Low progesterone concentration in early pregnancy is detrimental to conceptus development and pregnancy outcome in horses.

High progesterone concentrations in the early luteal phase support pregnancy, whereas subphysiological progesterone concentrations delay embryonic development at least until placentation. In this study, fetal growth and development of pregnancy was investigated in pregnancies with prostaglandin F2α-induced low progesterone concentrations (PGF) in the early luteal phase and control pregnancies (CON) in the same mares (n = 12). Mares were inseminated and in PGF pregnancies received the prostaglandin F2α analogue cloprostenol (62.5 µg) on days 0-3 after ovulation to induce subphysiological progesterone concentrations; CON pregnancies remained untreated. Mares were assigned to PGF or CON treatments in alternating order and received the opposite treatment in the following year. Blood was collected and conceptus size determined repeatedly by transrectal (≤day 101) and transabdominal (>day 101) ultrasonography. After birth, foals were weighed, measured and submitted to a clinical examination. Treatment PGF resulted in fewer pregnancies than CON treatment. All foals born from CON pregnancies were healthy and mature, whereas 4/7 PGF pregnancies were either lost (one embryonic death, one abortion) or resulted in the birth of compromised foals (P = 0.018). Size of the conceptus (e.g., diameter day 49: PGF 6.6 ± 0.7, CON 7.7 ± 0.7 cm, P = 0.006) and embryo proper (e.g., crown rump length day 54; PGF 4.4 ± 0.8, CON 5.8 ± 0.6 cm, P = 0.015) differed between treatments. These size differences decreased over time and at birth PGF foals did not differ significantly from CON foals. In conclusion, reduced progesterone concentration in the early luteal phase leads to delayed conceptus growth beyond placentation and increased pregnancy loss.

High Vitamin D Level in Female Mice Increases the Number of Live Fetuses.

Little is known about the impact of high-normal range of 25-hydroxyvitamin D [25(OH)D] on reproductive function. The aim of this study was to investigate the effect of different dose vitamin D supplementation in female mice on the pregnancy outcomes. Three groups of female mice were fed with fodder containing different dose of vitamin D at both pre-gestational and gestational stages. Serum 25(OH)D and calcium concentrations were monitored. The expression levels of vitamin D receptor (VDR) mRNA and protein in placenta were determined by real-time RT-PCR and western blot. Pregnancy outcomes were evaluated and compared among the three groups. Compared with the medium and low dose groups, serum 25(OH)D concentration was significantly increased and approximated to high-normal range in the high dose group (pre-gestational: 81.3±5.75 vs 52.8±6.24 and 25.0±3.99 ng/mL; gestational: 86.8±5.99 vs 52.6±9.29 and 27.9±4.96 ng/mL, respectively; all p<0.001). Interestingly, the average number of live fetuses per litter was much larger in the high dose group than in other two groups (19.8±5.31 vs 13.8±1.30 and 12.8±3.55 respectively, both p<0.05). However, no significant differences of the expression levels of VDR mRNA and protein in placenta were identified among the three groups. Supplementation of high dose vitamin D can enhance the female mice reproductive function. Further study is warranted to explore the mechanism by which high level of 25(OH)D in female mice increases the number of fetuses.

Ovarian follicle dynamics in ewes treated with intra-vaginal progesterone pessaries. 2. Factors affecting timing of estrus and reproductive outcomes following artificial insemination.

