The n-3 docosapentaenoic acid (n-3 DPA) could be a novel source of n-3 long-chain polyunsaturated fatty acids (LCPUFA) with beneficial physiological effects. Following the supplementation of 0.5% purified n-3 DPA for 3 weeks from weaning, the n-3 DPA content increased in one-half of the 18 studied tissues (from +50% to +110%, p < 0.05) and mostly affected the spleen, lung, heart, liver, and bone marrow. The n-3 DPA was slightly converted into DHA (+20% in affected tissues, p < 0.05) and mostly retroconverted into EPA (35–46% of n-3 DPA intake in liver and kidney) showing an increased content of these LCPUFA in specific tissues. The partial incorporation of dairy lipids in the diet for 6 weeks increased overall n-3 PUFA status and brain DHA status. Furthermore, the n-3 DPA supplementation and dairy lipids had an additive effect on the increase of n-3 PUFA tissue contents. Moreover, n-3 DPA supplementation decreased plasma cholesterol.