Semen Backflow Research Articles

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.

Post-cervical compared with cervical insemination in gilts: Reproductive variable assessments

The aim with this study was to compare cervical (CAI; 3 × 109 spermatozoa/90 mL) and post-cervical (PCAI; 1.5 × 109 spermatozoa/45 mL) artificial insemination (AI) techniques for frequency of incidences (unsuccessful or difficult probe passage, backflow, metritis and bleeding), values for reproductive variables and duration of the procedure in gilts. There were 644 gilts (255–270 days old, weighing 150 ± 5 kg) randomly assigned to PCAI (n = 320) and CAI (n = 324) groups. In total, there were 957 and 958 artificial inseminations performed in the CAI and PCAI groups, respectively (2–4 AIs/gilt). The frequency of unsuccessful or difficult PCAI probe passage/AI was 14.6% (140/958), therefore, there was a 85.7% probe passage success/AI rate (818/958). The semen backflow frequency/AI was less with PCAI than CAI (4.3% compared with 8.2%, P < 0.001). With the PCAI group, there were only a few cases of bleeding (11/958: 1.1% /AI) with no difference between the CAI and PCAI groups (P = 0.224). In gilts (n = 72) where there was not passage of the PCAI probe (72/320; 22.5%) there was use of CAI, (M, mixed group). For the CAI, PCAI and M groups, there were similar values for positive pregnancy diagnosis, farrowing rates and prolificacy (P > 0.05). The average duration for AI was shorter in the PCAI (2.34 ± 0.809 min) than CAI (4.77 ± 1.059 min) group, and it was longer in the M group (7.48 ± 2.454 min; P < 0.050). The PCAI procedure, therefore, is recommended for AI of gilts.

Combining Fixed-Time Insemination and Improved Catheter Design in an Effort to Improve Swine Reproduction Efficiency

Simple SummaryConventional practice is to breed sows by artificial insemination (AI) at least twice using approximately three billion sperm per insemination. Sows may be bred only once using the technique of fixed-time artificial insemination (FTAI) if ovulation is predictable. This research explored the use of combining a single fixed-time artificial insemination (FTAI) and an alternative insemination catheter design that reportedly reduces semen backflow in order to reduce semen dosage and maintain reproduction efficiency. The FTAI technique used in this study involved two hormone treatments, 80 h apart, after weaning followed by a single insemination. The two catheters used in this study were a conventional foam-tipped insemination catheter and a Gedis catheter, which is designed to be completely inserted into the vagina of the sow. The semen is enclosed along the length of the catheter and held in place by a gel cap that melts when inserted into the cervix. Sows were assigned to the following treatments: Group 1 (n = 135), bred twice with a conventional catheter and a standard semen dose of approximately three billion sperm in 80 mL; Group 2 (n = 123), FTAI with conventional catheter and a standard semen dose; Group 3 (n = 127), FTAI with Gedis catheter and a standard semen dose; Group 4 (n = 126), FTAI with Gedis catheter and a reduced semen dose with approximately one billion sperm. The farrowing rates were 81.6%, 77.7%, 74.0%, and 62.7% for Groups 1 to 4, respectively. Litter sizes of Group 3 and Group 4 were smaller than Group 1. Overall, the combination of Gedis catheter and FTAI resulted in decreased reproductive performance that outweighed the value of using less semen.Conventional practice is to breed sows by artificial insemination (AI) at least twice using approximately three billion sperm per insemination upon estrus at standing heat. This research explored the use of combined technologies, including fixed-time insemination (FTAI) and an alternative catheter design that reportedly reduces semen backflow, in order to reduce the number of inseminations and the semen dosage and maintain reproductive efficiency. The FTAI technique used in this study was to inject I.M. 600 IU equine chorionic gonadotropin (eCG) at weaning and 5 mg porcine luteinizing hormone (pLH) to stimulate ovulation 80 h later, followed by a single insemination 36 h after the pLH injection. The two catheters used in this study were a conventional foam-tipped insemination catheter and a Gedis catheter. The Gedis catheter is designed to be completely inserted into the vagina. The semen is enclosed along the length of the rod and held in place by a gel cap that melts when inserted into the cervix. Sows were assigned to the following treatments: Group 1 (n = 135), bred twice with a conventional catheter and a standard semen dose of approximately three billion sperm in 80 mL; Group 2 (n = 123), FTAI with conventional catheter and a standard semen dose; Group 3 (n = 127), FTAI with Gedis catheter and a standard semen dose; Group 4 (n = 126), FTAI with Gedis catheter and a reduced semen dose with one billion sperm. The farrowing rates were 81.6%, 77.7%, 74.0%, and 62.7% for Groups 1 to 4, respectively. The likelihood of farrowing was lower for Group 3 and Group 4 compared to Group 1 (odds ratio (OR) = 0.57; p = 0.08 and OR = 0.35; p = 0.001, respectively). Likewise, litter size of Group 3 and Group 4 was smaller than Group 1 (p = 0.006 and p = 0.04, respectively). Overall, the combination of Gedis catheter and FTAI resulted in decreased reproductive performance that outweighed the value of using less semen.

