de la Moneda, AnaCarro, Maria DoloresWeisbjerg, Martin R.Roleda, Michael Y.Lind, VibekeNovoa-Garrido, MargaritaMolina-Alcaide, Eduarda2025-06-212019-10-22de la Moneda, A., Carro, M. D., Weisbjerg, M. R., Roleda, M. Y., Lind, V., Novoa-Garrido, M., & Molina-Alcaide, E. (2019). Variability and potential of seaweeds as ingredients of ruminant diets: An in vitro study. <i>Animals : an open access journal from MDPI, 9</i>(10), 851. https://doi.org/10.3390/ani91008512076-261510.3390/ani9100851https://hdl.handle.net/20.500.14697/579This study was designed to analyze the chemical composition and in vitro rumen fermentation of eight seaweed species (Brown: <i>Alaria esculenta, Laminaria digitata, Pelvetia canaliculata, Saccharina latissima; Red: Mastocarpus stellatus, Palmaria palmata and Porphyra sp.; Green: Cladophora rupestris</i>) collected in Norway during spring and autumn. Moreover, the in vitro ruminal fermentation of seventeen diets composed of 1:1 oat hay: concentrate, without (control diet) or including seaweeds was studied. The ash and N contents were greater (p < 0.001) in seaweeds collected during spring than in autumn, but autumn-seaweeds had greater total extractable polyphenols. Nitrogen in red and green seaweeds was greater than 2.20 and in brown seaweeds, it was lower than 1.92 g/kg DM. Degradability after 24 h of fermentation was greater in spring seaweeds than in autumn, with <i>Palmaria palmata</i> showing the greatest value and <i>Pelvetia canaliculata</i> the lowest. Seaweeds differed in their fermentation pattern, and autumn <i>Alaria esculenta, Laminaria digitata, Saccharina latissima and Palmaria palmata</i> were similar to high-starch feeds. The inclusion of seaweeds in the concentrate of a diet up to 200 g/kg concentrate produced only subtle effects on in vitro ruminal fermentation.enMarine algaeRed algaeBrown algaeGreen algaeArticleSDG 14 - Life below waterseaweedschemical compositionmethanemethane fermentationruminant feedingruminantsChallenge 3: Sustainably feed the global populationChallenge 4: Develop a sustainable and equitable ocean economy