Transcervical Artificial Insemination Research Articles

Transcervical artificial insemination in the brown brocket deer (Subulo gouazoubira): a promising method for assisted reproduction in deer

The present study aimed to test the efficiency of transcervical artificial insemination techniques with cervical immobilization (TCAI-CI) or cervical traction (TCAI-CT), associated or not with the use of oxytocin (OT) as a protocol for cervical dilation, in the brown brocket deer (Subulo gouazoubira). The study was carried out in a crossover design using four adult females in two replicates with an interval of 60 days. Estrus was synchronized with oral melengestrol acetate (MGA) associated with estradiol benzoate and sodium cloprostenol. TCAI techniques were performed from 18 to 24 h after estrus onset. All females received either an i.v. application of 50 IU of OT (G-OT, n = 4) or 1 mL of saline solution (G-Control, n = 4) 20 min before the TCAI procedure. The TCAIs were performed using frozen-thawed semen motility 40%, vigor 3, acrosome integrity 87%, membrane integrity of 95% and 13% of total post-thaw defects from the same batch. Behavioral estrus was observed in 100% of the females, in both replicates. It was achieved a 50% (4/8) success of cervical transposition with semen deposition in the uterine. Regarding inseminations, most of them (87.5%) were performed using the TCAI-CT technique, and the overall conception rate was 50%. Cervical transposition times (< 1 min) and TCAI procedures (~ 17 min) were considered satisfactory. Thus, the performance of the TCAI-CI and TCAI-CT techniques was successful, regardless of using OT as a cervical dilation protocol. This procedure is proposed as a method of choice for artificial insemination with greater applicability in different conservation centers, compared to more advanced reproductive biotechniques, and with a favorable impact on the conservation of deer species.

Use of deslorelin acetate to advance ovulation in goats for timed artificial insemination

The objective of this study was to determine the efficacy of deslorelin in advancing ovulation for timed artificial insemination (AI) protocols in goats. We hypothesized that deslorelin treatment advances the onset of ovulation and improves AI pregnancy rates. Does were synchronized using a 5-day CIDR (controlled internal drug releasing insert) protocol with prostaglandin treatment at CIDR insertion. For Experiment 1, does received 0.2 mg of intramuscular deslorelin (n = 9) or saline (control, n = 10) at CIDR removal. Serial blood collections and transrectal ultrasonography were performed to assess ovarian dynamics and identify ovulation. For Experiment 2, does received 0.2 mg of intramuscular deslorelin (n = 42), 5 ml of PMSG (pregnant mare serum gonadotropin)/hCG (human chorionic gonadotropin) (n = 42), or were left untreated (control, n = 42) at CIDR removal, and were subsequently bred by transcervical AI with fresh semen after 48 to 56 hours. Pregnancy diagnosis was performed at 50 and 90 days after AI. In Experiment 1, compared to control does, deslorelin-treated does had an increased (p &lt; 0.01) number of ovulations and increased (p &lt; 0.01) serum estradiol concentrations from 48 to 72 hours after CIDR removal. Serum progesterone concentrations did not differ between treatments. In Experiment 2, there was a main effect (p = 0.02) of treatment on pregnancy rates, with control does tending (p = 0.06) to have greater pregnancy rates than those treated with deslorelin or PMSG/hCG. Deslorelin treatment also resulted in decreased (p = 0.04) breeding season pregnancy rates and increased (p = 0.05) number of cycles to achieve pregnancy compared to control does. These results demonstrated that deslorelin not only has a super-ovulatory effect but also, at the dose given, can negatively impact does’ subsequent ovarian function and ability to achieve pregnancy.

