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There are few existing publications that describe transvaginal ultrasound-guided Ovum Pick-Up (OPU) in sows, and the impacts of the procedure for the welfare of the animals are unknown. In this study, we evaluated the effects of OPU, performed following restraint in a claw-trimming chute, on the animal welfare and reproductive health of second parity hybrid sows. The study utilized a generalized randomized block design at a commercial sow pool. We assessed salivary cortisol levels before, during, and after the procedure to compare the physiological stress response between OPU and restraint chute procedures (control group). We found a significant increase in salivary cortisol caused by the physical restraint procedure, and that the salivary cortisol level at the end of the procedure did not differ between OPU and control groups (p = 0.51). Furthermore, we conducted a novel approach-aversion test for sows, designed to assess if a feed reward would motivate the animals to willingly participate in the OPU-procedure. The animals were trained daily to enter the chute to access a feed reward. Ten animals in each group failed to complete the training period and did not voluntarily enter the restraint chute on the experimental day. This indicates that even the short daily restraint procedure during the four-day long training period was aversive to some animals. There was no difference in aversion towards the restraint chute between OPU and control groups one day after the procedure. The reproductive performance of the animals was subsequently evaluated through oestrus synchronization and insemination of the sows after the experiment. There was no observed difference in the farrowing rate (p = 0.72) and total number of born piglets (p = 0.84) between OPU and control sows. On average, we retrieved 9.0 ± 5.9 oocytes during the OPU-sessions (N = 26). Our results show that a majority of the sows prioritize the motivation for feed over their aversion to the OPU procedure. However, the physical restraint procedure is unpleasant for the animals and elicits a temporary stress response. We suggest that transvaginal OPU may be used for the recovery of oocytes from live sows, but refinements are needed to avoid stress during the lifting procedure. Such modifications could also potentially reduce the observed inter-individual variations in oocyte recovery outcomes. • Physical restraint and OPU causes significant increase in cortisol levels. • Average oocyte retrieval during OPU was 9.0 ± 5.9. • Sows prioritized feed reward over aversion to OPU. • No difference in subsequent reproductive performance in OPU vs control groups. • Refinements are needed to reduce stress and increase efficiency of OPU in sows. [ABSTRACT FROM AUTHOR]

This study assessed the effects of dexamethasone treatment on farrowing performance and piglet traits in the first 5 days of life in multiparous sows, a high-risk group for stillbirths and prolonged farrowing. In this study, 185 multiparous sows (parity 4.25 ± 0.14) were selected on the day of farrowing and divided into three treatments: CON - control, without dexamethasone treatment; DexaPF - treatment with dexamethasone (20 mg im per female) at the time of copious colostrum secretion (pre-farrowing); and DexaFO - treatment with dexamethasone (20 mg im per female) when the first piglet was born (farrowing onset). All sows and their litters were monitored for farrowing duration, obstetric interventions, colostrum yield and intake, newborn piglet traits, and piglet performance until 5 d of age. A subsample of 106 females (∼35 per treatment) had their blood glucose concentration checked hourly shortly after the first piglet was born until the end of farrowing. Additionally, blood samples from 42 litters were collected for immunocrit evaluation. The results showed no differences regarding farrowing duration (CON = 258.02 ± 13.81 min; DexaPF = 251.29 ± 13.60 min; DexaFO = 294.92 ± 13.89 min; P = 0.06) and obstetric intervention rates among treatments (CON = 36.58 ± 6.78 %; DexaPF = 42.16 ± 6.89 %; DexaFO = 48.05 ± 7.08 %; P = 0.45). The blood glucose concentration during farrowing was higher in DexaPF (94.56 ± 1.57 mg/dL; P < 0.001) than in CON (73.50 ± 1.72 mg/dL) and DexaFO (87.94 ± 1.80 mg/dL). No differences were observed regarding total piglets born and born alive, stillborn, newborn piglet vitality, colostrum intake, immunocrit, colostrum yield, and glycemia and rectal temperature at 24 h of age (P ≥ 0.13). Regarding meconium staining, higher percentages of piglets born without meconium staining were observed in DexaFO (54.77 ± 5.21 %; P = 0.02) compared with CON (48.58 ± 5.26 %), and no difference was observed for the DexaPF group (53.23 ± 5.21 %). In addition, a higher unbroken umbilical cord rate was observed in DexaFO (92.41 ± 1.31 %; P < 0.01) than the CON or DexaPF (86.91 ± 1.97 % and 89.31 ± 1.67 %, respectively). However, the treatments did not affect piglet performance (weight gain and survival) until 5 d of age (P ≥ 0.15). In summary, dexamethasone treatment in periparturient multiparous sows did not improve farrowing performance and key production parameters, such as the piglet weight gain and survival up to 5 d of age. • Dexamethasone treatment did not affect the farrowing duration in multiparous sows. • Peripartum dexamethasone treatment had not reduced the obstetric intervention rate. • Increased glycemia was observed in dexamethasone-treated sows during parturition. • The incidence of stillborn piglets remained unaffected by dexamethasone treatments. • Piglet performance up to 5 days of age was not affected by dexamethasone treatment. [ABSTRACT FROM AUTHOR]

The current study investigated effects of dietary amino acid (AA) availability on lactational body condition loss and metabolic status, in relation to reproductive parameters after weaning up to Day 8 post-ovulation. Primiparous sows (n = 35) were allocated to one of two lactation diets containing either low crude protein (CP, 140 g/kg) with a low percentage (8%) of slow protein in total protein (LL, n = 18) or high CP (180 g/kg) with a high (16%) percentage of slow protein (HH, n = 17). The HH diet was expected to improve AA utilization by supplying more AA, in a more gradual fashion. The diets did not affect sow body condition loss during lactation, while the HH diet tended to increase litter weight gain during the week 3 of lactation (Δ = 1.3 kg, P = 0.09). On Day 14 post-farrowing, HH diet led to higher plasma urea both pre-feeding and post-feeding (Δ = 2.3 mmol/L, P < 0.01, Δ = 2.4 mmol/L, P < 0.01, respectively), whilst plasma creatinine, NEFA and IGF-1 were similar. No dietary effects on reproductive parameters were found, however several relationships were found between body condition and reproductive parameters. Sows with higher body weight on Day 1 or Day 21 post-farrowing had greater follicle size on Day 3 post-weaning (β = 0.03 mm/kg, P < 0.01, β = 0.04 mm/kg, P < 0.01, respectively). At Day 8 post-ovulation, plasma progesterone concentration was negatively related to loin muscle loss (β = −0.67 ng/ml · mm−1, P = 0.02), backfat loss (β = −2.33 ng/ml · mm−1, P = 0.02), and estimated body fat loss (β = −0.67 ng/ml · mm−1, P = 0.02). Both plasma progesterone and the number of corpora lutea were positively related to the energy balance during lactation (β = 0.03 ng/ml · ME MJ−1, P = 0.01, β = 0.01 CL/ME MJ, P = 0.02, respectively). The conceptus size at Day 8 post-ovulation was negatively related to body weight loss (β = −0.01 mm/kg, P = 0.01), estimated body fat loss (β = −0.02 mm/kg, P = 0.03) and estimated body protein loss (β = −0.06 mm/kg, P = 0.04), and was positively related to the energy balance during lactation (β = 5.2*10−4 mm/ME MJ, P = 0.01). In conclusion, body protein and fat losses during lactation reduced subsequent plasma progesterone concentration and conceptus development at Day 8 post-ovulation. • Lactational body condition loss impairs conceptus development at Day 8 post-ovulation. • A higher body condition loss relates to a lower plasma P4 at Day 8 post-ovulation. • A higher body weight on Day 1 or 21 post-farrowing relates to a larger follicle size. [ABSTRACT FROM AUTHOR]

Over the last few decades, there has been a constant increase in sow litter size, the consequences of which include parturition duration extension, an increase in the percentage of stillborn and hypoxic piglets, and increased variation in piglet birth weight, which reduces their vitality. As such, it seems clear that further increasing sow fertility will generate difficulties and costs in rearing numerous litters with low birth weights. Therefore, the current study aimed to analyze the genetic background of sow hyperprolifcacy using a genome-wide association study (GWAS). The research included 144 sows in the maternal component, divided into two equal groups. The first group (control) consisted of females giving birth to the optimal number of piglets in their third and fourth litters (14–16), while the second group (cases) included those with excessive litter size (>16). The analyzed sows were genotyped using Illumina's PorcineSNP60v2 BeadChip microarray, comprising 64,232 single nucleotide polymorphisms (SNPs). Statistical analysis using R included quality control of genotyping data and GWAS analysis based on five logistic regression models (dominant, codominant, overdominant, recessive, and log-additive) with a single SNP marker as the explanatory variable. On this basis, one SNP (SIRI0000069) was identified on chromosome seven within the EFCAB11 (EF-hand calcium binding domain 11) gene that had a statistically significant effect on sow hyperprolificacy. Additionally, ten SNPs (INRA0007631 , ALGA0011600 , ALGA0043433 , ALGA0043428 , M1GA0010535 ALGA00443338 , ALGA0087116 , MARC0056787 , ALGA0112928 , and ALGA0089047) had a relationship with the analyzed feature at a level close to significance, set at 1−5. These SNPs appear important since they are located on chromosomes on which a large number of quantitative trait loci (QTLs) and SNPs associated with reproductive characteristics, including litter size, have been identified. • Numerous piglets of hyperprolific sows generate additional costs for rearing them. • Sow hyperprolificacy decreases piglets survival rate during and after parturition. • SNP SIRI000069 have significant (p ≤ 0.05) relationship with excessive sow prolificacy. • Within this SNP sows with AA genotype are more likely to give birth to a surplus litter. • EFCAB11 gene is potentially related with litter size in sows. [ABSTRACT FROM AUTHOR]

In the modern swine industry, inflammation and pain in sows after farrowing represent a crucial animal welfare concern. Cannabis sativa , a medicinal plant, has analgesic, anti-inflammatory and antipyretic properties and is rich in fibre. The objective of this study is to examine the impacts of supplementing sows with Cannabis sativa byproducts during transition periods (7 days before and after farrowing) on various aspects including postpartum behaviour, feed intake, constipation, farrowing duration, colostrum yield and piglet performance. The experiment involved a total of 100 Landrace × Yorkshire sows. The sows were distributed according to parity numbers into two groups, i.e., control (n = 54) and treatment (n = 46). The control group was provided with a lactation diet at 3.0–3.5 kg per day for a period of 7 days before and after farrowing. The treatment groups received the same quantity of the diet but with an additional supplementation of 150 g/d of Cannabis sativa byproduct. The byproduct was analysed and contained 0.24 % (w/w) cannabidiol (CBD), resulting in a daily intake of 360 mg of CBD per sow. The conventional lactational diet had a dietary fibre content of 4.3 %, whereas the diet supplemented with Cannabis sativa byproduct had a higher dietary fibre content of 16.9 %. Video cameras were used to observe and document the behaviour of sows within the initial 24 h after farrowing. The duration in which sows engaged in activities such as sleeping, sitting, standing, feeding and nursing their piglets was quantified. Additionally, the rectal temperature of the sows was measured, and a temperature equal to or exceeding 39.5 °C was considered indicative of fever. The faecal score of the sows was assessed, and a faecal score of ≤2 was classified as constipation. On the third day postpartum, the proportion of sows with fever in the treatment group was lower than that in the control group (20.0 % and 38.9 % respectively, P = 0.051). Sows receiving supplementation with Cannabis sativa byproducts exhibited increased durations of standing and feeding compared to those in the control group (P < 0.05). Notably, overall, sows without constipation issues spent more time consuming feed than those experiencing constipation (P = 0.006). The prevalence of constipation was significantly lower in the treatment group compared to the control group (17.4 % and 81.5 %, respectively, P < 0.001). Furthermore, the postpartum sows demonstrated increased feed intake following supplementation with Cannabis sativa byproducts (P < 0.05). Sow colostrum yield, piglet colostrum intake, piglet mortality and other piglet traits did not differ between the control and treatment groups (P > 0.05). In conclusion, supplementing Cannabis sativa byproducts during the transition periods in peri-parturient sows under tropical conditions resulted in a reduction in constipation issues and improved sow activities, such as increased time spent standing and consuming feed within the first 24 h postpartum. • Cannabis sativa is a medical plant that have analgesic property. • Sow received 360 mg of CBD per day and 16.9 % dietary fiber for 14 days. • Sows supplemented with Cannabis sativa spent more time for consuming feed. • The prevalence of constipation in the treatment was lower than control groups. • Cannabis sativa byproduct supplementation boosted feed intake in postpartum sows. [ABSTRACT FROM AUTHOR]

