82 Invitro embryo production outcomes in adult goats is affected by season

In seasonal breeders, reproductive seasonality can have a substantial influence on the efficiency of assisted reproductive technologies. This study assessed seasonal effects on cleavage and blastocyst rates, as well as on quality of invitro-produced (IVP) goat embryos over 18 months. In total, 2348 (autumn: 811, spring: 404, summer: 639, and, winter: 494) cumulus–oocyte complexes (COC) were recovered from slaughterhouse ovaries during 49 replicates (autumn: 17, spring: 7, summer: 15, and, winter: 10) and matured in TCM-199 with 10ng mL−1 epidermal growth factor and 100µM cysteamine for 22h at 38.8°C (5% CO2 in air). Matured oocytes were fertilized with frozen/thawed semen in synthetic oviductal fluid (SOF) with 10% oestrus sheep serum. Sperm and oocytes were co-incubated for 16h at 38.8°C in a humidified atmosphere of 5% CO2 in air. Presumptive zygotes were cultured in SOF medium supplemented with bovine serum albumin (3mg mL−1) for 8 days at 38.8°C in a humidified atmosphere of 5% O2, 5% CO2 and 90% N2. At Day 2, 10% fetal calf serum was added to the culture droplets. The embryos produced were fixed and stained with Hoechst to count their total number of cells, under an epifluorescence microscope. The results of cleavage and blastocyst rates, including hatching rate, from each routine of IVEP were considered as replicates. These data were tested for normality by the Shapiro-Wilk test, before being subjected to ANOVA, followed by Tukey HSD test. The odds ratio (OR) among seasons (autumn: breeding; spring: anoestrus) were calculated. Values of P<0.05 were considered as significant, and the data reported are mean±s.e.m. Cleavage rate was lower (P<0.05) in spring (51±7.1%) than in either autumn (72±2.1%) or summer (71±2.0%) while winter (66±4.1%) had an intermediate value, being similar (P> 0.05) to all others. Indeed, greater possibility of cleavage was observed in autumn (OR: 2.43) and summer (OR: 2.39) compared with spring. The blastocyst rate from cleaved embryos was greater (P <0.05) in autumn (73±2.7%) than in spring (55±2.6%; OR: 2.18). As a result, the blastocyst formation rate from the initial number of COC entering IVM was greater (P<0.05) in autumn (52±2.5%) than in spring: 28±4.7%, summer: 45±2.3%, and winter: 42±2.1%; indeed, the spring season resulted in the lowest rate (P<0.05), compared with other seasons. Moreover, the OR in the blastocyst rate from initial number of COC was greater (P<0.05) in autumn compared with all other seasons and lower in spring compared with winter (OR: 0.54) and summer (OR: 0.48). There were no differences (P> 0.05) in the embryo hatching (mean: 66±2.0%) and blastocyst cell number (mean: 193±2.0 cells). In conclusion, the breeding season (autumn) leads to improved oocyte developmental competence, resulting in greater cleavage and blastocyst yield, whereas embryo quality remained similar throughout the year. Further studies at the molecular level might indicate the mechanisms involved and provide clues to alleviate the negative effect of season.

26 Effect of different cryoprotectant concentrations on vitrification of invitro-matured bovine oocytes in paper containers