Effect of L-arginine and Eugenol on Ram Semen Kinematic Parameters and Post Thawed Fertility Rate after Trans-cervical Artificial Insemination

Backgroung: Long term storage of spermatozoa is one of the most desirable tools of assisted reproductive technologies. The purpose of this research was to evaluate the effect of two antioxidants on sperm kinematic parameters after the freezing-thawing process and the post thawed fertility rate after the trans cervical artificial insemination. Methods: Ejaculates from Lacune rams were collected using artificial vagina, were pooled and diluted using based extender (Biladyl, Minitube) and based extender with antioxidants (Eugenol, Arginine). Trans-cervical artificial insemination was performed with frozen seminal material in straws. Result: No significant differences were observed in samples cryopreserved in a base extender and in the base extender supplemented with Arginine. In Eugenol supplemented extender the kinematic parameters were significantly higher for p=0.5 (30.15% progressive motility after thawing) than in the others groups (23.57%, 24.38%). The fertility rate was higher for the straws conserved in extender supplemented with Eugenol (80%) compared with the base extender (55.55%) and the base extender supplemented with Arginine (60%).

The Design of a New Catheter for Transcervical Artificial Insemination in Ewes.

Simple SummaryIn ovine species, transcervical artificial insemination is not easy to apply, due to the tortuous lumen of the cervix that does not allow the passage of routinely used catheters. Moreover, the quality of frozen–thawed semen in small ruminants is poor and these factors negatively affect the wide spreading of superior genotypes. The aim of this study was therefore to preliminarily test three newly designed insemination catheters, with bent tips of different lengths, in terms of reproductive performances in pluriparous ewes inseminated with frozen–thawed semen. Afterwards, the outcomes of insemination with the best performing catheter were compared to those obtained in ewes previously submitted to surgical incision of cervical folds, a technique that allows transcervical intrauterine deposition of semen. The results obtained indicated that a catheter with a bent tip of 5.0 mm allowed deep and fast intrauterine insemination, leading to pregnancy rates similar to those obtained following surgical incision of the folds. Further tests on the efficiency of the catheter are needed in field conditions and on a larger number of animals to assess the feasibility of the method in wide commercial insemination campaigns.In ovine species, transcervical artificial insemination (TCAI) is limited by the poor quality of frozen–thawed semen and by the convoluted cervical lumen hampering the passage of inseminating devices. The aim of the study was to test the efficiency of three newly designed catheters with bent tips of 3.5 mm, 5.0 mm or 8.0 mm in terms of reproductive performances (experiment 1) and to compare the results of TCAI with the best performing catheter of experiment 1 to those obtained in ewes submitted to surgical incision of cervical folds (SICF) prior to insemination (experiment 2). The following parameters were assessed: time to pass the cervix; depth of cervical penetration; site of deposition of semen; pregnancy (PR); and lambing rates (LR). The results of experiment 1 indicated that the 5.0 mm tip catheter resulted in deeper and faster TCAI and higher PR and LR compared to 3.5 mm and 8.0 mm tip catheters (p < 0.05). In experiment 2, TCAI with the 5.0 mm catheter did not differ from TCAI after SICF in terms of depth of semen deposition, time to pass the cervix, PR and LR (p < 0.05). In conclusion, the use of a catheter that allowed transcervical uterine deposition of semen without excessive manipulation led to satisfactory pregnancy rates.

Local α1-adrenergic blockers: An alternative for sheep cervix dilation?

To facilitate transcervical artificial insemination in sheep, the effects of local treatment with α1-adrenergic receptor antagonists on cervix dilation and hemodynamics were evaluated. Ewes (n = 7) were subjected to oestrous synchronisation every 40 days and assigned to treatments in a Latin square experimental design (seven animals × seven periods) with a factorial treatment arrangement (A × B), Factors A (prazosin or tamsulosin) and B (1, 2, or 4 mg/animal). Ewes of the six treatment groups (P1, P2, P4, T1, T2, and T4) were administered α1-adrenergic receptor antagonists while those of the control group (CG) were administered only α1-adrenergic antagonist carrier agent. Distance that the transcervical catheter penetrated without cervical resistance, mean arterial pressure, and uterine artery dopplerfluxometry were evaluated before and after 30 min, 1, 2, 4, 8, and 10 h of treatment. Catheter penetration distance was greater in ewes of the T4 and P4 groups (P < 0.01), with there being a positive correlation between dose and distance (r = 0.243). The penetration distance was similar (P = 0.84) for treated groups, with the greatest penetration occurring 2, 4, and 6 h after treatment (P < 0.01). The passage into the uterine lumen was greater (P = 0.013) in ewes of the P4 (17.9 %) and T4 (19.6 %) groups. There were no effects on blood pressure or uterine blood flow (P> 0.05). These preliminary results indicate there are benefits of treatment with 4 mg/animal of tamsulosin or prazosin in catheter passage through the sheep cervix 2–6 h after administration without hemodynamic effects.

