Reports

Seaweed supplementation to mitigate methane (CH4) emissions by cattle

Published:

27/09/2021

Authors:

Dr. Ásta H. Pétursdóttir (Matís), Dr. Helga Gunnlaugsdóttir (Matís), Natasa Desnica (Matís), Aðalheiður Ólafsdóttir (Matís), Susanne Kuenzel (University of Hohenheim), Dr. Markus Rodehutscord (University of Hohenheim), Dr. Chris Reynolds (University of Reading), Dr. David Humphries (University of Reading), James Draper (ABP).

Supported by:

EIT Food

contact

Ásta Heiðrún E. Pétursdóttir

Head of Public Health and Food Safety

asta.h.petursdottir@matis.is

SeaCH4NGE results include a detailed analysis of the chemical composition of seaweed, including heavy metals and nutritional composition. Iodine concentration proved to be the main limiting factor regarding seaweed as a feed supplement. The decrease in methane observed in laboratory methane production experiments (in vitro) is likely due to compounds called fluorotannin rather than bromoform, a known substance that can reduce methane production in ruminants. In vitro screening of the seaweed showed a moderate decrease in methane, but lower methane production was dependent on seaweed species. The reduction was dose-dependent, ie by using more algae, a greater methane reduction could be seen in vitro. The same two types of seaweed were used in the Rusitec experiment (in vitro), which is a very comprehensive analysis that provides further information. An in-vivo study in cows showed that feeding cattle with a mixture of brown algae has a relatively small effect on methane emissions. However, fluorotannins are known to have other beneficial effects when consumed by ruminants. The report also includes a survey of British cow farmers' attitudes towards algae feeding and climate change.

Skýrslan er lokuð / This report is closed

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Reports

Seaweed supplementation to mitigate methane (CH4) emissions by cattle (SeaCH4NGE-PLUS)

Published:

17/09/2021

Authors:

Matís: Ásta H Pétursdóttir, Brynja Einarsdóttir, Elísabet Eik Guðmundsdóttir, Natasa Desnica, Rebecca Sim. University of Hohenheim: Susanne Kuenzel, Markus Rodehutscord, Natascha Titze, Katharina Wild.

Supported by:

Climate Fund, Rannís

contact

Ásta Heiðrún E. Pétursdóttir

Head of Public Health and Food Safety

asta.h.petursdottir@matis.is

This report contains the main experimental results of the SeaCH4NGE-PLUS project. In short, screening of the chemical content showed approx. 20 algae species collected in Iceland in 2020 and 2021, not bromoform-rich seaweed, but bromoform-rich seaweed can have a methane-reducing effect when given to cattle. Samples of brown algae were often high in phenol content, indicating a high fluorotannin content that has been linked to moderate methane reduction. Studies on Asparagopsis algae. indicated that these samples could have a short shelf life, but the effect was smaller than expected. Fermentation can have a small positive effect on methane production (ie slightly reduce production), but the extraction of the florotannin did not have a decisive effect on methane production. This report is closed until 31.12.2023.

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