This study extends observations on the effects of intra-vaginal progesterone treatment on the relationships between the time of luteolysis, emergence of the ovulatory follicle, timing of estrus and ewe fertility. Observations were made in progesterone - treated ewes in autumn, the spring equinox and late spring (Experiment 1, Data set 1) and in progesterone - treated ewes and naturally cycling ewes in autumn and the spring equinox (Experiment 1, Data set 2). In Data set 1, the day of emergence of both the first and second ovulatory follicle was positively related to the day luteal regression within each season. In turn, the day of emergence influenced the timing of estrus by means of a season by day of luteal regression interaction (P < 0.001) indicating that the relationship was positive in autumn and the spring equinox but negative in late spring. In autumn, older ovulatory follicles were associated with an earlier onset of estrus compared with younger ovulatory follicles. In late spring, this relationship was reversed and was influenced by whether or not ewes were cycling at the time of pessary insertion. In Data set 2, the relationship between the day of follicle emergence and luteal regression was influenced by a treatment by day of regression interaction indicating the relationship was positive in treated ewes and negative in naturally cycling ewes. Timing of estrus was positively related (P < 0.001) to both the day of luteal regression and the day of follicle emergence (P < 0.05), with both relationships being stronger in naturally cycling ewes than in treated ewes. In Experiment 2, pregnancy rate following artificial insemination in autumn was highest (90.2%) when luteolysis occurred during Days 7-9 of the pessary period compared with Days 1-6 (77.8%, P = 0.16), 10 to 12 (68.8%, P < 0.05) or Days ≥13 (71.2%, P < 0.05). Timing of estrus was not affected. The mean diameter of ovulatory follicles that emerged during Days 7-9 was larger on Day 12 (5.8 ± 0.13 mm) compared with other periods (range 4.7 ± 0.05 to 5.6 ± 0.14 mm). This study provides two potential strategies to improve the success of AI programs. Firstly, appropriately timed treatment with PGF2α to control the time of emergence of ovulatory follicles and, secondly, earlier treatment with eCG to improve the development of ovulatory follicles that emerge late in the pessary period. Each is likely to be influenced by season and the cyclical status of the ewe.

The first week following insemination is the period of major pregnancy failure in pasture-grazed dairy cows.

A 60% pregnancy success for inseminations is targeted to optimize production efficiency for dairy cows within a seasonal, pasture-grazed system. Routine measures of pregnancy success are widely available but are limited, in practice, to a gestation stage beyond the first 28 d. Although some historical data exist on embryonic mortality before this stage, productivity of dairy systems and genetics of the cows have advanced significantly in recent decades. Accordingly, the aim was to construct an updated estimate of pregnancy success at key developmental stages during the first 70 d after insemination. Blood samples were collected for progesterone concentrations on d 0 and 7. A temporal series of 4 groups spanning fertilization through d 70 were conducted on 4 seasonal, pasture-grazed dairy farms (n = 1,467 cows) during the first 21 d of the seasonal breeding period. Morphological examination was undertaken on embryos collected on d 7 (group E7) and 15 (group E15), and pregnancy was diagnosed via ultrasonography on approximately d 28 and 35 (group E35) as well as d 70 (group E70). Fertilization, embryo, and fetal evaluation for viability established a pregnancy success pattern. Additionally, cow and on-farm risk factor variables associated with pregnancy success were evaluated. We estimated pregnancy success rates of 70.9%, 59.1%, 63.8%, 62.3%, and 56.7% at d 7, 15, 28, 35, and 70, respectively. Fertilization failure (15.8%) and embryonic arrest before the morula stage (10.3%) were the major developmental events contributing to first-week pregnancy failures. Embryo elongation failure of 7% contributed to pregnancy failure during the second week. The risk factors for pregnancy success that were related to the cows included interval between calving and insemination, and d-7 plasma progesterone concentrations, whereas insemination sire was associated with pregnancy outcome. Most pregnancy failure occurs during the first week among seasonal-calving pasture-grazed dairy cows.

Pregnancy stage-dependent modulation of neutrophil function may impact embryo survivability and pregnancy outcome in crossbred cows.

Pregnancy is a complicated physiological process that involves synchronized coordination between immune and endocrine systems. Neutrophils have been suggested as a critical immune cell for embryo implantation and pregnancy maintenance. The present study was conducted to evaluate the dynamic changes in the mRNA expressions of the cluster of designation (CD11b, CD31, CD44 and CD62L) molecules and interferon-stimulated genes (ISG15, MX1 and OAS1) in blood neutrophils throughout pregnancy in dairy cows and correlate them with the outcome of pregnancy. Blood samples were taken from negative control (NC) group, and non-pregnant (NP) group at the time of artificial insemination (AI, day zero) and on days 10, 14, 16, 18, and 21 post-AI. In pregnant (P) cows, samples were taken as described above and after every 30 days until the time of parturition. In aborted cows, samples were collected until the time of the abortion. Comparison between pregnant, non-pregnant and aborted cows revealed that the expression of CD molecules increased (p < 0.05) on days 14, 16, 18 and 21 post-AI only in NP cows as compared to other groups. Although the expression of CD molecules remained constant throughout the study period in pregnant and aborted cows, the expression of CD11b, CD31 and CD62L increased (p < 0.05) on the day of abortion and parturition. Unlike CD molecules, the expression of CD44 decreased significantly (p < 0.05) at the time of abortion. There was a significant (p < 0.05) increase in the expression of interferon-stimulated genes including MX1, OAS1 and ISG15 during the peri-implantation period in pregnant cows, and at the time of abortion in aborted cows. However, the expression of ISGs was lower (p < 0.05) in non-pregnant cows as compared to the other groups. The results revealed the critical role played by neutrophils during pregnancy and form the basis to unravel the underlying mechanism for neutrophil associated immunological infertility in bovines.