A great challenge for successful oocyte vitrification is the development of a low-cytotoxic cryoprotectant solution in a safe device allowing ultra-rapid cooling. This study compared different concentrations of cryoprotectants for bovine IVM-oocyte vitrification in a safe paper container device on oocyte survival and cleavage rates. Abattoir ovaries were obtained and cumulus–oocyte complexes (COCs) were recovered by aspirating follicles of 3 to 6mm in diameter. A total of 470 COCs with homogeneous cytoplasm oocytes, surrounded by several layers of cumulus cells were selected, in 5 replicates. Groups of ∼50 COCs were matured in 500µL of semi-defined IVM medium for 22h at 38.8°C in a humidified atmosphere with 5% CO2. After IVM, COCs were allocated to 1 of 3 groups of 20 to 30 COCs, differing only in final concentration of cryoprotectants. A nonvitrified control group (CG) was also tested, totalling 4 groups. Before vitrification, each group was transferred to 500µL of TCM-199 HEPES with 20% fetal bovine serum (FBS) (Base medium, BM) for 5min at 34°C, and COCs were partially denuded by gentle pipetting. Vitrification followed a 3-step protocol at room temperature and groups of 4 to 5 COCs were transferred to BM solution drops containing (1) 5% ethylene glycol (EG) + 5% dimethyl sulfoxide (DMSO) for 30 s; (2) 10% EG + 10% DMSO + 0.25M sucrose for 30 s; and (3) vitrification solution (VS), according to each group: high (HG), 20% EG + 20% DMSO + 0.5M sucrose; medium (MG), 15% EG + 15% DMSO + 0.5M sucrose; or low (LG), 10% EG + 10% DMSO + 0.5M sucrose for 30s. Afterwards, COCs were loaded in <1µL of solution and placed in a homemade paper container device, and immediately plunged in liquid nitrogen. Warming was performed placing the paper container in 3mL of 1M sucrose in BM for 2min. After warming, a 3-step protocol was conducted and COCs were transferred to (1) 500µL of 0.5M sucrose in BM for 2 min; (2) 500µL of 0.25M sucrose for 2 min; (3) 500µL of BM for 2min. Then, COCs from each group were transferred to 250µL of semi-defined IVF medium. Motile sperm were recovered by Percoll washing from one bull and added to IVF medium (Day 0) at final concentration of 106 sperm mL−1 for 18h. At Day 1, all presumptive zygotes were cultured in 25µL of SOF medium with 5% FBS under mineral oil at 38.8°C with 5% CO2 and 5% O2. Normal data were subjected to ANOVA and post hoc Tukey test. Cleavage rate was recorded at Day 2 after IVF. Oocyte survival rate was similar (P>0.05) among vitrified groups (HG, 80%; MG, 86%; LG,87%). Cleavage rate differed (P<0.05) in all vitrified groups compared with control (CG, 82%; HG, 10%; MG, 16%; LG, 16%). Although no difference (P>0.05) was observed among vitrified groups, MG and LG showed a slightly increased oocyte survival and cleavage rates compared with HG. In conclusion, the use of either medium or low concentrations of cryoprotectants may be a less toxic alternative for vitrification of IVM bovine oocytes on paper device. This research was funded by CAPES/COFECUB (#88881.142966/2017-01).

Evidence of biphonation and source–filter interactions in the bugles of male North American wapiti (Cervus canadensis)

With an average male body mass of 320 kg, the wapiti, Cervus canadensis, is the largest extant species of Old World deer (Cervinae). Despite this large body size, male wapiti produce whistle-like sexual calls called bugles characterised by an extremely high fundamental frequency. Investigations of the biometry and physiology of the male wapiti's relatively large larynx have so far failed to account for the production of such a high fundamental frequency. Our examination of spectrograms of male bugles suggested that the complex harmonic structure is best explained by a dual-source model (biphonation), with one source oscillating at a mean of 145 Hz (F0) and the other oscillating independently at an average of 1426 Hz (G0). A combination of anatomical investigations and acoustical modelling indicated that the F0 of male bugles is consistent with the vocal fold dimensions reported in this species, whereas the secondary, much higher source at G0 is more consistent with an aerodynamic whistle produced as air flows rapidly through a narrow supraglottic constriction. We also report a possible interaction between the higher frequency G0 and vocal tract resonances, as G0 transiently locks onto individual formants as the vocal tract is extended. We speculate that male wapiti have evolved such a dual-source phonation to advertise body size at close range (with a relatively low-frequency F0 providing a dense spectrum to highlight size-related information contained in formants) while simultaneously advertising their presence over greater distances using the very high-amplitude G0 whistle component.

