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Yang MK, Yeh RH, Lee CJ, Yeh YH, Chen YH, Banhazi T, Tu PA. Pregnancy maintenance and fetal loss assessment in Holstein cows through analyzing pregnancy-associated glycoproteins in milk. Theriogenology 2024; 217:11-17. [PMID: 38219409 DOI: 10.1016/j.theriogenology.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Fetal loss (FL) from the 45th day of gestation until calving can impose a significant economic burden on dairy farmers, resulting in lost profits and increased production costs. Pregnancy-associated glycoprotein (PAG) is commonly used for detecting pregnancy in cows. PAG is secreted by binucleated trophoblast cells of the placenta and regulated by more than 24 genes. The purpose of this study was to determine the PAG threshold for FL and a probability of pregnancy maintenance until calving based on milk PAG levels. Our results reveal that primiparous and multiparous cows that maintained pregnancy until the 40th week exhibited higher PAG sample-negative (SN) values in their milk in the 6th week of gestation than did those that experienced FL later in gestation. Pregnant cows with higher PAG SN values in the 6th week of gestation were more likely to maintain their pregnancies. The area under the receiver operating characteristic curve for predicting the probability of pregnancy maintenance was 0.722 for our prediction model. On the other hand, a milk PAG SN value of <0.192 indicated 95 % confidence that FL would occur between the 7th and 40th weeks of gestation. Milk PAG testing is a noninvasive sampling technique that does not induce additional stress in lactating cows. The study reveals that PAG SN values increase significantly in Holstein cows during the 6th week of gestation. The predictive model developed was effective in forecasting pregnancy outcomes up to the 40th week of gestation or calving. The model's performance is moderately good for field application and could be a useful tool for dairy producers.
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Affiliation(s)
- Ming-Kuew Yang
- Northern Region Branch, Taiwan Livestock Research Institute, Ministry of Agriculture, Miaoli, 368, Taiwan
| | - Ruei-Han Yeh
- Animal Products Processing Division, Taiwan Livestock Research Institute, Ministry of Agriculture, Tainan, 71246, Taiwan
| | - Chia-Jung Lee
- Livestock Management Division, Taiwan Livestock Research Institute, Ministry of Agriculture, Tainan, 71246, Taiwan
| | - Yi-Hsin Yeh
- Northern Region Branch, Taiwan Livestock Research Institute, Ministry of Agriculture, Miaoli, 368, Taiwan
| | - Yi-Hsuan Chen
- Northern Region Branch, Taiwan Livestock Research Institute, Ministry of Agriculture, Miaoli, 368, Taiwan
| | - Thomas Banhazi
- National Taiwan University, International College, Changxing st, Da'an, Taipei, 10672, Taiwan
| | - Po-An Tu
- Northern Region Branch, Taiwan Livestock Research Institute, Ministry of Agriculture, Miaoli, 368, Taiwan.
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Pohler KG, Oliveira Filho RV. Impact of the Sire on Pregnancy Loss. Vet Clin North Am Food Anim Pract 2024; 40:121-129. [PMID: 37884437 DOI: 10.1016/j.cvfa.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023] Open
Abstract
For over a century, scientists have attempted to develop techniques to accurately predict the fertility potential of a male's semen sample. In most livestock species, the sire is responsible for multiple pregnancies per year and up to hundreds of thousands of pregnancies if used for artificial insemination. Use of subfertile or infertile sires can have devastating impacts in regard to the reproductive efficiency of a cow herd. Despite the rapid expansion of fertility studies through advancements in molecular, genomic, and computer techniques, our understanding of male fertility is still far from complete. This article will provide an overview of the impact of the sire in pregnancy loss.