Positive relationship of rectal temperature at fixed timed artificial insemination on pregnancy outcomes in beef cattle.

The overarching aim was to examine the relationship of rectal temperature at fixed time artificial insemination (FTAI) on pregnancy outcomes in a typical breeding season with expected pregnancy rates approaching 50% using Bos indicus and Bos taurus cattle. This represents a continuum of steps to test the hypothesis that elevated body temperature at or around insemination is functionally important to maximize pregnancy outcomes. Rectal temperature of Bos indicus cattle at FTAI ranged from 37.0 to 40.9 °C; 60.6% were hyperthermic. Positive factors impacting pregnancy outcomes were rectal temperature at FTAI, body condition, and estrus patch scores. Rectal temperature at FTAI was positively associated with pregnancy outcomes (P < 0.0001); per each 1 °C increase pregnancy odds increased 1.9 times (95% CI: 1.4 to 2.6). Highest pregnancy outcomes occurred with rectal temperatures exceeding 40 °C (P = 0.0004). Rectal temperature before FTAI in Bos taurus cattle ranged from 37.8 to 41.8 °C; 43.3% were hyperthermic. Factors impacting pregnancy were rectal temperature at FTAI, estrus activity, parity, and ambient conditions on day of FTAI. Rectal temperature of Bos taurus cattle at FTAI was positively associated with pregnancy (P = 0.0286); odds increased 1.45 times (95% CI: 1.0 to 2.0) per each 1 °C increase. Highest pregnancy outcomes occurred with rectal temperatures at FTAI exceeding 40 °C (P = 0.057). Moreover, positive relationship of rectal temperature at FTAI to pregnancy persisted in estrual females (71.25% of total; P = 0.0408; OR 1.5; 95% CI: 1.0 to 2.2). Mindful that 1) elevated temperatures observed in Bos indicus and Bos taurus cattle directly promote meiotic resumption of the oocyte in vitro and that 2) in vivo hyperthermia alters intrafollicular components which others have shown to potentiate ovulation and promote meiotic resumption, it is biologically plausible that an acute elevation in body temperature at or around time of insemination is functionally important to maximize pregnancy outcomes.

Reproductive efficiency remains a major challenge for beef producers with 35% to 55% of females failing to become pregnant after a single insemination. While basis for failure is multi-factorial, heightened estrus activity matters for pregnancy outcomes, even when synchronizing ovulation for fixed time artificial insemination. Body temperature increases of 1.5 °C+ are common during estrus. We hypothesize that higher estrous-associated temperatures (HEAT) at/near insemination are functionally important to maximize pregnancy outcomes. Elevated temperatures equivalent to what is observed in females exhibiting HEAT have been shown to induce oocyte meiotic resumption. An acute episode of hyperthermia after the LH surge alters intrafollicular components known to potentiate ovulation and affect the oocyte. Effort to examine the relationship of rectal temperature at fixed time artificial insemination with pregnancy outcomes in a breeding season with expected pregnancy rates >50% represents a next step in the continuum of hypothesis testing. The positive relationship of rectal temperature at insemination with pregnancy outcomes that was discovered adds to foundational knowledge. Because the degree of hyperthermia is related to highest pregnancy outcomes, a case is made for HEAT to be biologically and functionally important to maximize pregnancy outcomes in cattle.

Clinical Outcome of Transcervical Infusion of a Combination of Procaine Penicillin and Gentamicin in Late-term Pregnant Mares.

