Single Artificial Insemination Research Articles

The use of machine learning methods to predict sperm quality in Holstein bulls

The aim of this study was to develop prediction models for total sperm motility, morphological abnormalities and sperm output based on 1,551 ejaculate records of 58 Holstein bulls. The data was collected from September 2019 to November 2020 in a single artificial insemination (AI) center located in Eastern Germany. Factors considered for the prediction models include barn climate conditions, semen collector, number of false mounts, libido, semen collection frequency, breed and age (10–74 months). In this study, the prediction models Lasso, Group Lasso and Gradient Boosting were evaluated. The best model for each sperm quality parameter was chosen using cross validation. The models were estimated with five algorithms for sperm motility and sperm morphology and three algorithms for the number of total sperm per ejaculate (sperm output). For sperm motility and morphology a binary classification algorithm was applied, reaching an accuracy of over 80% for all models. For sperm output, no such classification was used and the only variable selected by all three algorithms was age. Furthermore, for sperm morphology, climate variables were frequently selected. Additionally, network diagrams from Group Lasso show the interdependencies between the major variable groups influencing sperm motility and morphology. In conclusion, the implementation of such prediction tools could help AI centers to optimize management factors and stabilize bull semen production in the future.

Does a single fixed-time insemination in weaned sows affect gestation and lactation length, and piglet performance during lactation compared with multiple insemination protocols in a commercial production setting?

This study evaluated the effect of different single fixed-time artificial insemination (FTAI) protocols on gestation length, farrowing distribution (synchrony), and piglet performance. In Study 1, 866 sows were assigned to two groups: Multiple AI (n = 484) – multiple artificial insemination (AI) at 24 h intervals during estrus; and FTAI+MultAI (n = 382) – OvuGel® 96 h post-weaning and single FTAI 22–24 h later. In Study 2, FTAI protocols were retrospectively analyzed: pLH – sows received 2.5 mg (Exp.1, n = 184) or 5 mg (Exp.2, n = 362) of porcine luteinizing hormone (pLH) at estrus onset, and single FTAI 24 h later. The FTAI+MultAI resulted in shorter gestation length (P < 0.01) and greater synchrony of farrowing on days 114–115 of gestation (P < 0.01) than Multiple AI. Longer lactation length (21.2 vs. 20.9 d; P = 0.02) and greater piglet weaning weight (5378.9 ± 73.1 vs. 5153.2 ± 74.4 g; P = 0.03) for FTAI+MultAI compared to Multiple AI were observed. In Study 2, the gestation length based on the first AI record was shorter for FTAI and resulted in greater synchrony of farrowing on days 114–115 of gestation, compared with Multiple AI (P ≤ 0.05). Gestation length did not differ between groups (P > 0.05) when measured based on most probable AI responsible for fertilization (ultrasound evaluation). In conclusion, FTAI resulted in shorter gestation length and greater farrowing synchrony compared with Multiple AI. Longer lactation length and greater piglet weaning weight were observed for FTAI compared with multiple insemination protocols.

Fertility of Holstein cows and heifers submitted to timed artificial insemination and receiving one or two doses (12 h apart) of semen.

The objective of this retrospective study was to assess the effect of receiving a single (n=50,285) or double (n=4392) artificial insemination (AI), 12 h apart, within a timed artificial insemination protocol on pregnancy per AI (P/AI) in nulliparous heifers (inseminated with either sex-sorted or conventional semen) and pluriparous Holstein cows in a commercial dairy herd. Also, this study aimed to investigate the relationship between temperature-humidity index (THI) and time of the first AI and fertility. Fertility of cows receiving two AI with normothermia (THI <68) was higher (p<.05) than cows receiving a single AI (42.9% vs. 36.4%). P/AI of cows receiving two AI with severe heat stress (THI >85) was higher (p<.05) than cows receiving a single AI (21.0% vs. 12.6%). Regardless of heat stress conditions, applying the first AI in the morning increased (p<.05) P/AI in cows with double AI than in cows whose first AI occurred in the afternoon (38.4 vs. 33.3%). With moderate heat stress, and sexed-sorted semen, P/AI to timed AI was higher (65.0 vs. 51.9%; p<.05) in heifers receiving double AI than those serviced once. It was concluded that double AI, 12 h apart, enhanced fertility at timed AI than herd mates with a single AI, particularly with heat stress at breeding.