The present study was conducted to establish if laparoscopic ovum pick-up (LOPU) could be adapted to the swine species, and if the developmental competence of LOPU-sourced oocytes from peripubertal gilts could be improved by gonadotropin stimulation, by comparing with oocytes sourced from slaughtered gilts lacking hormonal stimulation. Estrus was synchronized in 34 gilts of ∼6–8 months of age by daily oral administration of 17.6 mg altrenogest for 13 days and 10 mg dinoprost IM on the last day of altrenogest. Follicular development was stimulated in all gilts with a single injection of 1250 IU eCG given 3 days before LOPU (together with the 12th dose of altrenogest). In about half of the gilts (Group eCG-hCG), 500 IU hCG were injected IM ∼72 h after eCG injection, or ∼16–18 h prior to LOPU, to initiate oocyte maturation in vivo, while the remaining animals only received eCG (Group eCG). Most gilts underwent LOPU twice alternating the gonadotropin protocol, thereby decreasing the impact of individual variation on results. Abattoir-sourced oocytes from prepubertal gilts served as Control. Following LOPU, oocytes were in vitro matured, fertilized, and cultured to the blastocyst stage following standard procedures, while oocytes collected from Group eCG-hCG gilts were considered partly matured in vivo and were matured for ∼24 h instead of ∼44 h. Embryos reaching the blastocyst stage were fixed and stained to assess quality through cell numbers. There were no significant differences in the number of follicles aspirated and cumulus-oocyte complexes (COCs) recovered between Groups eCG-hCG and eCG (22.4 and 16.9 vs. 22.6 and 17.6, P > 0.05), as well as the recovery rate (76.6 vs. 78.1, P > 0.05). Cleavage rate was not different between Group eCG-hCG, Group eCG and Control (61.1 vs. 64.4 vs. 53.4 %, P > 0.05). However, the blastocyst rate over total oocytes (32.2 vs. 36.9 vs. 11.1 %, P < 0.05), blastocyst rate over cleaved oocytes (51.8 vs. 55.1 vs. 21.2 %, P < 0.01) and the average number of cells/blastocyst (89.6 vs. 87.5 vs. 62.2, P < 0.01) were unaffected by hCG treatment in LOPU-sourced oocytes, but both LOPU groups were significantly higher than abattoir-sourced oocytes, respectively. Our results suggest LOPU may become a powerful tool for sourcing swine oocytes with higher developmental competence than abattoir-sourced oocytes and known disease status for creating swine models for human biomedical applications, as well as for accelerated genetic gain in swine breeding programs. • LOPU oocytes from stimulated gilts yield more blastocysts than abattoir oocytes. • Blastocysts from LOPU oocytes have higher number of cells than abattoir oocytes. • Similar blastocyst rates for LOPU oocytes from eCG or eCG + hCG treated gilts. [ABSTRACT FROM AUTHOR]

Transvaginal ultrasound-guided Ovum Pick-Up (OPU) is an established technique in other species. Due to several challenges, there are few publications addressing the procedure in sows. An efficient OPU technique may allow for the collection of numerous oocytes from valuable sows for porcine in vitro embryo production, gene editing and cloning programmes, or cryopreservation. We aimed to improve transvaginal OPU and equipment for this technique in sows. In experiment 1, we conducted 13 OPU sessions on three Landrace x Large White hybrid sows under general anaesthesia, while the second experiment explored OPU in non-sedated animals (N = 6) physically restrained in a commercial claw trimming chute. The experiments resulted in 6.6 ± 5.6 (mean ± SD) and 7.7 ± 8.9 recovered cumulus-oocyte complexes per session, respectively. Post-mortem examination of the pelvic and abdominal cavities of the three sows subjected to repeated OPU sessions did not reveal major acute or chronic pathological lesions. The only sow which was inseminated after the experiment delivered 16 liveborn piglets at term. Salivary cortisol levels increased during the procedure in non-sedated and physically restrained sows but returned to baseline 1 h later (n = 5), indicating a short-term stress response. The described OPU technique and equipment have the potential to retrieve considerable numbers of oocytes by repeated procedures on valuable mature sows. Follow-up studies are needed to optimize the efficiency of the aspiration of high-quality oocytes and to describe the developmental competence of these OPU-derived oocytes. It is also essential to further investigate sow welfare during and after the procedure before recommending porcine transvaginal OPU as a sustainable and welfare-friendly procedure. • The publication contributes to limited research on OPU in sows. • Transvaginal OPU could be used for the recovery of numerous oocytes from mature sows. • Salivary cortisol samples indicate a short-term stress response. • No major acute or chronic lesions were observed on post-mortem examination. • Delivery of a normal litter after 6 repeated OPU-procedures. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that visfatin participates in the regulation of female reproduction. Due to the lack of data concerning the level of visfatin in the ovarian follicles of pigs, one of the most economically important livestock species, the aim of this study was to investigate the expression and localisation of visfatin and the follicular fluid concentration in the ovarian follicles of prepubertal and mature gilts. We also aimed to examine the in vitro effects of gonadotropins (LH, FSH), insulin, progesterone (P 4), oestradiol (E 2), prostaglandin E 2 (PGE 2) and F 2α (PGF 2α) on visfatin levels. In the present study, we have demonstrated that visfatin expression is dependent on the maturity of the animals and the stage of ovarian follicle development. Visfatin signal was detected in individual follicular compartments from primordial to antral follicles and even in atretic follicles. We have shown that the expression of visfatin in granulosa cells was higher than in theca cells. The level of visfatin is upregulated by LH, FSH, E 2, and P 4 and downregulated by insulin, while prostaglandins have modulatory effects, dependent on the dose and type of ovarian follicular cells. To summarise, our research has shown that visfatin is widely expressed in the ovarian follicles of prepubertal and mature pigs, and its expression is regulated by gonadotropins, insulin, steroids, and prostaglandins, suggesting that visfatin appears to be an important intra‐ovarian factor that could regulate porcine ovarian follicular function. • Visfatin level depends on maturity of pigs and stage of ovarian follicle development. • Visfatin signal was present from primordial to antral and in atretic follicles. • Visfatin expression was higher in granulosa cells than theca interna. • LH, FSH, E 2, and P 4 increased visfatin level while insulin decreased. • PGE 2 and PGF 2α have a modulatory effect on visfatin level depending on type of cells. [ABSTRACT FROM AUTHOR]

This study evaluated the relationship between the steroidal anti-inflammatory action of dexamethasone treatment in primiparous sows and farrowing and piglet performance in the first 5 d of life. For this purpose, 234 gilts were selected on the day of farrowing and distributed among three treatments: CON - control, without dexamethasone treatment; DexaPF - treatment with dexamethasone (20 mg im) per female at the moment of copious colostrum secretion (pre-farrowing); and DexaFO - treatment with dexamethasone (20 mg im), per female when the first piglet was born (farrowing onset). All females and their litters were evaluated regarding farrowing duration, obstetric interventions, colostrum yield and intake, newborn piglet traits, and piglet performance until 5 d of age. A subsample of 79 females (∼26 per treatment) had their blood glucose concentration evaluated hourly shortly after the first piglet was born until the end of farrowing. Additionally, blood samples from 11 litters per treatment were collected for immunocrit evaluation. As a result, faster farrowing was observed in the DexaPF treatment (188.14 min; P = 0.002) compared with CON (229.99 min) and DexaFO (221.79 min). Additionally, lower obstetric intervention rates were observed in sows treated with dexamethasone (DexaPF = 7.69%; DexaFO = 5.13%) compared with CON (19.23%; P = 0.02). The sow's blood glucose concentration during farrowing was higher in DexaPF (90.55 mg/dL) than in CON (73.15 mg/dL) and DexaFO (80.06 mg/dL) treatments (P < 0.01). Besides the effect on farrowing duration, no differences among treatments were observed regarding piglets born alive and stillbirths, newborn piglet vitality, colostrum consumption, immunocrit, and colostrum yield (P ≥ 0.17). Regarding piglet traits, higher percentages of piglets born without meconium staining and lower percentages of piglets with meconium scores 2 and 3 were observed in the groups treated with dexamethasone (DexaPF and DexaFO; P < 0.01) compared with CON. However, piglet weight gain and survival rate until 5 d of age were not affected by the treatment (P ≥ 0.61). In summary, dexamethasone treatment before farrowing onset, in primiparous sows, had the potential to reduce the farrowing duration and the necessity of obstetric intervention, but it did not affect the main productive parameters such as the occurrence of stillbirths, piglet weight gain, and survival rates until 5 d of age. • Dexamethasone treatment before farrowing onset reduced farrowing duration. • Primiparous sows treated with dexamethasone had lower obstetric intervention rate. • Dexamethasone-treated sows had a higher blood glucose level over the farrowing. • The percentage of stillbirth was not affected by dexamethasone treatments. • Dexamethasone treatment did not affect piglet performance until 5 days of age. [ABSTRACT FROM AUTHOR]

Modern hyper-prolific sows produce large litters with a high within-litter variation in birth weight and an increased number of low-birth-weight piglets per litter with higher mortality rates and lower growth rates compared to heavier littermates. This study aimed to describe fetal development in hyper-prolific sows, to characterize differences between large and small fetuses, and to determine when within-litter variation in fetal weight can be detected. Forty-seven multiparous sows were blood-sampled and slaughtered at day 28, 33, 45, 50, and 56 of gestation. Number of fetuses were counted, fetal body and organ weights were measured, and the intrauterine positioning was recorded. Length, width, and area of each placenta was measured and the fetus weight/placental weight ratio was calculated. The umbilical cords of the smallest, medium and the largest fetus of each litter were sampled for histological analysis. In total measurements were obtained for 1161 fetuses. The results revealed no difference in fetal survival between the gestational days (P > 0.05). Intrauterine positioning near the cervix significantly reduced fetal weight at day 56 (P < 0.05). Total litter weight and average fetal weight increased with gestational age and individual fetal weight was negatively affected by litter size from day 33 and onwards (P < 0.05). The coefficient of variation for within-litter variation in fetal weight was higher at day 28 compared to the other gestational days (P < 0.05). Relative brain- and heart weights decreased from day 28–56 (P < 0.001). Small fetuses had relatively heavier brains and hearts at day 45, 50 and 56 (P < 0.001). Size of placenta, fetus weight/placental weight ratio and length of umbilical cord increased with gestational age (P < 0.001). There was a positive correlation between size of placenta and weight of individual fetus (P < 0.001), the weight of the fetus was positively correlated with umbilical cord length (P < 0.001) and the umbilical cross-sectional area was correlated to fetal weight at day 56 (P < 0.01). Individual fetal weight was positively correlated to the fetus weight/placental weight ratio (P < 0.001). In conclusion, fetal growth was affected by litter size, placental weight, and -area, and umbilical cord length. Lightweight fetuses were characterized by having placentas with lower weight and area and shorter umbilical cords. Lastly, within-litter variation in fetal weight was detectable at day 28, and the coefficient of variance remained stable from day 33–56. • Fetal growth is affected by litter size, umbilical cord length, placental size and -efficiency. • Light fetuses have relatively larger brains and hearts compared to heavier littermates. • Within-litter variation in fetal weight is detectable at day 28 of gestation. • Modern hyper-prolific gestating sows may carry over 20 live fetuses from day 28–56. [ABSTRACT FROM AUTHOR]

