Does “Stacking” Best Management Practices Known to Reduce Greenhouse Gases Have an Additive Effect on Environmental and Secondary Benefits in Beef Production Systems?

Background

Reducing emissions is a priority of the beef industry to improve sustainability and to meet the Canadian beef industry’s 2030 goal to reduce GHG emissions intensity from primary beef production by 33%. Dietary additives such as ionophores and by-products containing fat, and management practices like extending the grazing season, have been used as effective strategies to improve production efficiency and mitigate GHG emissions in beef cattle.

Although research has demonstrated that emissions reductions associated with any one dietary mitigation strategy may range from 5-20%, the net impact of combining or “stacking” mitigation strategies to achieve greater reductions is not known. In other words, does adding 1+1 = 2, or does it sometimes come to 1.5 or even 3? It is important to explore this potential additive effect as cattle producers may adopt two or more BMPs at the same time.

Objectives

• Evaluate the potential of “stacking” best management practices has on reducing GHG emissions (enteric methane, nitrous oxide) from Canadian beef cattle.
• Improve the ability to estimate whole-farm emission reductions when multiple strategies are adopted.
• Explore the potential secondary benefits of improved production efficiency seen when adopting these changes in management (e.g., improved calving rate, calf weight, reproductive performance, BCS, reducing days on feed and size of the cow herd while still having the same output etc.)

What they will do

 This team will use previously published data on animal performance and GHG emissions (CH₄ and N₂O) to estimate the mitigation potential of adopting two or more management practices with different mechanisms of action, concurrently.

Examples of practices that will be evaluated:

• Including improved forage quality through rotational grazing,
• Seeding legumes,
• Addition of high fat low-cost by-products,
• Addition of an ionophore, and
• Extending the grazing season.

All practices that will be evaluated have been proven to reduce emissions when adopted individually and combining them is expected to have an additive effect. The selected scenarios will be guided by the future farms scenarios generated by the Canfax Cost of Production Project.

Holos 3 Research Version will be used to estimate emissions. This includes, methane form enteric fermentation and manure handling, direct and indirect nitrous oxide emissions from N leaching, run-off and volatilization from manure, soil and cropping and CO₂ from fuel energy use on-farm and for fertilizer and herbicide manufacturing.

The production benefits of adopting these practices will also be evaluated. Improvements to production efficiency are typically seen in addition to reducing GHGs when best management practices are adopted. This project will look at the extent of these benefits on animal health, productivity, and welfare.

Implications

Having this information will help to evaluate whole-farm emission reductions when multiple known GHG reducing practices are adopted simultaneously. This can be used to help guide producers seeking to reduce GHG emissions and further the potential of reaching the beef industry’s goal of reducing emission intensity from Canadian cattle by 33% by 2030. This team also hopes this project can guide future field-based trials by identifying stacking combinations that are likely to have the most success. Finally, identifying the production benefits of stacking BMPs can also provide incentive for producers to adopt these strategies to improve their management whilst reducing GHG emissions.