Search

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]

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]

IntroductionReproductive efficiency in dairy cattle bred by artificial insemination (AI) or via embryo transfer (ET) is important as a means of facilitating the rate of genetic improvement by utilizing superior genetics from sires and donor dams. Fertility is especially challenging in primiparous cows as they have recently calved, are still growing, and are lactating. Fertility, measured by the conception rate from the first service (CCR1), is the number of cows that become pregnant as a result of the first AI or ET compared to all cows serviced, whereas times bred (TBRD) is the number of inseminations cows bred by AI needed to achieve a successful pregnancy.MethodsThis study aimed to identify the loci associated with and gene sets enriched for the CCR1 in primiparous cows that were bred by AI (n = 882) or were ET recipients (n = 353), and to identify the loci associated with the TBRD (n= 1,851) in primiparous cows. A genome-wide association analysis and gene set enrichment analysis were performed using single-nucleotide polymorphism (SNP) data for the CCR1 and TBRD in primiparous cows. In cows bred by AI, two loci containing five positional candidate genes were associated with the CCR1 (p < 1 × 10−5) and one gene set with 18 leading-edge genes was enriched (NES ≥3) for the CCR1.Results and discussionIn cows that were ET recipients, five loci were associated with the CCR1, but no gene sets were enriched for the CCR1. For the second phenotype, five loci with nine positional candidate genes were associated with the TBRD and two gene sets with eight leading-edge genes were enriched for the TBRD. Identifying the loci associated with or gene sets enriched for the CCR1 and TBRD provides an opportunity to better understand embryonic loss in AI-bred and ET-recipient cows and to use this information to select for higher reproductive efficiency.

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]

Milk production has doubled from 1970 to 2009 but has been associated with a decline in fertility. Around 25% of failed pregnancies in dairy cattle are due to embryonic loss. Mineral bioavailability may affect embryonic retention, so we hypothesized that Zn, Cu, and Mn sources will influence systemic immunological status, which affects early embryonic retention. Holstein cows (n = 58) were randomly assigned to one of two daily oral drench trace mineral (Zn, Cu, and Mn) treatments 30 d before breeding (d -30): 1) Inorganic (ITM) or 2) Metal Methionine Hydroxy Analog Chelate (MMHAC). Before treatments began, cows were assigned to a semen type, beef vs. Holstein, equally, across treatments. All cows underwent a double Ovsynch protocol and were artificially inseminated on d 0. Humoral immunological status was assessed in serum samples taken on d 0 and d 7. Immune activity was quantified via a D2Dx systemic immunity score, which assesses samples for the presence of IgG, IgM, cytokines, and complement proteins. Ultrasonography was utilized for pregnancy confirmation on d 35, classifying cows as pregnant (P) or open. Progesterone analysis from d 21 plasma was used to categorize open cows as either non-pregnant (NP) or early embryonic loss (EEL). Statistical analyses in R Studio were completed, in two models based on pregnancy (P vs EEL and NP vs EEL), to determine the effects of mineral treatment, pregnancy status, semen type, and all interactions on humoral immune status. In the P vs EEL model, there were no effects (P > 0.30) of semen type, mineral treatment, pregnancy status, or any interactions on systemic immunity score on the day of breeding (d 0) or d 7. On d 0, cows provided MMHAC had a systemic immunity score of 0.073 ± 0.008 but were not different (P > 0.34) from ITM cows (0.063 ± 0.006). This trend continued on d 7 with systemic immunity scores of MMHAC cows not differing (P > 0.32) from ITM cows (0.055 ± 0.004 and 0.061 ± 0.003; respectively). There was a tendency (P = 0.10) for the three-way interaction of semen type x pregnancy x treatment to influence the immunity score change from d 0 to d 7. Pregnant cows on ITM treatment bred with beef semen had a positive change in immunity score (0.020 ± 0.0085). Whereas ITM cows bred with Holstein semen that underwent EEL had a negative change (-0.015 ± 0.0085); all other means were intermediate. In the NP vs EEL model, there were no effects (P > 0.14) of semen type, treatment, pregnancy status, or any interactions on systemic immunity score on d 0, d 7, or the change between d 0 and d 7. In summary, trace mineral bioavailability tended to affect systemic immunological status in P vs EEL cows but not in NP vs EEL cows, which may allow for the elucidation of immunological status differences during pregnancy establishment. [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.