Two experiments were performed to evaluate the use of an intravaginal device (IVD) impregnated with medroxyprogesterone acetate (MPA) to avoid early parturition and synchronize farrowing in sows. In both experiments with IVDs, the gestation length, stillbirth rate, birth weight, colostrum yield, lactational litter performance, and subsequent reproductive performance of sows were assessed. In Experiment 1 (Exp. 1; n = 91), sows were assigned to four treatments to evaluate the minimum required MPA dose: without IVD (CONT; control), 400 mg (MPA400), 600 mg (MPA600), and 800 mg (MPA800) of MPA in the IVD. The IVD was inserted on day 110 of gestation and removed on day 115. No sows farrowed during IVD treatment. Gestation length was increased in treatments with MPA (116.4 days) compared to the control (CONT; 114.9 days; P < 0.01), without effects on piglet birth weight (P = 0.98). A lower percentage of deaths around the farrow (P = 0.02) was observed in the CONT (1.8%) compared to MPA treatments (6.8%). The dose of 400 mg of MPA, validated in Exp. 1, was used in Experiment 2 (Exp. 2; n = 84) to evaluate the performance of sows and piglets in a sow farrowing synchronization protocol. Sows were treated with MPA from days 110–114 of gestation with or without 0.168 mg of cloprostenol sodium (PGF2α), for luteolysis induction, at IVD removal. Thus, four treatments were considered: CONT – without MPA or luteolysis induction (no interventions); PGF2α – luteolysis induction on day 114 of gestation without MPA; MPA114 – MPA treatment till 114 days of gestation without luteolysis induction; MPA114 + PGF2α – MPA treatment and luteolysis induction on day 114 of gestation. The gestation length in treatments with IVDs was longer (P < 0.01) than CONT without a difference for PGF2α treatment (P = 0.46). No impact of IVD use on piglet birth weight (P = 0.67) and deaths around the farrow (P = 0.50) were observed. The colostrum yield (P = 0.65), immunocrit (P = 0.72), piglet performance during lactation (P = 0.81), and weaning-to-estrus interval (P = 0.21) were similar among treatments. In conclusion, the use of IVDs impregnated with 400 mg of MPA between days 110 and 114 of gestation prevented early parturition with no implications for piglet survival at birth, colostrum yield, or litter performance. • Intravaginal device with medroxyprogesterone acetate (MPA) blocks early parturition. • The lowest tested dose of MPA to prevent early parturition was 400 mg. • MPA was effective despite the decreasing on endogenous progesterone concentration. • MPA did not impair piglet survival at birth, colostrum yield or litter performance. [ABSTRACT FROM AUTHOR]

In order to expand previous knowledge about the farrowing process of hyperprolific sows, the effect of calcium, magnesium and phosphor concentration in the blood and the importance of husbandry were examined. The study was performed in a small educational agriculture institution in Germany comprising 61 sows of a hyperprolific hybrid line (BHZP db.Viktoria). The sows were either kept in farrowing crates (n = 36) or pens (n = 25). Blood samples were taken every 30 min during the farrowing process, using a central venous catheter (Cavafix Certo®, 16G, 32 cm, B. Braun SE, Melsungen, Germany) placed in an ear vein. Samples for ionized calcium concentration (Ca ion) were analyzed directly using epoc® BGEM test cards (Alere GmbH, Cologne, Germany). Samples for total calcium (Ca tot), magnesium (Mg) and phosphor concentration (P i) were deep-frozen (minus 80 °C, Innova® U202, Eppendorf SE, Hamburg, Germany) for photometric analysis at a later date. With an average farrowing duration of 267.6 ± 108.1 min (min. 71, max. 602 min), an average of 17.2 ± 4.2 piglets were born. Eutocic farrowing duration was 193.1 ± 75.2a minutes. Dystocic farrowing duration was 324.9 ± 94.1b minutes (a:b p < 0.0001). Farrowing duration did not differ between housing conditions (277.1 ± 117.4 min in crates, 275.0 ± 99.0 min in pens, p > 0.05). Dystocic farrowings were characterized by the occurrence of (at least) one time lapse of more than 60 min without piglet expulsion. In general, 35 of 61 sows suffered from dystocic parturition and received obstetrical intervention. 20 of 36 (55.6%) crate housed sows and 15 of 25 (60%) sows in pens experienced dystocic parturition (p > 0.05). Ca tot measured at the beginning of the expulsion stage had a prognostic value for the rest of the farrowing process. Above a threshold value of 2.385 mmol/l, eutocic parturition could be expected, while sows with a lower Ca tot value generally suffered from dystocic farrowings. Also, sows with eutocia had significantly higher Ca tot values during parturition than sows with dystocia (p = 0.001). The beginning of the lactation period was characterized by a rise in Ca ion (1.17 ± 0.04 to 1.21 ± 0.06 mmol/l; p < 0.0001). Mg was significantly higher before than during farrowing (p = 0.0003). During parturition, Mg decreased gradually from 0.86 ± 0.1 to 0.84 ± 0.1 mmol/l. Afterwards, Mg values showed an 18.45% increase. Sows without farrowing complications showed significantly higher Mg than those suffering from dystocia (p = 0.024). The same significant trend was observed for P i (p = 0.002). The deficiencies in Ca tot/ion , Mg and P i led to insufficient contractions and thus to farrowing problems. Parturition in the pen showed a general positive effect on the well-being of the sows and a stabilizing influence on the metabolic conditions compared to parturition in the crate. Sows in pens had higher Ca tot (p = 0.055) and Mg (p = 0.0004). In conclusion, the results provide clear evidence that a large proportion of hyperprolific sows suffer from previously unknown deficiencies electrolyte homeostasis around and during parturition, which is reflected by the large number of dystocic farrowings and the deficiencies in electrolyte concentrations during dystocia. • The total calcium concentration at the beginning of the expulsion stage had a prognostic value for the farrowing process. • Magnesium concentrations of sows with eutocia were significantly higher than the values measured in dystocic farrowings. • Already one day before farrowing the phosphor values were significantly higher in eutocic compared to dystocic sows. • Housing in pens showed a stabilizing influence on the metabolic situation of sows before, during and after parturition. • The results provide evidence that farrowing problems can partially be compensated in the pen. [ABSTRACT FROM AUTHOR]

The present study was performed to evaluate the reproductive performance of gilts inseminated using fixed-time artificial insemination (FTAI) protocol. A total of 408 Landrace × Yorkshire crossbred gilts were included in the experiment. Gilts at 8 months of age were randomly allocated into three groups: control AI (n = 192), treatment 1–TAI (n = 117) and treatment 2–FTAI (n = 99). Gilts in the control AI group were inseminated 2–3 times during standing oestrus at 0, 12 and 24 h after the onset of oestrus. Gilts in the treatment 1–TAI group were orally administered 20 mg per day of altrenogest for 18 days and then inseminated 2–3 times during standing oestrus by conventional AI. Gilts in the treatment 2–FTAI group were synchronized like gilts in treatment 1–TAI group but then GnRH (10 μg of buserelin) was administered 120 h after the end of altrenogest treatment and fixed time artificial inseminated twice at 24 and 32 h after GnRH irrespective of the presence of oestrus or not. Conception rate of gilts in treatment 2–FTAI (87.9%) was similar to the treatment 1–TAI (94.9%) and control AI (83.3%) (P > 0.05). Conception rate in treatment 1–TAI (94.9%) was higher compared to control AI group (83.3%, P = 0.040). Farrowing rate of gilts in treatment 2–FTAI (83.8%) was similar to treatment 1–TAI (89.7%) and control AI (76.0%) (P > 0.05). Farrowing rate of treatment 1–TAI (89.7%) was higher than control AI gilts (76.0%, P = 0.033). In treatment 2–FTAI, the conception and farrowing rate of the nine gilts that were inseminated even if they were not detected in oestrus (all during warm season) was 44.4% and 44.4%, respectively. Regular return to oestrus was similar between groups (9.4%, 0.9% and 4.1% for control AI, treatment 1–TAI and treatment 2–FTAI, respectively, P > 0.05). The total number of piglets born per litter in treatment 1–TAI group was higher than control AI (13.1 ± 0.2 versus 11.6 ± 0.2, respectively, P < 0.001) and treatment 2–FTAI groups (12.2 ± 0.3, P = 0.019). The number of piglets born alive was higher in treatment 1–TAI (12.1 ± 0.3) compared to treatment 2–FTAI (11.3 ± 0.2) and control AI group (11.2 ± 0.3). The percentage of stillbirth and mummified foetus were not different between groups (P > 0.05). The present study indicated that fixed-time AI in gilts can be successfully performed by administration of altrenogest for 18 days, GnRH at 120 h after altrenogest withdrawal and then double fixed-time AI at 24 and 32 h after the administration of GnRH. Fertility metrics such as conception rate, farrowing rate and litter performances using this method were similar to gilts inseminated at oestrus with conventional AI. • Under field conditions, 16.3% of mated gilts returned-to-oestrus. • GnRH administration can induce ovulation in gilts. • Conception rate of gilts after fixed-time AI was 87.9%. • Conception of the gilts inseminated even if they were not detected in oestrus was 44.4%. • Litter size of gilts after fixed-time AI was 12.2 piglets per litter. [ABSTRACT FROM AUTHOR]

An inadequate uterine involution can lead to postpartal disorders in sows and thereby negatively affects the reproductive cycle and performance of the animals. Therefore, the aim of the study was to evaluate the influence of the farrowing process and different sow and piglet traits on the uterine involution in a free farrowing system. In total three data sets of 48 crossbred sows (Large White x Landrace) from the peripartal period were synthesised and analysed. The uterine diameter of three uterine horns per sow was measured daily during the first two weeks postpartum using ultrasonography and then the uterine regression was calculated. Furthermore, the following sow and piglet traits before and during parturition were assessed: parity, body condition score, backfat thickness, gestation length, number of live born piglets, number of stillborn piglets, farrowing duration, duration of placenta expulsion, litter weight, placenta weight, number of placenta parts, faecal score, and birth induction. In addition, the following parameters were recorded five days after farrowing: body temperature, severity and amount of vaginal discharge, pathological colour of vaginal discharge, and lack of appetite. Spearman's correlation test was used to examine the association between the parameters within the group and uterine regression. In addition, a linear multiple regression was used to model the relationship between the uterine involution and explanatory variables from the peripartal period. The mean diameter of the uterus decreased from 32.5 mm on day 2 post-partum to 11.4 mm on day 12 post-partum , which is a relative regression of 66%. In the linear multiple regression model, a significant influence of the body condition score (p = 0.046) and the presence of high body temperature (p = 0.022) on uterine involution was detected. When the BCS increases by one unit (from BCS 3 to 4), the relative regression of the uterine involution decreases by approximately 8% and when fever is present, uterine involution is almost 6% slower. Furthermore, a significant correlation between the gestation length and the uterine involution (r = 0.31; p = 0.035) was identified. However, no correlation between the farrowing process and piglets' traits on the uterine involution was detected. This study showed that the body condition score, the gestation length and fever in the first five days after farrowing had significant effects on uterine involution in sows in a free farrowing system. Therefore, these parameters should be routinely monitored in the farrowing management to assess reproductive health post-partum and warrant early intervention. • First study that evaluated the influence of sow and piglet traits on uterine involution in a free farrowing system. • The uterine involution positively correlated with gestation length of the sows. • Increased body temperature and body condition score delay uterine involution. • No correlation between the farrowing process and piglets' traits on the uterine involution was detected. [ABSTRACT FROM AUTHOR]

The aim of the present study was to develop a protocol to reduce the variation in gestation length and synchronise the onset of parturition in sows by using altrenogest in combination with double administrations of prostaglandin F2alpha (PGF2α). In total, 188 Landrace x Yorkshire crossbred sows with parity numbers 3.1 ± 1.6 were included in the experiment. The sows were classified into two groups: CONTROL (n = 94) and TREATMENT (n = 94). CONTROL sows were allowed to farrow naturally, and TREATMENT sows were orally administered 20 mg/day of altrenogest starting when they entered the farrowing house (107.0 ± 2.0 days) until 113 (TREAT–113, n = 18), 114 (TREAT–114, n = 29) and 115 (TREAT–115, n = 47) days of gestation. The altrenogest-treated sows were administered PGF2α twice 6 h apart at 24 h after the withdrawal of altrenogest. The litters were randomly selected (25 and 26 litters from CONTROL and TREATMENT groups, respectively) to determine individual body weight at birth and at 24 h after birth. Gestation length of sows that farrowed naturally averaged 115.1 days (range 111–118), whereas gestation length of altrenogest-treated sows averaged 115.1–116.3 days (range 114–118). The colostrum yield of sows averaged 4.25 ± 1.19 kg and was not affected by the treatment (P > 0.05). Colostrum IgG in the CONTROL group was higher than in the TREAT–114 and TREAT–115 groups (P < 0.05) but did not differ significantly compared to the TREAT–113 group. The proportion of sows that farrowed during working hours (0700–1700 h) in the TREAT–113 group (72.3%) tended to be higher than in the CONTROL (46.4%, P = 0.053). The interval from the last altrenogest treatment until farrowing in the TREAT–113 group was longer than in the TREAT–114 and TREAT–115 groups (62.8, 40.7 and 34.6 h, respectively, P < 0.05). Similarly, the intervals from the first PGF2α administration to the onset of parturition in the TREAT–113 group (38.8 ± 3.8 h) was longer than TREAT–114 (21.9 ± 3.5 h, P = 0.002) and TREAT–115 (25.5 ± 3.7 h, P = 0.016) groups. However, the incidence of stillbirths in the TREAT–113, TREAT–114 and TREAT–115 groups was higher than in the CONTROL (16.4, 17.2, 11.8 and 5.8%, respectively, P < 0.05). In conclusion, altrenogest supplementation in combination with double administrations of PGF2α can reduce the variation in gestation length and synchronise the onset of parturition in sows. However, its side effects on the incidence of stillbirths should be considered. • Neonatal mortality in hyperprolific sow is due to unpredictable parturition time • Oral supplementation of altrenogest can prevent unscheduled early farrowing • Sows treated with altrenogest farrowed during working hours more than control • Incidence of stillbirths in the altrenogest-treated sows was higher than control • Colostrum IgG in sows treated with altrenogest was lower than control [ABSTRACT FROM AUTHOR]

