Seaweed Supplementation in Dairy Cattle: Implications for Methane Mitigation, Milk Yield and Nutritional Quality

The integration of seaweed into dairy cow diets has garnered increasing attention due to it’s dual potential to mitigate enteric methane emissions and improve milk production and quality. Seaweeds, classified broadly into brown, red, and green macroalgae, possess distinct biochemical profiles rich in polysaccharides, minerals, antioxidants, and secondary metabolites. Notably, brown seaweeds like Ascophyllum nodosum and Sargassum wightii have demonstrated promising effects in enhancing milk composition and reducing methane emissions. Despite variability in outcomes depending on species, dosage, and cattle breed, consistent improvements in milk iodine levels and rumen fermentation parameters have been observed. This article reviews recent findings on seaweed’s influence on dairy performance, methane mitigation, and nutritional enhancements, underscoring its potential as a functional and environmentally sustainable feed additive.