Dairy goats with a high body condition score (BCS) are more susceptible to fatty liver during the transition period. This study investigated the effects of Milk Thistle Extract (MTE) supplementation on antioxidant status, liver health, biochemical parameters, and milk production in dairy goats with high pre-kidding BCS (>3.5) during the transition period. Twenty-four close-up pregnant Mahabadi×Saanen crossbred goats were used in a completely randomized design from 21 days pre-partum to days +21 post-partum (N=8). Treatments were Control (CON, without additive), and MTE at 1.3 g/head/day (MTE1) or 2.5 g/head/day (MTE2). Daily dry matter intake (DMI) was recorded, and colostrum, milk, and blood samples were collected at specified intervals. Relative to the control, MTE supplementation resulted in a decrease (P < 0.05) in serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) concentrations. Serum alkaline phosphatase (ALP, except at day +21 post-partum) and paraoxonase-1 (PON1) were not affected by MTE supplementation. Compared to the CON group, MTE supplementation increased serum non-esterified fatty acid (NEFA) concentrations in the pre-partum period and decreased in the post-partum period. Beta-hydroxybutyrate (BHBA) concentrations were significantly lower (P < 0.05) in the MTE1 group at day +7 post-partum. Antioxidant enzyme activities varied, with higher pre-partum glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities in MTE1 goats, but no significant differences were observed in the post-partum period. Catalase activity, total antioxidant capacity (TAC), and malondialdehyde (MDA) concentration were unaffected by MTE supplementation. Colostrum quality, milk production and milk composition were not affected by MTE supplementation. Overall, MTE supplementation, particularly at 2.5 g/day, improved liver health and specific biochemical parameters, suggesting its potential benefits for dairy goats during the transition period. Future studies should aim to investigate the effects of extended use on liver health, metabolic resilience, and overall productivity in dairy ruminants.