Single fixed-time artificial insemination in gilts and weaned sows using pLH at estrus onset administered through vulvar submucosal route

This study evaluated the use of a single fixed-time artificial insemination (FTAI) in gilts and weaned sows using 2.5 mg of porcine luteinizing hormone (pLH) administered through vulvar submucosal route, at the onset of estrus. In experiment 1 (Exp.1), 318 pubertal gilts were assigned to two groups: control-G—no hormonal application and artificial inseminations (AIs) at 12, 36, and 60 hours after the onset of estrus if they were still in standing estrus; and FTAI-G—use of pLH at the onset of estrus and a single FTAI 12 hours later. In experiment 2 (Exp. 2), 309 weaned sows were assigned to three groups: Control-S—no hormone application and AIs at 0, 24, and 48 hours after the onset of estrus if they were still in standing estrus; FTAI-NH—no hormone application and a single FTAI at 24 hours after the onset of estrus, and FTAI-pLH—use of pLH at the onset of estrus and a single FTAI 24 hours later. Transabdominal real time B-mode ultrasonography was performed to determine whether the insemination had been performed within 24 hours before ovulation, considered as the optimal interval. In Exp. 1, ultrasound evaluation (12-hour intervals) was carried out to determine the interval between the onset of estrus and ovulation. In both experiments, 2 × 109 sperm cells in 80 mL were used to perform cervical and postcervical deposition of semen in gilts and sows, respectively. Compared with control-G, FTAI-G gilts had shorter (P < 0.05) duration of estrus (57.7 vs. 61.2 hours) and interval between the onset of estrus and ovulation (36.3 vs. 42.3 hours). The adjusted farrowing rate (AFR) was lower (P < 0.05) in FTAI-G (86.0%) compared with control-G (93.5%), but total piglets born (TPB) did not differ between these groups (12.3 vs. 12.5 piglets). Within the FTAI-G group, the AFR was lower (P < 0.05) in the presence (50.0%) than in the absence (94.9%) of semen backflow during AI. Also in the FTAI-G group, the insemination outside the optimal interval reduced (P < 0.05) the TPB (10.5 vs. 12.9 piglets) in comparison with gilts inseminated within the optimal interval. In Exp. 2, there were no differences in the AFR (Control-S: 94.1%; FTAI-NH: 86.1%; FTAI-pLH: 88.0%) and TPB (Control-S: 12.8; FTAI-NH: 12.7, and FTAI-pLH: 12.0 piglets) among treatments. The presence of semen backflow reduced (P < 0.05) the TPB in FTAI-pLH and FTAI-NH sows. In the FTAI-pLH, a single insemination performed too late relative to ovulation reduced the AFR (P < 0.05) compared with sows inseminated within the optimal interval. In conclusion, 2.5-mg pLH applied at the vulvar submucosa at the onset of estrus advances the ovulation in gilts, but a single FTAI performed 12 hours later reduces the farrowing rate. A single FTAI performed at 24 hours after the onset of estrus in weaned sows does not affect their reproductive performance, regardless of pLH application.