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: Recessive alleles represent genetic risk in populations that have undergone bottleneck events. We present a comprehensive framework for identification and validation of these genetic defects, including haplotype-based detection, variant selection from sequence data, and validation using knockout embryos. Holstein haplotype 2 (HH2), which causes embryonic death, was used to demonstrate the approach. Holstein haplotype 2 was identified using a deficiency-of-homozygotes approach and confirmed to negatively affect conception rate and stillbirths. Five carriers were present in a group of 183 sequenced Holstein bulls selected to maximize the coverage of unique haplotypes. Three variants concordant with haplotype calls were found in HH2: a high-priority frameshift mutation resulting, and 2 low-priority variants (1 synonymous variant, 1 premature stop codon). The frameshift in intraflagellar 80 (IFT80) was confirmed in a separate group of Holsteins from the 1000 Bull Genomes Project that shared no animals with the discovery set. IFT80-null embryos were generated by truncating the IFT80 transcript at exon 2 or 11 using a CRISPR-Cas9 system. Abattoir-derived oocytes were fertilized in vitro, and zygotes were injected at the one-cell stage either with a guide RNA and CAS9 mRNA complex (n = 100) or Cas9 mRNA (control, n = 100) before return to culture, and replicated 3 times. IFT80 is activated at the 8-cell stage, and IFT80-null embryos arrested at this stage of development, which is consistent with data from mouse hypomorphs and HH2 carrier-to-carrier matings. This frameshift in IFT80 on chromosome 1 at 107,172,615 bp (p.Leu381fs) disrupts WNT and hedgehog signaling, and is responsible for the death of homozygous embryos.

ABSTRACT: 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.

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. [Display omitted] [ABSTRACT FROM AUTHOR]

Recessive alleles represent genetic risk in populations that have undergone bottleneck events. We present a comprehensive framework for identification and validation of these genetic defects, including haplotype-based detection, variant selection from sequence data, and validation using knockout embryos. Holstein haplotype 2 (HH2), which causes embryonic death, was used to demonstrate the approach. Holstein haplotype 2 was identified using a deficiency-of-homozygotes approach and confirmed to negatively affect conception rate and stillbirths. Five carriers were present in a group of 183 sequenced Holstein bulls selected to maximize the coverage of unique haplotypes. Three variants concordant with haplotype calls were found in HH2: a high-priority frameshift mutation resulting, and 2 low-priority variants (1 synonymous variant, 1 premature stop codon). The frameshift in intraflagellar 80 (IFT80) was confirmed in a separate group of Holsteins from the 1000 Bull Genomes Project that shared no animals with the discovery set. IFT80-null embryos were generated by truncating the IFT80 transcript at exon 2 or 11 using a CRISPR-Cas9 system. Abattoir-derived oocytes were fertilized in vitro, and zygotes were injected at the one-cell stage either with a guide RNA and CAS9 mRNA complex (n = 100) or Cas9 mRNA (control, n = 100) before return to culture, and replicated 3 times. IFT80 is activated at the 8-cell stage, and IFT80-null embryos arrested at this stage of development, which is consistent with data from mouse hypomorphs and HH2 carrier-to-carrier matings. This frameshift in IFT80 on chromosome 1 at 107,172,615 bp (p.Leu381fs) disrupts WNT and hedgehog signaling, and is responsible for the death of homozygous embryos. [ABSTRACT FROM AUTHOR]

