To evaluate the effect of dietary and management factors on boar hormonal status during ejaculation, 39 boars were canulated to determine the profiles of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17 beta-estradiol (EA and testosterone (T) in blood plasma and seminal fluid. Prior to canulation, 18 boars were fed a basal diet (control), whereas the remainder (n = 21) were fed a basal diet supplemented with extra vitamins (supplemented). Within each dietary treatment, two regimens of semen collection were used over the 3 mo preceding the hormonal evaluation: three times per 2 wk (3/2) or three times per wk (3/1). Plasma E(2) was lower (P < 0.01) before ejaculation (232.5 +/- 22.6 pg/mL) than at the onset of ejaculation (255.2 +/- 27.1 ng/mL). Plasma T increased from 5.14 +/- 0.72, before ejaculation to 5.87 +/- 0.86 ng/mL at the onset of ejaculation in supplemented boars, whereas it decreased from 5.15 +/- 0.65 to 4.87 +/- 0.70 ng/mL in controls (diet by time, P < 0.05). At the onset of ejaculation, plasma FSH was higher in 3/2 boars (0.436 +/- 0.06 ng/mL) than in 3/1 boars (0.266 +/- 0.04 ng/mL; P < 0.05). During ejaculation, plasma LH increased linearly (P < 0.01) from 0.59 +/- 0.07 to 0.97 +/- 0.10 ng/mL, and plasma E(2) and T concentrations were correlated (r = 0.62, P < 0.01). Plasma FSH before and during ejaculation was negatively correlated with sperm production (r = -0.60, P < 0.01) and testicular weight (r = -0.50, P < 0.01). In conclusion, dietary and management factors had few impacts on hormonal profiles during ejaculation, but homeostasis of some hormones was related to some criteria of reproductive performance in boars.