Pregnancy Rate Of Ewes Research Articles

Use of coenzyme Q-10 to improve the pregnancy rate in sheep

One of the factors responsible for less pregnancy rates is the use of frozen semen in sheep due to the oxidative stress created by the process. The aim of this experiment was to test the effects of adding coenzyme Q-10 (CoQ10) to the seminal extender on sperm quality and the pregnancy rate of sheep. In this study, ejaculates from eight Dorper rams of reproductive age were used and tested in four treatments: Control (pure BotuBov®), C1 (175 µM of CoQ10), C3 (350 µM of CoQ10), and C7 (700 µM of CoQ10). Samples were collected in triplicate from each animal, and sperm analysis was performed by CASA after thawing at 0 h and 2 h. The samples were also analyzed by flow cytometry for plasma and acrosomal membrane integrity, stability, lipid peroxidation, mitochondrial potential, and superoxide anion production. In total, 198 ewes were inseminated by laparoscopy and divided into two groups: control (n=98) and C7 (n=100). Pregnancy diagnosis was performed at 30 days. Coenzyme Q10 proved to be safe for semen cryopreservation, not altering sperm kinetic values between the groups post-thawing. In flow cytometry, the C1 and C7 groups achieved a better index of plasma membrane integrity and membrane stability (P<0.05). A increased pregnancy rate was observed in C7 (52 %) compared to the control (38 %). In conclusion, coenzyme Q10 assists in the cryopreservation process, protecting the sperm cell and improving pregnancy rates in ewes.

Efficacy of Intravaginal Lactic Acid Bacteria, Cell-Free Supernatant, or Enrofloxacin on Vaginitis and Fertility in Ewes Synchronized with Progesterone-Based Protocol

An intravaginal sponge impregnated with progesterone is commonly used for estrus induction and synchronization in ewes. Although using an intravaginal sponge containing progesterone positively affects the synchronization rate, varying degrees of vaginitis occur during its application. This study aimed to investigate the impacts of various intravaginal treatment options on the vaginitis severity and pregnancy rate in Merino ewes synchronized with intravaginal sponges impregnated with progesterone. During the breeding period, 589 ewes, aged 2–6, received intravaginal sponges for 14 days. The control group (CON) received no treatment, whereas vaginal sponges absorbed with enrofloxacin (ENR), Lactobacillus plantarum (LAC), or Lactobacillus plantarum supernatant (CFS) were applied in the treatment groups. All groups received 500 IU of equine chorionic gonadotropin intramuscularly. The ENR group showed lower scores in vaginal discharge and sponge odor compared with the CON, LAC, and CFS groups. Although estrus responses did not differ between groups, the pregnancy rate tended to be higher in the ENR group. In conclusion, intravaginal ENR application, but not LAC or CFS, reduced vaginitis severity and tended to increase pregnancy rates in ewes synchronized with intravaginal sponges impregnated with progesterone.

Effect of GnRH and hCG Treatment Following a Short-Term Estrus Synchronization Protocol on Ovulation and the Fertility in Merino Ewes, During the Breeding Season

This study aimed to compare the effect of hCG or GnRH administered 36 h following a short-term estrus synchronization treatment on the ovulation time and pregnancy rates of Merino ewes during the breeding season. The estrus cycles of ewes were synchronized with an intravaginal sponge containing 60 mg of medroxyprogesterone acetate for 6 days, and an injection of 400 IU of eCG and 125 µg of d-cloprostenol 24 h before sponge removal. Thirty-six h after the sponge removal, ewes were injected intramuscularly either 1 ml of physiological saline solution (control-group; n=14), 100 IU of hCG (hCG-group; n=14) or 0.004 mg of buserelin acetate (GnRH-group; n=14). The estrus behavior was observed using teaser rams and the ovulation time was monitored using transrectal ultrasonography twice daily for 96 h after the sponge removal. Ewes in estrus were allowed a single mating using fertile rams. Estrus response was higher (P&lt;0.05) in the control group (92.86%) than in the GnRH group (50.00%). The interval from sponge removal to ovulation and from hCG to ovulation were shorter in the control group than in the hCG group (70.55, 80.83 h; 34.55, 44.83 h, respectively, P&lt;0.05). In conclusion, administration of hCG or GnRH at 36 h following a short-term estrus synchronization protocol did not affect estrus behaviors, ovarian findings and pregnancy rates in ewes during the breeding season.