High-quality follicles result in larger corpora lutea (CL), producing more progesterone, and having a fundamental role in pregnancy maintenance. For some sows, follicular growth takes place during lactation, and follicle selection occurs under a catabolic environment. As altrenogest inhibits follicular development, this study aimed to evaluate follicular growth, CL size, estrus expression, and subsequent reproductive performance of sows treated with altrenogest during the last seven days of a three-week lactation. A total of 81 primiparous and 319 multiparous sows were allocated to two treatments: CONT (control group) and ALT (20 mg of altrenogest/day during the last seven days of lactation). Subsamples of 20 primiparous sows and 97 multiparous were randomly selected to evaluate follicular growth and 26 multiparous sows for serum progesterone analysis at day 21 of gestation. On day 21 of pregnancy, CL measurement was performed by ultrasound. Once in estrus, sows were post-cervically inseminated with pooled semen doses with 1.5 × 109 sperm cells at estrus onset and every 24 h during the standing reflex period. Sows not showing estrus until 10 days after weaning were considered in anestrus. The variables weaning-to-estrus interval, CL size, litter size in the subsequent cycle, and piglet birth weight were evaluated using the GLIMMIX procedure and compared using the Tukey–Kramer test. Anestrus, pregnancy, farrowing, and adjusted farrowing rate were evaluated as binary responses using logistic regression. Follicular size was analyzed as a repeated measure during treatment and after weaning. Treatment was considered as a fixed effect. During the treatment period, follicular size was smaller in ALT sows than CONT sows (3.29 vs. 3.52 mm; P < 0.001). However, after treatment, ALT sows showed a larger follicular size than CONT sows (5.30 vs. 5.03 mm; P ≤ 0.01). There were less ALT sows showing estrus than CONT sows on days three (1.03 vs. 4.57%) and four (55.38 vs. 68.02%) after weaning (P ≤ 0.05), respectively. At 21 days after insemination, ALT sows showed larger CL size and lower CL size variation (P < 0.01) than CONT sows. Anestrus rate, pregnancy rate, farrowing rate, adjusted farrowing rate, litter size in the subsequent cycle, piglet birth weight, litter birth weight, and birth weight variation did not differ between treatments (P ≥ 0.14). In conclusion, altrenogest treatment during the last week of lactation concentrated estrus expression on day five after weaning, larger follicle and CL sizes; however, with no improvement in reproductive performance. • Altrenogest in late lactation prevented follicle growth. • During the four days before ovulation, ALT sows had larger follicles. • The ALT group had less sows with a short weaning-to-estrus interval. • Altrenogest during the last week of lactation did not improve piglet birth weight. • Sows with larger follicles on weaning showed a short weaning-to-estrus interval. [ABSTRACT FROM AUTHOR]

Control of the farrowing process is crucial to reduce the risk of post-parturient disorders in sows and newborn piglet mortality. Carbetocin is a long-acting oxytocin-like compound that has been introduced to domestic animal obstetrics. The aims of the present study were to evaluate the effects of carbetocin administration during the mid-period of parturition on farrowing duration as well as colostrum and milk production and its side effects on neonatal piglet characteristics in hyperprolific sows. The study included 89 Landrace x Yorkshire crossbred sows and 1534 piglets. Sows were randomly distributed into two groups: CONTROL (n = 46), where sows were allowed to farrow naturally, and TREATMENT (n = 43), where sows were administered 0.5 μg/kg carbetocin intramuscularly after the birth of the 7th piglet. In each litter, the piglets were classified into two groups according to birth order: 1–7 and ≥8. The colostrum yield of sows and the colostrum intake of each individual piglet were calculated. Litter weight gain of the piglets from 3 to 5 days of lactation was used to estimate milk yield. Farrowing duration tended to be reduced from 338.4 ± 35.2 min in the CONTROL group to 255.3 ± 36.4 min in the TREATMENT group (P = 0.105). However, the colostrum yield in the TREATMENT group was lower than that in the CONTROL group (3828 ± 149 and 3041 ± 158 g, respectively, P < 0.001). Nevertheless, milk yield during 3–5 days of lactation in the TREATMENT group did not differ significantly compared to that in the CONTROL group (7.53 ± 0.01 and 7.54 ± 0.01 kg/day, respectively, P = 0.643). The incidence of stillbirths in the TREATMENT group was not significantly different from that in the CONTROL group (8.3 and 7.4%, respectively, P = 0.944). However, the incidence of piglets born with umbilical cord rupture in the TREATMENT group with birth order ≥8 was higher than that in the CONTROL group in the same birth order (16.6 and 5.7%, P < 0.001). Across groups, colostrum intake of piglets born with birth order ≥8 was lower than that of piglets born in the birth orders 1–7 (187.4 ± 8.7 and 241.5 ± 9.0 g, P < 0.001). Interestingly, the colostrum intake of piglets with birth orders 1–7 in the TREATMENT group was also lower than that of piglets with the same birth order in the CONTROL group (214.9 ± 12.9 and 268.1 ± 12.5 g, respectively, P = 0.003). Colostrum intake was lowest in the piglets with birth order ≥8 in the TREATMENT group (159.6 ± 12.3, P < 0.001). Carbetocin administration after the birth of the 7th piglet reduced the birth interval of piglets but increased the incidence of piglets born with umbilical rupture and reduced colostrum intake. Therefore, colostrum supplementation and care of the newborn piglets immediately after birth are strongly recommended after carbetocin administration. • Carbetocin administration during the mid-period of parturition reduced farrowing duration from 338.4 to 255.3 min. • Colostrum yield in the carbetocin treated sows was lower than naturally farrowing sows. • Milk yield during 3 to 5 days of lactation in the carbetocin treated sows did not differ compared to control sows. • The incidence of stillbirths in the carbetocin treated sows was not different from naturally farrowing sows. • Colostrum intake of piglets in the carbetocin treated sows was lower than that of piglets in the control sows. [ABSTRACT FROM AUTHOR]

The last phase of parturition is the detachment and expulsion of the placentas and should not exceed a duration of 4 h after the birth of the last piglet. At present, only a small amount of information is available about factors influencing the expulsion of the placenta, especially in sows accommodated in free farrowing systems. This study aimed at investigating the influence of sow traits on placenta expulsion in a free farrowing system in Switzerland. In this study, 48 crossbred sows were included and the following traits of the sows were investigated: Backfat thickness, birth induction with at least 116 days of gestation with prostaglandin F2α, placenta parts and weight, placental efficiency (quotient of litter weight and placental weight) and expulsion of the first placenta part in relation to the last piglet. In addition, the farrowing process and litter parameters were recorded. The piglet expulsion duration (260.3 ± 199.5 min) and placenta expulsion duration (388.7 ± 300.2 min) were positively correlated (p = 0.001). Sows that expelled the first placenta part simultaneously with the last piglet or even before the last piglet was born showed a significantly prolonged piglet expulsion duration in comparison to sows that expelled the first placenta part after the last piglet was born (305 ± 216 min vs. 139.0 ± 34.9 min; p < 0.01). Sows with 2–4 placenta parts had a significantly shorter farrowing (292.91 ± 117.92 min) and placenta expulsion duration (160.73 ± 104.00 min) than sows with 5–7 placenta parts (634.63 ± 330.79 min farrowing duration; 460.77 ± 337.32 min placenta expulsion duration) and sows with 8–10 placenta parts (599.00 ± 138.20 min farrowing duration; 438.43 ± 117.98 min placenta expulsion duration) (p < 0.01). Sows with placental efficiency <5 were characterized by a significantly higher number of liveborn piglets compared to sows with a placental efficiency ≥5 (17.1 ± 2.7 piglets vs. 13.6 ± 2.8 piglets; p = 0.002). This is the first study that evaluated the placental characteristics in a free farrowing system and compared it with specific sow traits. Especially, the expulsion of the first placenta and the number of placenta parts could be a reliable parameter to detect sows with obstetric problems and therefore enable improvement sow and piglet health. • First study that evaluated placenta traits in free farrowing sows. • Expulsion of the first placenta reliable parameter to detect obstetric problems. • Placenta expulsion duration physiologically increased in free farrowing systems. • Higher backfat thickness and birth induction lead to prolonged farrowing duration. [ABSTRACT FROM AUTHOR]

A duration of parturition beyond 300 min negatively impacts the health of the sow and the survival of piglets during parturition. Hence, oxytocin is widely used to speed up the parturition. However, oxytocin's negative side effects raise the need of finding alternative treatments such as those already implemented in human medicine. The aim of this study was to evaluate the efficacy of Prostaglandin E2 (PGE2) applied intravaginally (PGE2-V) (1.0 mg) or intramuscularly (PGE2-M) (2.5 mg) to improve the parturition process after expulsion of the fourth piglet compared to a placebo (P–V), which was sterile intravaginal gel or intramuscular oxytocin application (OXY-M) (20 iu) in free farrowing systems.In total, 201 eutocic sows were examined after stratification by parity and random allocation into groups: 54 (P–V), 48 (OXY-M), 50 (PGE2-V), 49 (PGE2-M). Farrowing duration (time between first piglet and last piglet), piglet interval and placenta expulsion duration (time between first and last placenta) were recorded, and each piglet was scored for meconium staining and vitality. Furthermore, stillborn piglets were categorized into ante-partum and intra-partum deaths.Under the present conditions, neither administration of PGE2 nor oxytocin revealed a significant effect on the farrowing process or the vitality of the piglets when compared to untreated sows. Nonetheless, significant differences could be detected between PGE-2 and oxytocin treatments. The duration of farrowing was significantly shorter in oxytocin-treated sows (156 min) compared to sows treated intramuscularly with PGE2 (238 min). Furthermore, the placenta expulsion duration in the OXY-M group (130 min) significantly differed from PGE2-V (198 min) and PGE2-M group (218 min). Although these accelerations of parturition might be considered as a beneficial effect, routine treatment with uterotonic agents after birth of the fourth piglet in free farrowing eutocic sows cannot be recommended, because an overall benefit when compared to untreated sows was not approved. • First study that evaluated efficacy of PGE2 on the birth process in eutocic sows. • Routine treatment with uterotonic agents in free farrowing system not recommended. • Application of an intravaginal uterotonic agent in free farrowing systems is feasible. [ABSTRACT FROM AUTHOR]

