Angellotti, Melania
- Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
Abstract
Enteric methane (CH4) emissions from dairy cows contribute significantly to greenhouse gas production; mitigating these emissions is a major challenge for sustainable livestock systems. This thesis evaluated the potential of Asparagopsis spp. to reduce enteric CH4 emissions while considering animal performance, rumen and faecal microbiota, and the influence of algae cultivation conditions on bioactive compound concentrations.
Across three studies, Asparagopsis spp. consistently reduced CH4 production, although the effects and persistence of mitigation depended on algae composition and feeding duration. The use of Asparagopsis spp. also caused microbial changes in the rumen. Supplementation influenced fermentation patterns, including volatile fatty acid profiles, and altered both ruminal and faecal microbial communities, highlighting the interaction between chemical inhibition and microbial shifts. The thesis also showed variability in algae quality and bioactive compound concentrations such as bromoform, underlining the need for standardized production and dosing strategies. Furthermore, halogen intake and accumulation were monitored to assess food safety implications.
While many of the observed responses are consistent with earlier studies, this thesis reveals new mechanistic insights into how temporal changes in the rumen and faecal microbiome, halogen accumulation patterns, and fluctuations in algae composition collectively influence the variability in animal responses. These findings highlight that Asparagopsis spp. cannot be regarded as a uniform or fixed feed; instead, its impact emerges from a highly dynamic interplay between algal chemistry, microbial adaptation, and metabolic regulation.
Overall, this thesis demonstrates that Asparagopsis spp. is a promising strategy for enteric CH4 mitigation in dairy systems, but its practical application requires the careful consideration of algae quality and long-term efficacy.
Keywords
red algae; rumen microbiota; CH₄ mitigation; fermentation; halogen compounds; VFA
Published in
Acta Universitatis Agriculturae Sueciae
2026, number: 2026:3
Publisher: Swedish University of Agricultural Sciences
SLU Authors
UKÄ Subject classification
Animal and Dairy Science
Publication identifier
- DOI: https://doi.org/10.54612/a.27fpu0nagv
- ISBN: 978-91-8124-200-3
- eISBN: 978-91-8124-220-1
Permanent link to this page (URI)
https://res.slu.se/id/publ/130925