Intravaginal Sponges Research Articles

Dietary supplementation with different nano and organic selenium doses improves ovarian activity, fertility rate, and progesterone level in Ossimi ewes

This study aimed to investigate the effects of nano and organic selenium on ovarian activity, fertility rate, and progesterone hormone levels in Ossimi ewes. Thirty ewes were treated with intra-vaginal sponges impregnated with medroxyprogesterone acetate (40 mg) for 14 d and simultaneously assigned randomly to three groups. The 1st group ewe served as control (CG). Ewes in the 2nd and 3rd groups were treated orally with organic selenium 3 mg/ewe and Nano-selenium 0.2 mg/ewes during intra-vaginal sponges (IVS) treatment SeG and N-SeG, respectively. The ovarian activity was monitored using an ultrasonic device, and serum samples were harvested for progesterone measurement. The results revealed that ewes in SeG and N-SeG groups had a significantly (p < .05) higher number of small and large follicles after 48 h of IVS withdrawal than in the CG, respectively, on the left ovary. Also, the N-SeG group had a larger diameter of the Corpus luteum on both ovaries’ sides than CG, respectively, at the same time. However, the diameter of large follicles on both ovaries was significantly (p < .05) larger in the N-SeG after 72 h of IVS withdrawal than in SeG and CG. The ewes in N-SeG and SeG came in oestrus earlier (p < .05) than those in CG, and the oestrus durations were longer (p < .05) than that recorded in ewes of CG. The oestrus response and fertility rate were higher (p < .01) in N-SeG and SeG than in CG. Moreover, the progesterone concentrations were significantly higher (p < .05) in the N-SeG and SeG after 48 and 72 h of IVS withdrawal than in the CG. Also, the recorded serum progesterone concentrations in the included ewes non-significantly differed between groups during the first four months of pregnancy. It could be concluded that using nano and organic selenium can improve the quality of ovarian follicles and CL function and enhance the fertility rate in Ossimi ewes.

Effect of hCG administration on ovulation and estrus in Saanen goats subjected to short-term estrus synchronization protocol during the breeding season

This study aimed to compare the effect of hCG administered at 24 or 36 h following a short-term estrus synchronization treatment on the ovulation time and estrus parameters in non-lactating Saanen goats during the breeding season. The estrous cycles of does were synchronized with an intravaginal sponge containing 60 mg of medroxyprogesterone acetate (MAP) for six days, and an injection of 125 µg of d-cloprostenol at the time of sponge insertion in addition to an injection of 300 IU of eCG 24h before sponge removal. After removal of the sponges, does were injected intramuscularly either 1 ml physiological saline (0.9% NaCl) solution after 12 h (Group1/Control; n=10), 100 IU hCG after 24 h (Group2; n=9) or 100 IU hCG after 36 h (Group3; n=9). Estrus behavior after sponge removal was observed twice daily for 84 h using teaser bucks and transrectal ovarian ultrasonography was performed twice a day for seven days to determine small, medium and large follicle numbers, luteal development and the time of ovulation. Blood samples were collected on the same days to determine serum progesterone (P4) and estradiol (E2) concentrations. No significant differences were observed in terms of estrus parameters, ovarian structure and serum P4 and E2 concentrations between the hCG-treated groups and the control group. Average values observed for all groups: estrous response (53.57%), the interval from sponge removal to estrus and ovulation (35.2 h and 67.86 h, respectively), duration of estrus (18.4 h), the interval from estrus onset to ovulation (50.37 h), ovulation rate (96.43%), number of ovulations (1.36), ovulatory follicle diameter (6.86 mm), corpus luteum diameter (8.22 mm), follicle and luteal growth rate (1.17 and 0.68 mm/day, respectively). In conclusion, administration of hCG at 24 or 36 h following a short-term estrous synchronization protocol does not affect ovulation time, estrus parameters, and serum P4 and E2 concentrations in goats during the breeding season.

