Showing papers by "Gérard Baril published in 2008"

Time of ovulation in nulliparous and multiparous goats

Abstract: Fifteen nulliparous and nine multiparous Serrana goats were used, through two successive oestrous cycles, in order to characterize their ovulation time with regard to the number of ovulations after induced and natural oestrus during the breeding season. The onset of oestrus was detected by the amount of vasectomized bucks after oestrus synchronization with prostaglandin, given 10 days apart, and in the following two expected natural oestrus. The preovulatory LH peak was determined from blood samples collected 0, 4, 8, 12, 16, 20 and 24 h after onset of oestrus. A transrectal ovarian ultrasound scanning was performed 20, 24, 28, 32, 36, 40, 44 and 60 h after onset of oestrus, for the detection of ovulations by means of the disappearance of large follicles (.4 to 5 mm). Single ovulations were observed in 76% of oestrous periods in nulliparous goats and in 18% of nulliparous goats. The onset of oestrus to LH peak interval was lower in nulliparous (12.1 6 0.9 h, n 5 38) than in multiparous (15.6 6 1.0 h, n 5 22, P , 0.05) goats with no oestrus interaction effects (P . 0.05). The LH peak to first ovulation interval was higher after natural (18.9 6 0.7 h, n 5 36) than after induced (15.8 6 1.2 h, n 5 24, P , 0.05) oestrus. The onset of oestrus to total ovulation interval was influenced by parity (P , 0.01) and oestrus type (P , 0.05) with a length of 30.1 6 1.1 h (n 5 15) and 33.4 6 1.5 h (n 5 9) for induced oestrus of nulliparous and multiparous goats, respectively, and 32.5 6 1.0 h (n 5 23) and 36.5 6 1.1 h (n 5 13) for natural oestrus of nulliparous and multiparous goats, respectively. The onset of oestrus to first ovulation interval was not influenced by parity, but an interval of 8.0 6 1.6 h was observed between the first and second ovulations in polyovulatory oestrus. Consequently, nulliparous goats that are predominantly monovular ovulate earlier than multiparous goats that are predominantly polyovulatory. In conclusion, significant differences occurred in the number and time of ovulations between nulliparous and multiparous goats. More research is necessary for a deeper understanding of the mechanisms regulating monovularory and polyovulatory oestrous cycles regarding the parity of goats.

161 successful interspecific pregnancy after transfer of in vitro-produced sika deer (cervus nippon nippon) embryo in red deer (cervus elaphus hippelaphus) surrogate hind

Abstract: The aim of the present study was to assess the in vivo competence of in vitro-produced sika deer (Cervus nippon nippon) embryos after freezing–thawing and transfer into red deer (Cervus elaphus hippelaphus) recipients. During the breeding season, 11 adult sika deer hinds were synchronized as oocyte donors with an intravaginal sponge (45 mg of fluorogestone acetate, FGA) inserted for 12 days and removed immediately after laparoscopic ovum pick-up (LOPU), and renewed after 3 days. Ovarian stimulation was induced with an i.m. injection of 75 µg of cloprostenol (Estrumate) given on Day 8, followed by 3 i.m. injections of 0.1, 0.1, and 0.05 IU of ovine FSH (Ovagen) on Days 10 and 11 at 12-h intervals. On Day 12, hinds were anesthetized and oocytes were collected by LOPU from follicles >2 mm using an 18 G needle under moderate vacuum. COC were recovered and morphologically evaluated for quality (graded from 1 to 5). COC were then submitted to in vitro maturation, fertilization, and culture (IVM, IVF, and IVC) as described previously (Locatelli Y et al. 2005 Theriogenology 64, 1729–1739). For IVC, embryos were co-cultured with a monolayer of ovine oviduct epithelial cells in synthetic oviduct fluid medium supplemented with 10% FCS. On Day 8 post-insemination, all sika deer embryos at the blastocyst stage were cryopreserved via a standard bovine slow-freezing protocol. Of 44 LOPU sessions performed during the 1-month study, an average of 7.5 ± 0.38 follicles were aspirated (mean ± SEM), allowing the recovery of 3.65 ± 0.38 COC per hind and per session, of which 80.0% were suitable for IVM (grades 1 and 2). Of 142 oocytes recovered, 57 cleaved after IVF (40.1%), and 14 embryos (24.6% of cleaved) reached the blastocyst stage after 8 days. At the end of the breeding season, 7 adult red deer hinds were synchronized as embryo recipients by inserting 2 intravaginal sponges per female (90 mg of FGA), for 13 days. Injections (i.m.) of 400 IU of eCG and 125 µg of cloprostenol (Estrumate) were administered 72 h before sponge removal. At Day 8 after sponge removal, straws containing frozen embryos were thawed and cryoprotectant was removed as described previously (see Locatelli Y et al. 2005 Theriogenology 64, 1729–1739). Two sika deer embryos were surgically transferred into uterine horn (unilaterally) of each red deer recipient. One of 7 red deer recipients was diagnosed pregnant by ultrasonography on Day 56. A healthy male sika deer fawn was born unassisted after 224 days of gestation. No complications were observed in initial recognition of the sika deer fawn by the red deer surrogate mother, nor in subsequent interactions. To our knowledge, this is the first report of an interspecific pregnancy obtained after in vitro embryo production and embryo transfer in deer species. In conclusion, interspecific embryo transfer after IVP may represent a useful tool for the preservation and amplification of captive residual populations of endangered deer species. Further studies are required to increase the rate of cleavage after LOPU-IVF as well as viability of frozen–thawed IVP embryos.