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Affiliation(s)
- Ky G Pohler
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, 2471 TAMU, College Station, TX 77843, USA.
| | - Ramiro Vander Oliveira Filho
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, 2471 TAMU, College Station, TX 77843, USA
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3
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Ortega MS, Rizo JA, Drum JN, O'Neil EV, Pohler KG, Kerns K, Schmelze A, Green J, Spencer TE. Development of an Improved in vitro Model of Bovine Trophectoderm Differentiation. FRONTIERS IN ANIMAL SCIENCE 2022. [DOI: 10.3389/fanim.2022.898808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mechanisms regulating early stages of placentation and trophectoderm differentiation in the ruminant conceptus remain poorly understood. Here we present a model of trophectoderm (TE) differentiation in vitro from outgrowths of individual in vitro derived embryos. Cell outgrowths expressed markers of mononucleate (MNC) and binucleate (BNC) TE cells. The percentage of BNC ranged from 14 to 39% in individual outgrowths as determined by flow cytometry. Pregnancy-associated glycoproteins (PAGs), produced by BNC, were measured in culture media on days 35 to 54. Continuous secretion of PAGs was observed and indicative of BNC functionality. Gene expression was evaluated in 20 embryo cell outgrowths derived from two different sires. Expression of HAND1, which is involved in TE differentiation, and CSH2, a BNC-specific gene, was altered in cell outgrowths between the two sires tested. Single-cell RNA-seq analysis of day 40 TE cell outgrowths revealed 11 distinct cell populations, with specific clusters genes involved in TE lineage specification, proliferation, and differentiation. In addition, whole -RNAseq analysis was performed in day 35 and 40 TE cell outgrowths and confirmed sustained expression of genes expressed by BNC, such as CSH2 and some PAGs. The developed in vitro bovine embryo outgrowth culture found evidence for MNC and BNC differentiation and continuous production of PAGs, recapitulating key features of early bovine placenta development. This model can be used to understand the developmental biology of TE cells, provide insights into paternal influences on TE differentiation, and impact our understanding of early pregnancy loss in cattle.
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Stamperna K, Dovolou E, Giannoulis T, Kalemkeridou M, Nanas I, Dadouli K, Moutou K, Mamuris Z, Amiridis GS. Developmental competence of heat stressed oocytes from Holstein and Limousine cows matured in vitro. Reprod Domest Anim 2021; 56:1302-1314. [PMID: 34289185 DOI: 10.1111/rda.13993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/20/2021] [Indexed: 11/29/2022]
Abstract
The negative effects of heat stress on dairy cattle's fertility have been extensively studied, but the relevant knowledge for beef cattle is rather limited. The aims of this study were to investigate the effects of HS during in vitro maturation on the developmental potential of oocytes derived from Limousine and Holstein cows and to estimate the effect of the differential gene expression of important genes in oocytes, cumulus cells and blastocysts in the growth competence between the breeds. In seven replicates, cumulus oocyte complexes from Holstein and Limousine cows were matured for 24 hr at 39°C (controls C; Hol_39, Lim_39) or at 41°C from hour 2 to hour 8 of IVM (treated T; Hol_41, Lim_41), fertilized, and presumptive zygotes were cultured for 9 days at 39°C. Cleavage and embryo formation rates were evaluated 48 hr post-insemination and on days 7, 8 and 9, respectively. From all groups, subsets of cumulus cells, oocytes and blastocysts were analysed for the relative expression of genes related to metabolism, stress, apoptosis and placentation. No difference was detected in cleavage rate or in blastocyst formation rate among the control groups. In both breeds, heat stress reduced blastocyst yield, but at all days the suppression was higher in Limousines. In Holsteins, altered gene expression was detected in cumulus cells (G6PD, GLUT1) and blastocysts (PLAC8), while in Limousines, differences were found in oocytes (G6PD, HSP90AA1), in cumulus cells (CPT1B, HSP90AA1, SOD2) and blastocysts (DNMT, HSP90AA1, SOD2). It appears that Holstein COCs are more tolerant than Limousine COCs, possibly due to compulsory, production driven selection.
