title: Effects of dietary vitamin supplementation and semen collection frequency on hormonal profile during ejaculation in the boar.
abstract: 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), 17beta-estradiol (E2), 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 3mo preceding the hormonal evaluation: three times per 2wk (3/2) or three times per wk (3/1). Plasma E2 was lower (P<0.01) before ejaculation (232.5+/-22.6pg/mL) than at the onset of ejaculation (255.2+/-27.1ng/mL). Plasma T increased from 5.14+/-0.72, before ejaculation to 5.87+/-0.86ng/mL at the onset of ejaculation in supplemented boars, whereas it decreased from 5.15+/-0.65 to 4.87+/-0.70ng/mL in controls (diet by time, P<0.05). At the onset of ejaculation, plasma FSH was higher in 3/2 boars (0.436+/-0.06ng/mL) than in 3/1 boars (0.266+/-0.04ng/mL; P<0.05). During ejaculation, plasma LH increased linearly (P<0.01) from 0.59+/-0.07 to 0.97+/-0.10ng/mL, and plasma E2 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.
authors.affiliation: Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, 2000 College Street, Lennoxville STN, Sherbrooke, Que., Canada J1M 1Z3.
authors.forename: I
authors.initials: I
authors.lastname: Audet
authors.forename: N
authors.initials: N
authors.lastname: Bérubé
authors.forename: J L
authors.initials: JL
authors.lastname: Bailey
authors.forename: J-P
authors.initials: JP
authors.lastname: Laforest
authors.forename: H
authors.initials: H
authors.lastname: Quesnel
authors.forename: J J
authors.initials: JJ
authors.lastname: Matte
mesh_terms: D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D019587:Dietary Supplements; D004542:Ejaculation / Q000502:physiology*; D006728:Hormones / Q000097:blood*; D007315:Insemination, Artificial; D008297:Male; D012661:Semen; D013552:Swine / Q000502:physiology*; D013997:Time Factors; D014815:Vitamins / Q000008:administration & dosage*
chemical_list: D006728:Hormones; D014815:Vitamins