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Heifer conception rate to the first service (HCR1) is defined as the number of heifers that become pregnant to the first breeding service compared to the heifers bred. This study aimed to identify loci associated and gene sets enriched for HCR1 for heifers that were bred by artificial insemination (AI, n = 2829) or were embryo transfer (ET, n = 2086) recipients, by completing a genome-wide association analysis and gene set enrichment analysis using SNP data (GSEA-SNP). Three unique loci, containing four positional candidate genes, were associated (p < 1 × 10−5) with HCR1 for ET recipients, while the GSEA-SNP identified four gene sets (NES ≥ 3) and sixty-two leading edge genes (LEGs) enriched for HCR1. While no loci were associated with HCR1 bred by AI, one gene set and twelve LEGs were enriched (NES ≥ 3) for HCR1 with the GSEA-SNP. This included one gene (PKD2) shared between HCR1 AI and ET services. Identifying loci associated or enriched for HCR1 provides an opportunity to use them as genomic selection tools to facilitate the selection of cattle with higher reproductive efficiency, and to better understand embryonic loss. [ABSTRACT FROM AUTHOR]

Simple Summary: Early pregnancy diagnosis is of major importance to the economics of dairy herds. The detection of placental proteins, termed pregnancy-associated glycoproteins (PAGs), represents a diagnostic tool to identify both pregnant and non-pregnant cows. However, as milk production correlates negatively with plasma levels of PAGs during early pregnancy, detection of PAGs may be hindered by high milk production. This study evaluates a newly developed commercial PAGs-based pregnancy test using whole blood or plasma samples during early pregnancy (28–55 days of gestation) in high-producing dairy cows. This study evaluated a commercial pregnancy-associated glycoproteins (PAGs)-based pregnancy test using whole blood or plasma samples during early pregnancy (28–55 days of gestation) in high-producing dairy cows. Transrectal ultrasonography was used as the gold standard method. The study population constituted of 284 cows. False positive diagnoses were recorded from Day 60 to 89 and from Day 60 to 99 postpartum in blood and plasma samples, respectively. In early pregnancy screening, correct positive diagnoses were recorded in 75% and 100% of blood and plasma samples, respectively. High milk production was associated with negative results in blood samples and with the lowest test line intensity in plasma samples. False positive or negative diagnoses were recorded in 0% of both types of samples in cows previously diagnosed as pregnant and showing signs of estrus. In conclusion, the use of plasma was more effective than the use of blood in early pregnancy diagnosis. In cows previously diagnosed as pregnant and showing signs of estrus, both types of samples showed the same results. Because of large individual variations, normal single pregnancies could not be differentiated from twin pregnancies, from pregnancies with a recently dead conceptus, or from pregnancies that experienced subsequent pregnancy loss. [ABSTRACT FROM AUTHOR]

The current study was executed on postpartum (45-60 days) Jaffarabadi buffaloes from March to June 2023 (summer season), aimed at ascertaining how summer stress mitigation protocols affect conception rates and different biomarkers associated with oxidative stress of summer. The open animals were subjected to timed artificial insemination (TAI) Ovsynch protocol of estrus induction cum synchronization, and responded 24 buffaloes were randomly assigned to four different treatment/mitigation protocols or groups after AI (n=06 per protocol), viz., the NSAID protocol, the antioxidant protocol, the P4 protocol, and a control group. The percent conception rates at 35th day (USG) and at 60th day (per rectal palpation) in buffaloes under four groups were 50.00 and 0.00 %, 50.00 and 33.34%, 16.67 and 16.67%, and 16.67 and 16.67%, respectively, indicating embryonic loss between day 35 and 60 post-AI to the extent of 100% and 33.34% in NSAID and antioxidant treated groups, respectively, and nil in other two groups. The overall mean cortisol concentration was significantly (p<0.05) higher in P4 supplemented than the control group, but it did not vary statistically between conceived, non-conceived, or animals with embryonic death groups or sampling days. The plasma MDA was significantly (p<0.05) lower in the antioxidant group and higher in the P4 treated group. It also was significantly (p<0.05) higher in animals with embryonic mortality than those of the conceived and non-conceived groups. The TAC level was significantly higher in the antioxidant group and lower in the P4 group. However, among the conceived, non-conceived, and animals with embryonic mortality, as well as across the sampling days, the mean TAC levels did not differ significantly. It was concluded that oxidative stress was the reason behind the embryonic losses in Jaffarabadi buffaloes, and that no treatment protocol was able to improve the summer conception rate. [ABSTRACT FROM AUTHOR]