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Affiliation(s)
- Konstantina Stamperna
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Eleni Dovolou
- Department of Animal Science, University of Thessaly, Larissa, Greece
| | | | - Maria Kalemkeridou
- Laboratory of Genetics, Comparative and Evolutionary Biology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Ioannis Nanas
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Katerina Dadouli
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Katerina Moutou
- Laboratory of Genetics, Comparative and Evolutionary Biology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Zissis Mamuris
- Laboratory of Genetics, Comparative and Evolutionary Biology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Georgios S Amiridis
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
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Pérez-Gómez A, González-Brusi L, Bermejo-Álvarez P, Ramos-Ibeas P. Lineage Differentiation Markers as a Proxy for Embryo Viability in Farm Ungulates. Front Vet Sci 2021; 8:680539. [PMID: 34212020 PMCID: PMC8239129 DOI: 10.3389/fvets.2021.680539] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 05/24/2021] [Indexed: 12/28/2022] Open
Abstract
Embryonic losses constitute a major burden for reproductive efficiency of farm animals. Pregnancy losses in ungulate species, which include cattle, pigs, sheep and goats, majorly occur during the second week of gestation, when the embryo experiences a series of cell differentiation, proliferation, and migration processes encompassed under the term conceptus elongation. Conceptus elongation takes place following blastocyst hatching and involves a massive proliferation of the extraembryonic membranes trophoblast and hypoblast, and the formation of flat embryonic disc derived from the epiblast, which ultimately gastrulates generating the three germ layers. This process occurs prior to implantation and it is exclusive from ungulates, as embryos from other mammalian species such as rodents or humans implant right after hatching. The critical differences in embryo development between ungulates and mice, the most studied mammalian model, have precluded the identification of the genes governing lineage differentiation in livestock species. Furthermore, conceptus elongation has not been recapitulated in vitro, hindering the study of these cellular events. Luckily, recent advances on transcriptomics, genome modification and post-hatching in vitro culture are shedding light into this largely unknown developmental window, uncovering possible molecular markers to determine embryo quality. In this review, we summarize the events occurring during ungulate pre-implantation development, highlighting recent findings which reveal that several dogmas in Developmental Biology established by knock-out murine models do not hold true for other mammals, including humans and farm animals. The developmental failures associated to in vitro produced embryos in farm animals are also discussed together with Developmental Biology tools to assess embryo quality, including molecular markers to assess proper lineage commitment and a post-hatching in vitro culture system able to directly determine developmental potential circumventing the need of experimental animals.
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Affiliation(s)
- Alba Pérez-Gómez
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Leopoldo González-Brusi
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Pablo Bermejo-Álvarez
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Priscila Ramos-Ibeas
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
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Nanas I, Chouzouris TM, Dovolou E, Dadouli K, Stamperna K, Kateri I, Barbagianni M, Amiridis GS. Early embryo losses, progesterone and pregnancy associated glycoproteins levels during summer heat stress in dairy cows. J Therm Biol 2021; 98:102951. [PMID: 34016368 DOI: 10.1016/j.jtherbio.2021.102951] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/21/2021] [Accepted: 03/31/2021] [Indexed: 11/28/2022]
Abstract
Objectives of this study were to characterize the effects of heat stress on pregnancy associated glycoproteins (PAG) and progesterone and its involvement in embryo survival. In trial 1, blood samples collected from days 29 to 36 post insemination were examined for the comparison of PAG concentrations between winter (n = 3721) and summer (n = 2388). In trial 2, embryo losses were assessed in winter (n = 144) and in summer (n = 133), in days 31 or 32 of pregnancy. Pregnancy diagnosis was carried out by ultrasonography on days 24 or 25, and it was repeated a week later; in the second occasion PAG concentration was also determined. In trial 3 the PAG and progesterone concentrations were assessed in days 33 to 36 in winter and summer. In trial 1 PAG levels did not differ between winter and summer, the conception rate and the proportion of uncertain pregnancies were higher in winter than summer. The likelihood of pregnancy was 10 to 15% higher in winter. In trial 2, the embryo death rate was higher in summer, but the PAG levels of cows that had embryo loss in summer were higher than those in winter. In both seasons, lower PAG levels were associated with higher risk of pregnancy loss, while embryo death was five times more likely to occur in summer than in winter and lower PAG concentrations were positively associated with higher risk of embryo loss. In trial 3, mean PAG levels were higher and of progesterone were lower during the summer than during the winter. We infer that despite the devastating effects of heat stress on cows' fertility, those early embryos that survive under continuous heat stress can form a well-functioning placenta; hence, the high embryo mortality rate observed during the summer months could be mainly attributed to luteal insufficiency.
