Intrauterine Artificial Insemination Research Articles

Buserelin Acetate Added to Boar Semen Enhances Litter Size in Gilts in Tropical Environments.

The use of exogenous hormones has long been of interest for improving reproductive performance in swine production. Enhancing litter size directly impacts the economic efficiency of pig production. Various strategies, including nutritional, genetic, and hormonal approaches, have been explored with varying degrees of success. Administering a gonadotropin-releasing hormone (GnRH) agonist, such as buserelin, at the onset of estrus can induce ovulation and reduce the variation in ovulation timing among sows. This study assessed the impact of GnRH agonist supplementation in boar semen doses on the litter size of inseminated gilts. The research was conducted on a commercial swine herd in northern Thailand. A total of 231 Landrace × Yorkshire crossbred gilts, aged 224.5 ± 16.2 days at the onset of estrus synchronization, participated in the experiment. The gilts' estrus was synchronized with oral altrenogest supplementation at a dosage of 20 mg/day for 18 days. After exhibiting standing estrus, the gilts were randomly divided into three groups. Control group: gilts were inseminated at 0 and 12 h post standing estrus onset with a conventional semen dose (n = 94). Treatment 1: similar to the control group, but with an added 5 µg (1.25 mL) of buserelin acetate to the boar semen dose during the first insemination (n = 71). Treatment 2: similar to the control group, but with 10 µg (2.5 mL) of buserelin acetate added to the boar semen dose during the first insemination (n = 66). All gilts were inseminated twice during their standing estrus using the intrauterine artificial insemination method. Each semen dose contained 3.0 × 109 motile sperm in 80 mL. The farrowing rate averaged 78.8% and did not significantly differ between the groups (p = 0.141). The total number of piglets born per litter in the treatment 2 group was greater than in the control group (14.0 ± 0.3 vs. 13.2 ± 0.3, respectively, p = 0.049), but was not significantly different from the treatment 1 group (13.3 ± 0.3, p = 0.154). Similarly, the number of live-born piglets in the treatment 2 group was greater than in the control and treatment 1 groups (13.2 ± 0.4 vs. 12.3 ± 0.3 and 12.0 ± 0.4, respectively, p < 0.05). Moreover, the live-born piglets' litter birth weight in the treatment 2 group was greater than in the control group (17.0 ± 0.4 vs. 15.6 ± 0.3 kg, respectively, p = 0.008) and the treatment 1 group (15.7 ± 0.4 kg, p = 0.025). In conclusion, adding a GnRH agonist to boar semen appears to enhance the litter size of gilts. Further research should focus on understanding the underlying mechanisms and determining the optimal dose and timing for GnRH agonist supplementation.

Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows

AimThe present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo.Materials and methodsIn a double-blind study, six German Holstein cows were administered PGF2α during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography.ResultsAll animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h.ConclusionsThe natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.

Uterine tone influences fertility of Merino ewes following laparoscopic artificial insemination

Artificial insemination (AI) plays a critical role in facilitating rapid genetic and production gains within the sheep industry. However, variable rates of AI success remain a concern for the industry and a barrier to adoption. Furthermore, the degree to which female factors influence the success of intrauterine laparoscopic AI rather than natural mating remains unknown. As such, this study investigates the effect of several factors collected during the time of AI, on the success of intrauterine laparoscopic AI. Data was generously donated by artificial breeding companies and stud breeders during routine commercial AI operations. AI data was collected over 3 breeding seasons during commercial AI programs (N = 24 programs) using Merino ewes (N = 24,700). Sire ID (N = 253), time of AI following progesterone removal (approx. 43–59 h post removal), uterine tone and intra-abdominal fat (both scored 1–5) as well as age of the ewe were all recorded at the time of AI. Transcutaneous ultrasound subsequently determined pregnancy rate approximately 55 days post-AI. A multivariate regression analysis was performed and revealed pregnancy success to increase when semen was inseminated into a ewe with a uterine tone score of 4 or 5 (P < 0.001). The remaining factors fell short of significance within the multivariate model. An interclass coefficient variation matrix was also used to determine the proportion of variation contributed to AI success by random factors allocated in the model; site, sire, AI date and breeding season (45.99 %, 29.94 %, 15.15 % and 8.92 %, respectively). These results highlight the influence of uterine tone on ewe fertility following laparoscopic AI, but also that program location and the sire used can further modify this influence on pregnancy rate. These factors must now be considered in combination with semen factors per individual sire used during AI to ascertain the contribution of several factors to the success of laparoscopic AI in Australia.