Background: Hormonal and physiological changes during pregnancy period have significant effects on animals’ metabolisms. The purpose ofthe present study is to evaluate the variations of aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) levels according to different gestation trimesters of the pregnant mares to assess changes of embryonic losses and abortions. Materials, Methods & Results: Blood samples from 49 throughbred mares were analysed during this study. Age ratio of the mares is 5-18 years and their body condition score (BCS; score 1 to 9) varies between 5 and 6. A total of 28 mares had given birth to healthy foals at the end of a healthy gestation period (Group C), whereas 11 mares had embryonic losses (Group E) and 10 mares had late period abortions (Group A). Following the confirmation of pregnancy, one blood sample per gestation trimester were taken (14-16 days of pregnancy for 1st trimester; 180 days for 2nd trimester, 270 days for 3rd trimester). Early embryonic losses (loss of a 16-25 days embryo) were observed in 6 of 11 mares in Group E and the 5 of 11 mares had late period embriyonic losses (loss of a 35-40 days embryo). In Group A, 6 mares had the abortion within 7th month and the remaining 4 mares had the abortion within the 8th month of pregnancy. Repeated Measures ANOVA, Kruskal-Wallis test and Mann-Whitney test were performed for statistical analysis, the mean AST level in Group C (n = 28) was higher during the 1st trimester in comparison to 2 following trimesters (respectively: P = 0.011 ; P = 0.01). Besides, no statistical difference was observed between 2nd and 3rd trimester regarding AST activation (P > 0.05). The mean GGT level in Group C was significantly decreased lower in the 3rd trimester compared to 1st and 2nd trimester (respectively: P = 0.007 ; P = 0.009). No statistical difference was observed between 2nd and 3rd trimester regarding GGT activation (P > 0.05). Among all groups (C, E, A) no significant difference was observed on AST levels (P > 0.05), nonetheless GGT levels had a significant rise (P = 0.039) in Group A in comparison to the 1st trimester levels of Group C. In Group A, there was a statistical decrease of AST during the 2nd trimester in comparison to the 1st trimester (P = 0.001), accompanied by a decrease of GGT activation during the 2nd trimester compared to the 1st trimester (P = 0.009). Discussion: The aminotransferases are catalisors that play an important role on the metabolism of amino acids and carbonhydrates. Although serum AST levels were within the reference ranges during 3 trimesters in this study, serum AST levels were determined to be decreased in the 2nd and 3rd trimesters in healthy pregnant mares compared to the 1st trimester. It is thought that these results can be obtained due to the increase in metabolic needs during pregnancy. In this study, serum GGT levels remained within physiological limits with a tendency to decrease as the pregnancy advances, in accordance with previous study results. Serum GGT levels that are used as an indicator to liver damage may vary during the pregnancy as a result of increased metabolic load. It is thought that the increase of serum GGT levels in Group A might be related to the fetal (chromosome-related) issues that may result to pregnancy losses. As a result, it is considered that serum AST and GGT levels in mares might be valuable parameters that predict embryonic loss or abortus cases. [ABSTRACT FROM AUTHOR]

Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) and is primarily transmitted by Aedes species mosquitoes; however, ZIKV can also be sexually transmitted. During the initial epidemic and in places where ZIKV is now considered endemic, it is difficult to disentangle the risks and contributions of sexual versus vector-borne transmission to adverse pregnancy outcomes. To examine the potential impact of sexual transmission of ZIKV on pregnancy outcome, we challenged three rhesus macaques (Macaca mulatta) three times intravaginally with 1 x 107 PFU of a low passage, African lineage ZIKV isolate (ZIKV-DAK) in the first trimester (~30 days gestational age). Samples were collected from all animals initially on days 3 through 10 post challenge, followed by twice, and then once weekly sample collection; ultrasound examinations were performed every 3-4 days then weekly as pregnancies progressed. All three dams had ZIKV RNA detectable in plasma on day 3 post-ZIKV challenge. At approximately 45 days gestation (17-18 days post-challenge), two of the three dams were found with nonviable embryos by ultrasound. Viral RNA was detected in recovered tissues and at the maternal-fetal interface (MFI) in both cases. The remaining viable pregnancy proceeded to near term (~155 days gestational age) and ZIKV RNA was detected at the MFI but not in fetal tissues. These results suggest that sexual transmission of ZIKV may represent an underappreciated risk of pregnancy loss during early gestation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Faculty of Veterinary Medicine, Erciyes University / Erciyes Üniversitesi Veteriner Fakültesi Dergisi is the property of Erciyes University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-lactating multiparous NZW rabbit does (n = 227) were used in two experiments. In the 1st experiment (n = 87), does were i.m. injected with 0.1-ml saline/doe in day 0 (control, n = 29). Other does were injected with 25 IU equine chorionic gonadotrophin (eCG), followed by 0.2-ml gonadotrophin-releasing hormone (GnRH, n = 29) or 75 IU human chorionic gonadotrophin (hCG, n = 29) per doe 48 h later. After 60 h of day 0, does in all groups were artificially inseminated (AI). In the 2nd experiment, does (n = 140) were mated (AI) after synchronization of estrus/ovulation with 25 IU eCG, and 75 IU hCG 48 h later. On day 5 post-AI, does were injected with saline (control), 75 IU hCG, 0.2 ml GnRH, or 25 IU eCG per doe. Injection of eCG with GnRH or hCG pre-AI significantly increased corpora lutea number, ovulation rate, total number/doe and recovery rate of embryos, viable embryos, hatched blastocysts, in vivo reproductive parameters, and concentration of progesterone and progesterone/estradiol 17-β ratio. Injection of eCG on day 5 post-AI significantly improved large and total follicle number, and in vivo reproductive efficiency. The corpora lutea number and impantation sites were significantly increased in the hCG and eCG groups. Fetal loss rate significantly increased only in the GnRH group. Under high ambient temperature, administration of eCG with hCG or GnRH injection pre-AI could be synchronized estrus/ovulation for improving in vivo and in vitro embryo production. In addition, pregnancy outcomes could be enhanced in rabbit does induced to ovulation by a single eCG or hCG dose on day 5 post-AI. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the fertility of sexed semen compared with conventional semen with regard to the puberty and breeding ages of Holstein dairy heifers subjected to double Ovsynch protocol with fixed time of artificial insemination. A total of 468 Holstein heifers were divided into two groups. The first group was 122 dairy heifers inseminated via conventional semen, while the second group was 346 heifers inseminated with sexed semen. The puberty and breeding ages of heifers were determined from the farm records. Estrus was synchronized using the double Ovsynch protocol. Numbers were estimated for pregnancy at 40 and 60 days post insemination, embryonic loss, and abortion. The results revealed that the heifers inseminated with sexed semen had a significantly lower first-service pregnancy rate (51.45%) than those inseminated with conventional semen (61.47%). Heifers achieving puberty before 350 days old had a higher pregnancy rate. Embryonic losses and abortion rates did not differ between the two types of semen. Holstein heifers subjected to Ovsynch protocol with sexed semen had an acceptable first-insemination pregnancy rate. Even the applications of sexed semen reduce the reproductive fertility and pregnancy rate in Holstein heifers. [ABSTRACT FROM AUTHOR]