Widespread genotyping has enabled the identification of putative recessive mutations that affect fertility through early embryonic fetal loss, or that compromise neonate or calf viability. The use of artificial insemination in the global dairy population can rapidly spread these harmful mutations, and testing for multiple mutations can become relatively expensive if not all tests are available on the same SNP panel. However, it is possible to provide heifer and cow predicted carrier status to farmers at no additional cost if the animals are genotyped with a standard SNP panel. Additionally, for defects where the causal mutation is unknown but a haplotype of markers has been associated with the defect, the carrier status can be predicted based on that haplotype. The aims of this study were 3-fold: (1) to determine the accuracy of imputation of putative causal mutations for recessive deleterious conditions in Australian dairy cattle, (2) to impute carrier status for known recessive deleterious conditions in all genotyped Australian Holstein, Jersey, and Red breed cows, and (3) to determine the changes in carrier frequencies across time for these recessive deleterious mutations. We used the F1 statistic, combining precision and recall, to assess the accuracy of carrier status prediction. We showed that known deleterious mutations can be accurately imputed in Australian Holstein and Jersey cattle that are not directly genotyped for the causal mutation, with F1 ranging between 0.88 and 0.99. For recessive deleterious conditions not included on the standard Australian SNP panel, carrier status could be predicted using a marker haplotype, with F1 ranging from 0.91 to 0.92. Most putative causals and haplotypes were either stable with a low carrier percentage or had a declining carrier percentage. However, several recessive mutations showed a relatively high or increasing percentage, highlighting the importance of detecting carriers to reduce the number of at-risk matings. Furthermore, the high carrier percentage of the recently identified bovine lymphocyte intestinal retention defect mutation emphasizes the importance of detection of novel mutations., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016–2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (P < 0.001) by animal category. There was also an effect of farm (P = 0.0013) on P/AI and pregnancy loss (P = 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (P < 0.001) P/ AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (P < 0.001). Lower BCS at TAI was associated (P < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (P < 0.001) with reduced rates of embryonic mortality. There was a major effect (P < 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds. • Factors like Farm, Sire Breed, bull, Dam Category, BCS, parturition month, and Heat influence pregnancy loss in Nellore cows. • The pregnancy rate at TAI didn't correlate with pregnancy loss. • P/AI vary from 11% to 79% according to bull. • Pregnancy loss varies from 0% to 40% according to bull [ABSTRACT FROM AUTHOR]

Endometrial epidermal growth factor (EGF) shows a cyclic change with two peaks on Days 2–4 and 13–14 during the estrous cycle. An altered (i.e., loss of the two peaks) profile has been linked to reduced fertility in repeat breeder cows. We previously demonstrated that a form of osteopontin (OPN), with a molecular weight of 29 kDa and found in bull seminal plasma (SP), normalized the EGF profile and restored fertility in repeat breeder cows. OPN has many molecular forms due to post-translational modifications and is abundant in bovine milk. The purpose of the present study was to investigate whether mOPN normalizes the endometrial EGF profile and restores fertility in repeat breeder dairy cows with an altered EGF profile. OPN was separated by one-step anion-exchange column chromatography from the whey of bovine milk. Purified mOPN was verified by Western blotting and peptide mass fingerprinting analyses. The OPN fraction showed three major protein bands of 61, 37 and 31 kDa (peptides I, II, and III, respectively) on SDS-PAGE. All three major bands were identified as OPNs by Western blotting and their tryptic peptide masses were matched at approximately 50, 40, and 10%, respectively, to the bovine OPN amino acid sequence by a peptide mass finger printing analysis. The three bands accounted for approximately 85% of the total protein content and 6–23 mg of OPN was obtained from 1 L of bovine milk. A lyophilized eluate containing 1.3 mg of mOPN (171 cows), 0.5 mL of frozen SP (62 cows), and PBS (84 cows) was infused at estrus into the vagina of repeat breeder cows with an altered EGF profile. Some of the cows treated with mOPN, SP, and PBS (46, 50, and 45 cows, respectively) were inseminated immediately before the infusion and then examined for pregnancy between Days 60 and 65. The rate at which mOPN to normalize the EGF profile (56.1%) was similar to that of SP (58.1%) and higher than that of PBS (23.8%) (P < 0.05). The conception rate after the infusion of mOPN (43.5%) was similar to that of SP (40.0%) and higher than that of PBS (22.2%) (P < 0.05). The present results indicate that the infusion of mOPN into the vagina is a treatment option for repeat breeder cows with an altered EGF profile. Further studies are needed to compare the capacity of the three OPN molecules in milk to normalize the EGF profile, together with their molecular characteristics due to post-translational modifications. • OPN protein (mOPN) between 6 and 23 mg from 1 L of milk and with three different molecular masses are obtained. • mOPN normalized the endometrial EGF profile and restored fertility in repeat breeder dairy cows. • The effects of mOPN are at the similar levels to seminal OPN despite different molecular masses of OPNs in the two sources. [ABSTRACT FROM AUTHOR]