Metabolomics analysis of the effect of GnRH on the pregnancy rate of ewes with estrus synchronization scheme based on progesterone.

Gonadotropin-releasing hormone (GnRH) is widely used in the timed artificial insemination protocol for sheep. However, there remains a debate regarding its impact on pregnancy rates during artificial insemination. This study aims to evaluate the effect of GnRH on the pregnancy rates in Huyang ewes, analyze the pre-implantation metabolite changes caused by GnRH using metabolomics, and elucidate the mechanism effect on pregnancy rates. All ewes were administered a vaginal progesterone sponge containing 45 mg of flurogestone acetate for 12 days and received 330 units of equine chorionic gonadotropin (eCG) intramuscularly after sponge removal. The experimental group (n = 69) received an intramuscular treatment of 17 μg GnRH agonist triptorelin 48 h after sponge removal on Day 0, while the control group (n = 41) received 1 mL of sterile saline solution. All ewes underwent a single vaginal insemination 58 h after the withdrawal of the progesterone sponge. The difference in pregnancy rates between the two groups was calculated. Metabolomic analysis was performed on plasma samples collected on Day 7 after the treatment of GnRH agonist. Gonadotropin-releasing hormone (GnRH) treatment significantly reduced the pregnancy rate in the experimental group compared with the control group (72.2 vs. 82.9%, p < 0.05). Metabolomic analysis indicated that GnRH treatment affected metabolites involved in collagen synthesis and prostaglandin synthesis in the endometrial tissue, which includes a marked decrease in hydroxyproline amino acid content and a significant increase in corticosterone and prostaglandin D2 lipids and unsaturated fatty acids. In summary, the injection of GnRH agonist Triptorelin 48 h after progesterone sponges removal reduces the pregnancy rate of Huyang ewe following artificial insemination. It also affects the metabolite levels related to endometrial collagen and prostaglandin synthesis, harming embryo implantation.

Ram semen quality after supplementation with gelatin, agar or alginate prior to cooling storage.

Adding gelling agents to convert the liquid state of the semen extender to a solid state allows for an increased sperm life span. Gelatin and alginate have been used to study the effects of gelling agents on sperm quality. However, there are other gelling agents that have not been studied, such as agar. In addition, studying different sources of gelling agents or the effect of mixing more than one gelling agent with semen extenders on sperm fertility has received little attention. Therefore, the objective of this study was to evaluate the effect of adding agar and a mixture of gelling agents from different sources to semen extender on ram sperm traits and fertility. The first trial evaluated the effect of the addition of 2.5-3 mg mL-1 of gelatin mixed with 0.5-20 mg mL-1 of agar or alginate to ram semen extender on sperm (motility, progressive motility, live/dead, membrane integrity) and semen (pH) characteristics. The response variables were evaluated 1, 72 and 144 h after storage at 4°C. In the second trial, two sources (feed grade and bacteriological) of gelatin and agar were evaluated on the response variables as in Trial 1. In trial 3, a total of 34 ewes were inseminated with doses supplemented (n = 17) with or without (n = 17) agar and gelatin. The pregnancy rate was diagnosed 40 days after insemination. In general, adding agar and gelatin improves (p < .05) sperm motility, membrane integrity and the ratio of live sperm after 144 h of storage compared to the Control group, regardless of the source (bacteriological or feed grade). However, the pregnancy rate in ewes was not influenced (p ≥ .05) by semen doses stored with agar and gelatin. In conclusion, the addition of agar and gelatin preserves ram sperm motility and membrane integrity after 144 of storage at 4°C without affecting the pregnancy rate in inseminated ewes.