Transcervical intrauterine infusion of antibiotics may more effectively treat pathogens associated with fetal and neonatal disease in pregnant mares than standard systemic routes. The objective of this study was to assess the safety of transcervical antibiotic infusion by characterizing the gestational outcome in nine healthy pregnant pony mares following a single transcervical infusion of 2.4 million IU of procaine penicillin and 200 mg of gentamicin in a 10 mL volume during late gestation. Assessment of fetal-placental health was performed through serial measurement of the combined thickness of the uterus and placenta (CTUP) and fetal heart rate and mares and foals were closely monitored in the periparturient period. Fetal heart rate and CTUP remained unchanged after infusion, with no evidence of fluid accumulation or significant increase at the time-points 24, 48, and 72 hours. All mares foaled without complication 12-58 days after antibiotic infusion at a mean gestational age of 322.7 ± 12.7 days. Two out of nine foals displayed signs of mild neonatal maladjustment syndrome that responded to minimal supportive care and all foals survived to weaning without further complications.

Effects of the 2018 Camp Fire on birth outcomes in non-human primates: Case-control study.

The November 2018 Camp Fire, a devastating wildfire in Northern California, occurred during the peak of breeding season for field monkeys at the California National Primate Research Center (CNPRC). Effects of environmental stressors, such as wildfires, on birth outcomes in primates, and in humans, are poorly understood. Additionally, wildfires are of growing concern due to their increasing frequency and severity. The objective was to examine the impact of wildfire smoke on fertility, timing of birth, and pregnancy loss for field monkeys. A unique case-control study to investigate birth outcomes in rhesus macaques (Macaca mulatta) was conducted at the CNPRC. All females in the study were maintained in outdoor fields during a period of elevated ambient wildfire smoke from November 8-22, 2018. In addition to ambient air quality evaluations, the effects on fertility, timing to birth, and pregnancy loss were documented. Archival records of approximately 5,000 conceptions from the previous nine years served as control data. During the Camp Fire, ambient fine particulate (PM 2.5) levels exceeded the 24 -h National Ambient Air Quality Standard (35 µg/m 3) of the United States Environmental Protection Agency, reaching levels as high as 185 µg/m 3. A statistically significant association was observed between birth loss and the 2018-2019 CNPRC breeding season. As this wildfire event occurred during various stages of early pregnancy, an association can be inferred between early gestational exposure and increased risk of pregnancy loss.

Induced prostaglandin release alters steroid concentrations but not pregnancy survival in cows.

Embryonic mortality (EM) is a major factor limiting reproductive efficiency in cattle, and despite negative connotations related to reproductive performance, prostaglandin F2α (PGF2α) is capable of being released by the uterus by Day 30 of gestation. Therefore, the objective was to evaluate differences in PGF2α release after an oxytocin challenge between cows with high circulating concentrations of pregnancy-associated glycoproteins (PAGs) vs low PAG because of the association of increased PAG concentrations with pregnancy success. At Day 30 of gestation, pregnant cows were divided into oxytocin treatment (OT; n = 13) and control (CON; n = 12) groups. Treatment cows were further subdivided by circulating PAG concentration (high PAG, n = 7; and low PAG, n = 6). Blood samples were collected every 30 min beginning 1 h before oxytocin administration and continuing for 4 h. Prostaglandin F2α metabolite (PGFM), progesterone, estradiol-17ß (E2), and PAG concentrations were quantified. The peak concentration of PGFM occurred 2 h after oxytocin injection in treatment animals and returned to baseline levels by 4 h. No correlations were observed between PAG and PGFM, progesterone, or E2 concentrations (P > 0.05). There was no difference in initial or final PGFM concentrations between groups (P > 0.05). Progesterone and E2 concentrations decreased in cows after treatment of oxytocin (P < 0.05); however, only progesterone returned to basal concentrations by the end of the sampling period. In summary, cows with high vs low PAG concentrations at Day 30 of gestation have a similar PGFM response to oxytocin challenge.

Rewiring of gene expression in circulating white blood cells is associated with pregnancy outcome in heifers (Bos taurus).

Infertility is a challenging phenomenon in cattle that reduces the sustainability of beef production worldwide. Here, we tested the hypothesis that gene expression profiles of protein-coding genes expressed in peripheral white blood cells (PWBCs), and circulating micro RNAs in plasma, are associated with female fertility, measured by pregnancy outcome. We drew blood samples from 17 heifers on the day of artificial insemination and analyzed transcript abundance for 10,496 genes in PWBCs and 290 circulating micro RNAs. The females were later classified as pregnant to artificial insemination, pregnant to natural breeding or not pregnant. We identified 1860 genes producing significant differential coexpression (eFDR < 0.002) based on pregnancy outcome. Additionally, 237 micro RNAs and 2274 genes in PWBCs presented differential coexpression based on pregnancy outcome. Furthermore, using a machine learning prediction algorithm we detected a subset of genes whose abundance could be used for blind categorization of pregnancy outcome. Our results provide strong evidence that transcript abundance in circulating white blood cells is associated with fertility in heifers.