ABSTRACT: Determining if reproductive failures in ewes at the semiarid region in the state of Bahia are related to the consumption of the species Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, and this study was developed using pregnant ewes divided into six groups: G1, G2, G3, G4 with six animals each, G5 and G6 with ten animals. Each group received fence leaves in the proportion of 1%, 2%, 0.5%, and 0.25% of live weight (LW) respectively; G5 and G6, with ten animals each, receiving 0.25% and 0.5% of the LW, respectively, and the Control Group, comprising 16 ewes, were grass feeding (Cynodon dactylon). Ewes from G1 to G4 were the same, except for two, and started ingestion of the plant four days after ending of natural mating on the 80th day of gestation, while those regarding from G5 to G6 groups started ingestion on the 26th day of gestation ending on the 98 day. The ultrasonographic test was performed weekly. In G1 ewes (1%), there was an embryonic loss on the 32nd and 39th days of gestation and abortion on the 46th day. In G2 (2%), the embryo loss was earlier (on the 26th day of gestation), and abortion on the 46th day of gestation. In G3 group (0.5%), there was an embryonic loss around the 40th day of gestation. In G4 group (0.25%), it was observed the occurrence of one death lamb with bone malformations. In G6 (0.5%), abortion occurred later (108 days), followed by retained placenta. This was also verified in G5 group (0.25%). The presence of fetal malformation was found in death lambs born in G4 group, born alive from G5 and G6 groups, and one aborted from G6. In G5 and G6 groups, there were also genetic alterations on surviving lambs. In addition to these results, recurrent estrus was observed without gestation in G1, G2, G3, and G4 ewes. From the Control Group, 13 normal lambs were born without genetic alterations; furthermore, concerning a quadruple birth, three lambs were born dead. The results infer that species of C. pyramidale in low doses causes reproductive losses in pregnant ewes, therefore it is not recommended for sheep diet over the first 60 days of gestation.

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]

Objective: to evaluate the clinical efficacy and safety of Femibion Natalcare vitamin complex containing metafolin in women of late reproductive age with MTHFR C677T genetic polymorphism who had anamnestic embryonic losses. Materials and methods. Study included 100 women of late reproductive age with MTHFR C677T genetic polymorphism and anamnestic embryonic losses. Patients of main group were divided in subgroups: first – 45 women who received folic acid (400 mcg per day) and second – 55 patients who received vitamin complex Femibion Natalcare 1 tablet daily. Prescription of medications began before preconception (6–8 weeks), intake ended at 28 weeks of gestation. Control group included 40 healthy women with physiological pregnancy. The studied parameters reflected information about the features of the pregnancy and birth. Results. After a course of prophylactic supplementation with Femibion Natalcare compared with monotherapy of folic acid, it was possible to reliably reduce cases of early pregnancy loss (p =0.03), anemia in I trimester (p =0.009), preeclampsia (p =0.014), anemia in II and III trimesters (p =0.001), placental dysfunction (p =0.0005), decrease in the level of placental hormones (p =0.014), pathology of placental development and localization (p =0.0499), fetal growth retardation (p =0, 0499), premature maturation of placenta (p =0.02), induction of labor (p =0.015), disorders of neonatal adaptation (p =0.03), neonatal jaundice (p =0.018), postpartum anemia (p =0.015). There were no cases of side effects of drugs on the mother and child. Conclusions. The use of a vitamin complex containing active folate metapholine for women of late reproductive age with MTHFR C677T genetic polymorphism and anamnestic embryonic losses had a positive effect on clinical symptoms, helps to reduce cases of perinatal pathology and impaired early neonatal adaptation.