Summary: Background: In vitro embryo production (IVEP) is increasingly popular but data assessing the outcome of transferred embryos are scarce. Objectives: To determine the likelihood of pregnancy and embryonic loss after transfer of frozen‐thawed IVP embryos and identify factors influencing success. Study design: Retrospective clinical study. Methods: Blastocysts (n = 261) were produced from immature oocytes of Warmblood mares (n = 116) by Intracytoplasmic Sperm Injection (ICSI) and in vitro culture, and cryopreserved. Thawed IVP embryos were transferred into recipient mares on day 4, 5 or 6 after ovulation. The influence of donor mare (age, reproductive history), recipient mare (age, reproductive status, management; in‐house vs. outpatient, day post‐ovulation), embryo (interval from ICSI to blastocyst formation) and management factors (season when ovum pickup was performed, year and method of transfer) on likelihood of pregnancy and embryonic loss was examined, and the developmental stage of the IVP embryo at the time of transfer was estimated. Results: The percentage of mares pregnant 7–10, 23 and 37 days after transfer was 56% (147/261), 49% (129/261), and 48% (124/261), respectively. Development of IVP embryos after transfer equated to day 5 or 6 in vivo embryos. With the exception of year of transfer, none of the factors had an impact on the likelihood of pregnancy or embryonic loss. Nevertheless, the likelihood of pregnancy tended to be lower for IVP embryos from infertile mares or when embryos were transferred into recipient mares on day 6 after ovulation rather than on day 4 or 5. Finally, the diameter of the embryonic vesicle 7 days post transfer was lower for pregnancies that were lost compared to those that were maintained. Main limitations: Small sample size in some of the donor and recipient mare categories. Conclusions: Cryopreserved IVP embryos should be transferred into recipient mares on day 4 or 5 after ovulation and a slower rate of post transfer vesicle expansion indicates a higher risk of subsequent embryonic loss The Summary is available in Portuguese ‐ see Supporting Information [ABSTRACT FROM AUTHOR]

Association between circulating progesterone and oestradiol-17β concentrations and embryonic loss in Frisian cows (n=105) under Egyptian condition was investigated. Total embryonic losses in present study were 26.4%. On d25, progesterone (P4) concentrations and sonography revealed 79.3% cows were continuing gestation and 20.7% lost their pregnancies (early embryonic loss, EEL). Furthermore, 7.4% cows with late embryonic loss (LEL) were detected between d25-42. An increase in P4 levels started from day 4 to 7 in cows diagnosed pregnant compared to low P4 in cows that lost pregnancy (p<0.05). Cows with LEL had decrease in P4 from d28. Estradiol (E2) concentrations increased (p<0.05) in cows with EEL starting from d4 to 21 after AI compared to cows diagnosed pregnant. Starting from d4 to 40 after AI, P4/E2 ratio was higher (p<0.05) in cows diagnosed pregnant compared to cows exhibiting EEL loss, while cows with LEL had highest P4/E2 ratio till d25 post-AI and declined from d28 to 40. [ABSTRACT FROM AUTHOR]

High reproductive performance is an element factor for profitability in dairy herds; although, pregnancy loss of non-infectious nature during early and mid-to-late embryonic period is increasing in dairy cattle. Based on that, the present study aimed to determine the incidence of pregnancy loss before and after 60 days of insemination, and to identify some non-infectious causes that could enhance it. The herd was composed by 600 crossbred dairy cows and those with a corpus luteum (CL) were treated with prostaglandinF2α, then inseminated, on the other hand, those without a CL were submitted to a timed artificial insemination protocol (TAI). Pregnancy losses rates were analyzed by logistic regression by SAS, and differences were considered significant when P < 0.05. The overall pregnancy loss and mid-to-late pregnancy loss were not affected by animal category (P > 0.05); although, early pregnancy loss was higher in cows than in heifers (11.90 vs. 3.39%). The early pregnancy loss was higher in those cows that calved on spring/summer when compared to those calved on fall/winter (9.22% vs. 16.11%), moreover, those inseminated during spring/summer tended to have higher early pregnancy loss when compared to those inseminated on fall/winter (13.35% vs. 8.57%). In conclusion, when some of non-infectious causes were evaluated, it was observed that cows that calved on spring/summer had higher pregnancy loss. At this point, strategies should be developing to minimize pregnancy loss in dairy herds, as it could be considered an important reproductive problem. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the association between circulating (Progesterone, oestradiol-17β and P4/E2 ratio) concentrations and embryonic loss in Friesian cows under Egyptian condition. On day 25 by both progesterone (P4) level and sonography, 65.71% (69/105) cows continued their gestation normally and 17.14% (18/105) cows didn't conceive. While, 17.14% (18/105) of inseminated cows showed high progesterone level firstly and decline before day 25 suspecting early pregnancy loss, EPL. Also, 5 cows (7.25%) of the pregnant cows lost their feti from day 25 to day 45 (late pregnancy loss, LPL) were detected. Blood progesterone concentrations (P4 ) increased significantly in cows diagnosed pregnant (P<0.05) compared to low P4 in cows lost pregnancy (8.03 & 8.98 ng/ml vs. 4.4 & 4.9 ng/ml respectively), starting from day 4 to day 7after AI. Cows with LPL showed increasing P4 concentration in the first 25 days and got down on days 28 and 40 accompanied with embryonic loss. concentrations of estradiol were increased significantly(P<0.05) in cows with EPL starting from days 4 to 21 after AI compared to cows diagnosed pregnant. P4/E2 ratio was significantly (P<0.05) higher in cows diagnosed pregnant starting from days 4 to 40 after AI compared to cows loss their embryos early from days 4 to 25 after mating, while LPL cows has highest P4/E2 ratio during 25 days post AI and declined on days 28 to 40 in Friesian cows. It can concluded that the percentage of EPL was 17.14% and the percentage LPL was 7.25% during the first 45 days post mating in Friesian dairy cows raised in Sakha Experimental Station. [ABSTRACT FROM AUTHOR]

