The spleen, traditionally associated with its role in immune surveillance and blood cell turnover, nowadays is known to be engaged in metabolic control processes, e.g., in the metabolism of lipids. While input of energy sources is essential during animal ratio’ formulation, exploring the lipid composition of the spleen and its potential modulation by antioxidant supplements becomes particularly relevant. Our results may be practically applied in the food industry, as they may provide animal food, ensuring the nutritional requirements of especially poorly nourished consumers. Moreover, our findings could bridge the existing knowledge gap about the interplay of diet and lipid composition in the spleen. As this organ is considered to have an essential role in the development of atherosclerosis, obesity, nonalcoholic liver disease, nonalcoholic steatohepatitis, and fatty liver, understanding the function of this internal organ may be a starting point for developing efficient prevention strategies in order to counteract these disorders.