1COCs that were evaluated as Category II and III at 21–22 h of maturation were considered expanded. Data are Means ± SEM. a,b denotes differences between the hormone and dose groups versus the negative control (0) in a one-way ANOVA, P < 0.05. Two-way ranked ANOVA was used to test the effect of source of hormone, dose and interaction. l,m within hormone, values with different superscripts are different, P < 0.05. x,y within dose, values with different superscripts are different, P < 0.05. Data are from eight replicates with approximately 550 COCs per treatment.