Epidermal growth factor (EGF) concentrations in the uterus show two peaks on days 2–4 and 13–14 during the estrous cycle in fertile cows. Loss of the two peaks has been linked to reduced fertility in repeat breeder cows. This study aimed to examine the effect of seminal plasma (SP) on normalizing endometrial EGF concentrations and restoring fertility in repeat breeder cows with low EGF concentrations on day 3. In study 1, we examined the effect of the deposition sites (the vagina and uterus) of SP on the endometrial EGF concentrations in repeat breeder cows. SP infusion into the vagina, but not uterus, on the first day of the estrus cycle (day 0) normalized the endometrial EGF concentrations (≥ 4.7 ng/g tissue weight) on day 3. In study 2, the effect of SP volume (0.5 and 10 ml of SP and 0.5 ml of SP diluted to 10 ml) on EGF concentrations was examined. All groups with SP infusion had increased EGF concentrations on day 3, and cows with 10 ml of SP and 0.5 ml of SP diluted to 10 ml showed the highest levels of EGF concentrations. In study 3, we examined the effect of SP infusion on fertility. SP infusion normalized two peaks of endometrial EGF concentrations in about 60% of repeat breeder cows and produced more pregnancies than the controls (44.4 vs. 19.4%). Therefore, we concluded that SP may contain an activity to normalize the EGF profile and restore fertility in repeat breeder cows with altered EGF profiles.

What is the impact of radiation exposure on oocyte quality and female fertility? Prepubertal mice underwent whole-body irradiation with a single dose (0.02, 0.1, 0.5, 2, 8 Gy) of gamma- or X-rays. Oocytes were quantified in irradiated (n = 36) and sham-treated (n = 8) mice. After a single exposure to 2 Gy, formation of DNA double-strand breaks (n = 10), activation of checkpoint kinase (Chk2) (n = 10) and dynamics of follicular growth (n = 18) were analysed. Fertility assessment was performed in adult irradiated mice and controls from the number of pups per mouse (n = 28) and the fetal abortion rate (n = 24). Ploidy of mature oocytes (n = 20) was analysed after CREST immunostaining, and uterine sections were examined. Radiation exposure induced a massive loss of primordial follicles with LD 50 below 50 mGy for both gamma and X-rays. Growing follicles survived doses up to 8 Gy. This difference in radiosensitivity was not due to a different amount of radio-induced DNA damage, and Chk2 was activated in all oocytes. Exposure to a 2 Gy dose abolished the long-term fertility of females due to depletion of the ovarian reserve. Detailed analysis indicates that surviving oocytes were able to complete folliculogenesis and could be fertilized. This transient fertility allowed irradiated females to produce a single litter albeit with a high rate of fetal abortion (23%, P = 0.0096), related to altered ploidy in the surviving oocytes (25.5%, P = 0.0035). The effects of radiation on surviving oocyte quality question natural conception as a first-line approach in cancer survivors. Together, the data emphasize the need for fertility preservation before radiation exposure and call for reassessment of the use of cryopreserved oocytes. [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.