Avaliação reprodutiva e econômica da estimulação sexual durante o período antrópico em uma fazenda comercial com perdas neonatais de cordeiros

ABSTRACT This study was performed during the anestrous, involving 140 Akkaraman Kangal ewes whose lambs had died in the neonatal stage due to pneumonia and enteritis. Intravaginal sponge containing progesterone was placed to the animals (Group 1, n = 70) on day 0 and removed after 7 days, following which 263 µg PGF2α and 500 IU eCG were administered to the sheep. Ram introduction was performed for 7 days (days 8-14), starting from the day after the removal of the intravaginal sponge (day 8). The animals in Group 2 (n = 70) were not exposed to any treatment. Ram introduction was performed simultaneously in both the groups. To determine the reproductive response, reproductive parameters such as estrous, pregnancy, multiple pregnancy, and embryonic mortality rates, number of births, number of offspring, and fertility, as well as their economic implications, were compared between groups. Each reproductive parameter exhibited a statistical difference between groups. An economically positive trend was observed in the study group compared with the control group. It was concluded that in case of lamb losses in commercial farms that derive profit from lambing, pregnancy of ewes can be achieved via sexual stimulation without waiting for the next breeding season.

Comparation of Physiology, Diameter of Ovary and Follicle at PO Cows Treated Different Method of Estrus Synchronization

One of the biotechnology reproductive used is estrus synchronization. This study determined the body’s physiological, estradiol level, and ovarian and follicle diameter in Peranakan Ongole (PO) cow estrus synchronization using modified progesterone-PGF2α and double injection of PGF2α. This study used 10 PO cows which were divided into two groups. Group 1, cows were given a modified intravaginal sponge containing 250 mg progesterone/sponge for 6 days, followed by intramuscularly injection of PGF2ɑ 25 mg/cow on day sixth. Appearance of estrus was observed on day 7th -9th. Group 2, cows were given a double injection 25 mg/cow of PGF2ɑ intramuscularly at 14-day intervals, then estrus was observed on day 15th -17th. The vaginal temperature was checked using a thermometer, the respiratory frequency was checked by inspection of thorax movements, and the pulse rate was checked by palpation of the coccygeal artery. Ovarian and Graafian follicle diameters were examined using ultrasonography. The data were analyzed using either T-Test or descriptive test. The results showed that in cows that were synchronized to estrus using combination of modified progesterone-PGF2ɑ and double injection of PGF2ɑ, the vaginal temperature, pulse rate, and respiration frequency were 36.9±0.98 and 37.34±0.83, 57.60±12.52 and 74.80±26.59, 30.40±10.43 and 20.00±2.83 respectively. There was no significant difference in ovarian and follicle diameter (P>0.05). The conclusion was the results of body physiology were in normal conditions but still below the average of cows undergoing estrus, and there were no significant differences in ovarian and Graafian follicle diameters.

The investigation of the effects of vitamin A, vitamin E, and β-carotene plus vitamin E on some fertility parameters in ewes.

This study was aimed at investigating the effects of vitamin A (VITA), vitamin E (VITE), and combined β-carotene plus vitamin E (βCAR+VITE) injections on some fertility parameters in ewes. Estrus synchronization was performed by treating the ewes with intravaginal FGA sponges impregnated with 30 mg of fluorogestone acetate. On the days of the insertion and withdrawal of the intravaginal sponges, groups VITA, VITE, and βCAR+VITE were administered with 500 000 IU of vitamin A, 50 mg of vitamin E, and a combination of β-carotene plus vitamin E, respectively. The ewes in the control group (C) were maintained for control purposes. Statistically significant differences were determined between groups VITA and βCAR+VITE, groups VITE and βCAR+VITE, and groups C and βCAR+VITE, as well as groups VITE and C, groups VITA and C for the multiple birth rates. While significant differences were determined between groups VITA and C, groups VITE and C, and groups βCAR+VITE and C for the lambing rates, it was ascertained that the ratio of newborn lambs to delivered ewes (litter size) significantly differed between groups VITA and βCAR+VITE, groups VITA and C, groups VITE and βCAR+VITE, groups VITE and C, and groups βCAR+VITE and C. The highest MDA level and lowest GSH level were determined on day 20 after mating in the control group. In conclusion, it is suggested that both multiple birth rates and litter size can be increased by the combined administration of β-carotene and vitamin E.

Potential role for human menopausal gonadotropin in ovine superovulatory regimens during the breeding season.