Morphometry of boar sperm head and flagellum in semen backflow after insemination

Once deposited in the female reproductive system, sperm begin their competition and undergo a selection to reach the site of fertilization. Little is known about the special characteristics of sperm that reach the oviduct and are able to fertilize, with even less information on the role of sperm dimension and shape in transport and fertilization. Here, we examine whether sperm morphometry could be involved in their journey within the uterus. For this purpose, sperm head dimension (length, width, area, and perimeter) and shape (shape factor, ellipticity, elongation, and regularity), and flagellum length were analyzed in the backflow at different times after insemination (0–15, 16–30, and 31–60 minutes). Sperm morphometry in the backflow was also analyzed taking into account the site of semen deposition (cervical vs. intrauterine). Finally, flagellum length was measured at the uterotubal junction. Sperm analyzed in the backflow were small (head and flagellum) with different head shapes compared with sperm observed in the dose before insemination. The site of deposition influenced head morphometry and tail size both being smaller in the backflow after cervical insemination compared with intrauterine insemination. Mean tail length of sperm collected in the backflow was smaller than that in the insemination dose and at the uterotubal junction. Overall, our results suggest that sperm size may be involved in sperm transport either because of environment or through sperm selection and competence on their way to encounter the female gamete.

16 BIOCHEMICAL ANALYSIS OF COMPONENT IN SEMINAL GEL SECRETED WITH BOAR SEMEN

Seminal gel (SG), a part of semen, of the boar originates from secretions from the Cowper's gland and has a high viscosity and water-holding capacity, preventing backflow of semen at natural mating. However, there are is little information available about biochemical and functional characteristics of boar SG. In this study, as a first step to elucidate the chemical features of the SG, we examined the structure of O-glycans and the primary structure of protein from the boar SG. Seminal gel was collected from ejaculated semen of a Berkshire boar with high fertility and freeze-dried. Samples were preserved in a refrigerator until experiments were conducted. For Exp. 1 the presence of O-glycans in SG was confirmed by detection of the amino sugar, galactosamine (GalNH2), from acid hydrolysis of GalNAc. The freeze-dried SG (1 mg) was hydrolyzed with 4N trifluoroacetic acid at 110°C for 2 h. The resulting amino sugar was labelled with phenyl isothiocyanate (PITC) and then analysed by RP-HPLC. The GalNAc was detected as a main amino sugar, suggesting that the SG contains O-glycosylated glycoprotein. For Exp. 2 the O-glycans were prepared from the freeze-dried SG (5 mg) by hydrazinolysis at 100°C for 2 h. After N-acetylation, the O-glycans were pyridylaminated. The structures were identified by anion-exchange HPLC, size-fractionation HPLC, glycosidase digestion, and ESI-MS and MS/MS analysis. Almost all glycans were digested by α2–3,6-sialidasae, indicating that these O-glycans are sialylated and give the glycoproteins viscosity. Furthermore, the MS analysis showed that the de-sialylated O-glycans consist of HexNAc-PA (m/z 300.0) and Hex-HexNAc-PA (m/z 462.0) and major glycans are di- or tri-saccharides. For Exp. 3 proteins in the SG were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing condition with 5% 2-mercaptoethanol. Proteins were stained with Coomassie Brilliant Blue R-250. Three bands (~160, 140, and 70 kDa) were found on 7.5% polyacrylamide gel, but two bands (160, 140 kDa) were converted to ~130 kDa after the sialidase digestion, indicating that native two proteins (160 and 140 kDa) may be highly sialylated. For Exp. 4 internal amino acid sequence was analysed using one of the peptic peptides. The freeze-dried SG (5 mg) was digested with porcine pepsin in 5% formic acid at 37°C for 3 h. The resulting peptides were separated by RP-HPLC. N-terminal sequence of one of the peptic peptides was WSEKYGIPGGKAH. The amino acid sequence showed a high homology with tyrosine-protein kinase ZAP-70. These results suggest that boar SG contains mucin-like glycoproteins carrying heavily sialylated O-glycans. Additionally, the current study suggests a possibility that some protein components of the boar SG derive from high concentration of the kinase in (dead) sperms.

Improving of pig production by intrauterine artificial insemination and other biotechnological solutions