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Affiliation(s)
- Ioannis Nanas
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Thomas-Markos Chouzouris
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Eleni Dovolou
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece; Laboratory of Reproduction, Faculty of Animal Science, University of Thessaly, Greece
| | - Katerina Dadouli
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece; Laboratory of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Konstantina Stamperna
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Ilektra Kateri
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Mariana Barbagianni
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Georgios S Amiridis
- Clinic of Obstetrics & Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece.
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7
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Identification of plasma miRNA biomarkers for pregnancy detection in dairy cattle. JOURNAL OF ANIMAL REPRODUCTION AND BIOTECHNOLOGY 2021. [DOI: 10.12750/jarb.36.1.35] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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8
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Pohler KG, Reese ST, Franco GA, Oliveira RV, Paiva R, Fernandez L, de Melo G, Vasconcelos JLM, Cooke R, Poole RK. New approaches to diagnose and target reproductive failure in cattle. Anim Reprod 2020; 17:e20200057. [PMID: 33029221 PMCID: PMC7534570 DOI: 10.1590/1984-3143-ar2020-0057] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
Reproductive failure and pregnancy loss in cattle are some of the largest economic burdens to cattle producers and one of most perplexing factors influencing management decisions. Pregnancy loss may occur at any point during gestation with the largest percentage of loss occurring in the first 30 days and, subsequently, decreasing as the pregnancy progresses. Losses may be attributed to numerous factors, predisposed issues or environmental conditions such as nutritional stressors or disease. From a research perspective, determining the exact causes of pregnancy loss or embryonic mortality in cattle have been difficult, due to limitations of accurately determining early gestation pregnancy status. Until methods that precisely determine embryo success early in gestation are available, our understanding of in vivo pregnancy loss will lack clarity necessary to develop management strategies to decrease such loss. In this review, we will briefly discuss the pivotal periods of pregnancy loss affecting beef and dairy cattle, methods and technologies to determine pregnancy status and embryo viability and potential opportunities to decrease reproductive failure.
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Affiliation(s)
- Ky Garrett Pohler
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Sydney Taylor Reese
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Gessica Araujo Franco
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Ramiro Vander Oliveira
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Rafael Paiva
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Lohana Fernandez
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Gabriela de Melo
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | | | - Reinaldo Cooke
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
| | - Rebecca Kyle Poole
- Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station, TX, United States
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9
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Panda BSK, Mohapatra SK, Chaudhary D, Alhussien MN, Kapila R, Dang AK. Proteomics and transcriptomics study reveals the utility of ISGs as novel molecules for early pregnancy diagnosis in dairy cows. J Reprod Immunol 2020; 140:103148. [PMID: 32447181 DOI: 10.1016/j.jri.2020.103148] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/22/2020] [Accepted: 05/07/2020] [Indexed: 01/10/2023]
Abstract
An early and precise diagnosis of pregnancy in cows is critical to short the calving interval and to improve their reproductive efficiency. Neutrophils are the first blood cells to sensitize the embryo in the uterus and participate in maternal recognition of pregnancy after getting induced by interferon tau (IFNτ). To study the protein abundance ratio, blood samples were collected on 0th, 10th, 18th and 36th day post-artificial insemination (AI) from crossbred Karan Fries cows. Neutrophils were isolated through density gradient centrifugation and studied for protein abundance by high-performance liquid chromatography coupled with mass spectrometry (LC-MS). Protein abundance ratios for Myxovirus resistance (MX1 and MX2) were found to be higher (P < 0.05) on day 10 and day 18 post-AI, whereas Oligoadenylate synthetase-1 (OAS1) and Interferon stimulated gene-15 ubiquitin-like modifier (ISG15) proteins were more abundant on day 18 post-AI. The relative mRNA expressions of these molecules were also studied by qPCR. The gene expression of ISG15, MX1, MX2 and OAS1 was found to be higher (P < 0.05) on day 10th, 18th and 36th post-AI compared to day 0. The study indicates that ISGs on blood neutrophils are essential for the establishment of pregnancy and may be targeted as potential biomarkers for pregnancy diagnosis in cows.
