Succinate dehydrogenase (SDH) is a mitochondrial enzyme involved in the respiratory chain, Krebs cycle and gluconeogenesis. Hence, a drop in its activity may lead to energy deficit or decreased gluconeogenesis, which could in turn affect milk yield and metabolic status. Our aim was to study the effect of 2 feeding strategies on the activity and protein expression of SDH in liver biopsies during early (35 DPP) and late lactation (180 DPP). Multiparous Holstein cows (n = 24, 664 ± 65 kgBW, 3.0 ± 0.4 BCS, spring calving) were assigned in a randomized block design to (G0) a total mixed ration (TMR) fed ad libitum (70% forage: 30% concentrate) or (G1) grazing plus supplementation from 0 to 180 d postpartum (DPP). The G1 cows grazed Festuca arundinacea or Medicago sativa in 2 (18 h) or 1 (6 h) session depending on heat stress (30 or 20 kg DM/cow/day) and were supplemented with 5.4 kg DM of a commercial concentrate or offered TMR (50% of G0 offer). From 180 to 250 DPP, all cows grazed Festuca arundinacea (10h; 30 kg DM/cow/day) and were offered TMR (50% of G0 offer). Data were analyzed with a mixed model using repeated measures. Milk yield was greater at 35 DPP (36 vs. 20 ± 0.8 kg/d, P < 0.001) and BCS was greater at 250 DPP (2.45 vs. 2.70 ± 0.05, P < 0.001). SDH subunit A (SDHA) protein levels and specific activity were studied in liver biopsies during early (35 DPP) and late lactation (250 DPP). Protein levels of SDHA tended to be higher for cows in the pasture-based strategy (1.10 vs. 0.98 ± 0.05 relative intensity, P = 0.096; for G1 vs. G0). However, no differences in activity were observed between treatments. Nonetheless, SDH specific activity tended (P = 0.07) to be greater during early lactation (159 vs. 129 ± 17 mU/mg, 35 vs. 250 DPP, respectively) and it correlated positively (r = 0.3, P < 0.05) with milk yield, suggesting a link between this enzyme and increased milk production in early lactation.