An autosomal recessive genetic defect termed JH1 has been associated with early embryonic loss in the Jersey cattle breed. The genetic basis has been identified as a cytosine to thymine mutation in the CWC15 gene that changes an amino acid from arginine to a stop code. To screen for JH1 carriers in an imported Jersey population in China, a method based on a polymerase chain reaction amplification followed by a restriction fragment length polymorphism assay (PCR-RFLP) was developed for the accurate diagnosis of the JH1 allele. A total of 449 randomly chosen cows were examined with the PCR-RFLP assay, and 31 were identified as JH1 carriers, corresponding to a carrier frequency of 6.9%. The PCR-RFLP method was validated by DNA sequencing of 8 positive and 13 negative samples, with all 21 samples giving the expected DNA sequence. In addition, 3 negative and 3 positive samples were confirmed by a commercial microarray-based single nucleotide polymorphism assay. Finally, samples from 9 bulls in the United States of known status were correctly identified as carriers (5 bulls) or noncarriers (4 bulls). As the JH1 defect has most likely spread worldwide, implementing routine screening is necessary to avoid the risk of carrier-to-carrier matings and to gradually eradicate the deleterious gene. [ABSTRACT FROM AUTHOR]

The experimental objective was to examine the role of melatonin and its pathways in the maintenance of pregnancy in lactating dairy cows. Blood samples were collected at days 0, 16 and 32 after timed AI from cows (n = 200) in order to consider plasma melatonin concentrations and to conduct AOPP (advanced oxidation products of proteins) and TBARS (thiobarbituric acid reactive substances) tests. Luminal endometrial cells were collected at day 16 using a Cytobrush in all cows to determine mRNA expressions of melatonin receptor 1 (MT1), mouse double minute 2 (MDM2), MDM2 binding protein (MTBP), BCL2-associated X, apoptosis Regulator (BAX), p53 upregulated modulator of apoptosis (PUMA, gene symbol BBC3), mucin 1 (MUC1) and leukemia inhibitory factor (LIF). Plasma concentrations of melatonin were significantly greater in pregnant cows diagnosed pregnant at day 16 who sustained pregnancy to day 32 compared to nonpregnant cows at day 16, or pregnant at day 16 and who lost embryos by days 32. Concentrations of AOPP and TBARS were greater in nonpregnant cows at day 16 or pregnant at day 16 and who lost embryos by days 32 compared to those diagnosed pregnant at day 16 and who sustained pregnancy to day 32. In pregnant cows, endometrial mRNA expressions of MDM2, MTBP, MTR1 and LIF were higher compared to pregnant–embryo-loss cows (p < 0.05). In contrast, mRNA expressions of BBC3 and MUC1 were greater at day 16 in pregnant–embryo-loss cows compared to pregnant cows (p < 0.05). In conclusion, melatonin status is a modulator of embryo well-being and maintenance of pregnancy in lactating dairy cows. [ABSTRACT FROM AUTHOR]

