title: Administration of testosterone from day 13 of the estrous cycle to estrus increased the number of corpora lutea and conceptus survival in gilts.
abstract: The effects of exogenous androgens on the number of corporea lutea (CL) and conceptus survival were examined in crossbred gilts. In Exp. 1, gilts received 1 mg of testosterone per day from d 13 (d = 0 first day of estrus, n = 21) or d 16 until estrus (n = 23). Gilts in the vehicle group received corn oil (n = 20). Gilts were mated and on d 11.5 their concepti and CL were evaluated. In Exp. 2, conceptus survival was examined at the 4- to 8-cell, early blastocyst or hatching blastocyst stages for gilts given vehicle or 1 mg testosterone from d 13 (24 gilts per group). In Exp. 3, gilts received 1 mg of androstenedione (n = 20) or vehicle (n = 18) per day from 13 d to estrus and then were mated and evaluated on d 11.5. Results from Exp. 1 indicated that the number of CL was greater (P < .04) in gilts treated with testosterone from d 13 to estrus than in gilts receiving vehicle (16.4 vs 14.8, respectively). Similarly, the number (P < .01) and recovery rate (P < .04) of blastocysts were greater in gilts treated with testosterone from d 13 to estrus than in gilts treated with testosterone from d 16 to estrus in gilts receiving vehicle (number, 15.3 vs 12.8 or 12.8; recovery rate, 95 vs 87 or 86%, respectively). Gilts treated testosterone or vehicle did not exhibit differences (P > .05) in number of normal concepti at the 4- to 8-cell and hatching stages. However, prior treatment with testosterone delayed conceptus death; gilts treated with testosterone had more (P < .01) normal concepti at the intermediate stage (early blastocyst) than those treated with vehicle (treatment x embryo stage interaction, P < .05). In Exp. 3, androstenedione treatment did not influence (P > .10) the number of CL or the number and recovery rates of d-11.5 blastocysts. Treating gilts with testosterone from d 13 of the estrous cycle to the following estrus increased the number of CL and blastocyst survival, perhaps by improving some, as yet unknown, aspect(s) of oocyte quality.
authors.affiliation: Department of Animal Sciences, Ohio State University, Columbus 43210, USA.
authors.forename: H
authors.initials: H
authors.lastname: Cárdenas
authors.forename: W F
authors.initials: WF
authors.lastname: Pope
mesh_terms: D000735:Androstenedione / Q000494:pharmacology; D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000502:physiology*; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000187:drug effects / Q000502:physiology*; D004971:Estrus / Q000502:physiology*; D005260:Female; D011247:Pregnancy; D013552:Swine / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013739:Testosterone; D000735:Androstenedione