Short communication: Effect of timing of induction of ovulation relative to timed artificial insemination using sexed semen on pregnancy outcomes in primiparous Holstein cows.

Our objective was to determine the effect of increasing the interval from induction of ovulation to timed artificial insemination (TAI) on fertility by decreasing the interval from TAI to ovulation using sexed semen within a synchronized breeding program. Our hypothesis was that induction of ovulation earlier relative to TAI would increase pregnancies per artificial insemination (P/AI). Primiparous Holstein cows from 3 commercial dairy farms in the United States were submitted to a Double-Ovsynch protocol for first service as follows: Pre-Ovsynch (GnRH; 7 d, PGF2α; 3 d, GnRH), followed 7 d later by Breeding-Ovsynch [GnRH (G1); 7 d, PGF2α; 24 h, PGF2α], followed by the last GnRH treatment (G2), which varied between treatments, and TAI. To vary the interval between G2 and TAI, cows were randomized to 2 treatments to receive G2 either 16 (G2-16; n = 373) or 24 (G2-24; n = 357) h before TAI, which was fixed at 48 h after the second PGF2α treatment of the Breeding-Ovsynch portion of the protocol. All cows were inseminated with sexed semen, and each herd used sires of their choosing, which were randomly allocated between treatments. Pregnancy diagnosis was conducted by herd veterinarians using transrectal ultrasonography. In disagreement with our hypothesis, G2-24 cows had fewer P/AI than G2-16 cows at 34 ± 3 d (44 vs. 50%) and 80 ± 17 d (41 vs. 48%) after TAI. Pregnancy loss (5 vs. 6%) and fetal sex ratio (92:8 vs. 90:10, female:male) did not differ between treatments for G2-16 and G2-24 cows, respectively. Thus, we reject our hypothesis and conclude that induction of ovulation earlier relative to TAI with sexed semen for first service after a Double-Ovsynch protocol decreased P/AI in primiparous Holstein cows.

Ultrasonographic examination of postpartum uterine involution in sows.

Physiological uterine involution during the puerperium period is essential for sow reproductive health. Uterine involution in sows has mainly been described using macroscopic and histological examination after slaughter. The aim of this study, therefore, was to describe the continuous regression of uterine diameter from day 2-14 after parturition and on the day before weaning using ultrasonography in sows housed in a free farrowing system and in farrowing crates. Diameter of three uterine cross-sections was measured at 24 -hs intervals in 46 sows housed in a free farrowing system in Switzerland and 49 sows housed in farrowing crates in Germany. Overall, there was continuous regression of uterine diameter during the lactation period in both groups. Median diameter of the uterus decreased from 32.4 mm (min: 18.6 mm, max: 52.3 mm) on day 2-9.0 mm (min: 7.6 mm, max: 12.7 mm) on the day before weaning (on average 30 days p.p.) in sows housed in free farrowing systems. Median diameter of the uterus of sows in farrowing crates decreased from 38.5 mm on day 2 (min: 21.6 mm, max: 56.3 mm) to 10.1 mm (min: 8.8 mm, max: 13.6 mm) the day before weaning (on average 29 days p.p.). Interestingly, parity, obstetrical intervention and administration of oxytocin was not associated with the decrease of uterine diameter during the study period. In summary, the ultrasonic examination is a suitable method to evaluate diameter of the uterus during the puerperium period in sows and to describe uterine involution in vivo.

Maternal supplementation of organic selenium during gestation improves sows and offspring antioxidant capacity and inflammatory status and promotes embryo survival.