015 Treatment of ram semen post thaw with normo-osmolar extenders does not improve fertility after cervical or intrauterine artificial insemination

015 Treatment of ram semen post thaw with normo-osmolar extenders does not improve fertility after cervical or intrauterine artificial insemination

Estimation of sperm concentration limits to produce intrauterine insemination doses in swine.

This study evaluated the effect of sperm concentration of boar semen doses, for intrauterine artificial insemination (IUAI), on semen quality and established concentration limits for their production. Twenty ejaculates from four crossbred mature PIC® boars were collected to produce 50 mL semen doses in a split sample, reaching the following sperm concentrations: ~20, 30, 60, and 100 × 106 cells/mL. Doses were produced using Androstar® Plus, stored at 17°C, and evaluated until 120 h of storage. There was a linear decrease in sperm motility as the sperm concentration increased (p linear < .01). The concentration which no longer affected the total and progressive motility was 59 and 55 × 106 cells/mL, respectively (corresponding to 71% and 62%, respectively). The pH linearly decreased as the sperm concentration increased (p < .01); yet, at 72 and 120 h, the parameter dramatically reduced in boar semen doses with 60 and 100 × 106 cells/mL. The percentage of cells with intact plasma and acrosomal membranes or with high mitochondrial membrane potential was not influenced by the sperm concentration (p ≥ .15). In conclusion, sperm motility was negatively affected in highly (60 and 100 × 106 cells/mL) concentrated doses. To achieve suitable sperm motility, boar semen doses may not surpass the sperm concentration of 55 × 106 cells/mL. The effect of low-concentrated boar semen doses on sperm quality still needs to be better evaluated, mainly considering the influence of extender type and thermo-resistance conditions.

Effects of sperm processing techniques on IVF pregnancy rates: a mini-review.

Many factors associated with assisted reproductive technologies significantly influence the success of pregnancy after in vitro fertilization (IVF) either directly or indirectly. These factors include sperm processing techniques, egg retrieval, intrauterine artificial insemination, intracytoplasmic sperm injection, and embryo transfer. Among these technologies, sperm quality is one of the most critical factors for a successful IVF pregnancy. The method used for sperm processing plays a crucial role in determining the quality of sperm. Several widely used sorting techniques, such as conventional swim-up, density gradient centrifugation, magnetic activated cell sorting, and hyaluronic acid, have been extensively compared in various studies. Previous studies have shown that each sperm processing method causes varying degrees of sperm damage, particularly in sperm motility, concentration, morphological features, viability, and DNA integrity. However, sperm processing techniques have been developed slowly, and the impact of these methods on pregnancy rates is still unclear. Further exploration is needed. In this review, we aim to compare the results of different sperm processing techniques concerning sperm quality and IVF pregnancy rates. We will also discuss possible clinical approaches, such as microfluidics and integrated approaches, for testing and improving sperm quality.

Update on artificial insemination: Semen, techniques, and sow fertility.

Over the years, reproductive efficiency in the swine industry has focused on reducing the sperm cell number required per sow. Recent advances have included the identification of subfertile boars, new studies in extended semen quality control, new catheters and cannulas for intrauterine artificial insemination (AI), and fixed-time AI under commercial use. Therefore, it is essential to link field demands with scientific studies. In this review, we intend to discuss the current status of porcine AI, pointing out challenges and opportunities to improve reproductive efficiency.