Twin ovulations are common in horses, but twin pregnancies are rarely carried to term. Theories of how one or both twins is/are naturally eliminated in early pregnancy, termed 'embryo reduction', have been based on ultrasonographic, not morphological, studies. Here we describe conceptuses recovered transcervically between Days 15 and 28 from 31 twin and two triplet pregnancies. Signs of contact between conceptuses were deduced from those seen in one pair that remained attached by their capsules on Day 18. Signs were found on capsules in two of 10 pairs before or during fixation (immobilisation) at Days 16-17 even though contact had not been seen by ultrasound. After fixation, the signs became stronger in seven of nine unilateral pregnancies, indicated adhesion between pairs and included effects on the vitelline circulation and/or degeneration of one twin. Conceptuses recovered from five of seven unilateral twin pregnancies after the time of capsule disruption (~Day 21) evidenced embryo reduction; in the two surviving pairs, attachment between twins was near the trilaminar/bilaminar yolk-sac wall border. The findings are consistent with the notions that: (1) the capsule plays a role in initiating adhesion between twins; and (2) twin survival depends on an unencumbered trilaminar yolk-sac wall and a functional vitelline circulation. Twin births are rare in horses because contact between twin conceptuses in utero usually eliminates one by 'embryo reduction', as determined previously ultrasonographically. The present morphological study of 33 sets of multiple conceptuses reveals how contact before 'fixation' (immobilisation; Day 16) can progress to mutual adhesion and reduction before and after loss of the capsule (Day 21), with the site of adhesion affecting the severity of the effects on the conceptus undergoing elimination. [ABSTRACT FROM AUTHOR]

Reasons for performing the study: During embryo transfer (ET) the equine embryo can tolerate a wide degree of negative asynchrony but positive asynchrony of >2 days usually results in embryonic death. There is still confusion over whether this is due to the inability of the embryo to induce luteostasis or to an inappropriate uterine environment. Objectives: To assess embryo survival and development in an advanced uterine environment. Hypothesis: Embryo-uterine asynchrony, not the embryo's inability to induce luteostasis, is responsible for embryonic death in recipient mares with a >2 days chronologically advanced uterus. Methods: Experiment 1: Thirteen Day 7 embryos were transferred to the uteri of recipient mares with luteal prolongation, occasioned by manual crushing of their own conceptus, such that donor-recipient asynchrony was between +13 and +49 days. Experiment 2: Day 7 embryos were transferred to recipient mares carrying their own conceptus at Days 18 (n = 2), 15 (n = 2), 14 (n = 4), 12 (n = 4) or 11 (n = 4) of gestation. In addition, Day 8 embryos were transferred to 4 pregnant recipient mares on Day 11 of gestation. Results: No pregnancies resulted following transfer of Day 7 embryos to recipients in prolonged dioestrus with asynchronies between +13 and +49 days. However, the use of early pregnant mares as recipients resulted in 5/20 (25%) twin pregnancies, 4 of which came from the transfer of a Day 8 embryo to a Day 11 recipient. All transferred embryos showed retarded growth, with death occurring in 4/5 (80%). Conclusions and potential relevance: The results emphasise the importance of an appropriate uterine environment for embryo growth and the inability of equine embryos to survive transfer to a uterus >2 days advanced even when luteostasis is achieved. It is possible that in normal, non-ET equine pregnancy, embryo-uterine asynchrony may account for some cases of embryonic death. [ABSTRACT FROM AUTHOR]

Objective To evaluate the reproductive efficiency of horse farms in north-east Victoria and identify aspects of management to be targeted for improving reproductive efficiency. Design Retrospective study. Procedure Records from seven Thoroughbred (TB) and four Standardbred (STB) studs in north-east Victoria from 1990 to 2001 were reviewed; 8813 cycles in 4455 mares were analysed. TB mares were inseminated by natural mating, whereas STB mares (89%) were artificially inseminated. Results The overall early pregnancy rate per cycle was 68.8% for TB mares and for STB mares, 68.3%. Multiple pregnancy per cycle was more frequent in TB (8.3%) than in STB (4.6%) mares (P < 0.001). Early embryonic death occurred in 7.1% of TB and 7.5% of STB pregnancies. TB mares had fewer inseminations per cycle (1.03) than STB mares (1.43) (P < 0.001). There was a significantly lower proportion of barren reproductive status within the TB than the STB mares. Pregnancy rate per cycle among stallions ranged from 48% to 79%. Conclusions On-farm pregnancy rates in both breeds were higher than previously reported and likely reflect improvements in reproductive management. The disparity between breeds in the inseminations per cycle and proportion of barren mares exposed the differing structures of the two industries, and presents a target for improving the reproductive efficiency in STBs. The difference between breeds in the multiple pregnancy rate per cycle likely reflects the higher ovulation rate of TB mares. The variability in pregnancy rate per cycle between the 22 stallions was associated with differences in individual inherent fertility and the quality of stallion management. [ABSTRACT FROM AUTHOR]