Human menopausal gonadotrophin (hMG) has been reported to produce a comparable superovulatory response to that of follicle stimulating hormone (FSH). Furthermore, hMG has a long half-life as compared with FSH. The present study was designed to compare hMG administered once daily and FSH administered twice daily over a 4 - day period on superovulatory response of Suffolk ewes. During the mid-luteal phase, twenty-four Suffolk donor ewes received intravaginal sponges at day 0 for 12 days. The superovulatory regimens in the Control group (n=12) and the Treatment group (n=12) consisted of eight injections of FSH given at twice daily and four injections of hMG given at once daily, respectively. At day 13, the donor ewes were subjected to laparoscopic insemination. Embryos were recovered, classified, and transferred to recipient ewes at day 19. Pregnancy status was determined by ultrasound examination 40 days after transfer. Lambing rate was calculated after all the ewes had delivered. No significant differences were observed between the two groups in terms of the structures recovered, transferable embryos, degenerated embryos, unfertilized oocytes, pregnancy rate and lambing rate. The results showed that once daily injection of hMG can produce a comparable superovulatory response and embryo transfer outcomes to those obtained by twice daily injection of FSH over a 4 - day period. It is feasible that hMG is used to replace FSH and reduce the number of injection treatments in ovine superovulatory regimens.

Effect of oxytocin added into sperm on artificial insemination in sheep

Abstract. The use of additional oxytocin hormones in reproductive methods began in the 1970s in Europe. In recent studies, attempts have been made to achieve more successful pregnancies by adding oxytocin to semen rather than administering oxytocin exogenously to females. In light of this information, this study aimed to understand the effects of adding low-dose oxytocin hormone into ram semen on the pregnancy rate and reproductive efficiency of sheep. Semen was collected from five Chios rams. The ejaculates were pooled and Ovixcell® was used as the diluent. The estrus was synchronized using an intravaginal sponge (Chrono-Gest®) from 122 Chios ewes. After the sponge was left in the vagina for 12 d, a 500 IU PMSG injection was made. In every sheep, intramuscular (IM) injections were inseminated by the intracervical method using an insemination gun 50 h after injection. Pregnancy results were obtained by ultrasound examination without practice. Lambing performance was recorded at delivery; 53 out of 122 Chios ewes were inseminated with oxytocin hormone content, and successful pregnancy was achieved in 90.56 % of them. In the insemination of the remaining 69 sheep, oxytocin was not added, and the rate of successful pregnancy was 76.81 % (p=0.046). The overall success rate based on the insemination results of all the sheep was determined to be 82.77 %. In an examination of the pregnancy rate, one of the indicators of reproductive performance, the difference between the groups is statistically significant (p≤0.05). Higher pregnancies were obtained in insemination with semen fluid containing oxytocin.

The effect of reduced dose of PGF2α on certain reproductive parameters in awassi yearlings in anestrus synchronisation protocol following the end of the of the breeding season

The aim of this study was to investigate the effect of the administration of half or full dose of prostaglandinF2α (PGF2α; Gestavet Prost, d-cloprostenol, HIPRA®) injection in a routine synchronization protocol following theend of the breeding period including intravaginal sponge (medroxyprogesterone acetate; Espanjovet, HIPRA®) andeCG (Oviser 500, HIPRA®) on certain fertility parameters in ewes.Two hundred thirty-eight Awassi yearlings (agedone year old) divided into two groups:116 ewes received a half dose (HSDP; 37.5 μg) of PGF2α and 122 ewes receivedfull dose (FSDP;75 μg).The pregnancy rates were 67.2% and 72.1% for HSDP and FSDP, respectively (P&gt;0.05).The lambing rates were 64.7% and 63.9% for HSDP and FSDP, respectively (P&gt;0.05).The single lambing rate inHSDP(94.7%) was higher (P&lt;0.05) compared to that in FSDP (73.1%). The twin and multiple birth rates of FSDPwas higher (P&lt;0.05) than HSDP. As a result, it was inferred that aHSDP could be used in Awassi yearlings withoutexperience of lamb care and in a herd in which single lambing was preferable. Moreover, due to the fact that it is moreaffordable and not detrimentalto fertility, it was concluded that HSDPcan offer an advantage in large flocks and can beused for manipulating fecundity ratesin yearlings.

Effect of Strategic Supplementation of Dietary By-Pass Linseed Oil on Fertility and Milk Quality in Sarda Ewes.