Comparison of the effect of Gonadotropin-Releasing Hormone and Human Chorionic Go3nadotropin on Reproductive Performance of Romanov Ewes During the Natural Breeding Season.

Low pregnancy rate is an important issue in small ruminants. Superovulation protocols would serve as the possible techniques to increase the pregnancy rate in small ruminants due to the use of synthetic hormones. The present study aimed to assess the effect of gonadotropin-releasing hormone (GnRH) and Human chorionic gonadotropin (hCG) after artificial insemination (AI) on the pregnancy rate of Romanov ewes breed. To this end, estrus was synchronized in 140 ewes using a controlled internal drug-releasing (CIDR) device. Following CIDR removal, all ewes received 400 IU Pregnant Mare's Serum Gonadotropin (PMSG). The ewes were assigned to three groups (control, n=20; experimental groups, each of them was divided into three subgroups, n=20). The first group in each experiment was assumed as control. The second and third groups received three levels of GnRH, (400, 500, and 600 µg, n=20) and hCG (200, 300, and 400 IU) administered by the intramuscular (IM) route. As soon as the signs of estrus were observed, the ewes were isolated from the others and artificially inseminated with fresh sperm using the transcervical method. The results indicated that there were no significant differences between experimental groups in ovulation and pregnancy rates on days 33 and 90 post-AI (P>0.05). The highest twin birth rate (20%) was recorded in the hCG group (300 IU), as compared to GnRH and control groups (P<0.05). The effect of GnRH and hCG on the plasma concentration of progesterone was significant (P<0.01). The groups significantly differed in fecundity rate (Single birth, twin birth, and triple birth) (P<0.05), all of these parameters were significantly higher in the hCG 300 IU group. It can be concluded that the injection of 300 IU of hCG hormone after insemination improves pregnancy rate in ewes.

Pregnancy rate in ewes injected with zinc oxide during an estrus synchronization protocol

Objective: To measure the effect of zin injection, during an estrus synchronization protocol, on pregnancy rate in sheep from the “Valle de Mexicali”.Design/methodology/approach: The experimental units were 157 ewes, which wereallocated in five farms (UP): UP1 (n=19), UP2 (n=27) UP3 (n=20) UP4 (n=71) and UP5(n=21). In each farm, the ewes were randomly assigned to one of three treatments:control, z-100 and z-200. The ewes from control groups were subcutaneously injectedwith 4 mL of olive oil as placebo. The ewes from groups z-100 and z-200 weresubcutaneously injected with 100 and 200 mg of zinc oxide. The response variableswere the preovulatory diameter of the largest follicle and pregnancy rate.Results: The differences between experimental groups on diameter of the largestpreovulatory follicle and pregnancy rates were not significant different (p&amp;gt;0.05). Limitations of the study/implications: The ewe’s reproductive response to zincinjection might be affected by the animal mineral status, it is recommended to carry onsupplementation with base on mineral blood concentrations.Conclusion: The subcutaneous injection with 100 or 200 mg of zinc oxide did not affectthe size of the largest preovulatory follicle and pregnancy rate in ewes.

Desmosterol Incorporation Into Ram Sperm Membrane Before Cryopreservation Improves in vitro and in vivo Fertility.

