Freshwater Cladophora glomerata Biomass as Promising Protein and Other Essential Nutrients Source for High Quality and More Sustainable Feed Production

A scientific justification, focused on the development of the sustainability of feed ingredients and farm animals’ ecosystems, is required. Thus, it is crucial to search for alternative feed materials from natural sources for potential applications. The aim of this study was to evaluate the prospective utilization of freshwater Cladophora glomerata ( C. glomerata ) as an alternative source of protein and other essential nutrients in animals’ feed. For this purpose, chemical analysis was performed on collected biomass samples from the Lithuanian rivers, Dubysa (B1), Šventoji (B2), Nevėžis (B3), and Jūra (B4). Microelements (Ca > K > N > P > Mg), trace elements (Zn > Cu), and heavy metals (Cr > Ni > Pb > Cd) have not exceeded permissible levels. The crude protein content of C. glomerata biomass ranged from 16% to 21.5% DM. The essential amino acid profile excelled, with the highest total amino acid amount of 140.99 g/kg in B4. The highest total presence of polyunsaturated fatty acids (11.71%) as well as the ratio of polyunsaturated to saturated fatty acids (0.22) was observed in B1. The lowest ratio of omega-6/omega-3 was in B1 (1.30). As a result of bioaccumulation, C. glomerata could serve as a source of proteins, as well as amino and fatty acids, implying that biomass could be an alternative and a beneficial component of animal feed.