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.

Relationship between the Length of Sperm Tail Mitochondrial Sheath and Fertility Traits in Boars Used for Artificial Insemination.

The length of sperm tail midpiece, occupied by the mitochondrial sheath (MS), has been correlated with reproductive traits of mice, fish, and birds; however, it is not known whether such a correlation exists in higher order species such as domestic pigs. As the mitochondria provide for sperm motility and generate the fertility-affecting reactive oxygen species (ROS), we hypothesized that MS length correlates with boar semen parameters and artificial insemination (AI) fertility. Sperm samples collected from 57 boars and used for single sire AI were labeled with ProteoStat Aggresome probe (AGG; Enzo Life Sciences) for MS imaging by epifluorescence microscopy and image-based flow cytometry (IBFC). The mean boar MS length was 7.26 ± 0.2 µm, ranging from 6.94 ± 0.18 µm to 7.65 ± 0.31 µm. The absolute longest MS measured was 9.19 µm and the shortest was 5.83 µm. Boars in the high tertile of MS length had significantly higher conception rate (CR; p = 0.05) and sperm parameters. Boars within the high tertile of average number piglets born per litter had significantly shorter MS and more varied MS length than boars in the low tertile (p = 0.04). MS length data correlated with conventional sperm parameters including percent viable and intact acrosomes (p = 0.03), basal:induced oxidation ratio (measure of intracellular ROS levels; p = 0.02) and Comp DNA (chromatin integrity; p = 0.06) along with many flow cytometric AGG parameters in IBFC. Sperm head AGG intensity median absolute deviation had a negative correlation with total born (r = −0.423 p = 0.004). These data reveal a complex relationship between sperm MS length and aggresome abundance to sperm parameters and boar reproductive success in AI service.

Effects of the number of sperm and site of uterine semen deposition on conception rate and the number of embryos in weaned sows receiving a single fixed-time insemination.

Reducing the number of sperm needed to produce a litter with artificial insemination (AI) allows greater use of higher genetic merit boars. Induced ovulation with single fixed-time artificial insemination (SFTAI), combined with intrauterine (IUI) or deep uterine insemination (DUI), could improve fertility with low numbers of sperm. The objectives of the study were to determine the fertility effects of sperm numbers and the site of insemination. At weaning (0 h), sows (n = 534) were assigned by parity and estrus induction method (equine chorionic gonadotropin [eCG] or Control) to receive 1,200 × 106 sperm by IUI; 600, 300, or 150 × 106 sperm by IUI or DUI; or 75 × 106 sperm by DUI. At 80 h postweaning, sows received OvuGel and 26 h later a SFTAI using pooled semen. Sows were exposed to boars once daily and ultrasound was performed to determine follicle size and time of ovulation. Following SFTAI, sows were slaughtered 27 d after AI to determine pregnancy and litter traits. Data were analyzed using different models to test for effects of estrus induction, interaction of three levels of sperm (600 to 150) with two levels for site (IUI vs. DUI), and the overall effects of AI method (eight treatments). There was no effect (P > 0.05) of estrus induction on estrus (93%) within 5 d of weaning or on follicle size (6.1 mm) at OvuGel, but wean-to-estrus interval (3.8 vs. 4.0 d) was slightly reduced (P < 0.01) as was AI-to-ovulation interval (15.9 vs. 17.0 h, P = 0.04) for eCG and Control, respectively. There was no effect (P > 0.05) of estrus induction on pregnancy rate (78.6%), number of corpora lutea (CL; 21.7), or number of viable embryos (12.2). There was no effect of number of sperm or site of insemination and no interaction (P > 0.05) on pregnancy rate (range: 80.9% to 70.5%), but AI occurring after ovulation reduced the pregnancy rate (P < 0.02). The total number of embryos (range: 16.5 to 10.3) was not affected by estrus induction, number of sperm, or site of insemination (P > 0.05), but was influenced by AI treatment (P < 0.01). Treatments with a higher number of sperm (1,200 and 600) had more embryos compared with those with a lower number of sperm (300 to 75). The numbers of embryos also increased with the number of CL (P < 0.0001). These results suggest that the lower number of sperm affects litter size more than the pregnancy status. Acceptable fertility can be achieved with low numbers of sperm when using a SFTAI and uterine deposition, but AI-to-ovulation interval and ovulation rate influence final fecundity.