Selenium (Se) is an essential trace element in humans and sows, having a biological function mediated in part by its incorporation into selenoproteins. This study was conducted to investigate the effects of maternal 2-hydroxy-4-methylselenobutanoic acid (HMSeBA), an organic Se source, on reproductive performance, antioxidant capacity and inflammatory status of sows and their offspring. Forty-three Landrace × Yorkshire sows were randomly allocated to receive one of the following three diets during gestation: control diet (control, basal diet, n = 15), sodium selenite (Na2SeO3) supplemented diet (Na2SeO3, basal diet + Na2SeO3 at 0.3 mg Se per kg, n = 13), and HMSeBA supplemented diet (HMSeBA, basal diet + HMSeBA at 0.3 mg Se per kg, n = 15). Blood samples of sows and piglets, placentas and piglet liver samples were analyzed for selenium status, antioxidant capacity and inflammatory cytokines. Results showed that, as compared to the control group, HMSeBA supplementation increased the number of born alive piglets and plasma concentrations of total selenium and selenoprotein P in both sows and piglets. Besides, the activities of antioxidant enzymes in the blood of sows, umbilical cord and piglets, placentas and piglets' liver were increased by dietary HMSeBA supplementation as compared to the control group, while malondialdehyde concentration (p < 0.05) was decreased in the blood of sows, umbilical cord and newborn piglets. In addition, maternal HMSeBA intake during gestation up-regulated antioxidant-related selenoprotein gene expression in the placenta (GPx2, GPx3, p < 0.05) and in the liver of newborn piglets (GPx1, GPx2, GPx3, TXNRD2, p < 0.05). Moreover, as compared to the control group, sows and newborn piglets in the Na2SeO3 and HMSeBA groups had a lower serum interleukin-6 (p < 0.05) concentration, and placentas in the HMSeBA group had lower IL-1ß, IL-6 and IL-8 gene expression (p < 0.05). In conclusion, maternal supplementation of HMSeBA during pregnancy improved antioxidant capacities and reduced the inflammation level in mater, placenta, and fetus. This finding may highlight the important role of selenoproteins (especially GPXs) in preventing negative consequences of over-production of free radicals and inflammatory cytokines during gestation and at births.

Effect of estrous detection strategy on pregnancy outcomes of lactating Holstein cows receiving artificial insemination and embryo transfer.

Objectives of the current experiment were to evaluate the effects on reproductive performance of adding an automated estrous detection (AED) device to the reproductive management of Holstein cows. In addition, we aimed to determine whether the AED device would equally influence the reproductive performance of cows receiving artificial insemination and those receiving embryo transfer. Cows (n = 1,244) were observed daily for estrous detection by trained farm personnel with the aid of a tail head mounting device. Cows (n = 641) enrolled in the AED treatment were fitted with a neck-mounted automated estrus detection device, and cows enrolled in the control (CTRL, n = 603) treatment were not fitted with the AED device. Cows not detected in estrus by 54 ± 3 DIM received 1 injection of PGF2α, and those not detected in estrus by 68 ± 3 DIM were enrolled in an ovulation synchronization protocol. The hazard of first service tended to be affected by treatment [CTRL: referent, AED: adjusted hazard ratio (AHR) = 1.11, 95% confidence interval (CI) = 0.98, 1.25], and we determined a tendency for the AED treatment to reduce the proportion of cows receiving the first service at fixed time (39.7 ± 5.7 vs. 45.5 ± 5.8%). After the first service, high-producing cows enrolled in the AED treatment were more likely to be pregnant (19.1 ± 2.4 vs. 31.8 ± 3.0%), but no differences between the AED and CTRL treatments were observed among low-producing cows (24.9 ± 2.9 vs. 24.7 ± 2.9%). The hazard of second service was affected by treatment (CTRL: referent, AED: AHR = 1.22, 95% CI = 1.01, 1.47), and the AED treatment reduced the proportion of cows receiving the second service at fixed time compared with the CTRL treatment (15.7 ± 2.2 vs. 21.9 ± 2.5%). After the second service, the AED treatment tended to increase the proportion of cows pregnant (31.0 ± 3.0 vs. 24.9 ± 2.6%) and tended to reduce the proportion of cows that lost pregnancy between the first and second pregnancy exams (9.7 ± 3.3 vs. 16.7 ± 4.6%). The interaction between treatment and type of service did not affect percentage of cows pregnant and pregnancy loss to the first and second services. The hazard of pregnancy was affected by the interaction between treatment and milk yield, in that cows with above the median milk yield in the AED treatment became pregnant at a faster rate than CTRL cows, but no difference between treatments was observed among cows with milk yield below the median. Cows with above the median milk yield had shorter duration of estrus and were less likely to have activity peak at estrus ≥89 (0 = minimum, 100 = maximum). The current experiment suggests that AED devices may improve reproductive performance not only by increasing service rates but also by improving accuracy of estrous detection. According to the current experiment, high-producing cows may benefit most from the addition of AED devices to reproductive management.