Effects of cervical ripening treatments on pregnancy rates following transcervial artificial insemination in ewes

The study was aimed to identify the effective cervical ripening treatment to increase the pregnancy rates following transcervical artificial insemination (TC-AI) in indigenous ewes of Bangladesh. Three treatments schedules were compared, G1 (n = 6, control), G2 [n = 6, prostaglandin E1 (PGE1) as Misoprostol-Cytomis®] and G3 (n = 6, estrogen as Oestriol-Ovestin® + oxytocin as Linda-S® Vet). Ewes (n=18) were synchronized for estrus using two doses of 100 µg prostaglandin (PGF2α; Ovuprost®) 9 days apart. The cervical ripening treatments were administered just after the onset of estrus and left for 12 h before TC-AI. The cervical ripening was reflected with the depth of cervical penetration. The depth of cervical penetration in G1, G2 and G3 both before and after cervical ripening treatments were 0.33 ± 0.10 cm vs 0.43 ± 0.07 cm, 0.41 ± 0.09 cm vs 3.50 ± 0.26 cm and 0.43 ± 0.09 cm vs 1.54 ± 0.14 cm, respectively. The depth of cervical penetration increased significantly (p

Reproductive Performance Following Transcervical Insemination with Frozen Thawed Semen in Ewes Submitted to Surgical Incision of Cervical Folds (SICF): Comparison with Laparoscopic Artificial Insemination.

Simple SummaryThe anatomical barriers of the female reproductive tract and the low quality of the frozen thawed semen of rams are limiting factors in spreading superior genotypes in the ovine species. Artificial insemination (AI) is therefore mostly performed by laparoscopy. The surgical incision of cervical folds (SICF) has been demonstrated to allow transcervical intrauterine semen deposition. Here we present data regarding pregnancy (PR) and lambing (LR) rates obtained by transcervical AI following SICF, compared to those obtained by laparoscopic AI using frozen thawed semen. The results showed that in 89.7% of ewes submitted to SICF intrauterine, the deposition of semen was allowed. Moreover, in both experimental groups, the PR and LR were similar. These observations suggest that SICF could represent a valid preliminary procedure to allow transcervical AI in animals of superior genotypes contributing to genetic improvement.Transcervical artificial insemination (AI) after the surgical incision of cervical folds (SICF) could represent a valid alternative to laparoscopic AI when frozen thawed semen is used. The aim of this experiment was to compare pregnancy (PR) and lambing rates (LR) of ewes submitted either to transcervical AI after SICF or to laparoscopic AI using frozen thawed semen. Pregnant at term ewes (n = 80) were allocated in two experimental groups. After lambing, one group (n = 39) was submitted to SICF. The remaining ewes that were regularly lambed were allocated to the group of laparoscopic AI (n = 40). Six months later, oestrous cycle of both experimental groups was synchronised and all ewes were artificially inseminated with frozen thawed semen. Ewes submitted to SICF underwent transcervical insemination and intrauterine deposition of semen was recorded. The remaining animals were submitted to laparoscopic AI. Pregnancy and LR were recorded. Intrauterine deposition of semen was possible in 89.7% pf ewes submitted to SICF. This group showed similar PR and LR compared to the laparoscopic group (respectively: PR, 71.8% vs. 70% and LR, 64.1% vs. 65%; p > 0.05). Transcervical AI after SICF may represent a valid alternative to laparoscopy in AI protocols requiring the use of frozen thawed semen.

Welfare and pregnancy rate of ewes undergoing transcervical artificial insemination with ketamine subarachnoid anesthesia.

