Effects of Phytogenic Feed Additives on Serum Antioxidant Status and Immune Function Markers in Growing Pigs in Abia State, South East Nigeria

The withdrawal of antibiotic growth promoters from livestock production has intensified the search for effective phytogenic alternatives that support antioxidant capacity and immune function in pigs. This study evaluated the effects of a standardised blend of ginger, turmeric, and garlic phytogenic feed additive on serum antioxidant status and immune function markers in growing pigs in Umuahia, Abia State, South East Nigeria. Eighty Large White-Landrace crossbred piglets weaned at three weeks were assigned to four dietary treatment groups: control, low-dose (1 g/kg), medium-dose (2 g/kg), and high-dose (3 g/kg) phytogenic additive, maintained for ten weeks. Serum superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, total antioxidant capacity, and immunoglobulin G, immunoglobulin M, and lymphocyte proliferation index were assayed at the end of weeks five and ten. The medium-dose group achieved the highest superoxide dismutase and total antioxidant capacity values, alongside the most favourable malondialdehyde reduction. Immunoglobulin G and M concentrations were significantly elevated in the medium and high-dose groups at week ten. Lymphocyte proliferation was significantly higher in all supplemented groups compared to control by week ten. Feed conversion ratios were improved in supplemented groups. These findings provide empirical evidence that phytogenic additives at appropriate dose levels enhance antioxidant status and immune competence in growing pigs in South East Nigerian production settings. Keywords: phytogenic feed additives, antioxidants, immune function, pigs, Abia State.