Evaluation of Different Brown Seaweeds as Feed and Feed Additives Regarding Rumen Fermentation and Methane Mitigation

This study investigated the impacts of different brown seaweed species—Ascophyllum nodosum, Sargassum fulvellum, Ecklonia maxima, Lessonia flavicans, nigrescens, and Laminaria japonica—on rumen fermentation methane (CH4) mitigation. The current in vitro batch culture for 24 h at 39 °C evaluated these species two experimental designs: as feed additive feed. control group both designs was composed 500 mg basal diet (50% grass hay/50% concentrate). For additives design, each when it added 20% diet, while a feed, inclusion level to partially replace concentrate follows hay/30% concentrate/20% seaweed). Chemical analyses showed that seaweeds were characterized by high fiber content amounts minerals such calcium, potassium, phosphorus, protein ranged within 7 13%. When they applied additives, increased production volatile fatty acids, with L. japonica being most effective; however, failed suppress CH4 production. In contrast, their led significant reduction (p < 0.05) CH4, especially E. maxima japonica, up 18 21%, respectively, but this associated general inhibition fermentation. Therefore, tested could be used source improve fermentation, without anti-methanogenic potential. Meanwhile, reduce an adverse effect on Thus, further trials are needed identify appropriate achieve effective any detrimental effects