306 EFFECT OF DIFFERENT IN VITRO MATURATION MEDIA ON DEVELOPMENTAL POTENTIAL OF GOAT OOCYTES ALREADY FOUND DENUDED AT COLLECTION

A grade classification (I, II, and III) based on the number of cumulus layers and oocyte morphology is currently used by many laboratories. Oocytes found denuded at collection (grade III) are considered not suitable and routinely discarded. Thus, if a particular strategy could be applied to their use in labour-intensive processes, such as ovum pickup, it would be a benefit. This experiment was performed to examine the effect of IVM medium composition to produce goat embryos in vitro using oocytes already found denuded at collection (DOC). In total, 411 DOC and 141 intact COC (control treatment) obtained by slaughterhouse ovaries were analysed in 4 replicates. The maturation medium consisted in TCM199 supplemented either with (1) 10 ng mL–1 of EGF and 100 µM cysteamine (simplified); (2) 10 ng mL–1 of EGF, 5 IU mL–1 of hCG, 10 IU mL–1 of eCG, 19 ng mL–1 of IGF-1, 2.2 ng mL–1 of FGF, 5 µg mL–1 of ITS, 90 µg mL–1 of l-cystein, 0.1 mM β-mercaptoethanol, 75 µg mL–1 of vitamin C, 720 µg mL–1 of glycine, 0.1 mg mL–1 of glutamine, and 110 µg mL–1 of pyruvate (semidefined); or (3) 10% fetal calf serum (FCS), 100 µM cysteamine, and 50 ng mL–1 of oFSH (complex). Both DOC and COC were subjected to IVM, IVF, and IVD as previously described (Souza-Fabjan et al. 2014, Theriogenology 81, 1021–31). The COC were matured only in simplified medium. On Day 8, all expanded blastocysts were fixed and stained with Hoechst for cell counting. Statistical analysis was performed using all tests with a significant interval of 95%. All variables were compared among treatments using ANOVA and SNK test. The results are described as mean per replicate ± s.e.m. No significant differences were found in simplified, semidefined, or complex medium, respectively, in cleavage rate (52 ± 7.5, 60 ± 9.4, or 51 ± 15.0%), blastocyst from cleaved (36 ± 3.9, 39 ± 9.3, or 41 ± 4.8%), blastocyst from initial DOC (19 ± 5.0, 23 ± 8.1, or 21 ± 3.3%), hatching rate (55 ± 22.9, 55 ± 15.9, or 52 ± 14.8%), or total blastomeres number (184 ± 12.6, 179 ± 12.4, or 190 ± 13.8). The control COC showed no significant differences to any DOC treatment on cleavage (77 ± 3.4%) and blastocyst from cleaved (60 ± 2.2%). However, the blastocyst rate from initial COC was higher (46 ± 0.5%; P < 0.05) than all DOC treatments. Even though the blastocyst yield was lower than COC (~21 v. 46%), it is reasonable to affirm that it is possible to produce embryos from oocytes that would not be utilised, which may represent additional number of embryos. The blastocyst cell numbers in COC (192 ± 13.7) were similar (P > 0.05) to DOC, indicating that the goat embryos produced were of good quality. In conclusion, the inclusion of more complex substances in IVM media did not increase the development rate of DOC and, therefore, more simple IVM media could be used for this purpose. Finally, the goat embryos produced had satisfactorily number of blastomeres, demonstrating that the in vitro development step is able to generate good quality embryos from grade III oocytes. Therefore, some oocytes that in general would be discarded will develop to blastocysts and may represent benefits, especially after ovum pick-up from genetically valuable goats.