Managing embryonic and calves losses after twin pregnancies induced by transfer of in vitro-produced Nellore embryos.

Two farms applying reproductive technology for the Nellore beef cattle were selected. Both farms had the same technology programme of oestrous synchronization and embryo transfer, but management was different, especially regarding twins pregnancies. In the present study, we followed the farms from the moment of oestrous synchronization, embryo transfer (two per cow), until delivery and first care of the calves. In farm A, cows presenting twin pregnancies (5 from 13) were submitted to delivery induction, as well as calves and cows were monitored after birth. In farm B, such management was not followed with the twin pregnant cows (31 from 49). In both farms, freemartinism was detected, but this was not a problem as none of the animals would be selected for breeding. No dystocia was observed in farm A, while 48% of the twin pregnancies in farm B ended up in dystocia. Furthermore, the mortality rate of new-born calves in farm A was 10%, while in farm B it reached 32%. Although twin pregnancies remain a concern, we showed here that proper management during and after delivery minimizes animal and economic losses.

Characterization of Vaginal Microbiota Associated with Pregnancy Outcomes of Artificial Insemination in Dairy Cows.

The profitability of the dairy and beef industries is largely affected by the actually achieved reproductive efficiency. Although a large proportion of cows worldwide are bred by artificial insemination (AI) services, many potential factors affecting the outcome of pregnancy by AI remain to be addressed. In the present study, we investigated the vaginal microbiota by high-throughput sequencing of 16S rRNA gene and analyzed their association with differential pregnancy outcomes (i.e., pregnant vs. nonpregnant) of multiple AI services in dairy cows. Sequencing of the V3-V4 region totally produced 512,046 high-quality sequences that were computationally clustered into 2,584 operational taxonomic units (OTUs). All OTUs were taxonomically assigned to 10 bacterial phyla. There were statistically significant differences among the three AI service times (T1, T2 and T3) with respect to the Shannon index and number of observed OTUs (p < 0.05). Bray-Curtis distance-based PCoA analysis also revealed that T2 group could be significantly distinguished from T1 and T3. However, no significant difference between the pregnant and nonpregnant cows was found in confidence regarding both alpha diversity and beta diversity. These results could help us better understand the possible influence of vaginal microbial community on pregnancy outcomes of AI service in cows.

Reproductive Outcomes in Rhesus Macaques (Macaca mulatta) with Naturally-acquired Trypanosoma cruzi Infection.

Chagas disease is a zoonotic vector-borne disease caused by infection with the protozoan parasite Trypanosoma cruzi. T. cruzi is found in Latin America and the Southern United States, where it infects many species, including humans and nonhuman primates (NHPs). NHPs are susceptible to natural infection and can develop clinical symptoms consistent with human disease, including Chagasic cardiomyopathy, gastrointestinal disease and transplacental transmission, leading to congenital infection. Due to evidence of Chagas transmission in Texas, this study hypothesized T. cruzi infection was present in a closed, outdoor-housed breeding colony of rhesus macaques (Macaca mulatta) located at a biomedical research facility in Central Texas. In addition, we questioned whether seropositive female rhesus macaques might experience reproductive complications consistent with maternal-fetal Chagas disease. The seroprevalence of T. cruzi infection in the colony was assessed using an Enzyme Linked Immunosorbant Assay (ELISA) to detect antibodies against Tc24 antigen as a screening assay, and a commercially available immunochromatographic test (Chagas Stat Pak) as a confirmatory assay. Retrospective serologic analysis was performed to confirm the status of all T. cruzi-infected animals between the years 2012 to 2016. The medical history of all seropositive and seronegative breeding females within the colony from 2012 to 2016 was reviewed to determine each animals' level of reproductive fitness. The percentage of T. cruzi-seropositive animals ranged from 6.7% to 9.7% in adult animals and 0% to 0.44% in juveniles or weanling animals, depending on the year. An overall 3.9% seroprevalence of T. cruzi infection was found in the total population. No significant differences in any measure of reproductive outcomes were identified between seropositive and seronegative females from 2012 to 2016. The lack of significant adverse reproductive outcomes reported here may help inform future management decisions regarding seropositive female rhesus macaques within breeding colonies.

Cryopreservation of equine oocytes: looking into the crystal ball.

