New peer-reviewed study: 99% methane elimination in beef feedlots

Highlights

• A new study has rounded out the body of peer-reviewed research showing the safety and efficacy of Asparagopsis for beef feedlots, paving the way for its commercial use in Australia.

• The study evaluated the effects of feeding varying amounts of an Asparagopsis-oil formulation to beef cattle.

• Over an 81-day feeding period, 20 Angus heifers in a beef feedlot were divided into four groups with each being fed a varying amount of Asparagopsis-oil.

• The levels of methane (CH4) yield were reduced by 64%, 98% and 99%, respectively.

• The cows fed the finisher diet with the highest amount of Asparagopsis-oil recorded the highest reduction in methane.

• The results showed that the inclusion of Asparagopsis-oil to the cows’ diet did not have any impact on carcass characteristics.

• Iodide and bromide residues were maintained at levels safe for human consumption.

Over the past decade, the science of Asparagopsis as a livestock feed ingredient to reduce methane has been iterative. Early studies in this field showed the efficacy of Asparagopsis in the form of a freeze-dried powder, while a more recent group of trials has proven that by steeping Asparagopsis in an edible oil, such as canola, the bioactive compounds are just as effective.

With edible oils already a common ingredient in cattle diets, this delivery method is particularly straightforward to incorporate into beef feedlot and dairy systems .

Asparagopsis-oil has already been shown to be effective for dairy cows in a study co-authored by FutureFeed’s Dr Rob Kinley and Dr Breanna Roque.

In the most recent Asparagopsis-oil study by Cowley et al, ‘Bioactive metabolites of Asparagopsis stabilized in canola,’ the range of effective inclusion levels for Asparagopsis-oil in the diet of beef feedlot cattle were tested.

Twenty Angus heifers were allocated one of four treatments over an 81-day feeding period:

1. Control group

2. Low Asparagopsis-oil canola oil blend (14 mg)

3. Medium Asparagopsis-oil canola oil blend (34 mg)

4. High Asparagopsis-oil canola oil blend (51mg)

The results of this study showed that the levels of methane (CH4) yield, were reduced by 64%, 98% and 99%, respectively, with the cows consuming the highest amount of Asparagopsis-oil recording the greatest reduction in methane.

The trial was run by FutureFeed, University of New England and the University of Queensland, with FutureFeed scientists Dr Rob Kinley and Dr Breanna Roque co-authoring the paper with others.

FutureFeed CEO Alex Baker said the study provides practical information for animal nutritionists and feedlotters wanting to safely incorporate Asparagopsis-oil into livestock diets.

“We have a long history at FutureFeed, and earlier with CSIRO and James Cook University, of being highly transparent with our Asparagopsis research. Our studies go through rigorous peer review processes prior to publication, which gives the agriculture industry and regulators a lot of confidence in the safety of Asparagopsis as a methane reduction supplement,” Mr Baker said.

“Peer reviewed studies including Cowley et al (2024) also provide a reliable scientific basis for the calculation of methane reductions based on particular inclusion levels of the bioactive compounds from Asparagopsis. This builds a trusted foundation for carbon accounting, for those who wish to take advantage of carbon markets.”

Mr Baker said that the next study seeks to quantify the feed conversion efficiency for beef feedlot cattle. This highly anticipated study is currently in peer review and results will be released in coming months.