Objective A suboptimal uterine environment contributes to the bovine repeat breeder syndrome. Subclinical endometritis is a component, so the mechanism by which inflammation affects embryo survival was investigated by assessing the effect of non-cellular products of an inflamed endometrium on embryo development to blastocyst. Design Endometrial fluid from a lactating dairy cow was collected by lavage using embryo culture medium. Aseptic inflammation was then induced by infusion of glycogen and lavage was repeated 6 h later. The recovered fluid was used to culture Day 5 in-vitro-derived embryos for 2 days. Embryo development and quality were compared for two treatment groups (culture media conditioned by inflamed or non-inflamed endometrium) and two controls (control or control + serum). Results Development to blastocyst was higher for conditioned media or media + serum (inflamed 42.2%; non-inflamed 49.3%; control + serum 50.9%; control 16.9%; P < 0.001). Blastocyst cell numbers were lower for the conditioned-inflamed group (inflamed, 83.1; non-inflamed, 99.8; control + serum, 100.6; control, 110.1; P < 0.001). Trophectoderm cell number, but not inner cell mass number, was reduced in the conditioned-inflamed group and the inner cell mass:trophectoderm ratio was increased (P < 0.001). Conclusion Altering the embryo culture environment with the products of endometrial inflammation had a subtle effect on embryo quality. An increased inner cell mass:trophoblast ratio is likely to negatively affect embryonic survival. Altered embryo quality is a mechanism for early embryonic failure in cows with subclinical endometritis. Culture of embryos with normal endometrial fluid may improve in vitro embryo production. [ABSTRACT FROM AUTHOR]

After resection and reanastomosis, ovum recovery and fertilization were studied in the rabbit oviduct. From these data the ovum and embryo loss was calculated. Loss was most pronounced in ampullary operated tubes and after a short recovery period. [ABSTRACT FROM PUBLISHER]

Copyright of Journal of Faculty of Veterinary Medicine, Erciyes University / Erciyes Üniversitesi Veteriner Fakültesi Dergisi is the property of Erciyes University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Blood tests to determine pregnancy status as early as 28 days post-breeding based on circulating concentrations of pregnancy-associated glycoproteins (PAGs) are currently available for use in the beef industry. The objective of this study is to determine the accuracy associated with determining early embryonic loss based on visual observation of color change and optical density (OD) using the IDEXX bovine pregnancy test and the IDEXX rapid visual test. Beef cattle from 6 different herds were synchronized using a recommended CIDR based protocol. Pregnancy status was first determined by transrectal ultrasonography between day 32 to 42 post-breeding and blood samples were collected from pregnant animals at this time (n = 492). A final pregnancy determination was performed after the end of the breeding season to determine embryonic loss. Each serum sample was examined in duplicate using the IDEXX Bovine Pregnancy Test and the IDEXX Rapid Visual Test. The results from both the bovine pregnancy test and the rapid visual test were analyzed using a microtiter plate reader. Additionally, the rapid visual test was individually scored and evaluated by two technicians unaware of pregnancy status or embryonic loss. The scoring system consisted of yes/no and a numerical value (0-3) based on color compared to negative and positive controls. Data was analyzed using the GLIMMIX procedure of SAS with herd as a random variable. Overall there were 28 (5.7%) animals that lost an embryo. The bovine pregnancy test indicated decreased circulating concentrations of PAGs in animals that lost an embryo (P = 0.01; 2.45 ± 0.11 vs 2.74 ± 0.04 OD). With the rapid visual test both technicians visually scored the animals that lost an embryo lower compared to animals that did not lose an embryo (P < 0.01; 2.77 ± 0.6 vs 2.93 ± 0.01 and 2.78 ± 0.06 vs 2.96 ± 0.03 for technician 1 and 2, respectively). However, of the animals that lost an embryo only two were identified as not pregnant by the rapid visual test, and of the animals that maintained their embryo only one was falsely identified as not pregnant (0.2%). In summary, both bovine pregnancy tests were sensitive at detecting differences in circulating PAGs among animals that experienced embryonic loss, but the majority of these animals would have been classified as pregnant at time of sample collection. [ABSTRACT FROM AUTHOR]