Comparison of FTAI and Natural Service Breeding Programs on Beef Cow Reproductive Performance, Program Cost and Partial Budget Evaluation

The study compared a natural-service breeding (NSB) program to a single fixed-time artificial insemination (FTAI) program on beef cow reproductive efficiency, breeding costs and partial budget evaluation. Eighty Black Angus lactating beef cows (5-6 yrs of age; n = 80; BW = 599.4&amp;plusmn;78.6 kg) were randomly assigned by age, days postpartum to either FTAI (FTAI cow) or NSB (NSB cow) breeding program. The FTAI cows received a CIDR for 7 d and 100 &amp;mu;g (2 mL) i.m. injection of GnRH, following this 25 mg (5 mL) i.m. of PGF2&amp;alpha; i.m. with CIDR removed. Then a second 25 mg (5 mL) i.m. injection of GnRH approximately 66 h (d 10) after initial injection to ensure luteal regression, and artificially inseminated with semen by a trained technician. The NSB cows were exposed to bulls at a bull:cow ratio of 1:25 for a 63 d breeding season. Results indicated that a NSB program can be a lower cost ($85 vs. $123) compared to FTAI program on a per cow basis. If improvements in conception rate, calf weaning rate, and total 205 d adjusted wean weights are incorporated, a partial budget analysis reveals FTAI can increase net profit by $284 per cow.

Short-term oestrous synchronisation protocol following single fixed-time artificial insemination and natural mating as alternative to long-term protocol in dairy goats

Abstract This study investigated the hypothesis that the use of short-term synchronisation protocol following single fixed-time artificial insemination (AI) with extended cooled semen and natural mating in fertility management of dairy goats could be as good as or better than traditional long-term protocol. This was tested by designing an experiment using Toggenburg dairy goats raised under semi-intensive production system in the tropics. Twenty-eight (28) females Toggenburg dairy goats were randomly allocated to two synchronisation protocols in completely randomised design and within each synchronisation protocol the animals were further subdivided into two mating methods. Oestrus was synchronised using short (7 days) and long-term (12 days) protocols and animals mated using natural mating and AI. The onset and the duration of oestrus were monitored using two intact-aproned bucks following controlled internal drug release (CIDR) devices withdrawal. The non-return to oestrus method was used to determine conception rate. The onset and duration of oestrus, response to oestrus and conception rate were evaluated. The onset and duration of oestrus was analysed using one-way ANOVA, while response to oestrus, conception rate and kidding rate were analysed by using Chi-Square test. Generally, the two protocols realised 100 % response to oestrus. Onset and duration of oestrus in short-term protocol were 31.75 hrs and 31.70 hrs, respectively, while the corresponding values for long-term protocol were 33.33 hrs and 30.93 hrs. The two protocols did not significantly differ in onset and duration of oestrus, conception, kidding and twining rate. Similarly, the two mating methods did not differ significantly on conception, kidding and twining rates. The current study has an overall of conception rate, kidding and twinning rate of 71.42, 64.29 and 44.50 %, respectively. The short-term protocol following single fixed-time AI and natural mating therefore, can be alternative to long-term oestrous synchronisation protocol in dairy goats.