Thanks to constantly increasing human population number during the last few decades, the need for pork meat on market increased dramatically. That requirement made imperative for improvement of swine production efficiency. To achieve this goal, it is necessary to implement new biotechnological procedures and production protocols. The use of artificial insemination (AI) in intensive swine production increased notably during the last 30 years and there is a constant need for improvement of AI technologies. New insemination methods (insemination with frozen-thawed semen, different insemination techniques) as well as modern equipment for analysis (CASA microscope, flow cytometry) and sperms' triage (semen sexing), contributed to obtaining much better production results in modern pig industry. The aim of our research was to evaluate sows' reproductive performances after the usage of intrauterine (IU) insemination with reduced semen volume doses and reduced sperm number, in comparison on classical, intracervical artificial insemination. The experiment included a total of 200 sows from 3 pig farms, which were divided in two groups. Test group (n=100) was inseminated applying intra-uterine (post-cervical) insemination technique with special balooncatheters, while control group (n=100) was inseminated on the usual manner, using intracervical (IC) technique. Insemination in both groups was done after oestrus detection (standing reflex) in the presence of mature boar. For IU artificial insemination had been used chilled semen doses with 1,5 billion of spermatozoain total volume of 50 ml, while for IC insemination of control group had been used standard semen dose of 100 ml and 3 billion spermatozoa. In both groups, insemination had been done once. Insemination with catheter for IU artificial insemination was successful in 89 sows. From the total number of successfully inseminated sows, 84 sows farrowed (94.38 %), while farrowing rate in control group was 78%. Based on results from this experiment, we determined statistical significant (p<0,01) higher number of liveborn piglets after intrauterine insemination (11,00 ± 1,57) with regard to intracervical insemination (10,14 ± 1,10). Applying of intrauterine (postcervical) insemination technique increases a number of spermatozoa that get into oviduct, on site of fertilization. That raises farrowing rate, litter size and number of live born piglets in inseminated sows. In addition, the use of IU catheters decreases semen backflow which allows usage of semen doses of less volume with reduced number of sperm cells. Insemination with this type of IU catheters can't be done if sows aren't in optimal oestrus period. Insemination of double more sows with the same volume of quality semen, better using of genetic material from excellent boars, better assessment of optimal insemination time especially during warm period of the year, are reason good enough for applying IU techniques on pig.

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.

Endoscopic transcervical intrauterine artificial insemination in Labrador Retriever bitches

Besides post-thawing reduced semen quality, there are some difficulties in the execution of the endoscopic transcervical intrauterine artificial insemination (AI) with frozen–thawed semen in bitches. Therefore, the aims of the present study were to evaluate behavioral and reproductive parameters (i.e., vaginal cytology and serum progesterone level) to determine time of insemination and to investigate the particularities and difficulties of this technique in bitches using fresh semen. Ten Labrador Retriever bitches were submitted to three endoscopic transcervical intrauterine AIs (with 48h intervals). Oestrus and ovulation period were established by behaviour evaluation, progesterone assays and vaginal cytology, enabling optimal timing for AI during oestrus. During AI, the following aspects were evaluated: cervical os catheterization difficulty, semen deposition resistance, occurrence of semen backflow, and time required to perform the AI. In this study, it was possible to catheterize the cervical os in all bitches, with different degrees of difficulty, by manipulating the equipment to allow cervical visualization and catheter introduction in the cervical canal. Serial serum progesterone assays enabled estimation of LH surge day, and thus of ovulation. The pregnancy rate was 90%, with a litter size of 5.0±2.6 puppies per bitch. It was concluded that the difficulties in the execution of the endoscopic transcervical intrauterine AI technique in Labrador Retriever bitches were minimized by the equipment manipulation and practical experience.

Semen quality and reproductive performance after artificial insemination with boar sperm stored in a gelatin-supplemented extender

This study tested the effects of inclusion of gelatin in an extender for cooled boar semen on sperm quality during storage and reproductive performance after artificial insemination (AI). In Experiment 1, ejaculates from four boars were stored in Beltsville Thawing Solution (BTS) and BTS including 1.5% and 3.0% gelatin. Sperm motility and morphology were similar among extenders during 72 h of storage (P > 0.05). In Experiment 2, ejaculates from four boars were stored in BTS and BTS including 1.5% gelatin. Motility, normal morphology and membrane integrity declined over storage time for both extenders (P < 0.05). Decrease on normal sperm morphology over time was less severe in semen stored in gelatin-supplemented BTS (P < 0.05). In Experiment 3, AI was conducted in sows from a commercial farm using semen stored in BTS with or without 1.5% gelatin. Farrowing rate and total litter size did not differ (P < 0.05), but AI with gelatin-supplemented BTS was shorter and presented less semen backflow (P < 0.05). Semen stored in BTS including gelatin presented acceptable quality for longer periods and was efficiently used in AI with no losses in reproductive performance.