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]

The aim of the study, the relationship between coagulation parameters and embryonic loss in embryo transferred (ET) cows and heifers wereevaluated. The animal material of this study consisted of 19 cows and 19 heifers on farms located in East Mediterranean Agriculture Research Institute in Adana. Blood samples were collected before the ET application from the recipient cows and heifers. Coagulation parameters measured included prothrombin time (PT), activated thromboplastin time (APTT), fibrinogen, thrombin time (TT), anti-thrombin-III (AT3) and D-dimer using by Sysmex® CA-7000 and activated protein C resistance, protein C and protein S using by Sysmex CS-5100. The pregnancy rate was found 5/19 (26.3%) and 5/19 (26.3%) in cows and in heifers, respectively (P>0.05). The embryonic mortality ratio in cows was 60% (3/5) and in heifers it was 40% (2/5). The differences of D-dimer levels between pregnant and non-pregnant animals were significant (P<0.05). The APTT levels between the groups with pregnancy and embryonic loss were significantly different (P<0.05). As a result, it was determined that there is a relationship between plasma D-Dimer levels and embryonic loss in cows that were transferred embryo. To the best of authors' knowledge, this is the first study reporting the relationship between coagulation parameters and embryonic loss in ET cows and heifers. [ABSTRACT FROM AUTHOR]

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 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 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

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]

Several tools exist to diagnose pregnancy in dairy cattle. However, substantial pregnancy loss occurs within the first 60 d of gestation in cattle, and these losses have a profound adverse economic impact on the dairy and beef cattle industries. Detecting these impending pregnancy losses could offer producers an opportunity to reduce costs associated with this source of reproductive inefficiency. Several of the pregnancy diagnostic tools currently available and new technologies are being examined for their ability to predict pregnancies at risk for failing in early pregnancy. This review provides a synopsis of work undertaken recently to predict pregnancy losses in cattle. Currently, opportunities to predict pregnancy loss include (1) using transrectal ultrasonography to detect loss of the fetal heartbeat, floating debris within the placental fluids, and reductions in fetal size; (2) observing reductions in circulating progesterone concentrations; (3) detecting reductions in concentrations of circulating placental products; namely, pregnancy-associated glycoproteins and microRNAs; and (4) detecting reductions in the early pregnancy-dependent increase in interferon-stimulatory gene expression in peripheral blood leukocytes. An achievable goal may be to identify markers of embryo mortality so that researchers and clinicians can focus their efforts on developing intervention strategies for cows identified to be at risk for pregnancy failure. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the association between reproductive disorders and the main serogroups of Leptospira spp. in dairy herds. Blood samples from 216 cows from nine herds were collected for a Microscopic Agglutination Test (MAT), and a reproductive follow-up with ultrasonography was carried out monthly for at least 12 months. A total of 75 (16.5%) cows were reactive, while seroreactivity to a herd level ranged from 16.0% to 52.8%. Out of the nine herds, in five (55.0%) Sejroe was found to be the predominant serogroup and in four (45.0%) it was Icterohaemorrhagiae. The major reproductive problems identified were embryonic death (ED) and abortions. All herds presented ED and abortion was observed in three (33.3%). Herds with high seroreactivity (>20%) had more reproductive problems. Those with a predominance of Sejroe were associated with ED (P < 0.05), while those with Icterohaemorrhagiae were associated with abortion. The results show that different leptospiral strains lead to different reproductive problems, as well as showing that the main problem – ED – is caused by leptospirosis, particularly for those determined by strains of the serogroup Sejroe. • Bovine leptospirosis is reproductive disease and leads to reproductive disorders (ED, repetitive estrous, Abortion). • Cattle herds with high seroreactivity to leptospiral serogroups had more reproductive disorders. • Seroreactivity to Leptospira spp. strains of Sejroe serogroup was associated to embryonic death. • Seroreactivity to Icterohaemorrhagiae strains was associated to abortions. [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]

