Can Seaweed Be a Sustainable, One Health Resource in Livestock and Poultry Diets?

Seaweed is an abundant but underutilized resource in livestock and poultry feeds. The nutrient composition and digestibility are highly variable among and within seaweed species and geographic origin, and its ability to bioaccumulate several detrimental toxic substances in the marine environment can cause feed and food safety concerns. However, many seaweed species are rich sources of numerous bioactive compounds and phytochemicals that provide prebiotic, antioxidant, anti-inflammatory, antimicrobial, and antiviral properties as purified extracts that enhance animal productivity, health, and quality of animal-derived food products. Bromoform, which is found in high concentrations in red seaweed species, can be used as an effective dietary mitigation strategy for reducing enteric methane emissions from ruminants and subsequently reduce the environmental impact of meat and milk production. However, there are multiple tradeoffs between positive and negative environmental impacts, animal health benefits and risk factors, and improvements in quality of meat, milk, and eggs versus potential food safety concerns that are associated with the production, bioprocessing, and use of seaweed and bioactive compounds in animal diets that must be considered. This comprehensive review is intended to provide a synthesis of disparate threads of vast amounts of scientific information across multiple disciplines to help us answer the question "Can seaweed be a sustainable, One Health resource in livestock and poultry diets?".