Experts look at ways to reduce industry’s environmental footprint
RED DEER — Sustainable intensification may be the only way to feed the world, says a scientist with Agriculture Canada.
“If we are going to feed the people of the world, intensification is the only way we are going to do it,” Tim McAllister told the Alberta Beef Industry Conference held in Red Deer Feb. 19-21.
Under this concept, production is increased on the current land base using the current supply of water.
McAllister said countries such as Brazil already understand the im-portance of this idea.
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Brazil has shifted from being a food importer to a major exporter. Its beef exports increased 10-fold in 10 years, and crop production increased by 365 percent.
McAllister said Brazil managed this increased production partly because it understands the importance of sustainable intensification. A cover crop of corn is underseeded with grass, and cattle graze what’s left after harvest.
Beef production is often targeted as unsustainable and a major contributor to air and water pollution.
Canada is involved in an international partnership called Livestock Environmental Assessment and Performance, which was formed in 2012 to assess the industry’s environmental performance as well as its social and economic viability.
The partnership is European influenced and many members do not understand how efficient cattle production has become on the vast grasslands of North America, said McAllister.
Beef production has become considerably more efficient in North America, where fewer animals are needed to produce the same amount of beef as 30 years ago. They require less water on less land and release less methane.
“The greenhouse gas emission issue is more related to burning of fossil fuels. It is not due to cattle,” said McAllister.
Five to 10 percent of Canada’s green-house gas emissions come from cattle production.
Scientists have studied beef production’s environmental impacts, and new research initiatives are planned to further assess emissions, nutrient excretions, carbon balance, water quality and spread of pathogens.
“The role of agriculture and beef production on the environment has gained a lot of media time, positive and negative depending on the day of the week,” said Emma McGeough of the University of Manitoba’s animal sciences department.
“Beef offers so many other advantages aside from carbon footprints, so that is why we have to look at the bigger picture,” she said.
A 2005 report from the United Nations’ Food and Agriculture Organization, Livestock’s Long Shadow, said meat and milk production account for 50 percent of agricultural emissions, so efforts are needed to reduce the industry’s carbon footprint.
Total greenhouse gas emissions are calculated by looking at the release of carbon dioxide, nitrous oxide and methane from manure and digestive fermentation based on a per kilogram of beef.
Some assessments look at the entire beef cycle from pasture to consumption. Activity on the farm is considered the greatest producer of greenhouse gases. Methane, nitrous oxide, and carbon dioxide are emitted from feed use, manure, fuel, pesticides, fertilizers and transportation.
Beef emissions are higher than pork, chicken, eggs and milk because cattle live longer. It takes three years from the time a female is born until a calf is produced.
A 2010 life cycle assessment by scientists at Agriculture Canada’s Leth-bridge Research Centre estimated that cow-calf herds produce more emissions than feedlots because feedlots are more efficient.
As a result, efforts to reduce emissions should start at the cow-calf level.
“There are improvements that we can make,” McGeough said.
“Sometimes they look quite small, but it doesn’t mean a cumulative effect can’t make a difference.”
Backgrounding cattle could receive more dried distillers grain or oilseeds because higher fat diets tend to promote lower methane emissions.
Grass-fed cattle leave a greater carbon footprint, but the benefits of pastureland outweigh some negative aspects.
“There are areas where crops cannot or should not be grown,” she said.
Trees, woody plants and permanent grasslands are known for their ability to store carbon underground that can be converted into energy for plant growth.
However, changes in soil carbon take place over decades rather than a season.
Twenty-five percent of carbon has been lost in Canada since the 1900s because of extensive tillage. Potentially large amounts of carbon can be sequestered with permanent grass cover or including forage in a rotation.
Rangelands also need to be grazed to reduce dominant weeds from taking over. Managed grazing can stimulate plant growth, accelerate nutrient cycling and provide wildlife habitat.
Animals leave behind manure as they graze, which makes good and bad contributions to the environment.
Manure application can enhance biomass and microbial activities and add carbon to the soil. However, it also leaches nitrogen, phosphorus and potassium into the environment.
Therefore, the amount of protein in feed should be watched because a beef animal uses only 10 to 20 percent of the nitrogen that is present in feed. The excess is released as urine and manure.
“Protein is an expensive ingredient to supplement in diets, and if they are not using it, they are losing it,” she said.
Ammonia from urine, manure and fertilizer is a major air pollutant.
Ammonia is released into the atmosphere when animals defecate: 119 grams per day on average from feedlots.
Biofilters or bioscrubbers can be used, but these devices are more appropriate in poultry barns.
Life cycle studies include livestock’s impact on water, so protection of riparian areas is critical. These green zones areas occupy about five percent of the Prairies.
Well-kept riparian areas maintain banks, reduce water velocity and sediment buildup, recharge aquifers and reduce soil erosion.
McGeough said livestock production is a major consumer of water, but all food has an embedded water cost.
It can take 1,760 to 15,500 liters to produce a kilogram of beef, de-pending on what is included in the calculation.