The feeding of diets with greater energy content than that needed for body maintenance following mating is believed to reduce embryonic survival in pigs. In swine operations, therefore, feed intake is often restricted during the first and second week of pregnancy to reduce embryo mortality. There is thought to be a relationship between feeding diets that result in energy intake that is greater than that needed for body maintenance and embryonic death. This relationship is associated with lesser than typical progesterone (P4) concentrations when feeding diets with greater energy content due to increased hepatic clearance. There is no consensus, however, as to whether feeding should be restricted during early pregnancy to avert this possible detrimental effect. Thus, the aim of this systematic review is to assess the effect in sows and gilts of feeding diets with different energy contents post-mating on embryonic survival, evaluating when possible, the relationship of a greater energy intake and P4 concentrations on embryonic survival. An electronic search was conducted of the PubMed, Science Direct, Scopus, Web of science, and Scielo databases during June 2018. A total of 109 articles were retrieved, and of these, only 16 articles were selected after applying the selection criteria. There was no negative effect of a greater feed intake than that needed for body maintenance after breeding in 75% of the experiments. Results from 35% of the experiments indicated feeding early pregnant sows a diet with greater energy content than that needed for body maintenance resulted in augmented embryonic death. In 66.7% of the experiments, in which there was assessment of P4 concentration, there was no negative effect of feeding after farrowing a diet with greater energy than that needed for body maintenance. In conclusion, it appears that restricted feed intake in early pregnancy is no longer relevant when there are modern prolific dam lines utilized in swine production enterprises because dietary energy of as great as 54 MJ ME/day had no detrimental effect on embryo survival. [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]

Abstract The goal of this study was to evaluate the effect of long-acting progesterone supplementation on pregnancy rates and gestational losses in Nelore females (Bos taurus indicus) submitted to Timed Artificial Insemination (TAI). Ovulations of multiparous (n = 534), primiparous (n = 117) and nulliparous (n = 81) Nelore females were synchronized for TAI and the day of insemination was considered D0. After TAI, the animals were allocated into three groups. Two groups received 150 mg of long acting injectable progesterone (P4) in a single dose, 5 (D = 5) or 11 (D = 11) days after TAI, resulting in the following treatments: 1) Group P4 - D5 (n = 235); 2) Group P4 - D11 (n = 245); and 3) Control Group (n = 252). The animals in the control group did not receive any supplementation. Pregnancy was checked by ultrasonography, 30 days after the TAI. The gestational losses were evaluated at two different periods: 1) from 30 to 60 days, and 2) from 60 to 90 days. The pregnancy rate and the gestational losses as a function of the treatments were tested by the non-parametric binomial test with 5% significance level. The pregnancy rates were different between the groups P4 - D5 and Control (47 and 39%, respectively) (P < 0.05), but no difference was observed in relation to the P4 - D11 group. There was a difference in gestational losses from 30 to 60 days and total losses between the groups treated with P4 on the fifth day and eleventh day after TAI in relation to the control group (P = 0.0173; P = 0.0454), but no difference was observed between the treatments in relation to the losses between 60 and 90 days (P ≥ 0.0578). Among the animals that were cycling at the beginning of the protocol, the groups supplemented with progesterone at day 5 or 11 after insemination had gestational losses significantly lower (P = 0.04) than the control group (P4 - D5 = 2%; P4 - D11 = 2%, control = 14%). The animals in anestrous that received supplementation 5 days after TAI had lower gestational losses (P = 0.049) compared with the other groups (P4 - D5 = 3%, P4 - D11 = 7% Control = 10%). Under the conditions of this study, the use of long-acting injectable progesterone 5 days after TAI in Nelore females increased the pregnancy rates, but when supplemented 11 days after TAI, it did not have the same effect. Also, when used 5 days after TAI, it significantly decreased gestational losses on both anestrous and cycling animals. Therefore, it may be an interesting alternative to increase reproductive and productive efficiencies. Highlights • Pregnancy losses from 30 to 60 days were significant different between treated groups. • There was difference (P = 0.049) in pregnancy losses considering cyclicity. • For anestrous animals, control group presented pregnancy losses higher than P4-D5. [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]

