Reducing whole farm GHG emissions and improving nutrient utilization in cow-calf operations

with emphasis on integration of feeding, and animal and manure management practices


Principal Investigator: Dr. Kim Ominski, forage-beef production systems,  Email:
Co-lead Investigator: Mario Tenuta, soil ecology, Email:

Investigators from the University of Manitoba Faculty of Agricultural and Food Sciences with the National Centre of Livestock and Environment (NCLE), Agriculture and Agri-Food Canada and Virginia Tech University

Supporters include Manitoba Pork, Dairy Farmers of Manitoba and Feedlot Health Services

Global Linkages: The AGGP is part of Canada’s commitment to the Global Research Alliance on Agricultural Greenhouse Gases, aimed to find ways to grow more food without increasing greenhouse gas emissions. See:


 Agriculture and Agri-Food Canada Agricultural Greenhouse Gases Program

Project Goal:

The impact of changes in management on GHG emissions is not always clear due to the complexity of cattle production systems. Systems-based, whole farm analyses are necessary to address these complex issues to ensure that policy development and consumer information is founded on the basis of sound science.

This project will provide new science-based knowledge regarding net greenhouse gas (GHG: CH4 and N2O) emissions related to dietary and manure management practices, and their integration in beef cow-calf operations. Improved scientific understanding of GHG transfer in agricultural systems will lead to identification of BMPs that can be targeted for policy development and program delivery, in order to improve economic and environmental sustainability of the Canadian cattle industry.

Target Outcomes:

1) Understand the net impact of combining mitigation strategies on GHG emissions in cow-calf production systems.
2) Use of these findings to identify practices that Canadian farmers can adopt to improve environmental sustainability and profitability.
3) Transfer of scientific knowledge to the beef community through a variety of extension activities and materials.
4) Educational GHG programming for the general public and school-age children via the Faculty of Agricultural and Food Science’s Farm and Food Discovery Centre.

Why is this research important?

In western Canada, approximately 84% of enteric methane is produced from the cow-calf sector, highlighting the need and the opportunity for emissions reductions in this sector. Since agriculture contributes 10% to the global greenhouse gas emissions that cause climate warming, their reduction has both environmental and economic benefits.


The high proportion of emissions from the cow-calf industry can be attributed to the forage based diets which cows and replacement animals are fed. Enteric methane (CH4) emissions per unit of feed energy (6-11%) are 2-3 times greater than those in feedlots (2-4%) where animals are fed high concentrate diets for a relatively short period of time. Thus, it is important for the industry to focus its efforts to reduce enteric emissions with forage-based diets in cow-calf production.

However, since forage is the primary diet ingredient, mitigation options must be directed toward forage type and quality, leaving cow-calf producers with fewer options for addition of supplements than in mixed rations which are used in feedlot. Research to date has demonstrated that for any one mitigation strategy, the emission reductions may range from 5-20% (Beauchemin et al. 2011). The net impact of combining mitigation strategies is not known, so the next step to consider is combining or “stacking” dietary management and manure management strategies to optimize nutrient efficiency at the animal-plant-soil interface and obtain greater emission reductions.

The need for this integrative research is supported by a recent report released by The Canadian Round Table for Sustainable Beef (CRSB Meeting, Climate Change Working Group, April 21-22, Winnipeg, MB, 2016). They outlined priority areas for the beef industry regarding climate change including: 1) diet, 2) optimum fertilization (manure) use to reduce nitrous oxide emissions and 3) enhance knowledge of manure production and storage including impact of diet on composition, which will be addressed in this project by using models to assess impact of changes in diet, animal and manure management on whole farm GHG emissions.