Recent studies have reported that vitamin D 3 (VD) regulates ovarian function under physiological and pathological conditions. Due to a lack of information concerning the expression of VD-related molecules (receptors: VDR, PDIA3, and metabolic enzymes: CYP27B1, CYP24A1) in the porcine ovary, this research aimed to determine the mRNA expression, protein abundance and localization of VDR, PDIA3, CYP27B1 and CYP24A1 in small (SFs), medium (MFs) and large (LFs) antral follicles of sexually mature gilts. We also examined the concentration of active VD in the follicular fluid of SFs, MFs and LFs, and the effect of 1,25(OH) 2 D 3 on their steroidogenic activity in vitro. In the present study, we have demonstrated for the first time the patterns of VDR, PDIA3, CYP27B1 and CYP24A1 immunolocalization in porcine antral follicles of different sizes. Furthermore, the expression of VD-related molecules was influenced by follicle developmental stage. VDR and PDIA3 mRNA expression and protein abundance decreased with the follicle size: they were the greatest in SFs, and the lowest in LFs. CYP27B1 mRNA expression was the highest in MFs and differed from that in SFs, whereas protein abundance was greater in MFs and SFs than in LFs. The expression of mRNA for CYP24A1 was higher in MFs than in SFs and LFs, while protein abundance did not differ between follicle classes. We have also described changes in the concentration of 1,25(OH) 2 D 3 in the follicular fluid of antral follicles with its highest level in MFs. These findings show that the porcine antral follicle is a target tissue for direct VD action and is a local site of VD metabolism. Furthermore, we found that 1,25(OH) 2 D 3 increased the secretion of progesterone and estradiol-17β by SFs and MFs in vitro , implying a crucial role of VD in the regulation of ovarian steroidogenesis in mature gilts. Therefore, VD appears to be an important intraovarian factor that could regulate follicular development and function in pigs. • VDR, PDIA3, CYP27B1 and CYP24A1 are present in the porcine antral follicles. • Expression of VDR, PDIA3, CYP27B1 and CYP24A1 depends on the follicle size. • 1,25(OH) 2 D 3 is present in follicular fluid of porcine antral follicles. • 1,25(OH) 2 D 3 increases secretion of P 4 and E 2 by small and medium antral follicles. [ABSTRACT FROM AUTHOR]

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. • Older and heavier gilts had a higher percentage of IUAI cannula insertion. • Time to perform insemination was not optimized with IUAI in gilts. • Semen doses with 1.5 or 2.5 billion sperm cells did not affect performance of gilts. • Reproductive performance was not affected by cervical or intrauterine insemination. [ABSTRACT FROM AUTHOR]

This study evaluated reproductive indicators of gilts treated with altrenogest or an intravaginal device (IVD) containing medroxyprogesterone acetate (MPA) for estrous cycle synchronization, starting the protocol on different days of the estrous cycle or replacing the IVD in the middle of treatment. In Experiment 1, 126 gilts were assigned, according to the day of treatment onset (Day 5 or 10 of the estrous cycle), to the following treatments: Control-5 (no hormone); Control-10 (no hormone); IVD-5 (IVD with MPA); IVD-10 (IVD with MPA); ALT-5 (altrenogest); or ALT-10 (altrenogest). The first day of the previous estrus was considered as Day 0 of the estrous cycle, and progestogen groups were treated for 14 d. In Experiment 2, 63 gilts were assigned to Control, ALT, or IVD groups. Progestogen treatment started on Day 10 of the estrous cycle, and the IVD was replaced after 7 d of treatment. In both experiments, no gilts expressed estrus during progestogen administration. In Experiment 1, the interval hormonal withdrawal-to-estrus (IHE) tended to be shorter when treatment started on Day 10 than on Day 5 (3.6 vs. 4.1 d, respectively; P = 0.09). The percentage of gilts expressing estrus after hormone withdrawal was lower for IVD-gilts (76.3%) compared to ALT (100%) and Control-gilts (92.9%; P ≤ 0.07). The percentage of persistent follicles (PFOL) was greater in IVD-10 (60.0%) and ALT-10 (33.3%) than CONT-10 (0.0%; P ≤ 0.06). The adjusted farrowing rate (AFR) was lower in IVD (65.5%) and ALT (80.5%) compared with CONT (97.4%; P ≤ 0.08). In Experiment 2, the IHE was longer for ALT than IVD (4.9 vs. 3.9 d, respectively; P < 0.01). No difference among groups was observed in the percentage of gilts expressing estrus (overall 86.4%), but the occurrence of PFOL was higher in IVD (61.5%) compared to ALT (5.3%), and Control groups (10.5%; P < 0.01). The AFR was lower in IVD (53.8%) than in ALT (88.2%) and Control (94.7%; P ≤ 0.05). The total number of piglets born was not affected by hormonal treatments in either experiment. Estrous expression was delayed in gilts treated with altrenogest or IVD–MPA. However, the reproductive performance of IVD-gilts was compromised, which was not circumvented by IVD replacement in the middle of treatment. Therefore, further studies are necessary to understand MPA pharmacodynamics and investigate alternative devices for a steady release of progestogens in gilts. • Altrenogest or IVD-medroxyprogesterone controlled the estrous expression. • Resumption of follicle growth begins earlier in IVD-gilts treated on Day 10. • The replacement of the IVD still allows follicular growth close to end of treatment. • The estrous expression is reduced with IVD, regardless of the day of treatment onset. • The farrowing rate is compromised with IVD mainly when treatment starts on Day 10. [ABSTRACT FROM AUTHOR]

TGF-β1 is a ligand of the TGF-β superfamily and an important cytokine that regulates ovarian functions including follicular development, steroid production, ovulation, luteinization, and female fertility. However, little is known about the regulation of TGF-β1 expression in ovary. Here, we identified that TGF-β1 is a functional target of miR-130a in porcine ovarian granulosa cells (GCs). The 3′-UTR sequence of TGF-β1 gene (1137 bp in length) in Large White (LW) pig was isolated, and multiple RNA regulatory elements (RREs), including several binding motifs of different miRNAs, were identified in this region. Luciferase activity assay showed that miR-130a dramatically suppresses the 3′-UTR luciferase activity of TGF-β1 gene, and further inhibits the expression of TGF-β1 in porcine GCs. FACS revealed that miR-130a acts as a pro-apoptotic factor and promotes GC apoptosis by inhibiting TGF-β1. Two novel linked mutations (−573G > A and −540T > C) were identified in the promoter region of ssc-miR-130a , but their polymorphisms are not associated with sow reproductive traits. Importantly, combined genotype analysis with a known mutation (c.1583 A > G) in the 3′-UTR of porcine TGF-β1 gene showed a significant association with reproductive performance in LW sow population. Overall, our findings defined a novel regulatory axis, miR-130a/TGF-β1 axis, which is involved in regulating sow fertility. • TGF-β1 is a direct target of miR-130a. • miR-130a promotes apoptosis of porcine GCs by inhibiting TGF-β1. • Two novel linked mutations were identified in the promoter of porcine miR-130a. • miR-130a/TGF-β1 axis is involved in regulating sow fertility. [ABSTRACT FROM AUTHOR]

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. • Reproductive performance of sows after single fixed-time AI under a tropical climate were evaluated. • Sows were administered GnRH at 72 h after weaning and were inseminated 32 h later. • Farrowing rates did not differ between control and single fixed-time AI. • Litter size in the FIXED-TIME group was reduced in the sows inseminated in the hot season. • Single fixed-time AI using IUI with a reduced number of spermatozoa also decreased litter size. [ABSTRACT FROM AUTHOR]

l -arginine supplementation of sows has led to improvement of reproductive performance, but the mechanisms responsible for the positive effects of arginine during gestation on conceptuses survival and development are still poorly understood. Thus, we aimed to evaluate effects of 1.0% l -arginine supplementation (ARG) on phenotypic traits of commercial gilts, embryos and fetuses, concentration of gilts' blood metabolites, expression of developmental and cellular apoptosis genes in conceptuses of 25 and 35 days. At 25 days, IGF1 gene was more expressed in embryos from ARG than in embryos from control gilts (CON) (P = 0.05). At this same gestational age, ARG embryos tended to be heavier compared to CON (P = 0.07) and ARG gilts showed a trend to have a greater arginine concentration in blood plasma (P = 0.06). However, at 35 days of gestation, arginine concentration in blood plasma of ARG gilts tended to be lower compared to CON (P = 0.06) and ARG fetuses showed smaller cephalic-caudal length (P = 0.05). These results indicate that duration of supplementation is determinant for arginine effects, not only on the females performance but also on the conceptuses, since supplementation upregulated IGF1 expression at 25 days, in addition to the reduction of cephalic-caudal length of 35-day fetuses. • We compared phenotypic traits among pregnant gilts supplement with 1.0% l -arginine and not supplemented gilts. • We analyzed phenotypic traits in embryos/fetuses from gilts supplemented or not supplemented with l -arginine. • We sought to understand the influence of L-arginine supplementation in the expression of developmental genes and apoptotic genes. • We analyzed the effect of L-arginine supplementation in metabolites like amino acids, hormones and urea in gilts blood concentration. • We discussed some important events and modifications that occurs during the embryos and fetuses development, treated or not treated with L-arginine. [ABSTRACT FROM AUTHOR]

Litter size is one of the most important economic traits for pig production as it is directly related to the production efficiency. As an important litter size trait in pigs, the number of piglets born alive at birth (NBA) receives widespread interests in the pig industry. However, traits of piglets born dead, including the number of stillborn piglets (NS) and the piglets mummified at birth (NM) should be noted to explain the loss of reproduction. Herein, in the present study, a total of 803 producing sows were sampled and 2807 farrowing records for NBA, NM, and NS traits were collected in a Duroc swine population. Subsequently, a genome-wide association study (GWAS) was performed for NBA, NS and NM in parity groups 1 to 5. In total, 10 putative regions were found associated with these traits. After stepwise conditional analyses around the putative regions, eight independent signals were ultimately identified for NBA, NS, and NM, and there were seven promising candidate genes related to these traits, including ARID1A, RXRG, NFATC4, ABTB2, GRAMD1B, NDRG1, and APC. Our findings contribute to the understanding of the significant genetic causes of piglets born alive and dead, and could have a positive effect on pig production efficiency and economic profits. • This study explored underlying genetic architecture of piglets born alive and dead in a Duroc pig population. • ARID1A, RXRG, NFATC4, ABTB2, GRAMD1B, NDRG1, and APC were found to be related to traits of piglets born alive and dead. • The genomic structures of Duroc piglets born alive and dead were different among parities. [ABSTRACT FROM AUTHOR]

We aimed to characterize the expression of angiogenesis-related genes in corpus luteum (CL) and cumulus cells (CC) during estrous cycle in gilts of different genetic groups, as well as to study the relation between gene expression and phenotypic data. Forty five gilts were used as follows: L1, Commercial Line 1 (Large White x Landrace x Duroc) (n = 15); L2, Commercial Line 2 (Large White x Landrace x Pietrain) (n = 15); and Piau, Piau breed gilts (n = 15). Estrus observation started from 120 days of age. After the second observed estrus females were slaughtered (n = 3) on days 3, 5, 10, 14 and 18 of estrous cycle (first day of estrous cycle as Day 0). CL sampling was performed on days 3, 5, 10 and 14 and collection of CC and follicular fluid on days 14 and 18. Follicular fluid was used for analysis of estradiol levels and CC and CL samples for analysis of angiogenesis-related genes expression, ANGPT-1/-2 and TEK in CC and MMP-2, VEGFA, VEGFR-1/-2, ANGPT-1/-2 and TEK in CL. Piau gilts showed lower ovulation rate than both L1 and L2 gilts (P < 0.05), lower number of large antral follicles (>6 mm) at 18 days than L2 gilts (P < 0.05), and smaller diameter of the largest follicles at 14 days than L1 gilts (P < 0.05). Piau and L2 gilts showed higher estradiol levels in follicular fluid on day 18. Expression of ANGPT-1 and -2 genes in CC did not differ among genetic groups neither among days of the estrous cycle, but TEK gene expression was higher in L1 than L2 gilts on day 18. Expression of VEGFA, VEGFR-2 and MMP-2 genes in CL did not differ among genetic groups and days of cycle, but VEGFR-1 expression was higher in Piau than L2 gilts on days 10 and 14, and it was higher in L1 than L2 gilts on day 14. The ANGPT-1/-2 and TEK genes expression in CL were significantly higher in Piau than L1 gilts on day 10. The ANGPT-2/ANGPT-1 gene expression ratio in CL was higher in L1 than Piau and L2 gilts at 14 days, suggesting a shorter luteal phase for L1 gilts. Results indicated differences among genetic groups for the pattern of the angiogenesis-related genes expression in CL along estrous cycles, which may be reflected in phenotypic traits such as ovulation rate, estradiol levels in follicular fluid and number and diameter of antral follicles. • Piau and commercial line gilts were compared for angiogenesis-related genes expression in corpus luteum and cumulus cells during estrous cycle. • Phenotypic traits related to follicular development were assessed and compared. • Results indicated lower ovulation rate in Piau and higher estradiol levels in follicular fluid of Piau and L2 gilts. • Potential differences in angiogenesis among groups may be related to variations in ANGPT-1/-2/TEK system. [ABSTRACT FROM AUTHOR]

