Fig. 1.

Cumulus expansion of bovine COCs is negatively impacted when IVM occurs under low oxygen and low glucose levels. Average of cumulus expansion scores according to the Vanderhyden scoring system [56] following 21 h of IVM in two different oxygen and glucose concentrations (Experiment 1, 2×2 factorial design) (a), and with 4 varying treatment parameters (Experiment 4: oxygen; glucose concentration; volume of medium/COC; number of COCs/drop) (b). Data presented as mean ± SEM (n = 4 independent replicates with 40±5 COCs/treatment group/replicate). Means with different superscripts indicate significant differences between treatment groups (P < 0.05)