This study aimed to evaluate the impact of subarachnoid anesthesia with ketamine during transcervical artificial insemination (TCAI) on the welfare of ewes and on subsequent pregnancy rates. Ninety Suffolk adult ewes were randomized into three treatment groups: control group (CG), which underwent the TCAI procedure as established by cervical traction (CG; n = 30) and two groups that received subarachnoid anesthesia with ketamine at a dose of either 0.75mg/kg (KE0.75; n = 30) or 1.5mg/kg (KE1.5; n = 30) 5min before the cervical traction procedure. Intrauterine insemination was performed using frozen semen from three males previously analyzed and approved for fertility. The use of subarachnoid anesthesia decreased ewes' vocalizations (P = 0.0001) and abdominal contraction (P =0.0150) during cervical manipulations. The CG had more groans and vocalizations at the moment of cervix clamping and applicator passage through the cervix (P = 0.001). The cervix traction was facilitated by anesthesia. For the control group, most of the cervical traction was done just up to the middle of the vagina (P = 0.0021). Pregnancy rates increased significantly with anesthesia (P = 0.04) as shown by the rates of 40.0%, 56.7%, and 66.7% for CG, KE1.5, and KE0.75, respectively. The CG showed behaviors associated with absolute immobility, which is suggestive of distress. In brief, the use of ketamine in subarachnoid anesthesia for transcervical artificial insemination in ewes facilitated cervical traction, increased the pregnancy rate, and improved animal welfare.

Surgery on cervical folds for transcervical intrauterine artificial insemination with frozen-thawed semen enhances pregnancy rates in the sheep

In sheep industry, genetic progress rate achieved by artificial insemination (AI) is limited by the convoluted anatomy of the cervix, which does not allow the passage of an insemination catheter for uterine semen deposition. The aim of this study was to test, in 98 pregnant at term Sarda ewes, the effects of: Experiment 1) total or partial ablation of cervical folds and Experiment 2) 4 or 2 incisions of cervical folds, on the passage of an insemination catheter, deposition of frozen-thawed semen and pregnancy rates. Surgical procedures were performed within 24 h from parturition providing deep sedation and epidural anaesthesia. Duration of surgeries and post-operatory recovery were carefully monitored. For both experiments, 5 months since surgery, independently of the stage of oestrus cycle, cervical patency was tested through the transcervical passage of a palpation probe. Six months since surgery, in Experiment 1, ewes were naturally mated with fertile rams. In Experiment 2, ewes submitted to incisions of the cervical folds and a control group underwent synchronisation of oestrus and transcervical AI with frozen-thawed semen. Thirty days later, for both experiments, pregnancy rates were assessed by ultrasonography and lambing rates were recorded. Five months after surgery, in Experiment 1, transcervical passage of a palpation probe to reach the uterine lumen was possible in all ewes submitted to total and partial ablation of folds. In Experiment 2, this was achievable in 90.5% ewes with 4 incisions of the folds and in 89.6% ewes with 2 incisions with no significant differences among groups (P = 0.44). In Experiment 1, pregnancy rates in ewes mated to rams after total or partial ablation of the cervical folds was 100%. In Experiment 2, following transcervical AI, pregnancy rates were higher in groups submitted to 4 (63.7%) or 2 (41.4%) incisions of the cervical folds compared to the control group (8%; P<0.05). These data were confirmed at lambing with rates of 56.8% and 41.4% in ewes submitted to 4 or 2 incisions respectively, significantly higher than the control group (4%; P<0.05). Surgical ablation or incision of the cervical folds in post-partum ewes represent valid procedures for transcervical intrauterine deposition of semen for AI, obtaining satisfactory pregnancy rates. These procedures might be useful in programs of genetic selection and MOET.

Morphometry and depth of inseminating catheter penetration in prolific and non- prolific ewes at different ages: A post mortem study