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Affiliation(s)
- Bibhudatta S K Panda
- Lactation and Immuno-Physiology Laboratory, ICAR-National Dairy Research Institute, Karnal, Haryana 132001, India
| | - Sunil Kumar Mohapatra
- Department of Animal Biochemistry, ICAR-National Dairy Research Institute, Karnal, Haryana 132001, India
| | - Dheeraj Chaudhary
- Lactation and Immuno-Physiology Laboratory, ICAR-National Dairy Research Institute, Karnal, Haryana 132001, India
| | | | - Rajeev Kapila
- Department of Animal Biochemistry, ICAR-National Dairy Research Institute, Karnal, Haryana 132001, India
| | - Ajay Kumar Dang
- Lactation and Immuno-Physiology Laboratory, ICAR-National Dairy Research Institute, Karnal, Haryana 132001, India.
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10
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Applied use of interferon-tau stimulated genes expression in polymorphonuclear cells to detect pregnancy compared to other early predictors in beef cattle. Theriogenology 2020; 152:94-105. [PMID: 32387553 DOI: 10.1016/j.theriogenology.2020.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/17/2022]
Abstract
We aimed to evaluate the accuracy of Interferon-tau stimulated genes (ISG) abundance in peripheral blood polymorphonuclear cells (PMNs) on D20 after fixed-time artificial insemination (FTAI; D0) as a pregnancy diagnosis method against CL evaluation by Doppler ultrasonography and progesterone (P4) concentrations on D20, as well as Pregnancy Associated Glycoproteins (PAG) concentrations on D25. Additionally, we evaluated the potential of ISG abundance in PMNs as pregnancy loss predictors. Nelore heifers (n = 103) and cows (n = 144) underwent estrous synchronization and were artificially inseminated on D0. Pregnancy was diagnosed by B-mode ultrasonography on D30 and D70, and after the final diagnosis, females were classified in four groups: Pregnant; Non-pregnant; Functional CL on D20 but non-pregnant (CL-NP) and Pregnancy loss between D30 and D70 (PL). After determining cutoff values, the Sensitivity (SE), Specificity (SP), Positive Predictive Value (PPV), Negative Predictive Value (NPV) and Accuracy (ACC) were determined for each method. All methods were classified as significant (P < 0.05) predictors of pregnancy. Both ISG expression and PAG concentrations were greater (P < 0.05) in pregnant females than in non-pregnant and CL-NP females but did not differ (P > 0.05) from the PL group. ISG15 expression was greater (P < 0.05) in heifers than in cows, but this difference was not found in OAS1 expression and PAG concentrations. All the methods evaluated were proven to be adequate predictors of pregnancy, but greater accuracies were obtained through PAG concentrations and Doppler-US, due to the decreased number of false positive and false negative results.
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11
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Palhão M, Guimarães C, Lima J, Mendonça M, Fernandes C, Neves J, Garcia J, Gioso M, Miglino M, Viana J. Efficacy and limitations of different approaches to anticipate the diagnosis of pregnancy in cattle. ARQ BRAS MED VET ZOO 2019. [DOI: 10.1590/1678-4162-10698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT The study evaluated sonographic and serologic exams performed for early (20 to 30d) diagnosis of pregnancy. One hundred-twenty (n= 120) bovine recipients were synchronized (estrous=D0) and timed embryo transferred (TET, D7) with fresh in vitro produced embryos. In the first trial (n= 46), diagnosis of pregnancy was performed on day 20 (D20) by detecting CL blood flow (BF) and by Pregnancy-Associated Glycoproteins (PAGs) serology. In the second trial (n= 30), pregnancy diagnosis was performed on D25 by ultrasound visualization of uterine contents and by PAGs serology. In the last trial, PAG’s serology was performed on D30. Ultrasonographic detection of the uterine contents and embryo viability performed on D30 (DG30) was considered the gold standard. The PROC FREQ procedure was used to test the agreement between diagnostic methods. On D20, the Doppler ultrasonography of the CL had showed high sensitivity (100%), but only moderate specificity (53.3%). On the same day, serologic diagnostic had no agreement (k= -0.08, P< 0.46) with the gold standard, with very low sensitivity (6.3%). However, the sensitivity of the serologic exam increased dramatically (from 6.3 to 100%) from D20 to D25, and it contributed to detect false negatives from the ultrasound diagnosis, improving the overall accuracy from 90% to 96.7%.