Gene co-expression network analysis reveals key potential gene modules in utero-vaginal junction associated with duration of fertility trait of breeder hens

The number of days (DN) when hens lay fertile eggs as well as the number of fertile eggs (FN) were produced after a single artificial insemination (AI), including the two duration of fertility (DF) traits. Indeed, they are the key production performance that associates with the production cost of hatching egg when its determination the interval between successive artificial inseminations. However, the relevant genes response for regulating the DF has not been uncovered yet. Therefore, we performed a weighted gene co-expression network analysis (WGCNA) to investigate the insight into co-expression gene modules on DF process in hens. The total mRNA was extracted from the utero-vaginal junction (UVJ, with the sperm storage function in hen’s oviduct which is the biological basis for DF) of 20 hens with several levels of DF traits, and performed transcriptome sequences of mRNA. As a result, three co-expression gene modules were identified to be highly correlated with DF traits. Moreover, the expression changes of top 5 hub genes in each module with DF traits were further confirmed in other 20 hens by RT-PCR. These findings highlighted the co-expression modules and their affiliated genes as playing important roles in the regulation of DF traits.

Reproductive performance of weaned sows after single fixed-time artificial insemination under a tropical climate: Influences of season and insemination technique

We evaluated the reproductive performance of sows after single fixed-time AI under a tropical climate and investigated the influences of season and insemination technique on the efficacy of single fixed-time AI. After weaning, the sows were divided into CONTROL (n = 212) and FIXED-TIME (n = 212) groups. Sows in the CONTROL group were inseminated at 12 and 36 h after the onset of oestrus, while sows in the FIXED-TIME group were administered 10 μg of GnRH at 72 h after weaning and were inseminated 32 h later. Reproductive performance parameters, including total born, born alive, mummified foetuses and stillborn piglets per litter, piglet birth weight, variation of piglet birth weight within litter, regular return-to-oestrus and farrowing rate, were compared between the two groups. Season was classified into two groups: cool (n = 170) and hot (n = 254), and insemination technique was classified into two groups: conventional AI (n = 171) and intra-uterine insemination (IUI) with a reduced number of spermatozoa (n = 253). On average, regular return-to-oestrus (3.3 vs. 5.6%, P > 0.05) and farrowing rates (92.8 vs. 88.1%, P > 0.05) did not differ between CONTROL and FIXED-TIME groups. However, the total born and born alive piglets per litter in the FIXED-TIME were lower than in the CONTROL group (12.0 vs. 12.8 piglets/litter; P = 0.030 and 11.3 vs. 12.2 piglets/litter, P = 0.007). Interestingly, the number of total born piglets in the FIXED-TIME group was lower than in the CONTROL group only in the sows inseminated in the hot season (11.7 ± 0.32 and 12.9 ± 0.31, respectively, P = 0.005). Piglet birth weight, variation of piglet birth weight within litter, number of piglets at weaning and body weight of piglets at weaning did not differ between groups, irrespective of the season (P > 0.05). The total number of piglets born per litter in the FIXED-TIME group was lower than that in the CONTROL group in sows inseminated via IUI (11.7 ± 0.32 and 12.9 ± 0.32, respectively, P = 0.013), but not in sows inseminated using conventional AI (12.7 ± 0.42 and 12.5 ± 0.41, respectively, P = 0.772). Single fixed-time AI could be successfully performed in sows under a tropical climate, with a promising reproductive performance. However, a decreased litter size at birth after single fixed-time AI was observed when insemination was performed in the hot season. Moreover, single fixed-time AI using IUI with a reduced number of spermatozoa also decreased litter size at birth.