The aim of the present study was to assess whether the strategic supplementation of bypass LO can enhance reproductive indexes-fertility, lambing rate, and prolificacy-in dairy Sarda ewes at the end of lactation. To assess whether LO supplementation leads to the adsorptions of PUFAs and their subsequent utilization by the body tissues, milk composition and fatty acid content were analyzed. Forty-eight ewes were assigned to the following groups: the control group (CT; N = 24), fed with a control diet without LO; and the treatment group (LO; N = 24), fed with a diet supplemented with LO (10.8 g/ewe/day). Both diets had similar crude protein and energy levels and were offered for 38 days (-21 to +17 days after artificial insemination). The trial included an adaptation period (7 days) followed by a regular supplementation (31 days) period. Estrus synchronization was induced in all the ewes using an intravaginal sponge and equine chorionic gonadotropin. Fifty-five hours after pessaries withdrawal, all ewes were inseminated using the cervical route and fresh semen. Cholesterol (p &lt; 0.01), high-density lipoprotein (p &lt; 0.001), and triglyceride (p &lt; 0.05) levels in plasma were higher in the LO group. Plasmatic levels of non-esterified fatty acids were lower in the LO group after the end of the supplementation period (p &lt; 0.05). Milk unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), total polyunsaturated fatty acids (PUFAs), PUFAs omega 3 (PUFAs-ω3) and 6 (PUFAs-ω6), and trans fatty acids were higher in the LO group (p &lt; 0.001), while saturated fatty acids (SFAs) were higher in the CT group during the supplementation period (p &lt; 0.001). Three days after the end of the supplementation period, the content of milk UFAs (p &lt; 0.05), PUFAs (p &lt; 0.001), MUFAs, and PUFAs-ω6 (p &lt; 0.01) were still higher in the LO group. whereas SFA was higher in the CT group (p &lt; 0.01). There was no difference between groups in terms of ovulation rate, progesterone levels in plasma, fertility rate, prolificacy, and total reproductive wastage. However, the total area of luteal tissue was higher in the LO group (p &lt; 0.01). Results obtained demonstrated that LO supplementation exerts a positive role in corpus luteum size at the onset of the peri-implantation period in Sarda dairy ewes. Additionally, the results obtained in the present study showed that the use of dietary bypass LO affects lipid metabolites in plasma and milk fatty acid profiles, demonstrating the ALA uptake by body tissues.

Body temperature, heart rate, and locomotor activity measured by bio-loggers before and after a progestogen+eCG treatment for artificial insemination in sheep: effect of pregnancy

Context The introduction of bio-sensors for monitoring real-time changes in physiological variables has helped understand how external factors affect an animal’s resiliency to stressors. Aims To quantify changes in temperature, heart rate, and locomotor activity in ewes during hormonal treatments for artificial insemination (AI) for up to 15 days after insemination. Method Twelve ewes received a surgically implanted subcutaneous bio-logger to record data every 5 min. One week later, ewes received an intravaginal sponge for 12 days and AI was performed 54 ± 1 h after sponge withdrawal. The data were divided into the following four periods: ‘sponge in’ (Days −14 to −2), ‘day before AI’ (Day −1), ‘day AI’ (Day 0), and ‘post-AI’ (Days 1–5, Days 6–10, and Days 11–15). Key results Ewes presented significantly (P &lt; 0.001) higher mean temperature and activity, and a lower heart rate when the sponges were in place than they did in the days following AI. Mean body temperature in the ‘sponge in’ period and the ‘day before AI’, but not in ‘post-AI period’, differed significantly (P &lt; 0.001) between pregnant and non-pregnant ewes. Non-pregnant ewes had a significantly (P &lt; 0.001) higher heart rate than did pregnant ewes when sponges were in and in the ‘post-AI’ period. Non-pregnant ewes were significantly (P &lt; 0.001) less active than were pregnant ewes in the ‘sponge in’ period and on Days 1–5 after AI; however, the former were significantly (P &lt; 0.001) more active than were pregnant ewes on Days 11–15 after AI. Conclusions The subcutaneous bio-logger system documented 24-h variations in body temperature, heart rate, and locomotor activity before and after AI in ewes that had received an estrus-synchronising hormonal treatment. Pregnancy status affected those variables and their circadian fluctuations at the time of the hormonal treatment and in the ‘post-AI’ period. Implications Any device designed for use in the study of Precision Livestock Farming that allows a simple, non-invasive measurement of these variables might provide the basis for the development of a system that could identify females that are in an optimal state for insemination, and provide an early pregnancy prediction system.

