OBJECTIVE: Mulberry (Morus alba) leaf (ML) is a high-quality feed source for ruminants, while it is unclear whether it can enhance the growth performance and meat quality of Xiangdong black goats. METHODS: In this study, we investigated the effects of ML supplementation (0%, 5%, 10%, 15%, and 20%) on the growth performance, serum variables, and the profiles of amino acids and fatty acids in the muscle of Xiangdong black goats. RESULTS: Results showed that the final body weight, initial and final dry matter intake, and average daily gain increased linearly and quadratically with the increasing ML content (p<
0.05). The serum concentrations of total antioxidant capacity (T-AOC) increased linearly, while immunoglobulin G (IgG) increased quadratically with the increasing ML content (p<
0.05). Conversely, the saturated fatty acids (SFA) content in meat decreased linearly with the increasing ML content (p<
0.05). Compared to goats without ML supplementation, goats fed with 15% ML showed significant increases in serum concentrations of T-AOC, superoxide dismutase, catalase, and IgG (p<
0.05). Furthermore, goats fed with 20% ML displayed significant decreases in SFA (C18:0) content, compared to goats without ML supplementation (p<
0.05). CONCLUSION: These results suggest that ML supplementation promotes the growth performance of goats. A diet containing 15% ML showed better effects in promoting antioxidant and immunomodulatory activities, while a diet with 20% ML was more effective in enhancing meat flavor in Xiangdong black goats.