Pregnancy rates in ewes are markedly low after cervical insemination with frozen-thawed sperm. Sensitivity of ram sperm to freeze-thawing is related to the lipid composition of the membrane, particularly to its low sterol content. Recently, we proved that sterol content of ram sperm can be increased by treatment with methyl-β-cyclodextrin-sterol complexes and we provided mechanistic based evidence on the differential behavior of cholesterol and desmosterol in the ram sperm membrane. In the present study, we evaluated the role of increasing cholesterol and desmosterol content of ram sperm before cryopreservation, on the extent and distribution of sterols, cryocapacitation status, acrosome integrity, DNA damage associated with apoptosis and fertility competence in vitro and in vivo of post-thawed sperm. After freeze-thawing, similar levels of sterol content were evidenced in control sperm cells and in those pre-incubated with either cholesterol or desmosterol. Still, moderately higher levels of sterols were registered in treated sperm compared to the control, indicating no physiological excess of sterols after thawing or sterol losses that exceed the control. Live cell imaging of fluorescent cholesterol evidenced the presence of sperm sub-populations differentially affected by freeze-thawing. Similar unimodal frequency profiles were observed between sterol-enriched groups, while the control exhibited a sub-population of sperm compatible with low sterol content. Tyrosine phosphorylation was significantly lower when ram sperm incorporated cholesterol compared to the control. No difference in this capacitation parameter was found between the latter and desmosterol-enriched sperm. The percentage of sperm with damaged acrosomes post-thawing, assessed by a fluorescent lectin, was reduced in sperm that incorporated sterols before freezing, irrespective of the sterol class. These results suggest that sterols exert a stabilizing effect on the acrosome. No differences were found in levels of apoptotic DNA fragmentation among experimental groups. As to fertility trials, desmosterol-enriched sperm gave rise to higher rates of in vitro activated oocytes by heterologous fertilization and to significantly lower pregnancy loss in vivo. Our research provides new insights on sterol incorporation into ram sperm prior to cryopreservation, in particular on the additional benefit of incorporating desmosterol as a strategy to improve fertility outcome.

Comparative Data about Estrus Induction and Pregnancy Rate on Lacaune Ewes in Non-breeding Season after Melatonin Implants and Intravaginal Progestagen

Backgroung: Seasonal anestrus in ewes reduces reproductive efficiency and hinders productivity. Exogenous hormones can be used to facilitate the induction and synchronization of estrus in the anestrus period. The aim of this study was to evaluate the pregnancy rate in ewes after the treatment with different hormones and fixed time artificial insemination. Methods: The ewes were randomly divided in 4 (n=4) groups: Melatonin group (Group 1), Melatonin and Medroxyprogesterone group (Group 2), Medroxyprogesterone group (Group 3) and control group (Group 4). Pregnancy rate, estrus induction rate and litter size were determined and compared. Result: The estrus induction rate in our study was 100% for the first 3 groups and 6.25% for the 4th group. The pregnancy rate was between 4.16% (group 4) and 95.83% (group 2). For the others groups the values were 89.58% for the first group and 91.67%, for the 3rd group. The prolificacy rate was between 1 (control group) and 1.71 (2nd group), with intermediate values for the other 2 groups: 1.21 for 1st group and 1.27 for the 3rd group.

Oxytocin increases pregnancy rates after fixed time artificial insemination in Kazak ewes.

It is probable that reduced pregnancy rates in ewes after fixed time artificial insemination (FTAI) is attributable, in part, to the reduced number of normal spermatozoa that colonize the oviduct. Administration of oxytocin stimulates both cervical dilation and uterine/oviductal contractility. The hypothesis that oxytocin can enhance sperm transport into the uteri and the oviducts, and thereby increase pregnancy rates, was tested in the present study. Oestrus was synchronized in 199 multiparous Kazak ewes using intravaginal flurogestone-impregnated sponge. The sponge was left in the vagina for 12days followed with an injection of 330IU of eCG at sponge removal. Each ewe was intracervically inseminated twice at 50hr and 62hr after the removal of sponges using an insemination catheter containing 0.25ml of diluted semen. Semen was collected from seven Texel rams and all the ejaculates were pooled and diluted in ultra-high temperature-treated commercial skimmed milk without (Control group, 0.05ml of saline per mL milk, n=144) or with oxytocin supplement (Oxytocin group, 0.5U of oxytocin per ml milk, n=55). Pregnancy status was determined by transabdominal ultrasound examination 45days after insemination. Lambing performance was recorded at delivery. Significant differences were observed between the Oxytocin group and the Control group in terms of the pregnancy rate and the fecundity rate (85.5% and 92.7% versus 68.8% and 72.9%, respectively). In conclusion, low dose oxytocin supplementation of semen extender significantly increased pregnancy and fecundity rates in oestrus-synchronized Kazak ewes after FTAI.