Impact of prolonged one or more natural menstrual cycles on the outcomes of ovulation induction intrauterine artificial insemination pregnancy: a single-centre, retrospective study in China

ObjectivesWe determined if the time interval between two ovulation induction intrauterine artificial insemination (IUI) treatment cycles should be extended by one or more natural menstrual cycles in patients undergoing successive...

Genetic Variability and Population Structure of the Tunisian Sicilo-Sarde Dairy Sheep Breed Inferred from Microsatellites Analysis.

This study analyzed the genetic variability, inbreeding and population structure of the Tunisian–North African dairy sheep breed, the Sicilo-Sarde (SS), created by crossing the Sarda and Comisana dairy breeds. The level of variability in the SS, considered as an endangered breed after a dramatic decrease, was assessed using 17 microsatellite markers by analyzing the two breed populations sampled from their respective cradles: SS of Beja (SSB, n = 27) and SS of Mateur (SSM, n = 25). High levels of genetic diversity in SS were revealed, with a total of 212 alleles, a high mean number of alleles (12.47 ± 4.17) and a high average polymorphism information content (PIC) (0.81 ± 0.10). The observed heterozygosity was considerable in SSB and SSM (0.795 and 0.785, respectively). The inbreeding level measured by the population inbreeding coefficient FIS is higher in the SSM population (0.121) than in the SSB population (0.090). The higher genetic diversity level detected in SSB reflected the effect of new Italian Sarda genes introduced by intra-uterine artificial insemination recently practiced in this population. The Wilcoxon test and the mode-shift distribution indicated that the SS breed is a non-bottlenecked population. The structural analysis reflected the historical miscegenation practiced during the breed creation and highlighted further ancient miscegenation, which could date back to the first waves of sheep introduction to the western Mediterranean region. Microsatellite markers were successfully applied in the assessment of the genetic variability of SS and should be used in monitoring this variability during the application of conservation strategies.

Ultrasound-guided, Transabdominal, Intrauterine Artificial Insemination for Cynomolgus Macaques (Macaca fascicularis) Based on Estimated Timing of Ovulation.

Intrauterine sperm injection for artificial insemination is difficult in cynomolgus macaques (Macaca fascicularis) and rhesus macaques (M. mulatta) due to the complex structure of the cervical canal, which differs from that of humans. Despite the availability of several artificial insemination methods for macaques, pregnancy rates are inconsistent, and details regarding ovulation are unclear, thus warranting more effective methods. Therefore, we developed an effective, ultrasound-guided, transabdominal intrauterine artificial insemination method for cynomolgus macaques that involves timing sperm injection to coincide with the periovulation phase estimated according to rapid hormone measurement. We performed our intrauterine artificial insemination on 6 female macaques; 4 of the 5 animals that were predicted to have ovulated soon after insemination became pregnant, whereas the 1 macaque that was predicted not to have ovulated did not. Furthermore, we saw no evidence of injury, such as a conspicuous needle hole or bleeding on the surface of or inside the uterus, nor did our method result in any abnormalities in the mothers or their offspring. Thus, our ultrasound-guided, transabdominal, intrauterine artificial insemination method is rapid, safe, and effective in cynomolgus macaques.

Perspectives of intrauterine artificial insemination applicability in gilts

ABSTRACT: The application of the intrauterine artificial insemination (IUAI) technique allows optimization of a swine production system due to the reductions in volume and number of sperm cells in the insemination dose, and by reducing the time taken to perform the insemination. However, IUAI is not recommended for gilts due to the difficulty of intrauterine cannula passage through the cervix. This difficulty is associated mainly with the fact that the reproductive tract is smaller in gilts than in pluriparous females. However, few studies have evaluated the application of IUAI in gilts. In these studies, there are variations in approach concerning the definition of the success rate for cannula passage through the cervix, the type of cannula and the body characteristics of the gilts used, making it difficult to extrapolate the recommendation for the use of IUAI in gilts. Considering the evidence that such characteristics influence or even determine the success of the application of IUAI, there is a necessity for an understanding of the influence of these factors in the improvement and later application of the technique. Gilts represent about 15-20% of the breeding group, and the use of IUAI could optimize the processes of insemination on farms. The approach used in this review highlights the aspects that could aid in structuring further studies for improving IUAI in gilts, allowing its use on commercial farms.

