THE EFFECT OF MICROALGA CHLORELLA VULGARIS AND CYANOBACTERIA SPIRULINA PRATENSIS SUPPLEMENTATION ON RUMEN FERMENTATION IN CATTLE

Microalgae, such as Chlorella spp. and Spirulina (Arthrospira) spp., are rich in protein, pigments, vitamins, and bioactive compounds and are being explored as alternative or complementary protein sources for ruminants. Contemporary reviews highlight their potential to influence rumen fermentation, microbial ecology, and product quality. However, responses are heterogeneous and may depend on factors such as species, dose, processing, and the diet background (e.g., forage-to-concentrate ratio) (Saadaoui et al., 2021; Zhu et al., 2024). In vivo data in cattle remain limited; for instance, Chlorella spp. supplementation has changed rumen fatty acid profiles in cattle fed low-quality forages, and Spirulina spp. has affected rumen development and VFA in small ruminants; however, applying these findings across different species, diets, and dosages remains uncertain (Costa et al., 2020; Wang et al., 2023). We therefore tested whether practical amounts of C. vulgaris and S. platensis—alone or in combination—alter rumen fermentation endpoints in cannulated dairy cows fed diets formulated to meet the requirements.