title: Effects of dietary supplementation with an organic source of selenium on characteristics of semen quality and in vitro fertility in boars.
abstract: Semen characteristics in boars fed organic or inorganic sources of Se were assessed in 3 experiments. Crossbred boars were randomly assigned at weaning to 1 of 3 dietary treatments: I) basal diets with no supplemental Se (control), II) basal diets with 0.3 mg/kg of supplemental Se from an organic source (Sel-Plex, Alltech Inc., Nicholasville, KY), and III) basal diets supplemented with 0.3 mg/kg of supplemental Se from sodium selenite (Premium Selenium 270, North American Nutrition Co. Inc., Lewisburg, OH). For Exp. 1, semen was collected from boars (n = 10/dietary treatment) on 5 consecutive days at 15 mo of age. Effects of treatment × day were detected for the proportions of progressively motile (P = 0.02) and rapidly moving (P = 0.03) spermatozoa, and measures of sperm velocity, including path velocity of the smoothed cell path (P = 0.05) and average velocity measured in a straight line from the beginning to the end of the track (P = 0.05). Negative effects of day of semen collection on sperm motility were least pronounced in boars fed Sel-Plex. Experiment 2 was conducted when boars were 17 mo of age, and semen was collected (n = 10 boars/dietary treatment), diluted in commercially available extenders, and stored at 18°C for 9 d. Effects of treatment × day were detected for percentages of motile (P = 0.01) and static (P = 0.01) spermatozoa, amplitude of lateral head displacement (P = 0.02), frequency with which the sperm track crossed the sperm path (P = 0.04), straightness (P = 0.01), and average size of all sperm heads (P = 0.03). In general, sperm cells from boars fed Sel-Plex were better able to maintain motility during liquid storage compared with boars fed sodium selenite. For Exp. 3, semen was collected from boars (n = 6/dietary treatment) at 23 mo of age, and spermatozoa were evaluated at d 1 and 8 after semen collection using in vitro fertilization procedures. There was a tendency for an effect (P = 0.11) of dietary treatment on fertilization rate with Sel-Plex-fed boars having the greatest value (70.7%). The results of this study suggest that there are positive effects of dietary supplementation with Sel-Plex on boar semen characteristics and that organic Se supplementation may help ameliorate the negative effects of semen storage on characteristics of sperm motility.
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg 24061, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Speight
authors.forename: M J
authors.initials: MJ
authors.lastname: Estienne
authors.forename: A F
authors.initials: AF
authors.lastname: Harper
authors.forename: R J
authors.initials: RJ
authors.lastname: Crawford
authors.forename: J W
authors.initials: JW
authors.lastname: Knight
authors.forename: B D
authors.initials: BD
authors.lastname: Whitaker
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005298:Fertility / Q000187:drug effects*; D005307:Fertilization in Vitro / Q000662:veterinary; D008297:Male; D012643:Selenium / Q000737:chemistry*; D055101:Semen Analysis / Q000662:veterinary*; D018038:Sodium Selenite / Q000737:chemistry / Q000494:pharmacology*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology; D013552:Swine
chemical_list: D012643:Selenium; D018038:Sodium Selenite