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Affiliation(s)
- M.P. Palhão
- Universidade José do Rosário Vellano, Brazil
| | | | | | | | | | - J.P. Neves
- Universidade José do Rosário Vellano, Brazil
| | - J.A.D. Garcia
- Universidade José do Rosário Vellano, Brazil; IFSuldeMinas, Brazil
| | - M.M. Gioso
- Universidade José do Rosário Vellano, Brazil
| | | | - J.H.M. Viana
- Embrapa Recursos Genéticos e Biotecnologia, Brazil
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12
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Madureira AML, Pohler KG, Guida TG, Wagner SE, Cerri RLA, Vasconcelos JLM. Association of concentrations of beta-carotene in plasma on pregnancy per artificial insemination and pregnancy loss in lactating Holstein cows. Theriogenology 2019; 142:216-221. [PMID: 31622852 DOI: 10.1016/j.theriogenology.2019.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 10/25/2022]
Abstract
The objective of this study was to determine the association of beta-carotene concentration in plasma at the moment of artificial insemination (AI) on pregnancy/AI in lactating Holstein cows. A total of 399 events from 364 lactating Holstein cows were enrolled in the trial (143 primiparous and 221 multiparous). All cows were assigned to a timed AI protocol based on estradiol and progesterone. Blood samples were collected at the moment of AI and at 24 and 31d post-AI (samples on 31 d post-AI were collected only from cows that were diagnosed pregnant). The BCS were recorded at the time of AI. Plasma beta-carotene was quantified from blood samples taken at the time of AI using a single step denaturation and extraction into a solvent, followed by measurement using a portable spectrophotometer. Pregnancy-associated glycoproteins (PAG) were analyzed in blood samples taken at 24 and 31 d post-AI of pregnant cows. Milk production was collected for the entire experimental period. Pregnancy diagnosis was performed by ultrasound 31 and 60 d post-AI. Data was analyzed using the MIXED and GLIMMIX procedures of SAS. Cows classified as thin (<2.75) tended to have lower concentration of beta-carotene at AI when compared with those classified as Moderate (≥3.00; 3.8 ± 0.1 vs. 4.3 ± 0.1 μg/mL; P = 0.09). Concentration of beta-carotene were greater in multiparous compared with primiparous (P < 0.01). There was no correlation between concentration of beta-carotene and milk production (r = 0.04; P = 0.10). When plasma beta-carotene was categorized in quartiles, cows in the 1st quartile had lower pregnancy/AI and higher pregnancy losses when compared with cows that were in the 2nd, 3rd and 4th quartile (pregnancy/AI = 19.2 ± 4.5, 33.7 ± 4.7, 36.9 ± 5.0 and 39.8 ± 5.4%, respectively; P = 0.05; pregnancy losses = 41.9 ± 4.8, 20.4 ± 3.7, 22.1 ± 4.1, and 15.7 ± 4.2%, respectively; P < 0.05). There was no association between concentrations of beta-carotene at AI and PAG at 24 d post-AI (P = 0.60). Cows with greater concentrations of beta-carotene at AI were more likely to have greater concentrations of PAG at 31 d post-AI (P < 0.01). In conclusion, the concentration of beta-carotene at AI was affected by BCS and parity. Cows with higher concentrations of plasma beta-carotene at AI had greater pregnancy/AI, lower pregnancy losses and greater concentrations of PAG at d 31 post-AI, suggesting it may be associated with placental function in lactating dairy cows.
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Affiliation(s)
- A M L Madureira
- Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - K G Pohler
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - T G Guida
- Department of Animal Production, São Paulo State University, Botucatu, 18168-000, Brazil
| | - S E Wagner
- Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - R L A Cerri
- Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - J L M Vasconcelos
- Department of Animal Production, São Paulo State University, Botucatu, 18168-000, Brazil.
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13
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Ealy AD, Seekford ZK. Symposium review: Predicting pregnancy loss in dairy cattle. J Dairy Sci 2019; 102:11798-11804. [PMID: 31587904 DOI: 10.3168/jds.2019-17176] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/22/2019] [Indexed: 12/20/2022]
Abstract
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.