Reproductive performance of sows submitted to intrauterine insemination

The objective of this study was to evaluate the reproductive performance of sows artificially inseminated by the intrauterine (IAIU) technique. The experiment was arranged in a randomized complete block design, with 300 sows being distributed in five insemination techniques: control, intra-cervical (IAIC) with 3x10(9) spermatozoa/100 mL; intrauterine (IAIU) with 1x10(9) spermatozoa/100 mL; intrauterine with com 1x10(9) spermatozoa/50 mL; intrauterine with 5x10(8) spermatozoa/100 mL; and intrauterine com 5x10(8) spermatozoa/50 mL. The sows submitted to intrauterine insemination presented a farrowing rate of 90.8% and return to estrus rate of 9.2%, which did not differ from the rates obtained by the intra-cervical technique (90.0% and 10.0%, respectively). Total litter size did not differ between the techniques, with the means being from 11.4 to 11.9 piglets at farrowing. Although 4.6% of the sows submitted to intrauterine artificial insemination had difficulty with pipette insertion into the cervix, 100% of them were inseminated. When evaluating semen backflow, no difference was found between the intra-cervical and intrauterine insemination techniques. However, total semen backflow was higher in sows submitted to inter-cervical insemination. No difference was found in the presence of blood between the two methods evaluated. Hence, any of the intrauterine insemination techniques can substitute inter-cervical artificial insemination without damaging the reproductive performance of the animals.

Fertility after intrauterine insemination with conventional or low numbers of spermatozoa in sows with synchronized ovulation

Objective: To determine sow fertility to a single timed intracervical or intrauterine insemination of conventional or low sperm numbers. Materials and methods: A total of 411 mixed-parity sows were subjected to controlled ovulation by injection of 600 IU equine chorionic gonadotrophin at weaning and 5 mg porcine luteinizing hormone (pLH) 80 hours later. Sows were assigned to a single insemination of 1 or 3 × 109 sperm delivered into either the cervix or uterus. Inseminations were performed approximately 36 hours after pLH injection. Intensity of standing estrus at insemination was subjectively scored as 1 to 3, with 3 being a stronger response, and semen backflow was recorded as yes or no. Results: Number of sperm and site of deposition did not affect pregnancy or farrowing rates or subsequent litter size. Mean farrowing rates were 68.32% and 68.63% in sows inseminated using an intrauterine catheter and either 1 or 3 × 109 sperm, respectively. In sows inseminated using the cervical method, farrowing rates were 77.88% and 67.31% when 1 and 3 × 109 sperm were used, respectively. Greater intensity of estrus at insemination was associated with higher pregnancy and farrowing rates (P &lt; .001), and backflow during insemination was associated with lower pregnancy and farrowing rates (P &lt; .01). Implications: When appropriately timed after induced ovulation, insemination of low sperm numbers does not adversely affect sow fertility, and this lack of effect is independent of the site of sperm deposition.

Distribution of Spermatozoa and Embryos in the Female Reproductive Tract after Unilateral Deep Intra Uterine Insemination in the Pig

Distribution of Spermatozoa and Embryos in the Female Reproductive Tract after Unilateral Deep Intra Uterine Insemination in the Pig

Nova pipeta para inseminação intra-uterina em suínos

O objetivo deste trabalho foi avaliar o desempenho reprodutivo de 423 fêmeas suínas de ordem de parto 1 a 9 submetidas à inseminação intra-uterina (IAU), com um novo modelo de pipeta (T1) cuja extremidade não é fixada na cérvix ou uma pipeta de IAU modelo Verona® e que permite a fixação da sua extremidade em espiral na cérvix (T2). Para comparar as duas pipetas, foi considerado o grau de dificuldade para realização das inseminações, o tempo necessário para realizá-las, a presença de sangramento após a inseminação, a presença de refluxo no momento da inseminação, as taxas de retorno ao estro (TR), de prenhez (TPR) e de parto ajustada (TPA), além do número de leitões nascidos (NT). As fêmeas de ambos os grupos foram inseminadas com doses de 1 bilhão de espermatozóides, em intervalos de 24 horas. A passagem do cateter de IAU através da cérvix foi possível em 95,9% das fêmeas, sem diferença entre os tratamentos (P&gt;0,05). Em pelo menos uma das inseminações, foi observado sangue no cateter, após a realização da IAU, em 20,6% das fêmeas do T1 e 15,2% das fêmeas do T2 (P=0,14). O tempo médio necessário para realizar a inseminação foi de 2,1 minutos para o T1 e 2,3 minutos para o T2 (P=0,26). O percentual de fêmeas com refluxo de sêmen no momento da inseminação foi maior (P=0,01) no T1 (8,4%) em comparação ao T2 (2,9%). Não houve diferença (P&gt;0,05) nas variáveis TR (8,0 e 4,8%), TPR (93,4 e 96,2%) e NT (12,4 e 12,7 leitões) entre T1 e T2, respectivamente. A TPA do T1 (90,6%) apresentou tendência (P=0,07) de ser inferior à do T2 (95,1%). No T1, as fêmeas primíparas apresentaram maior TR e menor TPA em comparação às pluríparas (P&lt;0,05). Os resultados mostram que a nova pipeta pode ser utilizada sem prejuízos ao desempenho reprodutivo, em fêmeas pluríparas, mas sugerem cautela para sua utilização em fêmeas primíparas.