354 The effect of OvuGel® administered to weaned sows at proestrus or estrus on reproductive performance

Abstract The use of single-fixed time insemination enhances leverage of genetically superior boars. It is prudent to elucidate the appropriate strategy for using OvuGel® by season and parity given the potential economic return. It was hypothesized that OvuGel® could be used to mitigate seasonal anestrus, in particular for parity 1 sows. The objective was to evaluate reproductive performance of weaned sows administered OvuGel® (OG; n = 1342) that expressed proestrus or estrus on d 4 post-weaning, followed by a single post-cervical artificial insemination (PCAI) 24 h later. This protocol was evaluated as an alternative to treating all weaned sows regardless of estrous behavior. The Control (CO; n = 1530) sows were inseminated via PCAI after they were identified in estrus and again 24 h later if still expressing estrus. Sows were inseminated from May through November 2017. Prior to weaning, within each replicate, sows were equally assigned to OG or CO treatment by parity, genetic line, litter size, nurse sow status and health treatment status. Farrowing rate for OG was not different than CO (86.2 ± 1.2 vs. 86.6 ± 1.2%; P &gt; 0.10, respectively). There was no effect on total born between OG and CO (13.2 ± 0.1 vs. 13.3 ± 0.1; P &gt; 0.10, respectively). However, there was a parity × treatment interaction. Parity 1 OG (86.6 ± 3.0%) sows had greater farrowing rates than CO (74.5 ± 3.0%) sows (P &lt; 0.01), whereas there were no differences (P &gt; 0.05) between treatments for the other parities. These data indicate that producers can administer OvuGel® to sows in proestrus or estrus on d 4 post-weaning, followed by a single insemination 24 h later, and achieve similar performance as sows inseminated multiple times upon detection of estrus.

Vers une maîtrise de la reproduction sans hormones chez les petits ruminants

Dans les élevages ovins et caprins, la maîtrise de la reproduction est importante pour une reproduction hors saison sexuelle, pour grouper les mises bas et pour la pratique de l’Insémination Artificielle (IA). Le traitement hormonal d’induction et de synchronisation de l’œstrus et de l’ovulation est aujourd’hui le moyen le plus efficace pour atteindre ces objectifs. Le recours à des traitements photopériodiques et/ou à l’effet mâle apparait comme une solution pour limiter l’utilisation d’hormones dans ces filières.Cet article rappelle les spécificités de la réponse ovulatoire et comportementale des femelles à « l’effet mâle », ainsi que les bases physiologiques qui contribuent à la réussite de cette pratique chez les ovins et les caprins. Le prétraitement des animaux avec des traitements photopériodiques de désaisonnement est un prérequis pour une réponse à l’effet mâle efficace, notamment chez des races très saisonnées comme les races caprines alpine et saanen. Des traitements lumineux sont actuellement disponibles en élevage pour une reproduction par effet mâle en toute saison. Toutefois, ils requièrent l’utilisation de mélatonine à certaines périodes de l’année (notamment pour une reproduction en période estivale). Cet article expose différents travaux réalisés pour développer de nouveaux traitements lumineux sans mélatonine, pouvant être appliqués en bâtiment ouvert. Des protocoles d’IA qui font appel à « l’effet mâle » sont en train d’émerger. Il s’agit pour certains de protocoles basés sur l’association de l’effet mâle avec des progestatifs et/ou des prostaglandines, et qui permettent de pratiquer une seule IA à un moment prédéterminé. Des protocoles d’IA après effet mâle seul (sans hormones) sont également disponibles, et notamment basés sur une détection des chaleurs. Chez les caprins, ils comportent 1 ou 2 moments d’IA, avec ou sans détection de chaleurs préalable. Chez les ovins, la détection des chaleurs est obligatoire pour la pratique de l’IA après un effet bélier seul. Dans les deux espèces, le développement de la détection automatisée des chaleurs facilitera le déploiement des protocoles d’IA sans utilisation d’hormones.