Relative mRNA expression and immunolocalization for transforming growth factor-beta (TGF-β) and their effect on in vitro development of caprine preantral follicles

This study aimed to evaluate the immunolocalization and messenger RNA (mRNA) expression for transforming growth factor-beta (TGF-β) and its receptors (TGF-βRI and RII), as well as mRNA expression for P450 aromatase and FSH receptor in caprine preantral follicles. The effects of TGF-β, FSH alone, or in association on the in vitro follicular development were also assessed. Immunohistochemical analyses showed the expression of TGF-β and its receptors in oocytes of all follicle stages and granulosa cells of primary and secondary follicles. mRNA for TGF-β receptors and for FSH receptor (FSHR) was present in preantral follicles as well as in oocytes and granulosa cells of antral follicles. Isolated secondary follicles were cultured in α-minimum essential medium (MEM) alone or supplemented with either FSH (100 ng/ml), TGF-β (10 ng/ml), or TGF-β + FSH for 18 d. TGF-β increased significantly oocyte diameter when compared to FSH alone and control. After 18 d of culture, all groups showed a significant reduction in P450 aromatase and FSHR mRNA levels in comparison to fresh control. In contrast, treatment with FSH significantly increased the mRNA expression for TGF-β in comparison to fresh control and other treatments. In conclusion, the findings showed that TGF-β and its receptors are present in caprine ovarian follicles. Furthermore, they showed a positive effect on oocyte growth in vitro.

[Use of an in vitro model in bovine to evidence a functional and molecular dialogue between preimplantation embryo and oviduct epithelial cells]

Beyond being a pipe between ovary and uterus, the oviduct is an active player in different aspects of early reproductive processes, in particular in the transport of embryos to the site of implantation and the regulation of its early development. Different studies evidenced a communication between oviduct and early embryo at the molecular and functional levels. Since the study of these interactions is difficult in vivo, different in vitro systems have been developed to mimic the maternal milieu during early development. These systems allowed to confirm the action of the cells on the quality of early development (blastocyst rate and viability). In turn, the embryos are producing signals that are able to modify and adapt the activity of maternal cells.

190 JNK SIGNALLING IN FOLLICLE ACTIVATION

Primordial follicles are maintained in a quiescent state until they receive a signal to activate and join the growing pool. It is essential that the rate of follicle activation is well coordinated as it determines the reproductive lifespan of the female. This finely tuned process is under the control of a variety of positive and negative factors, and there is evidence that the JNK pathway is involved. The aim of this study was to assess the effect of a JNK inhibitor (SP600125) on follicle activation in vitro. Ovaries from 6 prepubertal sheep were dissected into 1-mm3 fragments and cultured in the presence or absence of SP600125 (0, 5, or 25 µM; SP0, SP5, and SP25, respectively). After 0, 2, 5, or 9 days, fragments were fixed, sectioned, and analysed by histological morphometry to determine the number and type of follicles in addition to TUNEL analysis for apoptosis. In total, 21 584 follicles were assessed. Follicles were classified as either primordial, intermediate, primary, secondary, or antral. Culture media were also assayed for steroid content. After multinomial regression analysis, there were no differences in the rate of follicle activation between groups on Day 2 of culture. However, after 5 days of culture there were significantly more primordial follicles in SP25 (69 ± 9.15%; P < 0.01) and SP5 (52 ± 8.12%; P < 0.05) groups when compared with SP0 (34 ± 3.98%). At the end of culture (Day 9), these differences continued to be observed (SP25: 63 ± 8.47%; SP5: 51 ± 6.62%; SP0: 34 ± 5.61%; P < 0.05). On Day 9 there were more intermediate follicles following treatment with SP0 (52 ± 3.27%) compared with SP5 and SP25 (42 ± 4.72% and 31 ± 7.41% respectively; P < 0.05). There was also a tendency for more primary follicles on Day 9 for the control (11 ± 4.29%) when compared with the other treatments (4 to 7%; P = 0.06). The proportion of apoptotic primordial follicles was greatest in the SP25 group when compared with SP5 and SP0 at all timepoints (P < 0.05). After 2 days of culture, progesterone concentration was highest in the SP25 group (4.1 ± 0.45 ng mL–1) compared with the SP5 and SP0 groups (2.9 ± 0.39 ng mL–1 and 1.6 ± 0.79 ng mL–1, respectively; P < 0.05). However, this dose effect was lost by the end of culture. There was no effect of the inhibitor on oestradiol synthesis. By using SP600125, we have observed a dose-dependent block on follicle activation. These results suggest that the JNK pathway is a novel regulator of follicle activation and development. However, further confirmation is required to determine its specific action. The mechanisms by which SP25 promotes progesterone synthesis and increases apoptosis are unknown and also require clarification.