Previous studies have shown that the composition and function of gut microbiota possibly contribute to the oxidative stress and host metabolism of sows. However, a functional link between gut bacteria with oxidative stress and stillbirth rate of sows remain unclear. To address this issue, the reproductive performance, oxidative stress and gut microbiota of sows with high (H) and low (L) stillbirth rate were analyzed. Results showed that, compared with the H group, the L group had a shorter farrowing duration as well as higher concentration of serum total antioxidant capacity and hydroxyl radical scavenging capacity. For the gut microbiota composition of the tested sows, 6 genera differed between the two groups, 7 genera were correlative with stillbirth rate, and 2 genera were correlated with farrowing duration. The relative abundance of Lachnospiraceae_UCG-001 , Marvinbryantia and Ruminococcaceae_UCG-004 were negatively correlated with antioxidant capacity, but positively correlated with the stillbirth rate of sows. Furthermore, the microbiota functions in the polyketide sugar unit biosynthesis and nitrotoluene degradation were found to be different between the two groups through the phylotypic investigation of communities by reconstruction of unobserved states. Collectively, gut microbiota and their functions vary between sows with high or low stillbirth rate, while stillbirth rate and farrowing duration are significantly correlated with the gut microbiota composition and oxidative stress status of sows. Image 102 • The farrowing duration is longer of sows with high stillbirth rate. • The oxidative stress status is higher of sows with high stillbirth rate. • Gut microbiota is correlative with oxidative stress and stillbirth rate of sows. • Microbiota functions were difference in sows with high or low stillbirth rate. [ABSTRACT FROM AUTHOR]

Abstract We investigated whether maternal dietary nitrate supplementation, leading to nitric oxide (NO) formation, would affect duration of farrowing, levels of asphyxiation, vitality of piglets at birth and/or loss of potential viable piglets in the form of stillbirth and pre-weaning mortality. Data were collected from 190 crossbred (Yorkshire x Dutch Landrace) sows, which were allocated, balanced for parity, to six dietary nitrate levels (0, 0.03, 0.06, 0.09, 0.12 or 0.15% of nitrate). Sow received the lactational diet containing nitrate from approximately 7 days before farrowing until 5 days after farrowing. Blood acid-base parameters (pH, p O 2 , p CO 2 , BE ecf , HCO 3 , sO 2 and lactate) and nitrate concentration were determined in umbilical cord blood. The farrowing process was video recorded and later analysed for total duration of farrowing, piglet birth interval, piglet vitality was scored and piglet latency to stand right after birth. Placentas were collected after expulsion during and after farrowing. Placenta length and width were measured and placental color scores were assessed based on redness of the placenta. The probability of a higher vitality score of piglets (being more vital) linearly increased with increasing levels of maternal dietary nitrate. This higher vitality score however, was not reflected by changes in the blood acid-base parameters in umbilical cord blood, except for a tendency for a higher p O 2 with increasing levels of nitrate, which could have been caused by a quicker onset of respiration or an increased blood flow to the piglets during birth. Placenta width increased with increasing levels of maternal dietary nitrate, but no effect on placenta length and redness was found. Neither duration of farrowing nor birth interval were affected by maternal dietary nitrate level. In conclusion, maternal nitrate supplementation may affect piglet vitality via vasodilatation (placental characteristics) rather than an increase in exercise efficiency (duration of farrowing). Highlights • Duration of farrowing was not affected by nitrate supplementation. • p O 2 in umbilical cord blood tended to increase with increasing dosage of nitrate. • Placenta width increased with increasing levels of sow nitrate supplementation. • Piglet vitality increased linearly with increasing levels of supplemented nitrate. [ABSTRACT FROM AUTHOR]

Boar exposure is used to stimulate follicle development and estrus in sows after weaning and also to improve semen uptake and sperm transport with insemination. However, the need and value of boar exposure is uncertain when ovulation induction is used. These studies were designed to determine the effect of daily boar exposure after weaning when used with ovulation induction and fixed time post-cervical artificial insemination (PCAI). In experiment 1, sows were weaned into stalls and assigned to receive 3 min of daily fenceline boar exposure (BE, n = 7) or no boar exposure (NBE, n = 8). All sows received OvuGel at 96 h after weaning and BE or NBE 30 min prior to a single PCAI 24 h after OvuGel. Ovaries were assessed daily for follicle size from weaning until ovulation. Cervical contractions were measured 30 min following BE or NBE and before PCAI, while uterine contractions were measured for 1 h following PCAI. In experiment 2, weaned sows (n = 244) were assigned by parity to receive once daily BE for 1.5 min each day or NBE. OvuGel, PCAI and ultrasound methods were performed similarly as in experiment 1. Results from experiment 1 indicated BE did not significantly influence follicle size or measures of fertility. However, BE did increase the frequency of cervical contractions (P < 0.05), but with no effect on the uterus. Results from experiment 2 indicated BE had no effect on catheter passage for PCAI but did increase the proportion of sows ovulating within 48 h after OvuGel (77.7 vs 67.5%, P = 0.05), and tended (P = 0.10) to increase the proportion of sows inseminated 24 h before ovulation (70.3 vs. 61.0%). However, BE had no effect on adjusted farrowing rate (84.4 vs. 77.4%) or total pigs born (13.2 vs. 12.5) for BE and NBE, respectively. There were treatment and parity interactions for follicle size at time of OvuGel and at time of PCAI (P < 0.05) with BE minimizing parity effects on follicle size. Parity effects were also evident on farrowing rate and litter size when inseminations occurred >24 h from ovulation but not when inseminations occurred ≤24 h before ovulation. The results indicate that boar exposure for only minutes each day after weaning had beneficial effects for improving follicle development, ovulation induction, and AI timing, most notably in parity 1 sows, but had no beneficial or detrimental effects on the ability to perform PCAI. [ABSTRACT FROM AUTHOR]

Ovarian follicular cysts are one of leading causes of infertility and financial loss in pig breeding program. This study was carried out to investigate the association between polymorphisms of estrogen receptor (ESR), follicle-stimulating hormone (FSH) β, and leptin genes and follicular cysts in sows. A total of 47 and 120 sows with follicular cysts and normal follicles, respectively, were selected to evaluate whether these candidate loci affect the formation of follicular cysts in sows. The polymorphisms of ESR, FSHβ, FSHβ/HaeIII and leptin genes were tested by PCR and PCR-RFLP methods. Cyst–normal case data analysis showed that ESR/PvuII polymorphisms are highly associated with follicular cysts and that sows ESR/PvuII genotype have lower rate of suffering from cysts (P = 0.021). Unfortunately, FSHβ, FSHβ/HaeIII, and leptin C3469T polymorphisms were found no significant difference in follicular cysts sows and normal sows. These results suggest that FSHβ, FSHβ/HaeIII, and leptin C3469T genotypes are not able to effect the presence of follicular cysts (P > 0.05). In addition, the haplotype EBCM and EBTM within four loci of genes had significant dominance effect on follicular cysts (P < 0.05). The detection of ESR/PvuII polymorphisms and haplotype EBCM and EBTM can positively improve the development of biological biomarkers, which is thereby beneficial in breeding and ovary-protective therapy of reproductive disease in pigs. [ABSTRACT FROM AUTHOR]

Post-cervical (pC) artificial insemination (AI) has been successfully developed for application in multiparous sows, although it has proved problematic in gilts. This study analyzes the use of pC-AI in gilts by two experiments. In the first experiment, the efficiency of pC-AI in gilts was evaluated using a multi-ring multiparous catheter (MpC), which led to 23.1% of the gilts being successfully inseminated. In gilts where insemination was not possible using an MpC, two alternatives were applied before a second attempt at insemination: 1) Vetrabutin Chlorhydrate (VC) was intramuscularly injected in order to relax the cervix; or 2) Warm extender (WE) was deposited in the cervix to modify the cervical muscle dynamics. After the application of these treatments, the success rates achieved with the MpC were 34.2% and 23.8% for VC and WE, respectively. No statistically significant differences were found in the reproductive parameters measured [farrowing (%), litter size and fecundity index] between the use of MpC, or the MpC combined with VC or WE, compared with gilts inseminated by cervical AI (control group). In the second experiment, new catheters based on the anatomical characteristics of gilts (GpC) were used, and the rate of successful pC-AI application were compared (experiment 2a): a) MpC: control; b) GpC1: multi-ring catheter of Ø 16 mm and inner cannula of Ø 3.5 mm; c) GpC2: a multi-ring catheter of Ø with an inner cannula of Ø 2.5 mm. The highest rate of successful cannula penetration was reached in the GpC2 group (60.3%) followed by GpC1 (37.0%) and MpC (19.6%) (p < 0.05). There were no differences in the above mentioned reproductive parameters using the three catheters compared with cervical AI method (control group). Moreover, prior cervical AI did not improve subsequent pC-AI application 24 h later (experiment 2b). In conclusion, Vetrabutin Chlorhydrate, warm extender or the new catheters can be considered as useful tools for improving the success rate of pC-AI technique in gilts. [ABSTRACT FROM AUTHOR]

Research was conducted to determine the effect of altrenogest and exposure to exogenous gonadotropins on ovarian function in prepubertal and mature gilts. Crossbred, presumably sexually mature gilts (n = 51), were fed with altrenogest for 18 consecutive days and the day after the last feeding with altrenogest, gilts were treated with eCG and 72 hours later challenged with hCG. Animals were slaughtered on Days 10 to 13 of their gonadotropins synchronized estrous cycle. Ovaries were examined for the number of CL, number of follicular cysts, and presence of corpora albicantia. Gilts were divided into two groups: those possessing corpora albicantia (group A—mature; n = 36) and those without corpora albicantia (Group W—prepubertal; n = 15) on their ovaries. In addition, each group was divided into two subgroups depending on the presence of follicular cysts (AC and WC) or their absence (AO and WO). There was no difference between the number of CL in group A and group W. Presence of corpora albicantia determined percentage of gilts possessing follicular cysts (13.9% group A vs. 66.7% group W). Gilts without follicular cysts (AO plus WO; n = 36) had higher number of CL (P < 0.01) than gilts bearing cysts (AC plus WC; n = 15). Comparison AO-AC did not show significant difference (P = 0.075) between CL number in mature cyst-free and cysts bearing gilts. A prepubertal gilts not bearing follicular cysts (WO) had higher (P < 0.02) number of CL than gilts bearing cysts. A significant negative correlation between the number of CL and number of follicular cysts was found (r = −0.664; P = 0.007). There were no differences in blood plasma progesterone and estradiol concentration between cyst-free and cyst-bearing gilts. These results indicate: (1) a higher follicular cysts appearance in prepubertal than mature gilts challenged with altrenogest and exposed to exogenous gonadotropins and (2) a negative effect of follicular cysts on the number of CL (ovulations) in prepubertal gilts. [ABSTRACT FROM AUTHOR]

Recent advances in nonsurgical deep uterine (NsDU) embryo transfer (ET) technology allow the noninvasive transfer of porcine embryos into recipients, overcoming the most important impediment for commercial ET in this species. Although many factors in the porcine ET-field have been recently evaluated, many others remain to be explored. We investigated here the future reproductive performance of donors and recipients after artificial insemination subsequent to the default surgical embryo recovery approach and to the NsDU-ET procedure, respectively. Although surgical embryo collection did not influence subsequent farrowing rates (90.5%), litter size decreased severely (8.9 ± 0.8 piglets) compared to presurgery (10.8 ± 0.3 piglets) and control group (10.7 ± 0.3 piglets). In contrast, NsDU-ETs did neither affect fertility nor prolificacy of recipients in the cycle subsequent to ET, regardless of whether they were pregnant after NsDU-ET or not. These results indicate that while the surgical embryo collection procedure compromises the reproductive future of donor sows, the NsDU-ET approach does not affect the reproductive potential of the recipients after reintroduction to the breeding stock of the farm. Further research is thus needed to improve surgical embryo collection. [ABSTRACT FROM AUTHOR]