The ewe's cervix structure is highly variable among females, which may limit the application of transcervical artificial insemination (TCAI). This work aimed to study the variation in cervix anatomy in two different prolificacy breeds (D’man a prolific and Boujaâd a non-prolific sheep). Reproductive tracts were collected from D'man (n = 64) and Boujaâd (n = 187) females aged between 1 and 4 years. The weight of the uterus, length of the cervix and depth of penetration of the inseminating pipette were recorded. The number of cervical rings was counted and their arrangement graded. The cervix anatomy of D’man ewes differs from that of Boujaâd. The cervix morphology of Boujaâd ewes is more complex compared to D’man ewes; this complexity depends on the age of the ewe. No significant difference was found regarding the depth of penetration of the insemination catheter for the two breeds at 1, 2 and 4 years old (P > 0.05). However, at 3 years old, the highest depth of penetration (P < 0.05) was recorded in D’man ewes. In addition, for both breeds, grade 2 was the most frequent (P < 0.05), and the cervix became less complicated for TCAI with advanced age (4 years old). To conclude, the cervix of D’man ewes is less complex and more favorable to TCAI. In addition, to overcome the complexity of the cervix in Boujaâd sheep, a selection of 4-year-old ewes will make the penetration of the artificial insemination catheter possible.

Efeito da Aplicação de Flunixin Meglumine Sobre a Taxa de Gestação de Ovelhas Inseminadas via Transcervical

Background : : : : In livestock animals, which artificial insemination (AI) is widely spread, a healthy uterine environment is an important factor that should be taken into account for an adequate fertilization and establishment and development of pregnancy. The main limitation to spread the frozen semen insemination in sheep is the high costs of the laparoscopy AI and the difficulty of traversing the cervix. To overcome problems associated with transcervical artificial insemination, new techniques and instruments have been proposed. The manipulation of cervix during transcervical artificial insemination in sheep can lead to a local inflammatory reaction that releases inflammatory mediators, such as prostaglandins and cytokines, that either can negatively affect the uterine environment and consequently, the conception. In this regard, the injection of a non-steroidal anti-inflammatory (NSAI) at the moment of AI could reduce the secretion of inflammatory mediators, promoting a healthier uterine environment favorable to conception. The flunixin meglumine is a NSAI which reduces the synthesis of PGF 2 a by the inibition of the cyclooxigenase. The objective of this study was to evaluate the effect of flunixin meglumine (non-steroid antiinflammatory) injection on pregnancy rate of ewes inseminated by the transcervical technique. Materials, Methods & Results : In this experiment 69 pluriparous ewes were used, 29 in control group (CG) and 40 in flunixin meglumine group (FMG). The estrus detection was performed twice daily for 5 days. The ewes detected with paint in the low back were considered in estrus. The AI procedure was performed 8 hours after the estrus detection. At the AI time, the ewes were separated according to body condition score in two experimental groups. The ewes of the FM Group were injected with 1.1 mg/Kg of flunixin meglumine, im, 1 hour before the AI procedure. In order to locate the ostium, a vaginal speculum and a source of external light were used; whereas the fixation and traction of the ostium were performed with an Allis clamp, allowing the penetration of the semen applicator throw the vagina and cervix. The insemination procedure was performed 8 hours after estrous detection. There was no difference (P > 0.05) on the pregnancy rate between groups, whereas the Control group had 68.9% and the FM group had 60.0% of pregnancy. Discussion : The result demonstrates that the local inflammatory reaction caused by the traction of cervix was not detrimental to uterine environment and fertilization, since a high pregnancy rate was detected in both groups. Although the hypothesis of this study was not supported by the results, the high pregnancy rate detected in this experiment was higher than the results normally detected. Several studies have shown low pregnancy rates when transcervical artificial insemination with frozen semen is used associated to protocols of estrous synchronization. The flunixin meglumine did not improve the pregnancy rate, probably due to the insemination procedure adopted, since the traction of the cervix were performed gently, and consequently minimized the tissue damage. Thus, the inflammatory reaction may not have been sufficiently extensive as to lead to alteration of the uterine environment. These results suggested that flunixin meglumine injection did not influence the conception when was used prior to the transcervical insemination.