207 in vitro maturation treatment affects developmental competence of laparoscopic ovum pickup-derived oocytes in folliclestimulating hormone-stimulated goats

Abstract: The aim of the present study was to assess the effect of IVM treatment on the developmental competence of oocytes recovered from repeated laparoscopic ovum pickukp (LOPU) in goats. A total of 94 LOPU sessions were performed on 33 adult goats of the Saanen and Alpine breeds. Females were synchronized (Day 0) during the nonbreeding season by inserting vaginal sponges (45 mg of fluorogestone acetate, Intervet, Boxmeer, The Netherlands). At Day 8, an i.m. injection of 50 μg of cloprostenol (Estrumate; Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) was administered. Porcine FSH (Stimufol, Merial, Brussels, Belgium, 160 mg/goat) was administered in 5 injections at 12-h intervals, starting on Day 8. The LOPU took place under general anesthesia on Day 11, and follicles ≥2 mm were aspirated with an 18-gauge needle connected to a controlled vacuum system. Vaginal sponges were removed at the time of LOPU. Treatments were repeated 2 times in a 2-week interval scheme (2 goats and 1 goat were excluded from the experiment during the second and third LOPU sessions, respectively). Cumulus–oocyte complexes were washed and evaluated for quality (graded from 1 to 3). Oocytes recovered from unstimulated slaughterhouse-derived ovaries served as a control. Cumulus–oocytes complexes from Grades 1 and 2 were submitted to IVM in TCM-199, supplemented with 100 μm of cysteamine and either 10 ng mL–1 of epidermal growth factor (EGF) or 10% follicular fluid and 100 ng mL–1 of ovine FSH (FF-FSH). Matured oocytes were then submitted to IVF and in vitro development as described by Cognie et al. (2004 Reprod. Fertil. Dev. 16, 437–445). Over the 94 LOPU sessions, 20.4 ± 0.9 follicles were aspirated (mean ± SEM), allowing the recovery of 12.3 ± 0.7 COC per goat and per session, of which 80.1% were suitable for IVM (Grades 1 and 2). Results of in vitro production are detailed in the table. The IVM treatment did not significantly affect cleavage or blastocyst development rates in oocytes derived from slaughterhouse ovaries. Cleavage rates were significantly decreased in LOPU-derived oocytes when compared with control oocytes. For LOPU-derived oocytes, cleavage and final blastocyst development rates were increased significantly and kinetics of embryo development were accelerated when FF-FSH was used during IVM as compared with EGF. The IVM with FF-FSH allowed us to produce 4.1 blatocysts per goat per LOPU session. These results demonstrate the interest in LOPU for goat embryo production once appropriate IVM treatment is used. The difference observed between LOPU and slaughterhouse oocytes in terms of response to IVM treatments may be related to FSH stimulation prior to the LOPU session or to postmortem changes in oocyte responsiveness in the slaughterhouse group. Table 1. Effects of oocyte origin [laparoscopic ovum pickukp (LOPU) or slaughterhouse derived] and maturation treatment [epidermal growth factor (EGF) or follicular fluid (FF)-FSH] on in vitro embryo production (6 replicates)

Le transfert embryonnaire chez la chèvre : un outil de gestion du risque de transmission du virus de l'arthrite encéphalite caprine (CAEV)

Abstract: Le virus de l'arthrite encephalite caprine (CAEV) a ete identifie 1) dans les tissus de l'appareil genital de chevres infectees et donneuses d'embryons et 2) dans les liquides de recoltes d'embryons. En absence de membrane pellucide, l'embryon caprin, infecte in vitro, est susceptible d'etre vecteur du CAEV. Les blastocystes sont sensibles / permissifs au virus et permettent la replication du CAEV. L'embryon caprin, infecte in vitro, et protege par la membrane pellucide n'est pas en revanche vecteur du CAEV. Le CAEV n'adhere pas a la membrane pellucide et est elimine apres quatre lavages. Apres lavage et elimination des cellules de la granulosa, l'ovocyte est indemne de CAEV alors meme que les cellules de la granulosa qui l'entourent peuvent etre infectees. Une etude de terrain realisee dans un contexte infectieux extreme a demontre que l'application des procedures sanitaires definies par l'International Embryo Transfert Society (IETS) pour les embryons bovins c'est-a-dire transfert d'embryons de bonne qualite avec une membrane pellucide intacte et laves dix fois, permet la production de chevreaux indemnes de CAEV a partir de meres infectees.