Post-cervical Insemination Research Articles

Single Fixed-Time Post-Cervical Insemination in Gilts with Buserelin.

Simple SummaryCurrent protocols for gilts recommend the deposit of two/three semen doses (2–4 × 109 sperm/dose) by cervical artificial insemination (CAI), 12–24 h after estrus detection. If ovulation were predictable, gilts could be bred only once using fixed-time artificial insemination (FTAI). Using a specific catheter makes the postcervical deposition of semen possible (PCAI). This work explored the use of combining FTAI-PCAI with buserelin in gilts. In the control group (C; n = 240), gilts were inseminated twice (8 and 12 h from estrus onset). Gilts in the treatment group (T; n = 226) received buserelin (10 μg, intramuscular) 120 h after altrenogest treatment (18 d) and one single PCAI 30–33 h after buserelin administration. No significant differences were found in reproductive and production performance between groups (p > 0.05). Piglets’ birth weight was greater in the T group (p < 0.001). Estrus duration was significantly shorter in the T group (p < 0.001). Delivery batch length significantly differed depending on the season (p < 0.05); both groups only differed significantly in spring (p = 0.018), with a shorter duration in the T group. This new FTAI-PCAI protocol with buserelin is recommended in gilts, helping with optimization of genetic diffusion, boars, and semen doses.Current protocols for gilts recommend the deposit of multiple semen doses in the cervix each 12–24 h after estrus detection. Our objectives were: (1) to determine the effect of buserelin and a single fixed-time artificial insemination using the new post-cervical artificial insemination technique (FTAI-PCAI) on reproductive and productive performance in gilts, and (2) to compare this protocol with conventional estrus detection and double PCAI without hormonal induction. In the control group (C; n = 240), gilts were inseminated twice (8 and 12 h from estrus onset). Gilts in the treatment group (T; n = 226) received buserelin (10 μg, intramuscular) 120 h after altrenogest treatment (18 d) and one single PCAI 30–33 h after buserelin administration. The groups did not differ in reproductive and production performance (p > 0.05). The T group showed greater piglet birth weight and shorter estrus duration (p < 0.001). Delivery batch length differed significantly depending on the season (p < 0.05); the shortest length corresponded to autumn. Both groups only differed significantly in spring (p = 0.018), with a shorter length in the T group. This new FTAI-PCAI protocol with buserelin is recommended in gilts, helping with optimization of genetic diffusion, boars, and semen doses.

DMEM and FBS as thawing solutions for frozen semen of pigs can improve sperm motility and sow reproductive performance

The purpose of this experiment was to investigate the effects of Beltsville thawing solution BTS , Androhep, and Dulbecco?s modified Eagle medium + Fatal bovine serum D-F as diluents of frozen semen on sperm motility and sow reproductive performance. In experiment 1, boar semen was collected and diluted to 2.0 × 109/60 mL, 1.5 × 109/60 mL, and 1.5 × 109/40 mL with Androhep. The appropriate semen dose was determined by postcervical insemination. In experiment 2, boar semen was fumigated with liquid nitrogen and thawed semen was diluted to 1.5 × 109/40 mL with D-F, Androhep, and BTS, respectively. The effects of above diluents on sperm motility and sow reproductive performance were studied by postcervical insemination. The appropriate semen dose for postcervical insemination was 1.5 × 109/40 mL. After thawing of frozen semen, sperm motility of semen diluted with D-F was significantly higher than that of semen diluted with Androhep and BTS. There was no significant difference in pregnancy rates among sows via artificial insemination. The litter size of sows using D-F diluted semen was significantly higher than that of sows using Androhep and BTS diluted semen. In conclusion, D-F freezing diluent can improve sperm motility of frozen boar semen after thawing, prolong sperm survival time, and increase sow reproductive performance.

Reproductive performance of sows inseminated with semen doses stored for up to seven days in long-term extender in a field condition.