Age as a Determinant of the Effectiveness of Intravaginal Sponges Impregnated with Progestin and Equine Chorionic Gonadotropin for Multiple Births Induction of Awassi Ewes

The present study was conducted to evaluate the role of age in the effectiveness of intravaginal progestin‐impregnated sponges (IPIS) along with equine chorionic gonadotropin (eCG) on the multiple birth rates of Awassi ewes. One hundred mature ewes (live weight was 35–40 kg and age 2–5 years) were allocated to three groups according to their ages (n = 29, 2‐3 years;n = 34, 3‐4 years; and n = 37, 4‐5 years). All ewes were impregnated with IPIS, injected with 20 mg cronolone, for 14 days, and eCG (400 IU, i.m.) at sponges withdrawal. All treated ewes came to estrus (100%); the highest twining rate was recorded in ewes aged 2‐3 years, while the highest triple rate were found in those aged 3‐4 years. A negative correlation coefficient was recorded between the age of treated ewes and the multiple births. In conclusion, the best age of Awassi ewes for estrus synchronization programs and multiple birth outcomes using IPIS along with eCG is 2–4 years.

Effects of selenium, vitamin E, and β-carotene administration on fertility of Awassi ewes synchronized for estrus in non-breeding season

The aim of this study was to evaluate the effect of selenium, β-carotene, and vitamin E administration on fertility of Awassi ewes synchronized in non-breeding season. A total of 80 multiparous Awassi ewes, aged 2 to 6 years were enrolled in the study. Intravaginal sponges containing flugeston acetate (20 mg cronolon) was inserted into vagina and allowed to remain in vagina for nine days. Ewes were randomly divided into two groups. Group I received intramuscular injections of 1 mg sodium selenite, 60 mg vitamin E, 75 mg β-carotene, and 100 mg DL-α-tocopherol acetate at sponge insertion, sponge removal, and 18 days after the introduction of ram. Group II remained as control group and received no treatment. On the removal of the sponges, 500 IU eCG and 0.075 mg D-cloprostenol were injected intramuscularly. Ram was introduced for 1 hr twice a day 24 hours after the sponge removal. Interval between sponge removal and estrus, estrus rates, conception rates, pregnancy rates, lambing rates, and fecundity rates in group I and group II were 45.30±1.71 and 43.94±1.72 hours, 79.1% and 86.6%, 66.66% and 72.41%, 54.05% and 58.33%, 100% and 100%, and 135% and 138%, respectively. There were no statistical differences between the groups (p&gt;0.05). In conclusion, the administration of Se, β-carotene, and vitamin E in estrus synchronization protocols in non-breeding season had no positive effect on the fertility characteristics of Awassi sheep.

Comparison of the Efficacy of Enrofloxacin and Lactobacillus Plantarum Cell-Free Supernatant Treatments on Vaginitis in Ewes

The aim of the study was to investigate the effect of different intravaginal treatment strategies on the vaginal discharge score, vaginal microbiota, bacterial and Enterobacteriaceae counts in nulliparous Merino ewes. All ewes (n=45) received intravaginal sponges containing 60 mg medroxyprogesterone acetate for 7 days and allocated into three equal groups (n=15). Sponges were injected Lactobacillus plantarum cell-free supernatant (SUPER), enrofloxacin (ENRO), or physiologic saline (CON) prior to sponge insertion. At sponge removal, 500 IU equine chorionic gonadotropin (eCG) were administered in all ewes. For the detection of vaginal microbiota, bacterial and Enterobactericeae counts, samples were collected prior to sponge insertion, at sponge withdrawal, and 48 h later after sponge withdrawal. Vaginal discharge score was not different in ENRO (2.26±0.18) and SUPER (2.20±0.14) compared to CON (2.46±0.16). The time-dependent alteration was significant for the mean bacterial and Enterobacteriaceae count in all groups (P

Effects of exogenous GnRH administration on lambing performance of oestrus-synchronized Kazak ewes during the breeding season.