161 SUCCESSFUL INTERSPECIFIC PREGNANCY AFTER TRANSFER OF IN VITRO-PRODUCED SIKA DEER (CERVUS NIPPON NIPPON) EMBRYO IN RED DEER (CERVUS ELAPHUS HIPPELAPHUS) SURROGATE HIND

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

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 Cognié 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)

Laparoscopic ovum pick-up and in vitro production of sika deer embryos: effect of season and culture conditions

Amongst the 200 deer subspecies worldwide, more than 40 are considered as endangered. In vitro embryo production may represent an efficient way to produce and disseminate offspring from sparse remaining individuals in these species. With a view to establishing a method of in vitro embryo production, we assessed the ovarian response after hormonal stimulation (oFSH), oocyte yield following laporoscopic ovum pick-up (LOPU) and oocyte developmental competence according to seasonal reproductive status in sika deer (Cervus nippon nippon). Twelve adult sika deer hinds were allocated between two groups and submitted weekly to oFSH follicular growth stimulation followed by LOPU. Hinds in Group A (n=6) were treated first during the breeding season (5 weeks), and then during the non-breeding season (3 weeks). Hinds in Group B (n=6) were submitted to similar procedures but in the reverse order (treated first during the non-breeding season). Cumulus-oocytes complexes (COC) recovered from Group B were allowed to mature in vitro for 24 h in TCM-199 medium supplemented with oFSH, goat follicular fluid and 100 microM cysteamine. In vitro fertilization was performed with frozen/thawed semen in SOFaa medium supplemented with 20% estrous sheep serum and presumptive zygotes were cultured in the presence or absence of ovine oviductal epithelial cell monolayer (oOEC) in SOFaa-BSA medium. Mean number of follicles aspirated per hind per session decreased significantly between breeding and non-breeding season in Group A (9.8+/-0.7 versus 3.2+/-0.7, mean+/-S.E.M., respectively, P<0.001) but did not change between the non-breeding and the subsequent breeding season in Group B (5.3+/-0.7 and 5.7+/-0.7, respectively, P>0.05). Irrespective of the season, good quality COC with complete and compact cumulus investments were recovered allowing a high cleavage rate after in vitro maturation and fertilization. Whereas development to the blastocyst stage did not occur in SOF medium alone, high development rates to the blastocyst stage were observed in oOEC co-culture regardless of season (22% and 34% of total oocytes in co-culture during non-breeding and breeding season, respectively).

Successful use of oviduct epithelial cell coculture for in vitro production of viable red deer (Cervus elaphus) embryos

Techniques for in vitro production (IVP) of viable embryos have been thoroughly developed in several domestic species in view to improve breeding efficiency. When applied to wild life, these techniques may also help the maintenance of biodiversity through amplification of sparse animals offspring and facilitation of genetic material exchange. During the successive steps of IVP, i.e. oocyte in vitro maturation (IVM), fertilization (IVF) and early embryo development (IVD) to the blastocyst stage, gametes and embryos are faced with unusual environment, including oxidative stress, known to be detrimental to their survival. In the present study, starting from methods developed in domestic species, we have adapted IVP to produce viable red deer embryos. In a first experiment, cumulus cells were removed from in vitro matured oocytes either before or after IVF. The presence of cumulus cells during IVF did not affect final cleavage or development rates. In a second experiment, in vitro matured oocytes were fertilized in the presence of cumulus cells and cultured in SOFaaBSA medium alone or in the presence of ovine oviduct epithelial cell (oOEC) monolayer. Whereas, oviduct cells did not improve the cleavage rate, they significantly increased the rate of embryos reaching the blastocyst stage (from 3 to 25% of total oocytes). Ten blastocysts from oOEC coculture were transferred after freezing and thawing to five recipient hinds and gave rise to three pregnancies. The three pregnant hinds gave birth to three live and normal calves.