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Affiliation(s)
- Alan D Ealy
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061.
| | - Zachary K Seekford
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061
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14
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Ealy AD, Wooldridge LK, McCoski SR. BOARD INVITED REVIEW: Post-transfer consequences of in vitro-produced embryos in cattle. J Anim Sci 2019; 97:2555-2568. [PMID: 30968113 DOI: 10.1093/jas/skz116] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/08/2019] [Indexed: 01/09/2023] Open
Abstract
In vitro embryo production (IVP) in cattle has gained worldwide interest in recent years, but the efficiency of using IVP embryos for calf production is far from optimal. This review will examine the pregnancy retention rates of IVP embryos and explore causes for pregnancy failures. Based on work completed over the past 25 yr, only 27% of cattle receiving IVP embryos will produce a live calf. Approximately 60% of these pregnancies fail during the first 6 wk of gestation. When compared with embryos generated by superovulation, pregnancy rates are 10% to 40% lower for cattle carrying IVP embryos, exemplifying that IVP embryos are consistently less competent than in vivo-generated embryos. Several abnormalities have been observed in the morphology of IVP conceptuses. After transfer, IVP embryos are less likely to undergo conceptus elongation, have reduced embryonic disk diameter, and have compromised yolk sac development. Marginal binucleate cell development, cotyledon development, and placental vascularization have also been documented, and these abnormalities are associated with altered fetal growth trajectories. Additionally, in vitro culture conditions increase the risk of large offspring syndrome. Further work is needed to decipher how the embryo culture environment alters post-transfer embryo development and survival. The risk of these neonatal disorders has been reduced by the use of serum-free synthetic oviductal fluid media formations and culture in low oxygen tension. However, alterations are still evident in IVP oocyte and embryo transcript abundances, timing of embryonic cleavage events and blastulation, incidence of aneuploidy, and embryonic methylation status. The inclusion of oviductal and uterine-derived embryokines in culture media is being examined as one way to improve the competency of IVP embryos. To conclude, the evidence presented herein clearly shows that bovine IVP systems still must be refined to make it an economical technology in cattle production systems. However, the current shortcomings do not negate its current value for certain embryo production needs and for investigating early embryonic development in cattle.
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Affiliation(s)
- Alan D Ealy
- Department of Animal & Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Lydia K Wooldridge
- Department of Animal & Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Sarah R McCoski
- Department of Animal & Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
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15
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Gifford CA, Aloqaily BH, Hernandez Gifford JA. BEEF SPECIES-RUMINANT NUTRITION CACTUS BEEF SYMPOSIUM: Maternal immune modulation prior to embryo arrival in the uterus is important for establishment of pregnancy in cattle1. J Anim Sci 2019; 97:3605-3610. [PMID: 31083718 PMCID: PMC6667245 DOI: 10.1093/jas/skz160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/10/2019] [Indexed: 01/26/2023] Open
Abstract
In 1953, Sir Peter Medawar first recognized the allogeneic properties of a developing conceptus and rationalized that an "immune-tolerant" physiological state must exist during pregnancy. Early theories speculated that the conceptus evaded the maternal immune system completely, but 40 yr after Medawar's observations, Wegmann proposed that the maternal immune system shifts the cytokine profile away from inflammatory cytokine production when an embryo is present. The economic consequences and production losses of subfertile animals have been well documented in studies evaluating calving distribution. Despite advances in understanding infertility or subfertility, few technologies exist to identify subfertile animals or improve fertility beyond hormonal intervention associated with synchronization protocols. Work in rodents and some livestock species indicates that the uterine immune cell population shifts dramatically after copulation and these early immune-modulated events establish a receptive uterine environment. Clearly, as evident in embryo transfer, the presence of a conceptus is sufficient to establish communication for pregnancy establishment but does not rule out the importance of other physiological events to prime the maternal immune system prior to blastocyst arrival in the uterus. In support of this concept, work in our laboratory and by others has demonstrated that autologous intrauterine transfer of peripheral immune cells prior to embryo transfer can increase pregnancy rates and accelerate conceptus development in women and cattle. Understanding aberrant immune regulation in subfertile animals may provide markers for subfertility or targets for clinical intervention to enhance fertility, particularly when using reproductive technologies.
