Figure 5. Leydig cell volume as a percentage of total testicular volume in control and letrozole-treated boars at 2, 5, and 8 months of age. Asterisks indicate significant differences in Leydig cell volume relative to total testicular volume between control and treated boars within a particular age. *P < .05. Percentage volume occupied by Leydig cells was initially lower (2 months) but had recovered at 5 and 8 months.