170      Reproduction, Fertility and Development                                                                          ...
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Lima: Artificial Insemination: Reproduction, Fertility and Development - 2010


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Lima: Artificial Insemination: Reproduction, Fertility and Development - 2010

  1. 1. 170 Reproduction, Fertility and Development Artificial Insemination 24 EFFECT OF GnRH ON FIXED-TIMED ARTIFICIAL INSEMINATION PREGNANCY RATES OF WHITE-TAILED DEER J. LambeA , W. ForbesB , B. M. OlcottC , D. E. SandersB , R. A. GodkeA , and G. T. GentryA A LSU Embryo Biotechnology Center, Reproductive Biology Center, St. Gabriel, LA USA; B Jones Idlewild Research Station, Louisiana State University AgCenter, Clinton, LA USA; C LSU School of Veterinary Medicine, Baton Rouge, LA USADuring the fall 2008 breeding season in Louisiana, 2 synchronization protocols for fixed-timed artificial insemination (FTAI) in White-tailed deerwere assessed. The objective was to determine if GnRH at FTAI improved pregnancy rates in White-tailed deer. White-tailed does (n = 35) with amean body weight of 65.8 kg (range: 54.0 to 79.8 kg) and average age of 5.9 years (range: 1.5 to 9.5 years) were stratified by weight, age, and lastfawning date into 2 groups. Treatment and control synchronization protocols were randomly assigned to each group. Does were synchronized with aCIDR-G device for 14 d and were then subjected to either FTAI 60 h post-CIDR removal (control, n = 17) or 100 µg (i.m.) injection of GnRH at FTAI60 h post-CIDR removal (treated, n = 18). At insemination (AI), insemination pipette placement score (IP; 0 = at cervical os to 3 = within uterinebody), mucous scores (clear/cloudy, viscous/nonviscous, or no secretions), vulva assessments (hyperemic/nonhyperemic and swollen/not swollen),and sperm progressive motility were recorded. Does were inseminated with frozen–thawed sperm (5 × 107 progressively motile cells pre-freeze)from 2 fertile bucks stratified across each treatment group. Starting 28 d following AI, intact bucks (ITB) were introduced into both groups for naturalmating. Pregnancy was determined via transrectal ultrasonography 73 or 80 d postinsemination. Does, confirmed pregnant via ultrasonography,had fawns within the reported gestation range of 187 to 222 days. Placentomes were visualized and measured in AI pregnancies (range: 32.7to 56.2 mm in length), whereas pregnancies derived from ITB presented no identifiable placentomes. However, crown-rump measurements wereobtainable from ITB pregnancies (range: 13.4 to 21.7 mm). Five does were not included in the final analyses as they were either lost to predators orremoved because of illness. IP (1.4 ± 0.24 v. 1.3 ± 0.30; P = 0.671), mucous classifications (3.0 ± 0.35 v. 2.5 ± 0.39; P = 0.311), vulva assessments(2.1 ± 0.29, 1.7 ± 0.23; P = 0.223), and sperm motility (1.6 ± 0.16, 1.7 ± 0.22; P = 0.829) were not different for pregnant and nonpregnant AIdoes, respectively. Treatment did not affect AI pregnancy rates (53 v. 27%) or fecundity rates (1.6 v. 1.3 offspring/doe) for the GnRH treated andcontrol groups, respectively. Addition of GnRH to a 14-day estrus synchronization protocol did not result in significantly higher pregnancy ratescompared with controls. More studies are needed to determine the effect of GnRH on White-tailed pregnancies following FTAI protocols. We havedemonstrated that differentiating pregnancies derived from AI and ITB could be accomplished by utilizing transrectal ultrasonography as early as73 d postinsemination in White-tailed does. 25 ADDITION OF FSH, IN CONTRAST TO eCG, DOES NOT INCREASE PREGNANCY RATES IN ANESTROUS NELLORE (BOS INDICUS) COWS TREATED WITH FIXED-TIME AI PROTOCOL L. A. Lima, V G. Pinheiro, J. R. Cury, and C. M. Barros . University of São Paulo State (UNESP), Botucatu, São Paulo, BrazilThere are reports in the literature indicating that use of eCG improves pregnancy rates in Bos indicus anestrous cows treated with a progesterone-basedfixed-time AI (FTAI) protocol. More recently, replacement of eCG by FSH in FTAI protocols was reported to have beneficial effects (Bos indicus)or no effect (Bos taurus) on pregnancy rates. In the present experiment the effects of eCG and FSH on pregnancy rates were compared in an FTAIprotocol. Primiparous lactating Nellore cows (40 to 80 days postpartum, n = 421) with a body condition score of 2.5 to 3.0 (on a 1 to 5 scale) wererandomly allocated in 3 groups: Control (CTR), eCG, and FSH. In the control group, all animals received a progesterone (P4 )-releasing intravaginaldevice (1.55 g, PRID® , Ceva Sante Animale S.A., Libourne, France) and 2.5 mg of estradiol benzoate (EB, i.m. Estrogin® , Farmavet, São Paulo,Brazil), on Day 0 (D0). Eight days later (D8), at the time of the intravaginal device withdrawal, PGF2α (150 µg, D-cloprostenol, i.m. Prolise® , ARSAS.L.R., Buenos Aires, Argentina) was administered. Twenty-four hours after PRID removal, cows were treated with EB (1.0 mg, i.m.), and FTAIwas done 30 to 36 h later. In the eCG and FSH groups, the cows were treated with 20 mg of FSH (Folltropin-V® , i.m. Bioniche, Belleville, Canada)or 400 IU of eCG (Novormon® , i.m. Syntex, Buenos Aires, Argentina), respectively, at the time of PGF2α administration. Ovarian ultrasonography(Aloka SSD 500, 7.5-MHz probe, Aloka, Tokyo, Japan) was performed 10 days prior to and at the beginning of FTAI protocol to select the animalsin postpartum anestrous (absence of CL in both examinations). The pregnancy diagnosis was performed by ultrasonography 30 days after FTAI.Data were analyzed by logistic regression (SAS Institute, Cary, NC, USA). Cows treated with eCG had a higher pregnancy rate (41.5%, 95/229;P < 0.05) than those treated with FSH (22.7%, 22/97) or in the control group (26.3%, 25/95). Pregnancy rates of animals treated with FSH did notdiffer (P > 0.05) from those in the control group. These results indicated that, in lactating primiparous anestrous Nellore cows, the use of eCG in aFTAI protocol improves the pregnancy rate, whereas FSH has no beneficial effect.V G. Pinheiro received a fellowship from FAPESP (São Paulo, Brazil). The authors are grateful to Ceva Animal Health for providing the intravaginal .devices (PRID® ) used in this experiment. 26 SPERM MOTILITY DECREASING AND SEMEN FERTILITY IN THE BULL EVALUATED BY BIOSPECKLE R. S. Macedo, J. B. Barreto Filho, R. A. Braga Jr, and G. F Rabelo . Lavras Federal University, Lavras, MG, BrazilSperm motility decreasing in a semen sample over time is an indirect approach to assess spermatozoa viability and should be related to the ejaculatefertility. The biospeckle (BSL) is an interacting phenomenon between laser light and biological specimens that allows measurement of sperm kinetic