This study aimed to investigate the effects of a single administration of one of three different gonadotropins on Day 7 post-insemination on ovarian activity, progesterone (P 4 ) concentration and pregnancy outcomes of rabbit does. Multiparous, non-lactating, V-line does were artificially inseminated after synchronization and ovulation induction with equine chorionic gonadotropin (eCG; 25 IU im) and gonadotropin releasing hormone (GnRH; 0.8 μg buserelin im) 48 h later. On Day 7 post-inseminarion, does were randomly allocated into four groups (n = 40/group). Does of each group were intramuscularly injected with a single dose of one of physiological saline ( placebo ; control), GnRH (0.8 μg buserelin), human chorionic gonadotropin (hCG; 25 IU) or eCG (25 IU). Concentration of serum P 4 was determined on Days 6, 9, 11 and 18 post-insemination. On Day 14 post-insemination, the ovaries and reproductive tracts of pregnant does were removed and weighed. Also, numbers of visible follicles, hemorrhagic follicles, corpora lutea of pregnancy (pCLs), new CLs (nCLs; formed after Day 7 post-insemination) and implantation sites were recorded. Conception rate, parturition rate, abortion rate, litter size/weight and litter viability were recorded. The highest (P < 0.05) reproductive tract and ovary weights were for eCG. The highest (P < 0.05) number of visible ovarian follicles was for eCG, whereas the lowest (P < 0.05) was for GnRH. Treatment with eCG increased (P < 0.05) numbers of pCLs and total implantation sites compared to the other groups. Treatment with GnRH or hCG increased (P < 0.05) number of nCLs compared to control and eCG. The highest rate of fetal loss was in does treated with GnRH. The concentration of serum P 4 decreased (P < 0.05) following the treatment with GnRH and continued low until Day 18. However, it remained in line for control, hCG and eCG groups up to Day 11, then decreased (P < 0.05) for control and hCG on Day 18, being lower for hCG than control, while continued to increase for eCG up to Day 18. Compared to control, treatment with eCG improved (P < 0.05) conception and parturition rates by 24 and 22%; respectively, while GnRH and hCG treatments decreased (P < 0.05) them by 57 and 47.6%; respectively. Litter size and litter weight at birth were improved by eCG, but were adversely affectd by GnRH and hCG. In conclusion, a single administration of eCG 7 Days post-insemination could be recommended for improving pregnancy outcomes in rabbits. [ABSTRACT FROM AUTHOR]

Defining factors associated with embryonic and/or fetal losses will be helpful in overcoming such problem, either by adjusting conditions or applying therapeutic approaches to high-risk cows. The objective of this study was to investigate the association between a number of maternal and non-maternal factors and the risk of late embryonic (LED) and early fetal death (EFD) in dairy herds. Additionally, we investigated the effect of treating pregnant cows either with GnRH on day 26 post-insemination, or GnRH on day 26 plus CIDR insertion between days 26 and 33 post-insemination, on the risk of LED/EFD. From 3826 pregnancies, diagnosed at day 30 post-insemination, 851 cows lost the pregnancy by day 70 post-insemination. A mixed-effects logistic model was constructed to assess the effect of cow breed, calving difficulty, postpartum problems, lactation number, days in milk, insemination number, actual 305-day milk production, temperature humidity index (THI) at insemination, estrus synchronization protocols, and other factors, on the risk of LED/EFD. Our findings indicated that Holstein X Brown Swiss crossbreed cows had a lower risk for LED/EFD than Holstein cows (P < 0.05). Cows that had postpartum problems, were inseminated for the first time, produced more milk, or were inseminated at THI ≥75, recorded higher risks of LED/EFD (P < 0.05). Calving difficulty, lactation number, and synchronization protocols were not found to be associated with LED/EFD. Moreover, treatment of the pregnant cows with GnRH on day 26 post-insemination plus CIDR insertion between days 26 and 33 post-insemination decreased the risk of LED/EFD. In conclusion, cows that had postpartum problems, were inseminated early postpartum, produced higher milk, and/or were inseminated at high THI, were under higher risk of LED/EFD. Treating such cows with GnRH on day 26 plus CIDR insertion between days 26 and 33 may decrease the possibility of the LED/EFD. [ABSTRACT FROM AUTHOR]