Reproductive performance of fixed-time artificial insemination in swine and factors for the technology success

ABSTRACT: Fixed-time artificial insemination (FTAI) is a reproductive technology that aids in obtaining an appropriate time to perform single artificial insemination (AI), thus reducing the number of inseminations per sow bred. FTAI protocols can either be based on estrus detection or day of weaning, aiming to synchronize ovulation using ovulation inducers. The protocols involving estrus detection usually employ porcine luteinizing hormone (pLH) as an inducer and, in general, satisfactory reproductive performance is observed. For protocols based on weaning day, the main hormone used is analog of gonadotropin-releasing hormone such as triptorelin and buserelin. Regardless of the protocol, the number of piglets born is usually not affected by FTAI. However, a possible compromise in the farrowing rate should be considered. The FTAI in gilts requires progestogen treatment for estrus synchronization, increasing the labor requirement and cost of protocol. Some of the benefits of FTAI are a reduced number of semen doses required, advantage of planning the breeding time and; consequently, optimizing labor involved. However, the limitations include a slight reduction in the fertility index due to the compromised farrowing rate in some cases, costs incurred by following the protocol, and difficulty in measuring all the conceptual benefits under commercial conditions. The aim of this review is to approach the reproductive performance of the current protocols of FTAI, considering the benefits and limitations of this technology in swine production.

Effect of timing of artificial insemination in relation to onset of standing estrus on pregnancy per AI in Nili-Ravi buffalo.

The aim of the present study was to determine the optimum time of artificial insemination after the beginning of standing estrus in buffalo. Nili-Ravi buffalo (n = 109) during breeding season were exposed to teaser bull at 12 hours interval to determine the standing heat (0 h). Buffalo were randomly allocated to different time groups and a single artificial insemination was performed either at 0 h (n = 30), 12 h (n = 27), 24 h (n = 28) or 36 h (n = 24). In a subset of buffalo (n = 38) ultrasonography was performed, twice daily from 0 h (onset of standing heat) to determine the time of ovulation. Pregnancy diagnosis was performed 35-40 days after AI. Results revealed that mean time of ovulation from onset of standing heat was 34.7 ± 0.96 h (range 30 to 42 h). Higher (P < 0.05) pregnancy per AI were achieved in buffalo when inseminated at 24 h (15/28; 53%) compared to 0 h (8/30; 26%) and 36 h (3/24; 13%). Pregnancy per AI, was in-between, in buffalo, inseminated at 12 h (10/27; 37%) and did not differ (P > 0.05) with those bred either at 24 h or 0 h. The odds ratio further confirmed that the occurrence of pregnancy per AI was two times higher in buffalo inseminated at 24 h as compared to those at 12 h. It is concluded that optimal pregnancy per AI can be achieved when buffalo are bred artificially 24 h after the onset of standing heat.

Postmating Endometritis and Pregnancy Rate Were Not Affected by the Addition to Frozen-Thawed Semen of Filtered Seminal Plasma When Mares Without Evidence of Endometritis Were Artificially Inseminated Once 40 Hours Post-Gonadotropin-Releasing Hormone Treatment

The main aim of this study was to evaluate the effect of the addition of seminal plasma (SP) to frozen-thawed semen on postmating endometritis (PME) and embryo recovery rate in mares when only one artificial insemination (AI) is performed. Forty hours following induction of ovulation, 15 fertile Standardbred mares were submitted to a single AI per cycle with frozen semen obtained from one of two different stallions, on two cycles, according to two different protocols: routine AI (200–280 × 106 frozen-thawed spermatozoa in 2 mL) and SP AI (200–280 × 106 of frozen-thawed spermatozoa in 2 mL to which 7.8 mL of frozen-thawed SP was added). Six and 20 hours after AI, mares were evaluated by ultrasound for the presence of uterine fluid. Six hours after AI, mares were also subjected to uterine lavage for the evaluation of the presence and number of inflammatory cells. Eight days after ovulation, pregnancy was diagnosed by embryo recovery. There was a significant effect of treatment on subjective motility, which was lower when SP was added (20%; interquartile range [IQR] 10) compared with undiluted semen (45%; IQR 10) (P < .05). There was no significant effect of stallion or treatment on PME or embryo recovery rate. In the mares and conditions of this study, the addition of SP to frozen-thawed semen had no effect on post-AI uterine inflammation and pregnancy rate.

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.