Influence of Sperm Cell Dose and Post‐insemination Backflow on Reproductive Performance of Intrauterine Inseminated Sows

This study was carried out to evaluate the effects of the sperm cell dose and semen backflow on the pregnancy rate and number of embryos of sows inseminated once at 0-24 h before ovulation, using an intrauterine technique. The results were analysed from a total of 211 sows assigned to three groups inseminated with doses of 0.25 x 10(9) (T1), 0.5 x 10(9) (T2) and 1.0 x 10(9) (T3) spermatozoa. Semen backflow was observed in 95% of the females (143/151) evaluated for this purpose. The percentage of semen backflow is close to two-third of the volume and the percentage of sperm is around 15% of the infused sperm dose. Intrauterine insemination can be successfully performed provided that at least 0.5 billion of sperm cell dose is infused at an interval of 0-24 h before ovulation.

Comparação entre diferentes métodos de inseminação artificial em suínos

O objetivo deste trabalho foi avaliar três métodos de inseminação artificial(IA) no suíno em relação ao tempo de infusão e perdas por refluxo da DI durante a IA e aos 120 minutos após a IA, bem como dados de operacionalidade medido pelo grau de dificuldade verificado para execução da IA e dados de desempenho reprodutivo. Foram utilizadas 604 matrizes até a parição 7 e IDE &lt; 7 dias. As fêmeas foram inseminadas em 3 tratamentos: T1= método auto IA com pipetas longas lameladas (Supertip®), sêmen acondicionado em flexitubos® e aparato de IA constituído por uma cinta abdominal e uma mala dorsal; T2= método intermediário, pipetas Supertip®, flexitubos® e sem aparato de IA; T3= método tradicional, pipetas tipo Melrose, sêmen acondicionado em bisnagas e sem aparato de IA, onde o tempo de IA ficou atrelado ao desempenho do funcionário. O tempo médio de IA foi diferente (P&lt;0,02) entre os três tratamentos (1,7±1,6; 2,2±1,8 e 3,6±1,1 minutos para T1, T2 e T3 respectivamente). Em uma parte dos animais (108 fêmeas distribuídas nos 3 tratamentos) foram coletados os refluxos até 120 minutos transcorridos das IAs por meio de uma bolsa de colostomia fixada na vulva . O volume de refluxo durante a IA foi maior (P&lt;0,02) em T1 (7,7±13,5mL) quando comparado a T3 (5,8±10,8mL). Não foram verificadas diferenças entre os tratamentos no número de espermatozóides eliminados por refluxo até 120 minutos após a IA. Independentemente do tratamento, em torno de 70% do volume e 30% do total de espermatozóides contidos na DI foram eliminados por refluxo em até duas horas após a IA. Na avaliação do grau de dificuldade, foi verificado que, no T1= 85,6%, no T2= 92,9 e no T3= 97,7% das fêmeas tiveram suas inseminações concluídas com até uma intervenção (P&lt;0,05 entre todos os tratamentos). Com relação as taxas de retornos ao estro, taxa de parto ajustada e número de leitões nascidos não foram observadas diferenças entre os tratamentos (P&gt;0,05). As taxas de retorno ao estro foram 10,3, 7,4 e 8,5 %, a taxa de parto ajustada foi de 90,8, 94,0 e 91,7% com 10,9, 11,1 e 11,1 leitões nascidos totais em T1, T2 e T3, respectivamente. O método auto IA e o método intermediário proporcionam IAs mais rápidas e podem substituir o método tradicional sem prejuízos ao desempenho reprodutivo.

