Seaweed shows promise in livestock feed, with safety caveats
Bottom line
A new review in Animals argues that seaweed remains a promising but still uneven fit for livestock and poultry diets. Author Gerald C. Shurson describes seaweed as abundant and underused, with potential value as a source of nutrients and bioactive compounds that may support gut health, immune function, antioxidant activity, and, in some ruminant applications, lower methane emissions. But the review also stresses that composition and digestibility vary widely by species, harvest conditions, and geography, and that some seaweeds can accumulate iodine, arsenic, cadmium, and other contaminants that raise feed and food safety concerns. (environment.umn.edu)
Why it matters: For veterinary professionals, the paper is a useful reminder that seaweed sits squarely in the One Health conversation: it may offer tools for animal performance, antimicrobial stewardship, and environmental sustainability, but only if sourcing, processing, inclusion rates, and contaminant monitoring are tightly managed. Broader reviews and FAO-linked food safety discussions echo the same point, noting that benefits in poultry and livestock are real but inconsistent, and that iodine, heavy metals, marine biotoxins, and regulatory gaps remain practical barriers to wider adoption. (frontiersin.org)
What to watch: Expect the next phase of work to focus on standardized composition reporting, safer processing methods, dose-response studies, and clearer regulatory guardrails for feed use. (www2.oceanvisions.org)
Seaweed is getting another close look as a livestock and poultry feed ingredient, and the latest review in Animals makes the case that it could become a more important One Health resource, but not without better evidence and tighter safety controls. Shurson’s review frames seaweed as an abundant, underused feed resource with nutritional and functional potential, while emphasizing that its value depends heavily on species selection, processing, and contaminant management. (environment.umn.edu)
That balance between promise and risk has been building for years. Seaweed has long been studied as a source of fiber, minerals, and bioactive compounds for farm animals, and more recent work has expanded interest because of possible prebiotic, antioxidant, anti-inflammatory, and antimicrobial effects. In ruminants, some seaweed species have also drawn attention for methane mitigation, which has pulled the ingredient into broader climate and sustainability discussions. At the same time, repeated reviews have found that results are highly variable across species, animal classes, and inclusion rates. (sciencedirect.com)
The central challenge is consistency. Brown macroalgae such as Saccharina latissima and other species may improve some production or product-quality measures, but nutrient composition can shift substantially with geography, season, and post-harvest handling. Processing can help: recent reviews suggest hydrothermal and other post-harvest treatments may reduce iodine and some metals of concern, potentially improving feed safety and usability. Still, the literature keeps returning to the same caution flags, especially iodine, arsenic, cadmium, lead, mercury, and, in some methane-focused applications, bromoform-related safety questions. (pmc.ncbi.nlm.nih.gov)
In poultry and monogastric systems, the opportunity looks somewhat different. Reviews describe seaweed as a possible functional ingredient that may support gut health, immunity, pigmentation, oxidative stability, and product quality, but they also note that inclusion rates are usually limited and performance responses are not always consistent. Researchers have also pointed to the need for better processing to reduce antinutritional factors and improve digestibility before seaweed can move from niche additive to routine feed component. (mdpi.com)
Industry and policy conversations appear to be moving in the same direction as the science: cautiously forward. A University of Minnesota project tied to Shurson’s work says feed and livestock industries still see major obstacles in reliable supply and economic sustainability. Stakeholder research in dairy has likewise identified cost, insufficient supply, and uncertainty around practical value as barriers, even as feed suppliers remain interested in methane reduction and health-related claims. Meanwhile, Codex discussions this year highlighted the need for stronger safety evaluation of seaweed products, including heavy metals, iodine, and marine biotoxins. (environment.umn.edu)
Why it matters: For veterinarians and animal health teams, this is less a story about a single new feed additive than a reminder that novel feed ingredients now have to perform across multiple fronts at once: animal health, food safety, environmental impact, and public trust. Seaweed may eventually help some producers improve gut health, reduce reliance on certain conventional additives, or support sustainability targets. But veterinary professionals will likely be asked to weigh those benefits against source verification, toxic element exposure, residue transfer into milk, meat, or eggs, and the quality of evidence behind product claims. In that sense, seaweed is a textbook One Health ingredient, promising precisely because it connects animal, human, and environmental health, and risky if those links aren’t managed carefully. (fao.org)
What to watch: The next milestones will likely be standardized feed specifications, more commercial-scale animal studies, clearer contaminant thresholds, and regulatory alignment on how seaweed ingredients should be evaluated and labeled. Until then, adoption will probably remain selective, with the strongest momentum in targeted functional uses rather than broad replacement of conventional feed ingredients. (www2.oceanvisions.org)
Common questions
Why is seaweed being considered for livestock and poultry diets?
The review says seaweed is abundant and underused, with potential as a source of nutrients and bioactive compounds that may support gut health, immune function, antioxidant activity, and, in some ruminants, lower methane emissions.What are the main concerns with feeding seaweed to animals?
Its composition and digestibility vary widely by species, harvest conditions, and geography, and some seaweeds can accumulate iodine, arsenic, cadmium, and other contaminants that raise feed and food safety concerns.Does seaweed work the same way in all animals?
No. The article says benefits in poultry and livestock are real but inconsistent, and results vary across species, animal classes, and inclusion rates.What needs to happen before seaweed is used more widely in feed?
The article says the next phase should focus on standardized composition reporting, safer processing methods, dose-response studies, and clearer regulatory guardrails for feed use.