Invitro embryo production has evolved rapidly in the horse over the past decade, but blastocyst rates from vitrified equine oocytes remain quite poor and further research is needed to warrant application. Oocyte vitrification is affected by several technical and biological factors. In the horse, short exposure of immature oocytes to the combination of permeating and non-permeating cryoprotective agents has been associated with the best results so far. High cooling and warming rates are also crucial and can be obtained by using minimal volumes and open cryodevices. Vitrification of invivo-matured oocytes has yielded better results, but is less practical. The presence of the corona radiata seems to partially protect those factors that are necessary for the construction of the normal spindle and for chromosome alignment, but multiple layers of cumulus cells may impair permeation of cryoprotective agents. In addition to the spindle, the oolemma and mitochondria are also particularly sensitive to vitrification damage, which should be minimised in future vitrification procedures. This review presents promising protocols and novel strategies in equine oocyte vitrification, with a focus on blastocyst development and foal production as most reliable outcome parameters.

Maternal weight affects placental DNA methylation of genes involved in metabolic pathways in the common marmoset monkey (Callithrix jacchus).

Accumulating evidence suggests that dysregulation of placental DNA methylation (DNAm) is a mechanism linking maternal weight during pregnancy to metabolic programming outcomes. The common marmoset, Callithrix jaccus, is a platyrrhine primate species that has provided much insight into studies of the primate placenta, maternal condition, and metabolic programming, yet the relationships between maternal weight and placental DNAm are unknown. Here, we report genome-wide DNAm from term marmoset placentas using reduced representation bisulfite sequencing. We identified 74 genes whose DNAm pattern is associated with maternal weight during gestation. These genes are predominantly involved in energy metabolism and homeostasis, including the regulation of glycolytic and lipid metabolic processes pathways.

Measurements of circulating progesterone and estrone sulfate concentrations as a diagnostic and prognostic tool in porcine pregnancy revisited.

The main goal of this study was to examine the utility of measuring systemic concentrations of steroid hormones, namely progesterone (P4) and estrone sulfate (E1S), for monitoring the progression of porcine pregnancy and predicting sow fertility. There were 3 subsets of artificially inseminated (AI'd) sows used in the present experiments: (i) animals sacrificed on gestational day 20 (gd20; n = 16) or (ii) gd50 (n = 16; Experiment 1), and (iii) animals maintained throughout pregnancy (n = 24; Experiment 2). Blood samples (10 mL) were drawn from the orbital sinus and the endocrine data determined at different time points around ovulation/artificial insemination (gd0 (first AI), gd1 (second AI), and gd2) and maternal recognition of pregnancy (gd11), as well as on gd20 and gd50 (during 2 periods of increased embryonic/fetal mortality in swine) were examined for correlations with the numbers of healthy, arrested, and reabsorbing embryos (Experiment 1) or with the number of live, stillborn, and mummified piglets recorded at farrowing (Experiment 2). No correlations were recorded between circulating concentrations of both steroids and the numbers of healthy, arresting, or reabsorbing conceptuses on gd20 or 50 (Experiment 1). The number of corpora lutea (CL) was directly related to the number of healthy embryos/conceptuses on gd20 and 50 (r = 0.71, P = 0.007 and r = 0.76, P = 0.0007, respectively) and the number of arresting embryos on gd20 (r = 0.54, P = 0.05), and negatively correlated with the number of reabsorbing embryos on gd20 (r = -0.53, P = 0.05). In Experiment 2, circulating P4 concentrations on gd11 related directly to the number of live-born piglets (r = 0.46, P < 0.04). Systemic E1S concentrations on gd0, gd1, gd2 and gd50 were correlated with the number of mummified conceptuses recorded at farrowing (r = 0.50, P = 0.03; r = 0.59, P = 0.01; r = 0.48, P = 0.04; and r = 0.56, P = 0.01, respectively) and plasma concentrations of E1S on gd20 related directly to the number of stillborn piglets (r = 0.60, P = 0.02). In summary, the number of CL on gd20 and 50 is a reliable marker of embryonic/fetal pig status. Measurements of P4 and E1S on gd20 and 50 showed limited diagnostic value (ie, were not indicative of the number of healthy and abnormally developing embryos/fetuses). However, measurements of circulating P4 and E1S concentrations during the periconceptional period and in the early/mid-pregnancy of sows have the makings of a practical method to predict gestational outcomes.