ABSTRACT: The residual black wolfberry fruit (RBWF), rich in nutrients and active substances, has the potential to serve as an antibiotic alternative. This study evaluated the concentration-dependent effects of RBWF on serum biochemistry, immunity, antioxidant capacity, and meat quality of fattening sheep. Forty 3-month-old sheep were randomly assigned into four groups with 10 replicates in each group and fed experimental RBWF-supplemented diets (0%, 2%, 5%, and 8%). The results showed that RBWF supplementation significantly increased the serum levels of TP, BUN, ALT, AST, IgA, IgM, T-AOC, SOD, and GSH-Px in sheep (p < 0.05), while significantly decreasing the levels of LDH, TG, LDL-c, IgG, and MDA (p < 0.05). Furthermore, dietary RBWF significantly increased the VB1 and IMP levels in
