Background: Improving energy efficiency is urgent during perinatal period because dairy ruminant is often in negative energy balance, resulting many metabolic disorders thus economic losses. It has been previously highlighted that nicotinamide (NAM) supplementation during perinatal period could benefit the energy balance, while the underlying metabolic alterations and the differences in NAM supplemented during different perinatal period have been poorly studied. This study aimed to elucidate the effects of NAM on energy efficiency, lipid metabolism, oxidative status, and liver metabolites profile of perinatal does during different perinatal period. Results: Fifteen multiparous does with similar parity, weight, and previous milk yield were paired and allocated to 3 groups (n = 5): control (C), postpartum supplementation (P, NAM supplemented after kidding), and entire-perinatal supplementation (EP, NAM supplemented from -21 to 28 d around kidding). Does were drenched with 5 g/d of NAM and slaughtered on d 28. The ruminal acetic acid tended to decrease, and the propionic acid and valeric acid were increased in P and EP. The does in P and EP had a decreased acetic acid to propionic acid ratio. Does in EP had higher liver mitochondrial respiratory chain complexes. The Complex Ⅱ was elevated in both P and EP and NAM supplementation tended to increase ATP production. Liver metabolomics analysis and tissues biochemical analysis revealed that lipid was decomposed in abdominal adipose, and in liver, the decomposition of lipid was more than the synthesis, and the amino acid metabolism were enriched by NAM. Moreover, the oxidative status of blood and liver were improved by NAM supplementation, and supplementation of NAM during postpartum only does not appear enough to cope with the metabolites of oxidative phosphorylation. Conclusions: Overall, these data suggested that NAM supplementation during perinatal period favored the rumen fermentation pattern to propionic acid-type, and improved liver energy efficiency with benefited lipid metabolism. The NAM supplemented from prepartum is needed for better oxidative status and energy metabolism of perinatal does.