Influence of age on fertility rate and chicken hatchability at artificial insemination by semen diluted with VNIIGRZH extender

The ewe's cervix structure is highly variable among females, which may limit the application of transcervical artificial insemination (TCAI). This work aimed to study the variation in cervix anatomy in two different prolificacy breeds (D’man a prolific and Boujaâd a non-prolific sheep). Reproductive tracts were collected from D'man (n = 64) and Boujaâd (n = 187) females aged between 1 and 4 years. The weight of the uterus, length of the cervix and depth of penetration of the inseminating pipette were recorded. The number of cervical rings was counted and their arrangement graded. The cervix anatomy of D’man ewes differs from that of Boujaâd. The cervix morphology of Boujaâd ewes is more complex compared to D’man ewes; this complexity depends on the age of the ewe. No significant difference was found regarding the depth of penetration of the insemination catheter for the two breeds at 1, 2 and 4 years old (P > 0.05). However, at 3 years old, the highest depth of penetration (P < 0.05) was recorded in D’man ewes. In addition, for both breeds, grade 2 was the most frequent (P < 0.05), and the cervix became less complicated for TCAI with advanced age (4 years old). To conclude, the cervix of D’man ewes is less complex and more favorable to TCAI. In addition, to overcome the complexity of the cervix in Boujaâd sheep, a selection of 4-year-old ewes will make the penetration of the artificial insemination catheter possible.

Fertility response of artificial insemination methods in sheep with fresh and frozen-thawed semen

The aim of this study was to evaluate the fertility response of artificial insemination (AI) methods with fresh and frozen sperm in sheep. In experiment 1, one hundred and fifty fat tailed Zandi ewes were assigned into 3 equal groups and inseminated with three AI methods consisting of vaginal, laparoscopic and trans-cervical AI with fresh semen. In experiment 2, a factorial study (3 AI methods × 2 extenders) was used to analyze the effects of three AI methods and two freezing extenders containing soybean lecithin (SL) or Egg yolk (EY) on reproductive performance of 300 fat tailed Zandi ewes. Also, total motility, progressive motility, viability and lipid peroxidation of semen were evaluated after freeze-thawing in two extenders. In result, there was no significant difference among three AI methods when fresh semen was used. In experiment 2, the highest percentage of pregnancy rate, parturition rate and lambing rate were obtained in laparoscopic AI group (P < 0.05). Although pregnancy rate, parturition rate and lambing rate in trans-cervical group were higher (P < 0.05) than vaginal group, the results were not as high as laparoscopic group. No difference was observed between SL and EY extenders and their performance was close to each other. It can be concluded that although no difference was observed on reproductive performance for fresh semen, trans-cervical AI was more efficient than vaginal method when frozen-thawed semen was used, but its efficiency was not as high as laparoscopic method. Also, SL extender can be an efficient alternative extender to preserve ram sperm during cryopreservation procedure without adverse effects of EY.

Retained fertilizing capability in cryopreserved feline spermatozoa.

Sperm cryopreservation offers a long-term preservation of male genetic materials for future assisted reproductive technologies. However, dramatic changes in temperature during freezing and thawing injure sperm cells. While motility is essential for AI and membrane integrity is crucial for in vitro fertilization (IVF), sperm DNA integrity is a common index of fertilizing capability required for AI, IVF and intracytoplasmic sperm injection (ICSI). In endangered felids died unexpectedly, attempts have been made to recover as many DNA intact spermatozoa as possible from epididymis and testis to increase the opportunity to produce offspring in future. Although sperm from caudal epididymis has shown retained fertilizing capability after freezing and thawing (27.3% conception rate after unilateral intrauterine insemination), sperm recovery from the corpus epididymis has been suggested as an alternative to increase the amount of preserved genetic materials. To improve epididymal sperm quality, pre-treatment with single-layer centrifugation resulted in selection of sperm cells with intact DNA while post-thaw treatment with extracellular ATP incubation promoted the blastocyst rate. Cold storage of domestic cat testis for 7days at 4°C demonstrated <1% of sperm cells with fragmented DNA. Moreover, isolated testicular sperm cells, stored for 7days at 4°C, produced after ICSI poorer percentages of cleavage, morula and blastocyst than the fresh control. In wild felids, a death-to-necropsy time of 2hr after a jungle cat (Felis chaus) aged 10years died during anaesthesia plus another necropsy-to-sperm recovery time of 25hr has been reported to yield the post-thawed testicular sperm with 22.2% intact DNA. In summary, the chromatin structure of feline ejaculated and epididymal sperm seems to be tolerated to cold storage and cryopreservation; thus, fertilizing capability is well protected. In contrast, the cat testicular sperm DNA is generally damaged through the cryopreservation.