Utilization of One-Dose Postovulation Breeding With Frozen-Thawed Semen at a Commercial Artificial Insemination Center: Pregnancy Rates and Postbreeding Uterine Fluid Accumulation in Comparison to Insemination With Chilled or Fresh Semen

Insemination with frozen-thawed (FZ) semen has been associated with an increased incidence of postbreeding intrauterine fluid (IUF) accumulation and decreased pregnancy rates (PRs) per cycle compared with fresh (F) and chilled (CH) semen. This retrospective study was undertaken to determine the PR and incidence of postbreeding IUF associated with insemination of FZ semen. Records for 1,023 insemination cycles (578 mares) using F, CH, or FZ semen from 240 stallions over a 3-year period from a single artificial insemination center were reviewed. Clinical data were collated for univariable and multivariable analyses. Over all semen types, PR was 52.2%. Frozen-thawed semen achieved a similar PR to CH semen (48.6% vs. 43%, respectively), and both were lower than F semen (63%). The use of FZ or CH semen also resulted in similar PR in mares of advanced age and old maiden mares (>11 years). The use of prophylactic uterine lavage (4–8 hours after insemination) in mares inseminated with FZ semen decreased over the study, being 40%, 22%, and 8% in years 1, 2, and 3, respectively. There was no difference in FZ semen PR over this time nor was there a difference in the incidence of >2 cm IUF 1-day after insemination in FZ cycles (5.5%, 8.3%, and 5.6%, respectively), and this incidence was less than that recorded for F (16.8%) and CH (17.8%) cycles over this time. These data indicate that FZ semen may be used in a commercial setting with no difference in PR or uterine sequelae to that for CH semen.

New Artificial Insemination Technologies for Swine.

Better efficiency in swine artificial insemination (AI) is accomplished by reducing the necessary number of sperm cells and achieving high reproductive performance. Some strategies have been developed for use under field conditions, such as the site of sperm deposition (post-cervical AI), a single AI with control of oestrus and ovulation (fixed-time AI), and the better use of high genetic merit boars, to spread their genes as much as possible. To apply these technologies, it is important to understand some anatomical limits, physiological aspects and farm requirements. In this review, we point out some strategies to achieve higher efficiency on the use of sperm for AI technology application in swine species.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos).

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie (h2 = 0.07±0.03) and M (h2 = 0.07±0.01), moderately low for Dm (h2 = 0.13±0.02), of medium values for H (h2 = 0.20±0.03) and F (h2 = 0.23±0.03). High and favourable genetic correlations existed between F and Dm (rg = 0.93), between F and H (rg = 0.97) and between Dm and H (rg = 0.90). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings’ feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

Comparative Study Concerning The Artificial Insemination Techniques In Mares

The mare is a seasonal poliestric animal. The reproductive season lasts from April till September. Forobtaining valuable offspring, the artificial insemination (AI) with frozen semen needs to be encouraged, becauseonly a rigorous selection of the paternal line allows the accomplishment of this desideratum. This goal can alsobe obtained on the field with minimal costs. The main purpose of this work was to evaluate the efficiency of theartificial insemination with frozen semen in mares and to compare it to natural breeding.This study was conducted from 2012 to 2014 on 45 adult mares of different breed and age. The total numberof animals was divided in three groups: group I (n=8) was inseminated with frozen semen, group II (n=16)with refrigerated semen and group III (n=21) had natural cover. For each technique the following aspects wereevaluated: the number of ultrasound examinations per cycle, the number of AI or natural covers per pregnancyand the pregnancy rate for each mare. For the lots with AI, the dynamic of the follicular growth, the dimensions ofgranulosa prior to ovulation and the number of the semen straws per gestation were also assessed.The mares from Group I needed the most ultrasound examinations (n=11), compared to Group II (n=7) andGroup III (n=8). The pregnancy was obtained after a single AI with frozen semen, 4 with refrigerated semen and 8natural covers. The pregnancy rate was 62.5% for AI with frozen semen, 70.5% with refrigerated semen and 71.4%with natural breeding.Since similar results have been obtained by using these three reproductive biotechnologies, the use of artificialinsemination with frozen semen is the most recommended; mainly to benefit from the advantages that it offers.