It is possible to control follicular development in gilts and sows with the use of hormones including the progestogen altrenogest, GnRH, eCG, hCG, and porcine luteinizing hormone (pLH). These hormones can be used to develop protocols for control of estrus with artificial insemination (AI) timed to estrus detection (timed artificial insemination; TAI) or to control estrus and ovulation with insemination at a fixed time without the requirement of estrus detection (fixed-timed artificial insemination; FTAI). In cyclic gilts, double TAI after protocols based on altrenogest and eCG plus hCG administration can achieve a 70% of farrowing rate. Valuable results can be obtained in weaned sows by the utilization of protocols based on eCG administration at weaning and then GnRH or pLH at estrus onset followed by single or double TAI. In cyclic gilts, single or double FTAI regardless of estrus expression can be applied after protocols based on altrenogest administration followed by eCG and then GnRH, hCG, or pLH some hours later; farrowing rates are similar to control animals inseminated at estrus detection. With sows, a protocol based on eCG administration at weaning and hCG, GnRH, or pLH some hours later followed by single or double FTAI can give fertility rates comparable to control animal inseminated at estrus. Most recently, injection or vaginal deposition of GnRH 96 hours after weaning followed by a single FTAI 24 to 30 hours later is resulting in reproductive performance not different to animals subject to multiple inseminations after natural estrus. It is possible to apply FTAI in lactating sows. The protocols are based on eCG during lactation followed by hCG and FTAI. These protocols will induce ovulation during lactation, but pregnancy rates are reduced. However, in the future, a better knowledge on the effect of hormone administration on follicular dynamics during lactation may allow the development of more effective protocols. [ABSTRACT FROM AUTHOR]

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 × 10 9 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. [ABSTRACT FROM AUTHOR]

Genetic selection in sows has substantially increased the total number of pigs born, but there has been an associated decrease in litter birth weight. Furthermore, irrespective of the total number of pigs born, a repeatable low litter birth weight phenotype has evolved in a subpopulation of mature sows, in which a high ovulation rate drives extremes of intrauterine crowding in early gestation and limits placental development: placental development continues to be compromised in later gestation and is associated with intrauterine growth restriction and a low litter birth weight. Furthermore, although contemporary commercial sows are increasingly resilient to the challenges of lactational catabolism in terms of the traditional measures of reproductive performance, gender-specific effects on early embryonic development of the subsequent litter are apparent and are likely linked to effects of sow catabolism on folliculogenesis and oocyte maturation. Recent transcriptomic studies that have helped elucidate some of the regulatory mechanisms mediating the evolving changes in the reproductive biology of contemporary commercial sows are summarized in the present review. However, the lack of clearly differentiated reproductive phenotypes among commercial sow populations is a problem for ongoing studies. Access to an unselected “wild-type” population with which to make comparisons, or the application of more standardized experimental approaches to mechanistic studies, may help advance the field of sow reproductive biology. [ABSTRACT FROM AUTHOR]

Ovarian follicular cysts are anovulatory follicular structures that have been identified in sows and are known to cause infertility. The pathogenesis of follicular cysts remains poorly understood. Hormones play key roles in the formation and persistence of cysts. The hormone inhibin is a member of the TGF-β superfamily and is named for its negative regulation of FSH, another hormone that controls follicular recruitment and growth. In the present study, 48 sows with follicular cysts and 60 normal sows with no cysts were screened for mutations in the inhibin-α gene to examine the association of inhibin-α gene polymorphisms with the presence of follicular cysts. The results show that the c.-42G>A and c.3222G>A polymorphisms are significantly associated with follicular cysts and that sows with c.-42GG and c.3222GG genotypes have lower risk of developing cysts. Our findings may provide novel biological biomarkers and promising gene therapy candidates for follicular cyst formation in sows, which would greatly benefit pig breeding programs. [ABSTRACT FROM AUTHOR]

It is well known that puberty has a strong impact on oocyte developmental competence in vitro ; however, the reason for this phenomenon at the cellular level has not been clarified yet. It is hypothesized that cytoplasmic maturation is responsible for oocyte quality and may be impaired in prepubertal gilts. Previous results on mitochondrial DNA copy number and mitochondria and cortical granule distribution showed that cytoplasmic maturation is a complex trait and should include multithreaded analysis. Therefore, the aim of the present research was to analyze the transcript abundance of developmentally important genes ( BMP15 , GDF9 , GSTA2 , ATP5A1 , EEF1A1 , BAX , BCL2 ) followed by investigation of the glutathione and apoptosis level in oocytes of prepubertal and cyclic gilts. We found differences in relative transcript abundance of BMP15 and GDF9 genes after IVM, whereas different concentrations of glutathione were noted before IVM (5.3 vs. 2.9 pmol, respectively). The glutathione level was equalized after IVM (10.3 vs. 9.1 pmol), whereas the incidence of apoptosis remained similar before (3.9% vs. 1.1%) and after IVM (4.5% vs. 1.9%) being higher in prepubertal oocytes. A potential impact of gilt puberty on oocyte quality has been therefore masked by the significant effect of IVM. Because the maternal effect genes, BMP15 and GDF9 , play key roles in regulation of folliculogenesis and oocyte–cumulus interaction, their upregulation in oocytes of cyclic gilts may result in increased developmental competence. On the basis of findings from this and our previous research, we suggest that the reduced quality of oocytes from prepubertal females is a complex phenomenon and is not related to a single marker trait. [ABSTRACT FROM AUTHOR]

Successful fertilization is essential for reproduction and might be negatively affected by stressful events, which could alter the environment where fertilization occurs. The aim of the study was to determine whether an altered hormonal profile in blood plasma caused by adrenocorticotropic hormone (ACTH) administration could affect in vitro fertilization in the pig model. In experiment 1, gametes were exposed for 24 hours to plasma from ACTH-treated, non-ACTH–treated sows, or medium with BSA. Fertilization, cleavage, and blastocyst rates were lower in the ACTH group compared with the no ACTH or BSA control groups (P < 0.01). In experiment 2, the exposure of matured oocytes for 1 hour before fertilization to the same treatments did not have an impact on their ability to undergo fertilization or on embryo development. In experiment 3, spermatozoa were incubated for 0, 1, 4, and 24 hours under the same conditions. There was no effect of treatment on sperm viability. The percentage of acrosome-reacted spermatozoa remained higher in the ACTH group compared with the non-ACTH–treated group through the incubation period (P < 0.001). Protein tyrosine phosphorylation (PTP) patterns were also affected by treatment (P < 0.001). The presence of an atypical PTP pattern was higher in the ACTH group at all the analyzed time points compared with the BSA and no ACTH groups (P < 0.001). In conclusion, this altered environment may not affect oocyte competence but might affect the sperm fertilizing ability through alterations in the acrosome reaction and correct sequence of PTP patterns. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the effects of feeding a blend of corn contaminated with Fusarium mycotoxins on the physical condition of pregnant and suckling sows and the development of their offspring. Halloysite nanotubes modified using the surfactant, stearyldimethylbenzylammonium chloride, were tested for its efficacy in protecting against the detrimental effects of zearalenone (ZEN) exposure. A total of 18 pregnant second parity Yorkshire sows (six per treatment) were fed control diet, contaminated grain diet (ZEN, 2.77 mg/kg), and contaminated grain + 1% modified halloysite nanotube (MHNT) diet (ZEN, 2.76 mg/kg) from 35 to 70 days in pregnancy (DIP), which is the critical period in development of fetuses. The results show that consumption of ZEN led to a reduction in sow's mass gain during 35 to 70 DIP and mass at 110 DIP, backfat at 70 DIP and weaning, placenta weight at 70 DIP and farrowing, the lactation average daily feed intake, and an increase in the weight of ovary at 70 DIP of sows (P < 0.05). The total number and average body weight (BW) of fetuses at 70 DIP, the number of piglets born, the litter birth weight, the average BW of piglet at birth, the number of piglets born alive, the born alive litter weight, and born alive piglet BW at farrowing were also decreased by ZEN exposure (P < 0.05). The increased expressions of P53, Bax, Cyto C, caspase 9, and caspase 3 and decreased expression of Bcl-2 were observed in the uterus and placenta of sows at 70 DIP, the placenta and fetal uterus at farrowing, and the piglet uterus at weaning (P < 0.05). Adding 1% MHNTs decreased the residue of ZEN in maternal and fetal tissues. The number of fetuses and the average fetus BW at 70 DIP, the total number of piglets born, the litter birth weight, the born alive piglet BW at farrowing, the average piglet BW, the litter weaned weight, and the average day gain at weaning were increased by adding 1% MHNTs, compared with the ZEN-treated group (P < 0.05). The MHNTs significantly reduced the damage to the fat in the colostrum and the protein and lactose in the milk induced by the ZEN-contaminated feed (P < 0.05). Modified halloysite nanotubes could be used as adsorbent in the feed to reduce the toxic effects of ZEN. [ABSTRACT FROM AUTHOR]

A combination of eCG (400 IU) and hCG (200 IU) (P.G. 600; Merck Animal Health, Summit, NJ, USA) stimulates puberty in gilts, but variation in the estrual response exists among farms. We hypothesized that some of the variability is a consequence of gilts that have commenced cycling being inadvertently treated. The objective of experiment 1 was to determine the effect of intramuscular (im) P.G. 600 on estrous cycles in sexually mature gilts. Gilts in treatment 1 (n = 16) received P.G. 600 at the onset of daily boar exposure. Gilts in treatments 2 to 5 (n = 16 per treatment) were allowed to express a natural first estrus and were then treated with P.G. 600 during the first estrous cycle as follows: treatment 2 at Day 6, treatment 3 at Day 12, and treatment 4 at Day 18 of the estrous cycle. Treatment 5 gilts received no P.G. 600. The proportion of gilts displaying a normal estrous cycle (18–24 days) was greater (P < 0.05) for treatments 4 (100%) and 5 (100%) compared with treatments 1 (73.3%) and 3 (60%), with treatment 2 having a value (87.5%) that was not different from the other groups. For treatment 3, 33% of gilts displayed an increased interestrus interval that averaged 32.5 days. Concentrations of progesterone remained elevated 20 days after the onset of first estrus in treatment 3 gilts, which supports the concept that P.G. 600 administered at Day 12 of the estrous cycle induced follicular growth, ovulation, and formation of CL that functioned for approximately 15 days, increasing the length of the estrous cycle. It is common for swine producers to have groups of replacement gilts that include both cycling and prepubertal animals, or individuals, the cycling status of which is unknown. The objective of experiment 2 was to evaluate a system using a combination of a progestogen (Matrix; Merck Animal Health) and P.G. 600 to synchronize estrus in replacement gilts. Crossbred gilts, assumed to be a mix of cycling and prepubertal females, were allocated to one of four treatments (n = 12 per treatment): treatment 1, Matrix (15 mg/day) fed for 14 days and im P.G. 600 24 hours after the last feeding of Matrix; treatment 2, Matrix for 7 days and P.G. 600; treatment 3, P.G. 600 only; and treatment 4, im water only. The percentage of gilts in estrus within 7 days after im treatment was the greatest (P < 0.02) and days to estrus the least (P < 0.05) for gilts receiving Matrix for 14 days and P.G. 600 (treatment 1, 91.7% and 5.4 ± 1.9 days; treatment 2, 50% and 9.2 ± 2.0 days; treatment 3, 33% and 13.8 ± 2.1 days; and treatment 4, 50% and 9.1 ± 1.9 days). The results of these experiments suggest that P.G. 600 administered to gilts that have already obtained puberty may cause abnormal estrous cycles and demonstrate to swine producers the need to correctly classify replacement gilts as prepubertal or cycling before administering the product. The use of Matrix and P.G. 600 in combination has potential as an effective strategy for synchronizing estrus in a mix of prepubertal and mature, cycling gilts. [ABSTRACT FROM AUTHOR]