First live offspring of Amazonian brown brocket deer (Mazama nemorivaga) born by artificial insemination

The Amazonian brown brocket deer (Mazama nemorivaga) is an endemic species of the Amazon rainforest region, which has suffered constant threats due to hunting and increasing deforestation. Artificial insemination (AI), combined with genomic banks, is considered an important tool for maintaining conservation programs of endangered species; however, the number of live offspring born from AI in non-domesticated cervids is extremely low. Thus, studies designed to develop, adapt, or enhance AI techniques are of fundamental importance. This report describes a successful transposition of the cervix with semen deposition in the uterine lumen of a M. nemorivaga female, based on the transcervical AI technique used in sheep, as well as using specific tools develop for IA in small ruminants, which have resulted in the birth of a healthy male fawn.

Assessing the usefulness of prostaglandin E2 (Cervidil) for transcervical artificial insemination in ewes

The underlying theme of this study involved the evaluation of the dilatory effects of prostaglandin E2 on the ovine cervix and thus the assessment of its potential applicability to transcervical artificial insemination (TCAI) in ewes. A novel method of prostaglandin E2 administration (controlled slow-release vaginal inserts) was examined, and the practical implications of this approach including cervical penetrability and posttreatment pregnancy rates were evaluated. The Guelph method of TCAI was performed during the seasonal anestrus (n = 40) and the breeding season (n = 40) on multiparous Rideau Arcott × Polled Dorset ewes, with or without the pretreatment with Cervidil (for a duration of 12 hours or 24 hours before TCAI). Cervical penetration rates averaged 82.5% (66 of 80), and they varied neither (P > 0.05) between the two seasons nor between Cervidil-treated ewes and their respective controls. Cervidil priming significantly reduced the total time required for TCAI during the breeding season in comparison with controls (54 vs. 98 seconds), especially after the 24-hour exposure (38 vs. 108 seconds). The time taken to traverse the uterine cervix was negatively correlated (P < 0.05) with the breed (percentage of Rideau Arcott genotype) and lifetime lamb production in seasonally anestrous ewes. Four out of 36 (11%) successfully penetrated ewes in the breeding season (three ewes allocated to the 12-hour control group and one ewe that had received Cervidil for 12 hours) became pregnant and carried the lambs to term. Vaginal mucus impedance at TCAI was significantly and positively correlated with the total time required to complete the procedure in cyclic ewes, and the negative correlation between vaginal mucus impedance and total time values at the time of controlled intravaginal drug release device removal approached to significance in anestrous ewes. The present results indicate a moderate benefit of using Cervidil for inducing cervical dilation before TCAI in ewes, mainly in the breeding season. The specific reason(s) for impaired fertility after the TCAI using frozen–thawed ram semen remains to be elucidated.

Use of reduced doses of eCG applied by different routes in the TAI program in Santa Ines sheep

The aims of this study were to improve the cost-benefit ratio of the application of artificial insemination in fixed time (TAI) by the transcervical route in sheep, to test the dosage reduction and the use of the vulvar submucosa (VSM) route as an alternative for the application of equine chorionic gonadotropin (eCG) on the efficiency of the synchronization protocol and fertility to artificial insemination (AI) and to measure the level of cortisol in ewes as a result the application of this biotechnique. Blood samples were collected before AI, immediately after AI and seven days after AI. Six groups of twenty animals were used, and each group received doses of 200, 300 and 400 IU of eCG by the intramuscular route (IM) and VSM. Estrus was detected, and 48 hours later, the inseminations were performed by the transcervical route. Among the 120 treated ewes, 87.5% came in estrus. The percentage of the intrauterine deposition of semen was 88.3%. The pregnancy rate ranged from 20 to 70% between treatments, with an average of 46.66%. The VSM route was viable for the application of eCG in doses of 300 and 400 IU. The reduction in the eCG dose to 200 IU by the IM route reduces costs while maintaining the efficiency of estrus synchronization protocols and TAI with frozen semen in Santa Ines ewes. The average levels of cortisol were significant, at 1.15, 2.86 and 0.52 ?g/dL according to the three collections, being higher after the animal was off the easel at the end of AI. The procedures for performing the transcervical AI technique indicate that stress in the animals produces satisfactory fertility results and a low cost in multiparous ewes of the Santa Ines breed.

