Effect of Fatty Acid Mixture on the Hyperplastic and Hypertrophic Growth of Subcutaneous Bovine Stromal Vascular Fraction Cells In Vitro

Background: Adipose tissue growth follows a biphasic process involving both cellular hyperplasia (an increase in adipocyte number) and hypertrophy (an increase in adipocyte size). Rumen-protected fatty acid supplements have been utilized to alter fat deposition, modify the fatty acid composition of meat, and reduce methane emissions. However, limited research has explored how different fatty acid mixtures influence adipose tissue’s biphasic growth phases. Methods: The objectives of this study are to investigate the effects of fatty acid mixtures (seven different mixtures) on: (1) hyperplasia of undifferentiated stromal vascular fraction (SVF) cells, or (2) hypertrophy of chemically differentiated SVF cells isolated from subcutaneous adipocytes of finished steers. Results: Mixtures containing palmitic and linoleic acids stimulated hyperplasia, enhancing the proliferation of undifferentiated SVF cells, while mixtures with oleic acid (50%) predominantly promoted hypertrophy, driving lipid accumulation and adipocyte maturation. Conversely, mixtures composed solely of saturated fatty acids (50% palmitic and 50% stearic acids) exhibited a profound inhibitory effect on both hyperplasia and hypertrophy, underscoring the importance of fatty acid composition in regulating adipogenesis. Conclusions: These findings demonstrate that the composition of fatty acid mixtures directly influences adipogenesis and lipogenesis in vitro, highlighting their potential role in designing tailored rumen-protected supplements for modifying fat deposition in livestock.