Background: Pregnancy loss is a major source of infertility in dairy cows. Despite a fertilization rate after insemination (AI) of approximately 90%, calving rates are 30%–50%, indicating the occurrence of extensive embryonic and foetal losses. The aim of this study was to establish the extent and pattern of embryonic and foetal loss in Swedish Red (SR) and Swedish Holstein (SH) dairy cows, as well as, the relationship to oestrus intensity (OI) and progesterone (P4) concentration. In total, 2130 AIs and 16,176 milk P4 samples from 359 SR and 212 SH dairy cows were included in the study. Pregnancy losses were estimated using data from P4 values combined with AI information and calving data. Results: Total pregnancy loss from AI to the day of calving was 65%. Early embryonic loss, late embryonic loss and foetal loss were estimated to be 29, 14 and 13%, respectively. There is strong evidence in the literature that P4 concentrations at different time points are associated with pregnancy loss. In the present study, cows with pregnancy losses had significantly higher P4 levels at the day of AI and significantly lower P4 concentration at days 10, 21 and 30 after AI compared to pregnant cows. Swedish Red cows had significantly lower total pregnancy losses compared to SH cows (62% and 68% respectively, P = 0.017). Early embryonic loss was 6.7% points lower for cows inseminated at a stronger OI (OI = 3) compared to at a weaker OI (OI = 2, P = 0.006). Cows inseminated at ovulation number ≥ 5 had significantly lower early pregnancy losses compared to cows inseminated at first or second ovulation (11.5 and 8% points, respectively, P < 0.05). With an increase of one SD of milk (448 kg ECM) during the first 60 days in milk, early embryonic loss increased by 4.7% points (P = 0.006). Conclusions: It is important to increase the number of cows calving per insemination by reducing embryo/foetal loss. This outcome can be achieved by management and breeding for optimal P4 levels at critical time points, and by considering oestrus expression in the breeding programmes to facilitate the correct timing of insemination. [ABSTRACT FROM AUTHOR]

To advance the understanding of early pregnancy and pregnancy failure in horses, this study determined how luteolysis induced by cloprostenol (an analogue of prostaglandin F2ɑ) affects conceptus development. Mares were injected on Days 12, 14, 16 or 18 of pregnancy with either cloprostenol (treatment groups, total n = 83 pregnancies) or saline (controls, n = 81), and growth of the conceptuses was monitored and compared by daily ultrasonography until they were collected transcervically on Days 15–22, 1–4 days after the injections. The comparisons were extended in the recovered conceptuses by counting somites, measuring the volume and osmolality of yolk-sac fluid and its concentrations of proteins, estrone sulfate and progesterone, and by assessing the morphology of the capsule and vascular system. When luteolysis was initiated on or before Day 16, most pregnancies survived until the time of collection and the conceptuses in respective treated and control groups on Days 15–20 were very similar except for some effects of treatment on the capsule and vascular development. In contrast, after luteolysis was initiated on Day 18, abortion often ensued within 3 days and most conceptuses collected had degenerated, therein constituting a predictable system in which to study the pathogenesis of a particular cause of pregnancy failure. Early pregnancy and embryonic loss have been studied in mares treated with a prostaglandin to stop progesterone production. Treatment on or before Day 16 had minimal effects on the conceptus (the embryo and its membranes) whereas treatment on Day 18 usually led to abortion and/or conceptus degeneration within 3 days, thereby providing a predictable system in which to investigate molecular changes underlying pregnancy failure. [ABSTRACT FROM AUTHOR]