Desempenho reprodutivo de fêmeas suínas inseminadas pela técnica intra-uterina ou tradicional

O desempenho reprodutivo de fêmeas suínas foi avaliado com o objetivo de comparar duas técnicas de inseminação. Foram inseminadas, em delineamento inteiramente casualizado, 608 fêmeas com ordem de parto de dois a quatro, em dois tratamentos: inseminação intra-uterina com 1,5 bilhão de espermatozóides em 60 mL e inseminação tradicional, com 3 bilhões em 90 mL. Foi possível introduzir o cateter intra-uterino em 97,4% das fêmeas e houve sangramento em 9,5%, as quais apresentaram retorno ao estro superior (p&lt;0,05). O porcentual de volume refluído até duas horas após a inseminação foi maior (p&lt;0,05) na inseminação intra-uterina do que na tradicional, enquanto o porcentual de espermatozóides refluídos foi semelhante. Não houve influência do porcentual de espermatozóides refluídos sobre a taxa de parto e tamanho da leitegada. Não houve diferença nas taxas de retorno ao estro (3,6% e 4,3%), de prenhez aos 21 dias (99,5% e 97,2%), de parto ajustada (94,9% e 94,3%) e tamanho da leitegada (11,6 e 11,8 leitões) entre os dois tratamentos, respectivamente. A inseminação intra-uterina permite a obtenção de desempenho reprodutivo semelhante ao observado na tradicional, porém com uso de menor número de espermatozóides.

Influence of hormone supplementation to extended semen on artificial insemination, uterine contractions, establishment of a sperm reservoir, and fertility in swine.

This study was performed to quantify the effect of hormone addition to semen using a low-fertility model to evaluate its effectiveness and mode of action. At 24 h after the onset of estrus, all gilts received a single low-dose AI (0.5 x 10(9) sperm/80 mL) with no hormone (control, C), estrogens (E, 11.5 microg), PGF2alpha (PG, 5 mg of Lutalyse), or oxytocin (OT, 4 IU), which were then evaluated for semen backflow (n = 48), oviductal and uterine sperm numbers (n = 28), uterine contractions (n = 12), pregnancy rate (PR, n = 120), and number of fetuses (n = 67). In Exp. 1, backflow of semen from the uterus was collected for 8 h after AI, whereas PR and fetuses were assessed at d 25 to 30 after AI. In Exp. 2, backflow was collected and reproductive tracts flushed to determine sperm numbers in the oviducts and the anterior segments of the uterus. In Exp. 3, sows were monitored for uterine contractions for 1 h before AI and for 2 h after AI. In Exp. 1, there was a treatment x time interaction for fluid loss (P < 0.001), but by 8 h after AI, there was no difference in the total volume (70 +/- 1 mL) of semen lost between hormone treatments (85%) compared to controls (90%). There was also a treatment x time interaction (P < 0.05) for number of sperm lost in the backflow (2.1 +/- 0.1 x 10(8)), but by 8 h following AI, there was no effect on total sperm lost for the hormone treatments (38%) compared to C (54%). There was a trend (P = 0.10) for increased numbers of sperm in the uteri of hormone-treated gilts (6.0 +/- 1.3 x 10(4)) compared with C gilts (2.2 +/- 1.3 x 10(4), but there was no effect of treatment on sperm numbers in the oviducts (3.2 +/- 1.3 x 10(4)). Within 0.5 h of AI, there was an increase in the frequency of contractions for PG compared with the other treatments (14.2 vs. 6.3/h, P < 0.005), however there was no effect on amplitude (54 mmHg) or duration (35 s) of contractions. The PR was not influenced by treatment and averaged 54% (P > 0.60), but total numbers of healthy fetuses were increased (P < 0.04) by PG (8.7) and tended (P = 0.06) to be increased for OT (8.4), but not for E (7.2) compared to C (5.8). Hormone addition to semen increased numbers of fetuses and this may be related to an alteration in the pattern of fluid and sperm loss after AI and a tendency for increased numbers of sperm in the anterior segment of the uterus. Therefore, in situations of lowered fertility, hormone addition could be a strategy to limit infertility in swine.

Effect of boar exposure at time of insemination on factors influencing fertility in gilts.

