze. Fecal pats provide nutrients to insect communities such as dung beetles and the readily available nitrogen in urine is quickly utilized by plants.

For optimal production, cattle require an array of nutrients including protein, carbohydrates, fats, vitamins and minerals. Under grazing conditions, most of these nutrients are acquired directly from forages and cattle require minimal supplementation with trace minerals and salt.

In feedlots

feedlot

In intensive feedlot systems, feed is transported to the cattle and placed in feed bunks once or twice daily. Diets have a greater energy density as a result of the inclusion of grains increasing the efficiency of beef production.

However, in this system some dietary nutrients such as phosphorus exceed requirements, even though diets are not supplemented with this mineral. Because the only component that leaves this system is the cattle when they are shipped to market, other nutrients also accumulate.

Most nutrients are in the manure with the exception of the gaseous emissions described above. Manure is a valuable source of fertilizer and is applied to surrounding farmland, reducing the reliance on chemical fertilizers and increasing the organic matter content of soils. However, due to its high water content, manure is economical as fertilizer only if it is transported within a radius of 20 - 30 km of the feedlot. Furthermore, manure is usually applied to cropland based on the nitrogen requirements of the crop. This leads to excess application of other nutrients such as phosphorus and potassium, which accumulate in the soil.

Areas adjacent to intensive feedlot operations need to implement rotational cropping systems or increase manure transport distances to slow the rate of nutrient accumulation in soils. 

To date, there is little evidence that the accumulation of nutrients in cropland adversely impacts the surrounding environment or crop production. This is likely due to the fact that much of the phosphorus is in an insoluble form. In regions where livestock production systems are more intensive than in Canada, such as Denmark and the Netherlands, the long term impacts of using livestock manure as fertilizer has become an important issue.

Areas adjacent to intensive feedlot operations need to implement rotational cropping systems or increase manure transport distances to slow the rate of nutrient accumulation in soils.

Impact of Beef Cattle on Water Use and Quality

Estimates of the amount of water needed to produce 1 kg of beef range from 3700 L to 20,000 L. The majority of water used in beef production is for crop production. The large variation in estimates reflect differences in the assumptions in water use prediction models, such as the inclusion of natural rain fall, wastage during irrigation, and the degree to which recycling of water is considered (e.g., irrigation from catch basins).

Water UseWater plays a critical role in beef cattle production. Many of Canada’s largest feedlots depend on irrigation water during arid periods. The impact of climate change on water availability in these areas remains unknown, but many models predict an increase in rainfall in the prairie regions where the majority of beef cattle production occurs.

Cattle can also contribute to the conservation of wetlands as these surface waters are not drained as they are for cropping systems. Many of these areas serve as important habitat for aquatic birds and mammals.

Pathogens

Not all microbes shed by beef cattle cause disease in humans. Some strains are adept at persisting in cattle but not in humans. 

Beef cattle can carry protozoa (e.g., Giardia, Cryptosporidium) and bacteria (e.g.,, Escherichia coli O157, Campylobacter) that cause disease in humans. Water can serve as a vector for these microbes and steps are commonly taken to reduce the risk of manure coming in direct contact with surface water.

Modern feedlots are designed with slopped pens and ditches that drain into catch basins with a capacity to hold the precipitation from an extremely intense 24-hour storm. This prevents water from the feedlot directly entering surface streams and creeks. Numbers of pathogens in this water decreases with time and water from catch basins is used in feed crop production. Use of this water to irrigate vegetable crops that are not cooked prior to consumption should be avoided.

Sensitive riparian areas along streams and rivers are often fenced or lined with buffer strips to reduce the access of cattle to surface water whereas the access of cattle to irrigation canals is restricted. Completely limiting the access of cattle to surface water on grazing lands is impractical and cattle can defecate while drinking and crossing streams. Likewise, wild ruminants (deer, moose) aquatic mammals (beavers, musk rats) and birds (geese, ducks) which can also carry human pathogens, occupy this ecosystem and defecate in the surrounding water. Consequently, when a pathogen does cause disease, its true point of origin is often difficult to determine. The majority of the risk associated with acquiring pathogens can be eliminated by filtering or treating surface water prior to consumption.

