Methane emmissions of Australian feedlot cattle as influenced by 3-Nitrooxypropanol and diet composition | 2021

Summary

A novel feed additive for ruminants, Bovaer 10® (3-NOP) has been developed by DSM as a tool to reduce enteric methane emissions. The product takes effect immediately when fed to animals and is underpinned by ten years of R&D, with over 48 peer reviewed publications that demonstrate a substantial reduction in methane production, whilst having no negative effects on animal welfare, feed consumption, performance or food safety.

This project determined the effect of varied diet concentrations of Bovaer 10®on methane (CH4) emissions and rumen fermentation patterns of cattle fed typical Australian feedlot diets. It also evaluated the current baseline CH4 prediction-equations for feedlot cattle in the Australian Government greenhouse gas (GHG) accounting framework.

Objectives

The project objectives were to:

• determine the effect of 3-NOP titration regimen on rumen fermentation and methane emissions during starter- and finishing phases in beef cattle; and
• validate current methods for predicting methane production of feedlot cattle, including the Moe and Tyrrell equations (used for methane calculation in Australian National Greenhouse Gas accounts) and the IPCC Tier 2 methodology (commonly used in the US).

Key findings

• Bovaer 10®added from 50 to 125mg 3-NOP/kg DM to Australian finishing diets containing monensin and 7% fat (DM-basis) can reduce methane production and yield by up to 90%.
• All Bovaer 10®titration regimens significantly reduced methane production and methane yield of feedlot cattle from d 21 to 112.
• Although this experiment was not designed to make conclusions on an effect of Bovaer 10®on feedlot performance, no negative effects of Bovaer 10®diet supplementation on the animal performance parameters measured were observed. Average daily gain and feed conversation rations for steers were in line with industry expectations.
• The study also demonstrated a substantial overprediction of methane by the current national inventory equation for the control cattle.

Benefits to industry

Supplemental Bovaer 10® in white-grain and high-fat finishing diets can allow Australian feedlots to produce low-methane-emission beef from the grain-finishing phase. It has also demonstrated that there is a low baseline level of methane production from typical Australian feedlot diets.

Ultimately, the knowledge on the methane suppression pattern of Bovaer 10®may facilitate sustainable pathways for the feedlot industry as well as enabling Australian producers to benefit from carbon credit trading schemes.

MLA action

The full results of the research will be published in a scientific peer-reviewed journal in the coming months. Planning is underway for further trials with the support of MLA, including the use of Bovaer 10®as an additive for grazing cattle, as well as discussion on inclusion in carbon accounting methodologies and sustainability frameworks.

Future research

Testing Bovaer 10®in other commercial-feedlot settings will be explored, to investigate possible productivity co-benefits and practicalities of 3-NOP supplementation in feedlot diets.