Addition of eCG to a 14 d prostaglandin treatment regimen in sheep FTAI programs

In the present study, there was evaluation of the alternative of adding eCG as part of a long-interval prostaglandin-F2α (PG) treatment on the reproductive efficiency of Merino sheep during the breeding season. A total of 210 ewes and 182 ewe lambs were randomly assigned to three experimental groups to induce the timing of estrus among ewes in a: Long-interval PG, group being synchronized using two doses of PG 14 days apart; Long-interval PG + eCG group being synchronized using the same treatment regimen as Group PG with the addition of 200 IU eCG to the regimen, administered concomitantly with the second PG administration; and MAP + eCG group being synchronized with intravaginal progestin sponges for 14 days plus 200 IU eCG, administered at the time of sponge removal. The percentage pregnancy rate in ewes of the MAP + eCG group was greater than the ewes of the Long-interval PG and Long-interval PG + eCG groups (76.4 % compared with 52.0 % and 62.5 %, respectively; P < 0.05). The prolificacy rate was greater in the ewes of the Long-interval PG+eCG group compared with the other groups (114 % compared with 100 % and 103 %, respectively; P < 0.05). When considering the fecundity rate, ewes of the Long-interval PG+eCG and MAP+eCG groups had greater values than ewes of the Long-interval PG group (71.2 % and 78.8 % compared with 52.0 %, respectively; P < 0.05). The Long-interval PG+eCG is an alternative to the conventional progestin sponge plus eCG treatment regimen with there being a greater fecundity rate when this regimen is used compared with the Long-term PG and similar to MAP-eCG treatment regimens.

Effect of different protocols for estrus synchronization on reproductive performance of Santa Inês ewes under Amazon environmental conditions

The objective of this study was to evaluate the effect of different hormonal protocols on the reproductive performance of Santa Inês ewes in Amazon environmental conditions. Twenty-two Santa Inês ewes between 3 and 4 years-old were distributed in a randomized block experimental design, where the treatments consisted of two protocols for estrus synchronization (short and long) with eleven animals each. Data on the occurrence of estrus were described for each protocol. Data of estrus, pregnancy, and prolificity were firstly subjected to ANOVA and a subsequent Tukey’s test. Results were considered significant at p ≤ 0.05. The short-term protocol presented an interesting successful rate, where above 70% ewes tested had estrus. The long-term protocol also achieved a high successful rate, where above 80% ewes tested had estrus. However, comparing the protocols, the long-term protocol presented better results of positive estrus and pregnancy rates in ewes. Thus, it can be concluded that both protocols presented satisfactory results regarding estrus manifestation, and prolificity (lambs produced per ewe). However, under Amazon environmental conditions, the long-term protocol presented better results regarding positive manifestation of estrus and pregnancy rate.