This study aimed to evaluate the reproductive performance of sows inseminated with semen doses preserved at 15-18 °C for up to seven days in long-term extender (Duragen®). Parity one (PO1) to PO7 sows were randomly assigned to the following groups: AI1-3 (n=190), insemination with semen doses stored between one and three days; and AI5-7 (n=124), insemination with semen doses stored between five and seven days. Sows were submitted to estrus detection twice a day. Post-cervical insemination according to weaning-to-estrus interval was performed. The farrowing rate (FR) did not differ between the groups (AI1-3=83.2%; AI5-7=82.2%; p>0.05) nor did the total number of piglets born (TPB; AI1-3=14.2±0.3; AI5-7=14.5±0.3; p>0.05). Considering the semen dose most likely responsible for fertilization according to its storage time (1, 2-3, 5, and 6-7 days), the FR (72.7%, 87.8%, 85.7%, and 79%, respectively) and TPB (14.4, 14.0, 14.9, and 13.5, respectively) were similar among the groups (p>0.05). In conclusion, the use of semen doses extended with long-term extender stored for up to seven days did not impair the reproductive performance of sows. Therefore, it’s using could optimize production efficiency and logistics of semen dose deliveries to sow farms.

Effect of boar seminal dose type (cervical compared with post-cervical insemination) on cooling curve, sperm quality and storage time

Seminal doses used for cervical and post-cervical artificial insemination (CAI and PCAI, respectively) vary in volume, the number of spermatozoa and packaging. The aim was to evaluate the outcomes when there was use of routine processing procedures for CAI- and PCAI-doses. Two different types of seminal doses were processed: 1) CAI: 2.7 × 109 sperm/80 ml; 2) PCAI: 1.5 × 109 sperm/45 ml. In Experiment 1, the cooling curve of seminal doses during processing occurred in two phases: 1st) At room temperature (23.4 ± 0.5 °C) from 0 (just after packaging) to 120 min; 2nd) At refrigeration (15.7 ± 0.8 °C) from 121−240 min. For the PCAI-doses, the time required to reach room temperature was 47 min compared to 107 min for CAI-doses (decreasing velocity of 0.093 °C/min and 0.048 °C/min, respectively). During refrigeration, for the PCAI-doses the time required to reach the desired preservation temperature was 20 min less than for CAI-doses (PCAI: 90 min, 0.074 °C/min; CAI: 110 min, 0.066 °C/min). In Experiment 2, sperm motility, kinetic parameters and acrosome damage for both types of doses were evaluated at 0, 24, 48 and 72 h of refrigeration. Also, morphology, pH, and osmolality were assessed at 0 and 72 h. Values for all these did not differ between CAI- and PCAI-doses. In conclusion, PCAI-doses took less time than CAI-doses to reach the desired temperature, but sperm quality was similar for CAI- and PCAI-doses during storage. Nevertheless, the different cooling curves should be taken into consideration for further investigation.

Swine artificial insemination: development and biotechnology applications

Traditional artificial insemination has been highly contributed in swine global industry development. However, in order to improve the productivity and the reproductive performance of pig farms, new techniques have been performed. Among them, post cervical or intrauterine insemination, deep intrauterine insemination (DUI), intra-oviductal insemination (ΙΟΙ) by laparotomy or laparoscopy, as well as the biotechnological applications, such as sex sorted semen, frozen semen and sperm mediated genes' transfer, have been investigated concerning their efficiency in pig production development. One of the main targets of the aforementioned techniques is to benefit the potential advantages of the high genetic value boars by using the minimal number of spermatozoa needed to achieve a high fertilization rate following artificial insemination. On the other hand, biotechnology could lead in rapid transfer of high genetic potential in inaccessible areas through frozen semen. Moreover, biotechnology could support pig industry increasing the female pigs' production according to the consumers' choices and animals' welfare by sex sorted semen application, as well as producing of transgenic pigs aiming an increased disease resistance, improvement carcass composition, increased feed intake and growth rate. In vivo studies have evaluated the efficiency of the new developments in insemination technology. The results of these studies demonstrated that a satisfactory conception rate and litter size can be obtained by the insemination of low number of spermatozoa in the appropriate position of the female genital tract at the right time, close to ovulation. High farrowing rate and number of live born piglets were noticed after the post cervical insemination with low number of spermatozoa (lxlO9), compared to the traditional artificial insemination. Similar results were observed in other experiments, where 150xl06 or 3xl05 spermatozoa were inseminated using DUI or ΙΟΙtechnique, respectively. Furthermore, the improvement of the materials of the new artificial insemination procedures (catheters, extenders etc) makes the application of it simpler and easier for the workers after a few training. Although the traditional artificial insemination is an indispensable method for the commercial pig farms, the application of currently available sperm technologies is feasible to be performed in selected animals of pig farms with high quality control and management system. The aspects of the development on swine artificial insemination technology concerning the biotechnological applications of boar sperm are reported in the present study.