The fertility of female pigs is impaired during summer and in response to restriction of feed intake, resulting in reduced productivity of the breeding herd. This study determined the effect of season and moderate nutritional restriction on ovarian function and oocyte developmental competence of cycling gilts. Eighty prepubescent gilts were used across two seasons—summer (S: January to March) and winter (W: June to August)—and received either a high (2.5× maintenance) or a moderately restricted (1.5× maintenance) feeding level for the first 19 days of their second estrous cycle. On Day 19, ovaries were collected post-slaughter. Diameters of all surface follicles over 1 mm were measured. All follicles ≥4 mm were aspirated and cumulus–oocyte complexes underwent in vitro maturation for ∼44 hours to assess oocyte developmental competence on the basis of metaphase II (MII) attainment. Moderate dietary nutrition reduced daily liveweight gain but did not affect the ovarian follicle population or oocyte developmental competence. The number of large follicles (≥6 mm) was lower during summer (S: 10.7 ± 1.74 vs. W: 15.5 ± 1.15, P < 0.05), as was the proportion of oocytes at the germinal vesicle stage of meiosis (S: 0.06 ± 0.02 vs. W: 0.08 ± 0.02, P < 0.05). However, the proportion of oocytes attaining MII was similar in summer and winter (S: 0.72 ± 0.04 and W: 0.69 ± 0.06, P > 0.05). Intrafollicular concentrations of luteinizing hormone were higher in summer (S: 43.05 ± 6.44 vs. W: 12.05 ± 5.12 ng/mL, P < 0.001), whereas estradiol was lower (S: 1.27 ± 0.36 vs. W: 27.52 ± 5.59 ng/mL, P < 0.001). In conclusion, our data demonstrated that in summer, follicle growth beyond 6 mm is impaired during the periovulatory period, without affecting oocyte meiotic competence. Importantly, these data also demonstrated that ovarian follicle growth and the capacity of oocytes to reach MII in vitro appear unaffected by moderate nutritional restriction during the preceding estrous cycle. [ABSTRACT FROM AUTHOR]

The prediction of ovulation time is one of the most important and yet difficult processes in pig production, and it has a considerable impact on the fertility of the herd and litter size. The objective of this study was to assess the vulvar skin temperature of sows during proestrus and estrus using infrared thermography and to establish a possible relationship between the variations in vulvar temperature and ovulation. The experimental group comprised 36 crossbred Large White × Landrace females, of which 6 were gilts and 30 were multiparous sows. Estrus was detected twice daily and the temperature was obtained every 6 hours from the vulvar area and from two control points in the gluteal area (Gluteal skin temperature [GST]). A third variable, vulvar–gluteal temperature (VGT) was obtained from the difference between the vulvar skin temperature and the GST values. The animals were divided into two subgroups: group A consisting of 11 animals with estrus detected at 6:00 AM, Day 4 postweaning, and group B comprising seven animals with estrus detected at 6:00 AM, Day 5 post-weaning. Both groups showed a similar trend in the VGT. The VGT increased during the proestrus, reaching a peak 24 hours before estrus in group A and 48 hours before estrus in group B. The VGT then decreased markedly reaching the lowest value in groups A and B, respectively, 12 and 6 hours after estrus. Although the time of ovulation was only estimated on the basis of a literature review, the matching between the temporal variations of the VGT values and the predicted time of the peak of estradiol secretion that ultimately leads to the ovulation processes suggests that the VGT values represent a potential predictive marker of the ovulatory events. [ABSTRACT FROM AUTHOR]

Previous studies have shown that triptorelin gel (TG) given intravaginally in gel form is effective for advancing the time of ovulation in weaned sows. Three experiments were performed to determine the effects of altering the dose and timing of administration of intravaginal TG for advancing and synchronizing ovulation in weaned sows. In all experiments, estrus was detected twice or three times daily and ultrasound was performed to determine ovulation at 8-hour intervals. In experiment 1, sows (n = 131) received intravaginal gel containing 0 (Placebo), 25, 100, or 200 μg of TG at 96 hours after weaning and sows were inseminated on each day of standing estrus. Wean-to-estrus interval and duration of estrus were correlated (P < 0.0001) with estrus duration longer in TG (P < 0.05) compared with Placebo. More sows ovulated (P < 0.001) by 48 hours after treatment with 200 (81%), 100 (64%), and 25 μg (63%) of TG compared with Placebo (42%). The farrowing rate and total pigs born did not differ (P > 0.10). In experiment 2, sows (n = 126) received 200 μg of TG at 72, 84, or 96 hours after weaning or were untreated (Control-96). Sows receiving TG were inseminated once 24 to 28 hours after treatment. Control-96 sows were inseminated on each day of standing estrus. Wean-to-estrus interval was not affected by treatment, but wean-to-ovulation interval was reduced (P < 0.05) by TG-72 and TG-84 compared with TG-96 and Control-96. More sows ovulated 40 hours after treatment (P < 0.001) with TG-72 (56.5%) and TG-84 (32.2%) compared with TG-96 and Control-96 (13%) and for all TG treatments 48 hours after treatment (64%) compared with Control-96 (34%, P < 0.05). The farrowing rate was lower (P < 0.05) for sows assigned to TG-72 and TG-84 compared with TG-96 and Control-96, whereas the number of liveborn pigs did not differ (P > 0.10). In experiment 3, sows (n = 113) were assigned to receive no treatment (Control), intravaginal gel alone (Placebo), or 200 μg of TG given intravaginally (OvuGel) at 96 hours after weaning. Wean-to-estrus interval did not differ, but the duration of estrus tended (P < 0.10) to be reduced with OvuGel compared with the other treatments. More sows ovulated (P < 0.001) by 48 hours after OvuGel treatment (79.1%) compared with Control (46.4%) and Placebo (37.9%) and by 56 hours (P < 0.05). The farrowing rate and the number of liveborn pigs did not differ among treatments. The results of these studies indicate that 200 μg of TG given intravaginally at 96 hours after weaning (OvuGel) synchronizes ovulation and results in fertility similar to Controls. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to evaluate the influence of vascular architecture of broad ligament of the uterus on fetal and placental development in gilts. Fifteen gilts DB-90 (DanBred) were divided into three groups according to gestational age at slaughter (50, 80, and 106 days). After slaughter, fetuses and placentas were collected, weighed, and measured. The uterine arterial system was detached by latex repletion for quantification of the number and diameter of the terminal vessels in different regions of the uterine horns (apex, middle region, and base). Fetal and placental measurements were statistically analyzed and correlated with the number and diameter of arteries in each uterine segment. No correlation was observed (P > 0.10) between the number and diameter of arteries destined to the uterus with the number or weight of fetuses or placental weight in any gestational group. It was observed (P < 0.05) that more vessels destined to the medium region of the uterine horns, independent of the gestational age or uterus side. At the 80th day of gestation, fetuses located at the base of the uterus have (P < 0.05) smaller cephalic and thoracic perimeters. It was concluded that there were differences in vascularization of broad ligament that irrigates the different uterine segments, but this was not sufficient to influence the development of fetuses in gilts. The middle region of the uterine horns was the segment with a greater number of vessels, regardless of gestational age. [Copyright &y& Elsevier]

Abstract: This study aimed to evaluate the effectiveness of superovulation protocols in improving the efficiency of embryo donors for porcine nonsurgical deep-uterine (NsDU) embryo transfer (ET) programs. After weaning (24 hours), purebred Duroc sows (2–6 parity) were treated with 1000 IU (n = 27) or 1500 IU (n = 27) of eCG. Only sows with clear signs of estrus 4 to 72 hours after eCG administration were treated with 750 IU hCG at the onset of estrus. Nonhormonally treated postweaning estrus sows (n = 36) were used as a control. Sows were inseminated and subjected to laparotomy on Days 5 to 6 (Day 0 = onset of estrus). Three sows (11.1%) treated with the highest dosage of eCG presented with polycystic ovaries without signs of ovulation. The remaining sows from nonsuperovulated and superovulated groups were all pregnant, with no differences in fertilization rates among groups. The number of CLs and viable embryos was higher (P < 0.05) in the superovulated groups compared with the controls and increased (P < 0.05) with increasing doses of eCG. There were no differences among groups in the number of oocytes and/or degenerated embryos. The number of transferable embryos (morulae and unhatched blastocysts) obtained in pregnant sows was higher (P < 0.05) in the superovulated groups than in the control group. In all groups, there was a significant correlation between the number of CLs and the number of viable and transferable embryos, but the number of CLs and the number of oocytes and/or degenerated embryos were not correlated. A total of 46 NsDU ETs were performed in nonhormonally treated recipient sows, with embryos (30 embryos per transfer) recovered from the 1000-IU eCG, 1500-IU eCG, and control groups. In total, pregnancy and farrowing rates were 75.1% and 73.2%, respectively, with a litter size of 9.4 ± 0.6 piglets born, of which 8.8 ± 0.5 were born alive. There were no differences for any of the reproductive parameters evaluated among groups. In conclusion, our results demonstrated the efficiency of eCG superovulation treatments in decreasing the donor-to-recipient ratio. Compared with nonsuperovulated sows, the number of transferable embryos was increased in superovulated sows without affecting their quality and in vivo capacity to develop to term after transfer. The results from this study also demonstrate the effectiveness of the NsDU ET procedure used, making possible the commercial use of ET technology by the pig industry. [Copyright &y& Elsevier]

Abstract: The objective of the present research was to eliminate seasonal fluctuations in year-round reproductive performance of sows and to improve litter parameters by administration of oxytocin into liquid semen insemination doses. A 2-year experiment was performed on crossbreed sows, Polish Large White × Polish Landrace, which were partitioned into two groups: control, insemination without any modification with 100 mL semen doses and oxytocin, insemination with 100 mL semen doses to which 5 IU of oxytocin was added just before insemination. A total of 10,486 inseminations were made. The farrowing rate and obtained litter parameters, including the effect of season, were analyzed. For each litter, the following factors were defined: average litter size, percentage of fetal death and mummified piglets, average piglet birth weight, percentage of piglet mortality, fecundity index, average number of piglets weaned, weaned piglet weight, and daily gain. Sows presented a positive reaction to the experimental factor. A statistically higher farrowing rate for oxytocin group in summer and autumn seasons was confirmed (P ≤ 0.01). Regardless of the season, a higher average litter size was observed in the oxytocin group with the most evident differences for winter, spring (P ≤ 0.01), and summer (P ≤ 0.05). The effect of oxytocin on the percentage of fetal death and mummified piglets born was not confirmed statistically except for winter. Analyzing the fecundity index, higher values were obtained for the oxytocin group in all seasons (P ≤ 0.01), including the lowest difference between groups for winter (51.43) and the highest for summer (100.61). A higher average birth piglet weight and weaned piglet weight were recorded for the oxytocin group in all seasons. The highest differences in birth piglet weight between groups were noted for spring (0.22 kg; P ≤ 0.01) and winter (0.17 kg; P ≤ 0.05) and in weaned piglet weight for winter and spring (0.58 kg and 0.52 kg; for both, P ≤ 0.01). The greatest daily gains were observed in the winter season (P ≤ 0.05) in favor of oxytocin. On the basis of the presented results, it should be noted that the use of oxytocin into insemination doses improves the farrowing rate and other parameters of the reproductive performance of sows. In the absence of negative effects, year-round insemination with oxytocin addition into seminal doses is recommended, which effectively improves the production performance and reduces the problem of seasonality in reproduction. [Copyright &y& Elsevier]

Abstract: The objective of this study was to examine the competence of mature oocytes aspirated from small follicles (SF, <2 mm in diameter) and medium follicles (MF, 3–6 mm) of abattoir-derived prepubertal gilt ovaries. Oocytes were selected by the presence of the first polar body (1pb) after IVM in a chemically defined medium, for sperm penetration, pronuclear formation, cleavage rate, and development to the blastocyst stage. Relative transcript abundance of genes associated with regulation of oocyte maturation (AURKA, AURKB, and MOS), fertilization (ZP3 and ZP4), maternal effect (NALP9 and HSF1), and anti-apoptosis (BCL2) were also examined in oocytes at germinal vesicle (GV) and metaphase-II (MII) stages. In SF, compared with MF, the maturation rate post-IVM was lower (P < 0.05), but there were no differences in sperm penetration rate (78.2% and 68.5% at 6 hours after insemination and 90.8% and 91.9% at 9 hours after insemination, P = 0.51 and P = 0.67, respectively), the percentage of oocytes that formed both female and male pronuclei (27.9% and 25.8% at 6 hours after insemination and 79.4% and 76.1% at 9 hours after insemination), or cleavage rate at 48 hours after insemination (85.9% and 89.7%, respectively, P = 0.46), whereas blastocyst formation rate was lower (P < 0.05) in oocytes from SF versus MF (14.7% and 31.0%). Transcript abundances decreased (P < 0.05) in all genes examined between the GV and MII stages, although only transcript abundance for MOS was lower (P < 0.05) in GV oocytes from SF versus MF. In conclusion, mature oocytes from SF and MF of prepubertal gilts with a visible 1pb had similar fertilizability in vitro and relative transcript abundance of nine genes. However, follicle size affected meiotic competence, early embryonic development to the blastocyst stage, and transcript abundance of the MOS gene. [Copyright &y& Elsevier]