Factors affecting the pregnancy rate of Bangladeshi ewes following Laparoscopic Artificial Insemination (LAP-AI)

The study was conducted to determine the effects of different factors on increased pregnancy rate of Bangladeshi ewes through LAP-AI. A total of 24 indigenous ewes and 4 rams were selected. Frozen semen with a concentration of 100×106 spermatozoa/ 0.25 ml straws were produced. The selected ewes were synchronized using two doses of PGF2α @ 175µg per ewe at 9 days intervals intramuscularly. Estrus was confirmed by the vasectomized ram. The LAP-AI was performed at two different times from the onset of estrus, two angles of placement on the laparoscopic cradle, and two different puncture sites. Pregnancy was confirmed by ultrasonography on days 45-50 following insemination. The pregnancy rate of ewes 2.5-4 years of age and 16-20 kg bodyweight was higher (75% vs. 41.67%) than ewes 1-2 years and 9-13 kg. However, this was not significant (p&gt;0.05). The pregnancy rate of ewes having BCS &gt;3 was significantly higher (p&lt;0.05) (78.57% vs. 30%) than BCS 2-2.5. The 20-24 hours insemination time from the onset of estrus yielded a significantly higher (p&lt;0.05) (75% vs. 25%) pregnancy rate than 12-16 hours. The pregnancy rate was higher (66.67% vs. 50%) at 45° than 30°angle of placement of ewes on the laparoscopic cradle. However, there was no significant difference (p&gt;0.05). The puncture point, 4-5 cm away from the udder resulted from a significantly higher pregnancy rate (p&lt;0.05) (83.33% vs. 33.33%) than 7-10 cm. The present study indicates that the pregnancy rates following LAP-AI using frozen semen could be increased if the significant factors are considered.

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.

Effect of different dosages of PG-600 on ovulation and pregnancy rates in ewes during the breeding season.

This study compared the reproductive effects of different dosages of PG-600 (Intervet/Merck Animal Health, Madison, NJ) during the breeding season of ewes. PG-600 is a single-dose injectable product labeled for estrous induction in swine, containing equine chorionic gonadotropin (80 IU/mL) and human chorionic gonadotropin (40 IU/mL). PG-600 is routinely used off-label for out-of-season estrous induction in sheep. However, at the most common dose administered to ewes (5 mL), PG-600 is likely to overstimulate the ovaries, resulting in reduced pregnancy rates. Following estrous synchronization with intravaginal progesterone and cloprostenol, Polypay ewes were treated with 5 mL PG-600 (T1; n = 8), 1.5 mL PG-600 (T2; n = 8), or 5 mL saline (C; n = 8) and then mated to rams. Jugular vein samples were collected prior to the PG-600 injection (0 hr) and at 2, 4, 8, 12, and 24 hr after injection. Serum estradiol-17β was determined by chemiluminescence and among groups using repeated measures analysis of covariance. Ovulation and pregnancy rates were determined by transrectal ultrasonography and compared by one-way ANOVA and chi-square, respectively. Estradiol-17β concentrations were greater in T1 compared to T2 and C (P < 0.001). Ovulation rate was greater (P < 0.001) but pregnancy rate was lower (P < 0.001) in the T1 compared to C and T2. These data confirm that a 5 mL dose of PG-600 administered to ewes during the breeding season overstimulates the ovaries, which may then reduce fertilization or embryo survival. Future research will focus on the effects of different dosages of PG-600 on pregnancy rate of ewes during the nonbreeding season.

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.

Effect of a new device for sustained progesterone release on the progesterone concentration, ovarian follicular diameter, time of ovulation and pregnancy rate of ewes

This study evaluated the effectiveness of a new progesterone intravaginal device (DPR) in ewes through four experiments: Experiment 1 compared the circulating progesterone concentration of ovariectomized ewes that received either a new or a re-used DPR. Experiment 2 compared the progesterone concentration between DPR-estrous-synchronized ewes and naturally estrous-cycling ewes. Experiment 3 evaluated the effect of new and re-used DPRs on ovarian follicular dynamics and time of ovulation of estrous cycling ewes. Experiment 4 compared the pregnancy rate after the use of a DPR and Controlled Internal Drug Releasing Device (CIDR). The mean concentration of progesterone released by the DPR device during its first use (New Group: 5.1±0.5ng/ml) was greater than that during the second use (Re-used Group: 2.4±0.3ng/ml). There was no difference between the animals that received DPR devices for first and second use in terms of ovulatory follicle diameter, follicular wave emergence day for ovulatory follicle and period of ovulatory wave of ovarian follicular development. However, there was a significant difference between groups regarding the time between DPR device removal and first ovulation (New Group: 71.7±2.5h and Re-Used Group: 63.9±2.7h). Pregnancy rates were similar between ewes with DPR and CIDR devices. It was concluded that DPR is effective in increasing and maintaining progesterone concentrations, controlling follicular dynamics, promoting synchronized times of ovulation from healthy follicles, promoting development of a competent corpus luteum and when used results in pregnancy rates similar to that with use of the CIDR.