Reproductive performance in gilts following applications of different insemination doses and techniques

This study evaluated the applicability of intrauterine artificial insemination (IUAI) in gilts and the impact of age at insemination and different body characteristics of gilts on the success rate for cannula insertion. Additionally, reproductive performance was evaluated for IUAI and cervical artificial insemination (CAI), considering different semen dose sizes. A total of 636 gilts were assigned in a 2 × 2 factorial design: two artificial insemination techniques (CAI and IUAI) and two semen dose sizes (1.5 × 109 sperm cells/50 mL or 2.5 × 109 sperm cells/80 mL). In those gilts assigned to IUAI (n = 319) the success rate for intrauterine cannula insertion was evaluated according to weight at first detected estrus, body condition score (BCS), and age at insemination. Reproductive performance, occurrence of bleeding, and semen backflow during all inseminations were compared among groups (2 × 2). Two subgroups were evaluated regarding the time expended to perform insemination (n = 380), and the semen backflow collected during 1 h after insemination (n = 114). The success rate for intrauterine cannula insertion, based on a successful insertion in all inseminations performed during estrus, was 58.9%. Additionally, greater possibility (>60%; P ≤ 0.04) of cannula insertion was observed in heavier gilts (≥124 kg), as well as in older gilts (≥225 d) and those with greater BCS (>3). There were no differences among the groups in pregnancy rate (≥95.3%; P = 0.23), farrowing rate (≥93.7%; P = 0.54), total piglets born (≥14.5; P = 0.45), as well as, bleeding (P = 0.48) and backflow (P = 0.48) during insemination. However, the percentage of semen backflow volume and percentage of sperm cells in the backflow were lower in gilts inseminated by CAI with 1.5 billion sperm cells/50 mL (P < 0.01) than in the other groups. There was no expressive reduction in time expended to perform IUAI compared to CAI. However, gilts inseminated with 1.5 billion sperm cells/50 mL showed a lower total time to inseminate than all other groups (P < 0.01). In conclusion, higher weight, BCS, and age increased the success rate for cannula insertion. However, IUAI did not optimize the insemination procedure, and remains limited for gilts due to the low success rate for cannula insertion. Reproductive performance was not affected by IUAI or CAI using 1.5 or 2.5 billion sperm cells in 50 or 80 mL, respectively, suggesting the possibility of using CAI with 1.5 billion sperm cells/50 mL in gilts.

Sexing mammalian spermatozoa and embryos – state of the art

Methods for sexing preimplantation embryos range from karyotyping to recording speed of development in vitro. The only method used routinely on a commercial scale is to biopsy embryos and amplify Y-chromosome-specific DNA using the polymerase chain reaction. This method is effective for more than 90% of embryos and is > 95% accurate. Within males, spermatozoa are essentially identical phenotypically due to: (1) connection of spermatogenic cells by intercellular bridges, (2) transcriptional inactivation of sex chromosomes during meiosis and spermiogenesis, (3) severe limitation of all gene expression during the later stages of spermiogenesis, and (4) coating all spermatozoa with common macromolecules during and after spermiogenesis. One consequence is that no convincing phenotypic difference has been detected between X- and Y-chromosome-bearing spermatozoa. The only consistently successful, nondestructive approach to sexing spermatozoa is to quantify DNA in spermatozoa using a fluorescing DNA-binding dye followed by flow cytometry and cell sorting. X-chromosome-bearing ruminant spermatozoa have about 4% more DNA compared with Y-chromosome-bearing spermatozoa; accuracy of sorting can exceed 90% routinely, and sorting rates currently exceed 10(3) live spermatozoa of each sex chromosome composition s-1. Hundreds of apparently normal offspring from a number of species have been produced from sexed semen, some via intrauterine artificial insemination.