The objective of this study was to investigate the effects of GnRH at insemination on lambing performance of Kazak ewes. Oestrus was synchronized in 774 adult Kazak ewes using an intravaginal sponge impregnated with flurogestone acetate. The sponge was left in the vagina for 12 days followed with an injection of 330 IU of eCG at sponge removal. Each ewe was inseminated twice at 48 h and 60 h after sponge removal. The treatment group (n=387) was intramuscularly injected at the first insemination with a dose of 25 μg GnRH and the control group (n=387) with saline solution. The results showed that GnRH administration significantly decreased the fertility rate. In addition, significant differences were observed between the two groups in terms of the twin birth rate, the abortion rate and the litter size. In conclusion, GnRH administration at insemination was not recommended in Kazak ewes undergoing the fixed time artificial insemination during the breeding season. The breed may be a critical determinant of the potential for the exploitation of GnRH application in sheep breeding programmes.

Bio-loggers inserted in intravaginal sponges, or subcutaneously, as tools to measure body temperature

The body temperature of animals can be measured by thermistors, thermocouples, or radiotelemetry devices that are implanted surgically under the skin, although the suitability of subcutaneous temperature as an indicator of core temperature can be limited because of abnormal temperature readings, probably affected by ambient temperature and animal inactivity. This study compared the use of bio-loggers designed to monitor subcutaneous temperature (Tsub), with their use embedded in intravaginal sponges to measure vaginal temperature (Tvag). Three ewes were implanted with a subcutaneous temperature bio-logger that was configured to record Tsub every 30 min for a month. Ewes were given an intravaginal sponge for 12 days two days later. Inside the sponges were installed programmed bio-loggers that measured Tvag every 5 min. The ambient temperature (Tamb) and relative humidity were monitored using mini data-loggers. Mean Tsub was lower (P < 0.001) during the day (38.02 ± 0.02 °C) than at night (38.10 ± 0.02 °C), with maximum Tsub (38.57 °C) at 20:00 h and minimum temperature (37.36 °C) at 08:00 h; however, mean Tvag was higher (P < 0.001) during the day (38.71 ± 0.01 °C) than at night (38.62 ± 0.01 °C), with maximum Tsub (39.02 °C) at 20:55 h and minimum temperature (38.33 °C) occurred at 08:25 h. Mean Tsub (38.08 ± 0.02 °C) was lower (P < 0.0001) than was Tvag (38.65 ± 0.10 °C) in the daytime and at night (P < 0.001). Both temperatures had a 24-h rhythm (P < 0.0001), but differed (P < 0.001) in the mean midline estimating statistic of rhythm (MESOR) (Tvag: 38.67 ± 0.02 °C, Tsub: 38.09 ± 0.02 °C), amplitude (Tvag: 0.21° ± 0.01C; Tsub: 0.25 ± 0.01 °C), and acrophase (Tvag: 18:27 ± 0.38 h, Tsub: 20:48 ± 0.44 h). The coefficient of correlation between the two temperatures, measured simultaneously for 12 d was 0.644 (P < 0.01), and between Tamb and the two physiological temperatures, measured at the same time throughout the 12 d experiment, was 0.319 (P < 0.01) for Tsub and 0.287 (P < 0.01) for Tvag. The linear regression analysis of the 24 h circadian rhythm in Tsub and Tvag indicated a high coefficient of determination with Tvag (0.9255) and a lower coefficient of determination with Tsub (0.4292). In conclusion, the integration of a mini body temperature logger into a vaginal sponge, or their subcutaneous insertion, provided a continuous and accurate record of body temperature. Furthermore, the strong correlation between mean 24 h circadian Tvag and Tamb, demonstrated the usefulness of Tvag in biometeorological studies in sheep. As an alternative to employing these devices subcutaneously, they can also can be utilized as a biomarker of core body temperature inserted in vaginal sponges.