Effect of numbers of sperm and timing of a single, post-cervical insemination on the fertility of weaned sows treated with OvuGel®

Variability in estrus and ovulation requires multiple inseminations during estrus to ensure one AI occurs close to ovulation. Induction of ovulation after weaning improves synchrony of ovulation and allows for fixed time AI. However, the interaction between number of sperm in the AI dose and the timing of insemination has not been fully investigated. The objective of this study was to determine the effects of sperm numbers used in a single post-cervical insemination (PCAI) and the timing of insemination following induced ovulation in weaned sows. The experiment was performed using sows (n = 641) allotted by parity (1–6) and lactation length (19.5 d) to receive a single PCAI using 1.5 or 2.5 billion motile sperm at either 22, 26, or 30 h following administration of a GnRH agonist, triptorelin acetate (OvuGel®) at 96 h post-weaning. Sows received boar contact once daily 3–6 d following weaning. A sub-population of the sows (n = 499) were assessed for follicle size and ovulation utilizing ultrasound at 8 h intervals. There was no interaction of number of sperm and timing of insemination for any response measure (P > 0.10). Wean to estrus interval (4.8 d), duration of estrus (1.9 d), and expression of estrus (88.0%), were not different among treatments (P > 0.10). Of sows scanned by ultrasound at the time of OvuGel®, 88.2% had large follicles, 10.9% had small, medium or cystic sized follicles, and 0.9% had corpora lutea. The proportion of sows that ovulated averaged 94%, and differed by time of AI (P ≤ 0.05) but not by number of sperm. Pregnancy rate and farrowing rate tended to be affected by dose (P ≤ 0.10), while time of insemination affected pregnancy rate and tended to influence farrowing rate (P ≤ 0.10). Farrowing rate was greater (P < 0.0001) with use of 2.5 than 1.5 billion sperm and insemination at 22 and 26 h compared to 30 h after OvuGel® (P ≤ 0.10). Farrowing rate was also affected by parity, estrus expression, ovulation and ovarian abnormalities (P < 0.05). Of the 12% of weaned sows that did not exhibit estrus, approximately 50% farrowed a litter. Total born and born alive were affected by dose (P < 0.05) but not time of insemination with both measures increased with 2.5 compared to 1.5 billion sperm (P < 0.05). The results of this study indicate that induction of ovulation in weaned sows resulted in 88% of sows ovulating within a 24 h period. Fertility was improved with a single, fixed time AI using 2.5 compared to 1.5 billion motile sperm and insemination at 22–26 h after OvuGel® compared to 30 h.

The Post‐Cervical Insemination does not Impair the Reproductive Performance of Primiparous Sows

The study evaluated the reproductive performance of primiparous sows submitted to post-cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning-to-oestrus interval and total born in previous farrowing, in two treatments: PCAI (n=165) with 1.5×10(9) sperm cells in 45ml (2.4±0.04 doses per sow) and CAI (n=165) with 3×10(9) sperm cells in 90ml (2.5±0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real-time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24h after last insemination. There was no difference (P>0.05) between treatments in farrowing rate (91.5%×89.1%) and litter size (12.5×11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P>0.05). Bleeding during insemination did not affect (P>0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P≤0.06). Percentage of spermatozoa present in backflow within 1h after insemination was greater in CAI than PCAI sows (P<0.01). More than 85% of primiparous sows can be successfully post-cervical inseminated with doses containing 1.5×10(9) sperm cells in the absence of the boar during insemination without impairing the reproductive performance.

Morphological characteristics of the cervix in domestic sows

Artificial insemination is commonly practiced in several domestic animals, including sows. Postcervical insemination is used to increase the fertility index, given that the volume of semen is optimized. Knowledge of the anatomical and physiological characteristics of the genital tract can be used to improve our understanding of the fertilization process that occurs during artificial insemination, and possibly to improve the technique. The aim of our study was to examine the gross morphology and histological properties of the cervix of recently slaughtered multiparous sows, using different stains. The results indicate that the porcine cervix has two regions: a uterine region characterized by the presence of glandular acini, and a vaginal region with a large vascular network. Both regions showed a mixed secretory activity by epithelial cells, which produced sulfated mucins (mucous secretion), intermingled with abundant glycogen-rich cells (serous secretion). This study contributes to the understanding of the morphologic features of the porcine cervix.