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.

Laparoscopie collection and transfer of Chios sheep embryos

The efficiency of two different laparoscopic techniques for embryo collection was examined. Two groups (A and B) of 12 Chios breed ewes were used as donors and 20 crossbred Chios ewes as recipients. Oestrus was synchronised by intravaginal sponges, the donors were supervoulated by 8,8 mg of ovine FSH and laparoscopic intrauterine artificial insemination was conducted with extended fresh ram semen. Embryo collection was carried out the 6th day after AI. The uteri of the animals of group A were flushed after catheterisation of the ipsilateral oviduct. In the animals of group Β a flushing catheter was inserted close to the tip of the horn. Fifty nine and 46 embryos were collected from groups A and Β corresponding to recovery rate of 51.75% and 39% respectively (P&gt;0.05). Laparoscopic transfer of 43 fresh embryos resulted to 11 (55%) pregnancies with (39.5%) surviving fetuses.

Sperm subpopulations in ejaculated sperm and spermatozoa recovered from ovine epididymides up to 48 h after death

The objectives of this study were threefold: to identify subpopulations of sperm based on the kinetics of frozen/thawed sheep epididymal spermatozoa or semen collected with an artificial vagina; to evaluate the effects on sperm subpopulations in the thawed samples of post mortem storage at room temperature and the addition of 20% of seminal plasma to the freezing extender and to correlate the percentage of subpopulations with gestation rate following artificial intrauterine insemination. The categorization of the subpopulations was based on sperm kinetic data from Computer Assisted Sperm Analysis (CASA). A hundred ewes were inseminated with thawed spermatozoa and gestation rate was correlated with the proportions of each subpopulation using Pearson correlation matrix and linear regression. Three distinct subpopulations were identified in the thawed samples of either ovine ejaculate collected in artificial vaginas (AV) or ovine spermatozoa retrieved from the cauda epididymis. Subpopulation 1 (SP1) was characterized by spermatozoa with slow and non-linear motion, subpopulation 2 (SP2) was classified as hyperactived spermatozoa and subpopulation 3 (SP3) was composed of spermatozoa with fast, linear motion. The largest subpopulation in all groups was SP1. The semen collected in an artificial vagina had a higher (P<0.05) percentage of SP2 and lower (P<0.05) percentage of SP1 when compared to spermatozoa recovered after death. Increasing time of storage after death had a detrimental effect on sperm samples, increasing (P<0.05) the percentage of SP1 and decreasing (P<0.05) SP2. Length of storage after death was the only variable that influenced, with an inversely proportional relationship, SP3. In samples stored for 48h after death no SP3 spermatozoa were present. The addition of seminal plasma to the cryopreservative decreased (P<0.05) the subpopulation of hyperactived spermatozoa (SP2). We conclude that, after thawing there are three sperm subpopulations in the spermatozoa obtained from the cauda epididymides and the semen collected in AVs and that the relative proportions of these subpopulations varies with the time of storage post mortem and the presence of 20% of seminal plasma in the extender. However, we conclude that these subpopulations do not correlate with fertility after intrauterine artificial insemination.

Use of industrial wireless endoscope in intrauterine artificial insemination in sheep

Use of industrial wireless endoscope in intrauterine artificial insemination in sheep

Reproductive features and use of an anti-inflammatory drug in estrus-induced dairy goats artificially inseminated in a standing position with cervix immobilization