Laparoscopic intrauterine artificial insemination and ultrasonic pregnancy diagnosis in Arabi ewes

Laparoscopic intrauterine artificial insemination (LAI) refers to a special technique by which the operation is done through several small holes in the abdomen with the aid of telescope. These incisions are much smaller than wound required in traditional surgery. This study aimed to evaluate the efficacy of laparoscopic artificial insemination. To increase the pregnancy and twins rate by using gonadotrophic releasing hormone (GNRH) and accurate pregnancy diagnosis in ewes by using ultrasonography, the present study was carried out in the animal farm college of veterinary medicine/Basrah University. Thisstudy started in 3rd August 2009 to 12th February 2010. This study included 9 ewes aged about 8 to 10 months and 2 rams aged between (9 to 11 months) and one of them was vasectomized. The rams were kept and separated from ewes for 2 weeks; at the beginning all ewes were checked for previous pregnancy by using of laparoscope. Injection of 0.00421 mg Buserelin hormone was given to induce estrus. The estrus ewes were prepared for surgical operations and made sedation by injection of Xylazine 0.11 to 0.22 mg/kg body weight (BW); and then 1 ml/cm2 of 2% of lidocaine was injected as local anesthesia. The animal was fixed on surgical table and then prepared for aseptic technique; afterwhich the ewes were inseminated laparoscopically by intra uterine injection of 0.25 ml of fresh ram semen. The results show the possibility of laparoscope as a technique used for artificial insemination in ewes in 71.4% of pregnancy rate. The laparoscopic insemination was successfully done in ewes without complication; there was no critical effect of intra-abdominal pressure (14 mmHg) by CO2 in small ruminants and pregnancy rate in ewes was successfully diagnosed by ultrasonography. Key words: Laparoscopic surgery, artificial insemination, ultra sonic, estrus, pregnant diagnos.

Ram seminal plasma improves pregnancy rates in ewes cervically inseminated with ram semen stored at 5 °C for 24 hours

In this study, we compared pregnancy rates obtained using ram semen stored at 5 °C for 24 h, with ram or bull seminal plasma (SP) added to TRIS-egg yolk extender. During the breeding period, 670 adult Corriedale ewes were cervically inseminated with semen (2 × 10 8 sperm in a volume of 0.2 mL) from eight adult Corriedale rams. Ejaculates, obtained using an artificial vagina, were split into three aliquots and diluted with the following: TRIS-egg yolk based extender (T), T + 30% ram SP (R), or T + 30% bull SP (B). Samples were refrigerated and stored at 5 °C for 24 h until used for AI. Pregnancy was assessed by ultrasonography 35 to 40 d after AI. Pregnancy rate was not affected by ram (P = 0.77) or breeding period (P = 0.43), and there were no interactions between extender and ram (P = 0.94), or extender and breeding period (P = 0.24). However, there was an effect of extender (P = 0.0009) on pregnancy rates; ram SP, but not bull SP, increased pregnancy rates compared with extender without SP (49.7, 38.1, and 31.1%, for R, B, and T respectively). In conclusion, ram SP added to TRIS-egg yolk extender had a beneficial effect on the pregnancy rate of ram sperm stored at 5 °C for 24 h and used for cervical insemination of ewes.