New developments in low-dose insemination technology

New nonsurgical procedures for inseminating swine with a low number of spermatozoa have been developed and/or evaluated over the last few years. These procedures allow the deposition of the insemination dose into the uterine body (post-cervical insemination) or directly into the uterine horn (deep intrauterine insemination). With the use of the post-cervical insemination, a threefold reduction in the number of fresh sperm has been successfully used to achieve pregnancy. Using deep intrauterine insemination (DUI), up to a 20-fold reduction in the number of fresh spermatozoa or a sixfold reduction in the number of frozen/thawed spermatozoa can be achieved, with reproductive performance very similar to that obtained after standard AI. Complementing these nonsurgical insemination techniques, a new procedure for depositing spermatozoa into the oviduct by laparoscopy has been recently described. This laparoscopic technique has proven to be applicable to diluted and sex-sorted spermatozoa. The development of new insemination procedures will help achieve more efficient application of currently available sperm technologies. Using appropriate insemination procedures, it is now feasible to achieve high fertility rates with cooled, frozen–thawed, or sex-sorted semen.

Effect of Oxytocin Treatment on Artificial Insemination with Frozen-Thawed Semen in Murciano-Granadina Goats

The site where the semen is deposited appears to be one of the most important factors affecting pregnancy of inseminated goats. In Murciano-Granadina (MG) goats, post-cervical insemination is achieved in a limited number of females. An effective way to increase fertility rate could be by increasing post-cervical inseminations. Effect of exogenous oxytocin application to facilitate the cervical penetration and its effect on kidding rate and prolificacy in MG goats were investigated. Oestrus was synchronized using progesterone-impregnated sponges for 11 days. Females were randomly divided into three groups (n = 190) and received either an i.v. injection of 100 or 200 IU of oxytocin or saline solution 15 min before being inseminated. Data on semen deposition depth were recorded for each animal using a catheter scaled in centimetres (up to 4 cm). Depth of semen deposition was affected by the oxytocin treatment (p < 0.05). Oxytocin enhanced cervical passage only with the dose of 200 IU compared with the control group, increasing the deposition depth (2.9 cm vs 1.9 cm). No significant effect of oxytocin treatment on kidding rate and prolificacy was detected. Depth of semen deposition affected kidding rate (p < 0.01). In conclusion, oxytocin treatment improved the depth of semen deposition in AI of MG goats, but kidding rate and prolificacy was not affected. More studies must be conducted to assess the minimal effective dose required for sufficient cervical dilation, and to determine the effects of such doses of oxytocin on uterine motility, sperm transport and fertility in goats.

Factors Affecting Pregnancy Rate in Artificial Insemination with Frozen Semen During Non‐Breeding Season in Murciano–Granadina Goats: a Field Assay

An artificial insemination programme was carried out to study the effect of factors such as depth of semen deposition, inseminator skill, farm, sire and expression of oestrus on pregnancy rate in Murciano-Granadina (MG) goats during non-breeding season and using frozen semen. Frozen-thawed semen from six males was applied by three technicians to inseminate a total of 551 goats in 17 farms distributed throughout the Mediterranean area of Spain. Pregnancy rate was determined at 6 weeks after insemination by transabdominal ecography. Overall pregnancy rate was 57%. Farm and depth of semen deposition affected pregnancy rate, whereas the sire and the technician had no effect. The deeper the semen was deposited in the genital tract, the higher was the rate of pregnancy obtained, being greater when the catheter reached the uterus. In spite of the relevant difference observed (48.2% vs 59.0%), pregnancy rate of females not coming into oestrus until 30 h after sponge removal was not significantly different, compared with those showing oestrus during the OD procedure. In conclusion, our field assay data on AI in MG goat with frozen-thawed semen showed that post-cervical insemination presented significantly greater pregnancy rate in comparison to when semen is deposited in the vagina or in the caudal part of the cervix.