The effect of boar exposure during artificial insemination (AI) on semen backflow, fertilization, and embryo quality was evaluated. Gilts (approximately 170 d) were induced into estrus with PG600, and ovulation was synchronized using hCG 72 h later. Estrus detection was initiated after PG600 and continued at 12-h intervals. At estrus, gilts were allotted to receive boar exposure (BE, n = 20) or no boar exposure (NBE, n = 20) during AI. Gilts receiving NBE were identified to be in estrus prior to AI and the boar was then removed for 1 h, whereas gilts in the BE group received 15 min of exposure during AI. Insemination occurred in crates at 12 and 24 h after onset of estrus with 3 x 10(9) sperm/80 mL. Backflow was collected continuously with samples taken at time 0, (during AI), and at 0.25, 0.5, 0.75, 1, 2, 4, and 8 h after first and second AI. The effect of treatment was evaluated for time of insemination (min), backflow (mL), and sperm in backflow samples. Oviducts were flushed 2 d after first AI to evaluate the effect oftreatment on fertilization rate, accessory sperm numbers on embryos (scored 1 to 5), and embryo quality. There was no effect of first or second AI; therefore, data were pooled. Average duration of AI was 3.7 +/- 0.2 min and was not influenced by BE (P < 0.10). However, during the initial stage of AI, BE reduced the volume of semen (18.6 vs 32.4 +/- 3 mL) and the number of sperm lost (0.8 vs 1.3 +/- 0.15 x 10(9) sperm) compared to NBE (P < 0.05). There was a treatment x time effect (P < 0.05) for volume of backflow. By 45 min, the BE gilts lost more volume (9.0 vs 3.6 mL) compared to the NBE group, but sperm loss did not differ. Between 1 and 8 h after AI, neither volume nor sperm loss was influenced by treatment. By 8 h, total leakage (65 vs 63 mL) and total sperm loss (1.6 x 10(9) vs 1.8 x 10(9) sperm) were not influenced by BE (P > 0.10). However, more accessory sperm (P < 0.01) were found on embryos for the NBE (> or = 11 sperm/embryo) compared to BE embryos (< or = 10 sperm/embryo). Despite this observation, percentages of fertilized embryos (99.5 +/- 0.5 %) and number of embryos (11.5 +/- 0.1) were not different (P > 0.10). In conclusion, AI in the presence of a mature boar did not affect total semen leakage, sperm loss, fertilized embryos, or embryo quality. The importance of boar exposure during insemination was evident from less leakage during insemination, but had no effect on fertility; this suggests that the elimination of boar exposure during AI may not be deleterious to reproductive performance.

Semen backflow after insemination and its effect on fertilisation results in sows.

The aim of the present study was to investigate the volume of and number of spermatozoa in semen backflow during and after insemination, and the effect of backflow on fertilisation results assessed at day 5 of pregnancy. Multiparous sows (n = 140) were artificially inseminated with either (1, 3 or 6) x 10(9) mixed spermatozoa from three boars in a constant volume of 80 ml. Backflow of semen was measured three times: during insemination (M1); during the first half hour after insemination (M2); and from 0.5 h until about 2.5 h after insemination (M3). Transrectal ultrasonography was performed at intervals of 4 h to determine the time of ovulation. Sows were sacrificed at 120 +/- 0.4 h after ovulation to assess the results of fertilisation. Every sow had some backflow and the variation in volume, and number of spermatozoa within the backflow was high. The average semen backflow within 2.5 h after insemination was 70 +/- 3.4% of the volume and 25 +/- 1.4% of the spermatozoa of the inseminated dosage. The concentration of the backflow (% of the inseminated dosage) decreased with time after insemination from 65% at M1 to 40% and 26% at M2 and M3, respectively. The correlations between volume and number of spermatozoa were high: r = 0.97, r = 0.73 and r = 0.81 in M1, M2 and M3, respectively. More than 5% of the inseminated spermatozoa in backflow during insemination affected fertilisation negatively in those sows inseminated with 1 x 10(9) spermatozoa (P < 0.05). Backflow after insemination had no effect on fertilisation results (P > 0.05). Timing of insemination relative to ovulation and oestrus were not related to backflow during or after insemination (P > 0.05). Of the sows which had backflow, those of parity 1 tended to have the highest proportion of sows with more than 5 ml backflow (47%; n = 8 of 17) compared with sows from parity 2 and higher (24%; n = 14 of 59) (P = 0.075). It was concluded that excessive backflow of semen during insemination had a negative effect on fertilisation results when sows where inseminated with only 1 x 10(9) spermatozoa. Causes of variation in backflow between sows were not clearly identifiable.