Sirtuins are a family of NAD+-dependent protein deacetylases that have been implicated in cellular aging and oocyte quality. Supplementing the diet of mice with the NAD+ precursor nicotinamide mononucleotide (NMN) has been shown to ameliorate the detrimental impacts of generational obesity on female fertility [1], suggesting involvement of NMN in promoting oocyte maturation. Using small antral follicle-derived porcine oocytes, a well-established model of poor oocyte quality, the aim of this study was to examine the effect of NMN supplementation during in vitro maturation (IVM) on oocyte developmental competence. Oocytes were matured for 44 h in defined IVM medium without (control) or with increasing doses of NMN (0.1, 1, 10 and 100 µM). Mature oocytes were artificially activated by sequential treatment with ionomycin and 6-dimethylaminopurine/cytochalasin B. Presumptive zygotes were cultured for 7 d in Porcine Zygote Medium-3. Cleavage and development to the blastocyst stages were assessed and total blastocyst cell numbers were determined. The experiment was replicated five times. Supplementing the IVM medium with NMN did not significantly affect the rates of cleavage (range: 62.8±8.5% to 74.6±5.7%) or blastocyst formation (range: 21.8±3.7% to 28.6±6.9%) compared with the control group (cleavage: 67.0±8.8%; blastocyst: 19.6±9.1%). The proportion of blastocysts that had partially or fully hatched from their zona pellucida by 7 d of culture was markedly greater in the 1 and 100 µM NMN groups (29.5±2.2% and 23.3±3.8%, respectively) compared with the control group (12.5±9.7%; P<0.05). Surprisingly, the total blastocyst cell numbers did not differ among the groups (P>0.05), suggesting the NMN treatment had resulted in changes to the function and/or development of blastocyst cells. Further studies are needed to determine the processes by which NMN influences the acquisition of developmental competence during oocyte IVM.