Source: University of Manitoba
BENEFICIAL MANAGEMENT PRACTICE (BMP) FOR GREENHOUSE GAS MITIGATION
BACKGROUND
Enteric methane is produced by microbes during digestion of feed in the rumen of cattle.
Between 2 and 11% of the feed energy offered to cattle is lost as methane.
Enteric methane contributes 3% of total greenhouse gases (GHG) in Canada.
The cow-calf sector feeds mostly high fiber forages and therefore produces the greatest amount of methane. Up to 78% of methane from cattle is produced by the cow-calf sector.
Feeding cattle efficiently by offering high quality forages and formulating rations to meet animal requirements will lower methane emissions and improve energy utilization by cattle.
Cow-calf producers manage much of the pasture land in Canada. Wellmanaged pastures remove GHGs (carbon dioxide) from the atmosphere through a process called carbon sequestration.
WHAT SHOULD WE DO?
Grow, harvest and feed high quality forages.
Formulate diets based on feed tests and feed to meet animal requirements.
Manage pastures to produce high quality forage and avoid overgrazing.
WHY SHOULD WE DO IT?
Cattle can lose up to 1 in 10 bales worth of feed energy as methane when digesting low quality hay. Feeding high quality forages has the potential to reduce methane emissions by 8% (when crude protein is increased from 6.9 to 13.6%).
Cattle that lose a higher percentage of their feed energy as methane are less efficient. This means that more days are required to reach a target gain and feed costs are higher for the producer.
Feeding high quality grass and legume forages that meet animal nutrient requirements will improve production, shorten the time to reach a target weight or body condition score and lower feed costs.
HOW SHOULD WE DO IT?
Time forage harvest and grazing to coincide with peak quality to improve cattle average daily gain and reduce enteric methane emissions.
For optimum forage quality, cut legumes in early bloom and grasses in early heading stage.
It is paramount to keep your harvesting equipment in good condition in order to maintain hay quality. Dry matter loss from standing hay can occur during harvest. Mowing can cause losses of 2% and baling of 6%, but a poorly adjusted pick-up can cause losses of up to 12% of available dry matter.
Consider covering or shedding your hay. Storage without cover can result in dry matter losses of between 5 and 35%, depending on the amount of precipitation, storage site and original bale condition.
Implement planned grazing systems and avoid overgrazing pastures.
Test your forages for nutrient composition to accurately formulate rations for efficient feeding.
HOW DO WE KNOW THIS?
Forages harvested at optimum maturity maximize digestible energy content and reduce enteric methane emissions – Boadi et al.
Inclusion of legume forages harvested at optimum maturity will ensure adequate dietary protein and maximize digestibility – Blair
Feeding to meet the nutrients required by all animal classes (i.e. lactating, dry, replacements) will improve productivity for cows and reduce the number of days on feed for growing animals.- Blair
Cattle turn grasses, inedible to people, into high quality protein.
OTHER BENEFITS OF WELL-MANAGED FORAGE AND GRASSLANDS
Perennial grasslands protect sensitive lands from erosion.
Perennial grasslands remove carbon from the air and store it in soil as root material (carbon sequestration).
Perennial grasslands provide ecosystem services through habitat preservation and enhanced biodiversity.
POTENTIAL DISADVANTAGES OR UNCERTAINTY
Dietary protein (nitrogen) in excess of animal requirements will be excreted. Feeding above requirements results in unnecessary feed costs and may have environmental implications via nitrates in water or nitrous oxide emissions from manure.
RESEARCH HIGHLIGHTS
Blair, K. 2015. Measured and modelled enteric methane emissions from beef cattle as affected by dietary crude protein of forage diets. University of Manitoba Thesis (M.Sc.). University of Manitoba, Department of Animal Science
Boadi, D., K. Wittenberg, S. Scott, D. Burton, K. Buckley, J. Small and K. Ominski. 2002. Methane production from dairy and beef heifer fed forages differing in nutrient density using the sulphur hexafluoride (SF6) tracer gas technique. Can. J. Anim. Sci. 82:201-206
Farm software and worksheets: Forage and livestock. Manitoba Agriculture Food and Rural Development. Retrieved from: https://www.gov.mb.ca/ agriculture/business-and-economics/financial-management/farm-software-andworksheets.html#ForageandLivestock
Fraser, T.J. and B.D. Amiro. 2013. Initial carbon dynamics of perennial grassland conversion for annual cropping in Manitoba. Can. J. Soil Sci. 93:379-391
Hay harvesting loses. Alberta Agriculture and Forestry. Retrieved from: http:// www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/faq14040
How stage of maturity affect forage quality. Alberta Agriculture and Forestry. Retrieved from: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/ faq14096
Legesse, G, K. A. Beauchemin, K. H. Ominski, E. McGeough, R. Kroebel, D. MacDonald, S. Little and T. A. McAllister. 2016. Greenhouse gas emissions and resource use of Canadian beef production in 1981 as compared to 2011. Anim. Prod. Sci. 56:153-168
Reducing storage quality losses. Foragebeef.ca. Retrieved from: http:// www1.foragebeef.ca/$foragebeef/frgebeef.nsf/all/ccf61
Taylor, A.M., et al. 2013. Net CO2 exchange and carbon budgets of a threeyear crop rotation following conversion of perennial lands to annual cropping in Manitoba, Canada. Agric. Forest Meteorol. 182-183:67-75
Waghorn, G. Best management practices for lowering greenhouse gases from pastoral farming Dexcel Ltd, Hamilton, New Zealand. Retrieved from: http:// www1.foragebeef.ca/$foragebeef/frgebeef.nsf/all/ccf759/$FILE/ CcBMPforloweringgreenhousegasesNZ.pdf
Funding for production of this factsheet was provided by the Government of Canada through the Agricultural Greenhouse Gases Program of Agriculture and Agri-Food Canada.