Beef Cattle Production in a Larger Context

Indirectly, the environmental footprint of beef is a reflection of mankind’s demand for high quality protein in their diet. In North America, grains represent a significant proportion of the diets of feedlot cattle and contribute to the efficiency of this production system. Even in this case, grains are often initially grown for more value-added markets (e.g., brewing, distilleries, flour), and only end up as feed after they fail to make the grade for human consumption.

Global meat consumption is predicted to double by the year 2050

By 2050, as the human population reaches 9 billion and the average household income continues to rise, meat consumption is predicted to double. Consequently, it is important that environmental footprints are assessed from the standpoint of the efficiencies of meat production or expressed on impact per kg of meat produced.

Livestock production systems are complex and improvements in an area of production can lead to deficiencies or degradation in other areas. Presently, the economic conditions are favorable for the production of beef from grain in many regions of the world, largely because of the availability of inexpensive fossil fuels. As the price of fossil fuels increase, beef production may revert entirely to relying on what ruminants do best – the conversion of forages into high quality protein.

It is important to keep in mind that as one drives through the country side and sees the fields of hay and hills of native pasture, that ruminants are the only livestock that can effectively convert this biomass into high quality protein for human consumption.

Environmental Stewardship

Cattle producers utilize many grazing management techniques, participate in training and follow expert studies/research to enhance land use, conservation and management of resources.  Other tools may include cross-fencing, intensive rotational grazing, pasture or rangeland assessment, and fragile lands left in natural grassland or re-seeded to tame grass and forages.  In addition, many beef cattle operations and feedyards have completed an Environmental Farm Plan to manage potential risk and undertake many practices beneficial to their local ecosystem, in addition to meeting provincial regulations on confined feeding operations. 

The Verified Beef Production Plus (VBP+) program may assist your self-evaluation on important aspects.

To contact a provincial VBP+ coordinator in your region, visit http://verifiedbeefproductionplus.ca/contact-us.cfm

Videos

https://www.youtube.com/watch?v=UIfxCPRMVpE

https://youtu.be/8XScBqeXTSs

Learn More

To learn more on this topic, see the fact sheets posted on the right side of this page. External resources are listed below.

Explaining Growth Promotants Used in Cattle
BeefResearch.ca
http://www.beefresearch.ca/blog/growth-promotants/

Special Issue: Greenhouse Gases in Animal Agriculture - Finding a Balance between Food and Emissions
Animal Feed Science and Technology
http://www.sciencedirect.com

What place for livestock on a re-greening earth?
Animal Feed Science and Technology
http://www.journals.elsevierhealth.com

Challenges and opportunities for carbon sequestration in grassland systems: A technical report on grassland management and climate change mitigation
Food and Agriculture Organization of the United Nations (FAO)
www.fao.org

Beef and Ecosystems Services
Ecosystem Services and Western U. S. Rangelands
http://www.farmdoc.illinois.edu

Special Issue: Greenhouse Gases in Animal Agriculture - Finding a Balance between Food and Emissions
Animal Feed Science and Technology
http://www.sciencedirect.com

Video: Allan Savory - How to green the world's deserts and reverse climate change
TED Conferences, LLC
http://www.ted.com/talks/allan_savory_how_to_green_the_world_s_deserts_and_reverse_climate_change.html?utm_source=direct-on.ted.com&awesm=on.ted.com_Savory&utm_content=awesm-publisher&utm_medium=on.ted.com-static&utm_campaign

Changes in Greenhouse Gas Emissions from Beef Cattle in Canada
Saskatchewan Beef Industry Conference

 

Feedback

Feedback and questions on the content of this page are welcome. Please e-mail us at info [at] beefresearch [dot] ca.

Acknowledgments

Thanks to Dr. Tim McAllister, Agriculture and Agri-Food Canada Principal Research Scientist for contributing his time and expertise in writing this page.

This topic was last revised on October 19, 2017 at 08:10 AM.

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