Comparison of fertility parameters in Romanov sheep synchronized with progesterone-based protocol plus PMSG or GnRH

Objective: The aim of this study was to compare the fertility parameters in response to pregnant mare serum gonadotropin (conventional treatment) or gonadotrophin-releasing hormone (alternative treatment) in Romanov sheep subjected to a 7-d short-term protocol out of breeding season. Materials and Methods: Sheep (n=57) received an intravaginal sponge impregnated with 20 mg fluorogestone acetate for 7 days and 125 µg cloprostenol at sponge removal. Sheep were randomly assigned to receive no treatment (CON, n=16), 240 IU pregnant mare serum gonadotropin (PMSG, n=24) at sponge removal or 10 µg busereline acetate (GnRH, n=17) at 30 h after sponge removal. Results: Estrous response and pregnancy rate were 86% and 75.4% in all sheep, respectively. Estrous response was numerically higher about 7% (p&amp;gt;0.05) in treatment groups (PMSG, 87.5%; GnRH, 88.2%) than CON (81.2%). However, pregnancy rate was numerically higher in PMSG (83.3%) than GnRH (70.6%) and CON (68.7%). As in pregnancy rate, lambing rate was approximately 15% numerically greater (p&amp;gt;0.05) in the PMSG (79.1%) than in GnRH (64.7%) and CON (62.5%) groups. Similarly, litter size numerically higher (p&amp;gt;0.05) in PMSG (2.1) than GnRH (1.9) and CON (1.9) groups. Conclusion: The use of GnRH offered similar estrous response compared to PMSG in Romanov sheep synchronized with short-term protocol. However, PMSG had numerically higher pregnancy rate, lambing rate, and litter size than GnRH. Considering the serious ethical concerns and animal welfare for the production of PMSG, it is necessary to use alternatively gonadotropins. Comprehensive studies are needed to compare the fertility parameters between PMSG and GnRH in Romanov sheep.

GnRH administration after estrus induction protocol decreases the pregnancy rate of recipient ewes following transfer of frozen-thawed embryos

The objective of this study was to investigate the effects of GnRH on the pregnancy rate and the embryo survival rate of recipient ewes following embryo transfer. Estrus was synchronized in 83 nulliparous Huyang ewes using intravaginal sponges impregnated with 45 mg flurogestone acetate. The sponge was left in the vagina for 12 days followed with an injection of 330 IU of eCG at sponge removal. The treatment group (n = 34) was subjected 48 h after sponge removal to intramuscular administration with 16 μg of the GnRH agonist triptorelin and the control group (n = 49) with 1 mL of saline solution. Embryo transfer was performed by laparoscopy on day 8 after sponge removal, which transferred frozen-thawed embryos of Suffolk ewes directly to the anterior third of the corpus luteum ipsilateral uterine horn of the recipient ewe.Each recipient with at least one normal corpus luteum received one grade I embryo. The proportion of ewes with at least one normal corpus luteum in the control group was significantly lower compared to the treatment group (73.5 % vs 91.2 %, P < 0.05). In total, 62 embryos were transferred into 62 ewes and 29 lambs were born. The pregnancy rate (59.4 % vs 33.3 %, P < 0.05) and the embryo survival rate (56.3 % vs 30.0 %, P < 0.05) in the control group were significantly higher compared to the treatment group. In conclusion, a single dose of GnRH administered 48 h after sponge removal significantly decreased the pregnancy rate and the embryo survival rate of recipient ewes following transfer of frozen-thawed embryos.

Success of captive breeding and a hormonal trial to increase the reproductive efficacy of Arabian Tahr, Arabitrgus jayakari

This is the first study shows the results of breeding of Arabian Tahr, Arabitrgus jayakari, with a hormonal attempt to increase its reproductive efficacy in a captive breeding unite. Data of reproductive success of a small population of Arabian Tahr kept in a protected area of Wadi Wurayah, Fujairah, was summarized from 2018-2022. The pregnancy rate, which was around 90% in the first three breeding seasons, decreased to 66.7% in the last breeding season. Rate of late abortion and/or still birth in all breeding seasons was between 11-25%. No multiple births or abortion of fetuses were observed during the four recorded breeding seasons. A hormonal trial was performed in the last breeding season 2021-2022 to synchronize the estrus and increase the reproductive efficacy. Eighteen parous females and 9 adult males were randomly mixed and divided into three groups: two treatment groups and a control group (G3; n = 6). Females were treated with an intravaginal sponge impregnated with 30 mg of Flurogestone acetate (FGA) for either fourteen (G1; n = 6) or seven (G2; n = 6) days, respectively. At the sponge removal, females of G1 and G2 groups were received intramuscular injections of 200 IU of eCG and 75 µg of Cloprostenol. Pregnancy rate was higher in G2 compared to the other two groups and it was also higher in G1 than in G3. Lambing rate was 100% in the control group, and it was higher in G2 compared to G1. Rate of estrous synchronization was similar in both treated groups. In conclusion, Breeding of Arabian Tahr in captivity can be improved by estrous synchronization and induction of ovulation early in the breeding season by using short-term progestagen treatment followed by&#x0D; eCG injection. More research on other doses of eCG and on the nutritional requirements are required to increase the reproductive efficacy of Arabian Tahr in captive breeding.