Transcervical artificial insemination in dogs and cats: review of the technique and practical aspects.

The technique of transcervical catheterization for artificial insemination has gained practical importance over the last 3 and 1 decades in bitches and queens, respectively. The vagina of both species has a thickening of the dorsal aspect called dorsal medial fold, which restricts the lumen of the paracervix, making catheterization of the cervix difficult both with manual and endoscopic techniques. Manual catheters have been used initially in the bitch and are now gradually being replaced by rigid endoscopy through the adaptation of human cystoscopes and ureteroscopes. Cystoscopes provide excellent imaging of the vagina, but cervical catheterization is more difficult due to the oblique 30° viewing angle of its telescope and may not be long enough to catheterize large size bitches. Ureteroscopes allow an acceptable view of the vaginal mucosa and offer advantages such as the possibility to catheterize the cervix of bitches of all body sizes, manipulate the cervical tubercle when the external cervical os is not visible, offer a better visualization of the cervix using the shunt (a large Foley catheter which allows insufflation and distention of the vagina). Feline cervical catheterization has been achieved with three different types of catheters; the last one, developed following careful anatomical studies of how the feline vaginal lumen changes during estrus, allows cervical catheterization thanks to digital manipulation of the cervix through the rectum.

Effect of estradiol and oxytocin on ovine cervical relaxation

The aim of this study was to examine the effect of estradiol (E2) and oxytocin (OT) treatments on the cervix dilation of three breeds of Iranian ewes. Cervix dilation was measured by penetration of scaled bovine catheter into the cervix of the ewes. In experiment 1, 60 Zell ewes were equally assigned to three groups in the breeding season. At first, the ewes received 100 μg intravenous (i.v) E2. 12h later, the ewes received 150, 100, and 50 IU OT. In experiment 2, 27 Zandi ewes were equally assigned to three groups in late breeding season and after jugular E2 injection, received 100, 80, and 60 IU OT. In Experiment three, 15 Lori-bakhtiari ewes were equally assigned to three groups during anestrous season and received 100, 80, and 60 IU OT after jugular E2 reception. Cervix dilation were examined before and 10 to 15 min after E2 and OT injection. This study indicates that just E2 had no effect on cervix dilation but injection of E2 and more than 80 IU OT can completely dilate the cervix of Iranian ewes (P < 0.05). Reproductive seasons (anestrous, late breeding season and breeding season) have no significant effect on induced cervix dilation by E2 and OT. In conclusion, this is good procedure for improve cervix relaxation and perform transcervical artificial insemination and transcervical embryo transfer in ewes. Key words: Ewes, Estradiol, Oxytocin, Cervical dilation.

Effects of exogenous oxytocin on cervical penetration of Iranian ewes

The objective of this study was to determine the effect of exogenous oxytocin (OT) treatments on the cervix dilation of three breeds of Iranian ewes. Cervix dilation was measured by transcervical passage of scaled bovine catheter into the uterus of the ewes. Fifty four healthy Zandi ewes were equally assigned to six groups in the late breeding season. Thirty healthy Lori-bakhtiari breed ewes were equally assigned to six groups during anestrous. The ewes received 100, 80 and 60 IU of intravenous (i.v) and intramuscular (i.m) OT. In the breeding season, 120 healthy Zell breed ewes were equally assigned to six groups and received 150, 100 and 50 IU of i.v and i.m OT. Cervix dilation was examined before OT injection 10 to 15 min following treatment. This study indicates that injection of more than 80 IU OT can completely dilate the cervix of Iranian ewes (P < 0.05) and the reproductive seasons (anestrous, late breeding season and breeding season) and the type of injection (i.v or i.m) has no significant effect on induced cervix penetration by OT. Therefore, this dose is the applicable dose for the cervix dilation and transcervical artificial insemination and embryo recovery in Iranian ewes. Key words: Iranian ewes, oxytocin, cervical dilation, transcervical artificial insemination, transcervical embryo transfer.