This study evaluated reproductive features and role of Flunixin-Meglumine at timed artificial insemination (AI), using a new technique of standing position with cervix immobilization. In Experiment 1, 10 goats (n=5 nulliparous [Null] and 5 pluriparous [Plu]) were evaluated after estrus induction by recorded reproductive parameters to define the ideal time for AI. In Experiment 2, goats were artificially inseminated 51–54h after sponge removal with frozen–thawed semen. At AI, 1mL saline (CONTROL; 18 Null and 14 Plu) or 50mg Flunixin-Meglumine (FLUNIXIN; 15 Null and 18 Plu) was administered i.m. Location of semen deposition was recorded for both groups. In Experiment 1, all sexual behavior and ovulatory parameters were similar between Null and Plu for estrus response and ovulation (100%), interval from sponge removal to ovulation (∼64.2h), largest ovulatory follicle diameter (∼6.6mm), and number of ovulations (∼2.0). In Experiment 2, pregnancy rate was superior (P<0.01) for CONTROL (62.5%; 10 Null and 10 Plu) than FLUNIXIN (30.3%; 3 Null and 7 Plu) goats. Regardless of the treatment, intrauterine AI was more frequent (P<0.01) in Plu (100.0%; 32/32) than in Null (69.7%; 23/33) goats. Moreover, AI was more time-consuming (P<0.01) in Null (44±37s; 4–139s) than in Plu (21±19s, 4–78s) goats. Therefore, administration of Flunixin-Meglumine at the time of AI adversely affected pregnancy rate. High rates of intrauterine cervical penetration were obtained, achieving good pregnancy rates in goats not receiving Flunixin-Meglumine.

Decreased Implantation Number After In Utero Artificial Insemination Can Reflect an Impairment of Fertility in Adult Male Rats After Exogenous Leptin Exposure.

Leptin is a protein secreted by the adipocytes, which serves as a link between fat and brain. Its main action is to decrease appetite and increase energy expenditure, but it is also involved in the control of different neuroendocrine systems, including gonadal axis. Although the effects of leptin deficiency on reproduction are well recognized, the effect of excess leptin on male reproductive function is not clear. The aim of this study was to evaluate fertility and sperm parameters of male rats exposed to exogenous leptin. A group of adult male rats received exogenous leptin intraperitoneally (30 μg/kg/day) for 42 days, and a control group received only the vehicle during the same period. After the treatment, animals were evaluated for sperm count, sperm motility, and fertility after intrauterine artificial insemination. There was no statistically significant difference between the groups related to sperm production, sperm concentration, and sperm motility. However, fertility evaluation after artificial insemination showed a quantitative decrease in the uterus plus fetuses weight, number of implantation sites, and number of live fetuses. The fertility potential showed a reduction of about 40%, whereas the preimplantation loss rate increased more than 2-fold in leptin-treated animals. In conclusion, leptin administration to nonobese male rats impairs ability of treated animals to generate offspring, since the occurrence of implantation was diminished. So leptin can impair sperm quality, affecting the reproductive capacity.

Enhancing captive Indian rhinoceros genetics via artificial insemination of cryopreserved sperm

The objective of this study was to design an artificial insemination (AI) protocol using cryopreserved spermatozoa to obtain pregnancies in captive Indian rhinoceroses (Rhinoceros unicornis). Four methods developed varied by timing and approach, as follows; Method 1: females (n=2) were inseminated pre- and post-ovulation under general anesthesia, Method 2: females (n=2) were inseminated pre-ovulation without anesthetic via endoscopy, Method 3: females (n=1) were inseminated pre-ovulation without anesthetic via manual insertion of an insemination catheter, Method 4: females (n=2) were inseminated same as Method 3 with the addition of standing sedation. Semen deposition site varied as a result of changes in AI technology and experience. All females conceived following intrauterine AI using three methods. Four pregnancies (n=3 females) produced via Method 3 and 4 resulted in term births (n=2 male calves, n=2 female calves) at 481.8±12.8days post-AI. Unfortunately, two early pregnancy losses were documented in a fourth female conceiving via Method 2. Pregnancy rates were 0%, 22%, 17%, and 50% for Method 1–4, respectively. Method 3 and 4 rates improved to 29% and 67%, respectively when accounting for AI’s conducted only on ovulatory estrous cycles. Spermatozoa (n=5 males) were cryopreserved 0.3–9.3 y prior to successful AI procedures. The lowest dose of frozen-thawed sperm resulting in conception was 500×106 motile sperm. Mean time from AI to ovulation in conceptive and non-conceptive cycles was 26±11.8h and 66±80.7h, respectively.