Effect of the breed, reproductive season, doses and time of application of eCG in the estrous cycle in hair ewe lambs

Objective: to evaluate the effect of breed, reproductive season, dose and time of application of equine chorionic gonadotropin (eCG) on the estrous cycle and ovarian activity in hair ewe lambs.&#x0D; Design/methodology/approach: 216 Hair lambs were used (62 Dorper, 69 Katahdin y 85 Pelibuey), 91 in the high reproductive season and 125 in the low reproductive season, they were synchronized with intravaginal sponges containing 20 mg of fluorogestone acetate (FGA) and equine chorionic gonadotropin (eCG; 200 and 300 IU) intramuscularly. The treatments are the breed, reproductive season, dose and time of application of eCG. The presence of estrus was analyzed under a logistic regression model, the interval to estrus and ovulation rate were analyzed by analysis of variance using a completely randomized design with a 2x2x2x3 factorial arrangement with the PROC LOGISTIC and PROC GLM procedures.&#x0D; Results: the breed influenced (P&lt;0.01) the presence of estrus, Dorper ewe lambs presented 9.74 times more possibilities than the Pelibuey. The interval to estrus was shorter in duration (P&lt;0.05) in Dorper (29.5±0.9 h) and Katahdin (29.1±0.9 h) compared to Pelibuey (34.8±0.9 h). The interval to estrus was lower (P&lt;0.05) with the application of 200 or 300 IU of eCG 24 h before the end of the protocol, compared to the application of 200 IU of eCG at the time of progestogen withdrawal. Ovulation rate was only affected by breed (P&lt;0.05), being higher in Pelibuey (2.4±0.1) compared to Dorper (2.0±0.1) and Katahdin (1.9±0.1).&#x0D; Study limitations/implications: To complement the study, it would be convenient to take the research to a second phase where the gestation part of the females is included to relate it to the ovulation rate, and also to make measurements of ovarian structures by means ultrasound.&#x0D; Findings/conclusions: Estrus and ovarian activity in hair ewe lambs synchronized with progestogens is mainly influenced by breed.

Effects of Short-Term Melatonin or Progestogen with Gonadotropic Treatments on Reproductive Performance, Hormonal Levels and Ovarian Activity of Ewes

The study compares the effects of short-term application of melatonin alone with a commonly used progestogen + gonadotropin on the reproductive performance, serum hormone concentrations, and ovarian activity of Improved Wallachian sheep. To induce ovarian cyclicity, 382 ewes were allocated into two treatment groups. Ewes of treatment group 1 (n=26) received dietary melatonin (5mg/head/day) for 18 days. Ewes of treatment group 2 (n=356) received intravaginal sponges (FGA, flugestone acetate 20mg) for 12 days followed by injection of eCG (equine chorionic gonadotropin, 500IU i.m.) at the time of sponge withdrawal. Forty-eight hours after sponge or melatonin withdrawal, sheep were exposed to rams, and recorded reproductive performance. Six ewes from each group were selected for hormone assessment and their ovaries removed for histological analysis. Ewes receiving melatonin had lower fertility, fecundity, smaller follicles (0 – &lt;1mm), and lower follicular atresia compared to group 2. In addition, the concentration of progesterone and IGF-I, ovulation rate, and the number of healthy follicles were increased compared to FGA+eCG-treated ewes. Our results indicate that short-term application of melatonin is effective in inducing ovarian cyclicity in ewes with an increased ovulation rate despite low fertility and fecundity.