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Affiliation(s)
- Craig A Gifford
- Department of Extension Animal Sciences and Natural Resources, New Mexico State University, Las Cruces, NM
| | - Bahaa H Aloqaily
- Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM
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16
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Reese ST, Geary TW, Franco GA, Moraes JGN, Spencer TE, Pohler KG. Pregnancy associated glycoproteins (PAGs) and pregnancy loss in high vs sub fertility heifers. Theriogenology 2019; 135:7-12. [PMID: 31185426 DOI: 10.1016/j.theriogenology.2019.05.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/01/2019] [Accepted: 05/29/2019] [Indexed: 11/16/2022]
Abstract
Reproductive inefficiency and infertility are major financial burdens to domestic livestock. Variables associated with these reproductive losses during early gestation include contributions from the oocyte, uterus, sperm, embryo and placenta. Bovine pregnancy associated glycoproteins (PAG) are produced by the binucleate cells of the ruminant placenta and can be used to diagnose pregnancy. Increased circulating concentrations of PAG early in gestation have been correlated with pregnancy success and decreased concentrations are predictive of impending embryonic mortality in both beef and dairy cattle. The objectives of the current study were to determine whether: 1) heifer fertility status is associated with circulating concentrations of PAG and pregnancy loss; and 2) PAG concentrations within the same animal are repeatable across multiple pregnancies. We hypothesized maternal PAG concentrations would be increased in high fertility compared to subfertile heifers but not repeatable across subsequent pregnancies in the same heifer. Serial embryo transfer (ET; n = 4 rounds) was used to classify predominately Angus heifers (n = 92) as highly fertile (HF = 30; 100% pregnancy success) or subfertile (SF = 62; average = 33%; range = 25-75% pregnancy success) based on day 28 ultrasound diagnosis. Blood samples were collected at both day 28 and 44 for quantification of circulating PAG concentrations by an in house PAG ELISA with antibodies raised against early secreted PAGs. Pregnancy was terminated at day 44 of gestation and heifers were allowed 30 days recovery before synchronization for the next ET. Only heifers that were diagnosed pregnant by ultrasound were used in this study (HF: n = 30, SF: n = 62). Serum concentrations of PAGs were not different between HF (5.90 ± 0.27 ng/mL) and SF (5.56 ± 0.31 ng/mL; P = 0.16) heifers at day 28 of gestation nor was there a difference at day 44 of gestation (P = 0.32). Subfertile heifers had increased pregnancy loss between days 28 and 44 of gestation. Based on odds ratio analysis, SF heifers had a 2.41 times chance to undergo pregnancy loss between day 28-44 compared to HF heifers (P < 0.05). There was no correlation (P > 0.05) in maternal circulating concentrations of PAG between pregnancies on day 28 or 44 of gestation in samples obtained from HF heifers. In summary, circulating concentrations of PAG are not different between HF and SF heifers; however, HF classified heifers have decreased pregnancy loss between days 28 and 44 of gestation.
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Affiliation(s)
- S T Reese
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - T W Geary
- USDA-ARS, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT, USA
| | - G A Franco
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - J G N Moraes
- Division of Animal Sciences, University of Missouri, Columbia, MO, USA
| | - T E Spencer
- Division of Animal Sciences, University of Missouri, Columbia, MO, USA
| | - K G Pohler
- Department of Animal Science, Texas A&M University, College Station, TX, USA.
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17
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Smith MF, Geisert RD, Parrish JJ. Reproduction in domestic ruminants during the past 50 yr: discovery to application. J Anim Sci 2018; 96:2952-2970. [PMID: 29684167 PMCID: PMC6095338 DOI: 10.1093/jas/sky139] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/18/2018] [Indexed: 12/18/2022] Open
Abstract
The study of reproductive physiology in domestic ruminants has progressed from the whole animal to the molecular level in an amazingly short period of time. The volume of information on this subject is enormous; therefore, we have focused on domestic ruminants, with an emphasis on cattle. To date, artificial insemination (AI) is perhaps the most powerful technique that reproductive physiologists and geneticists have provided the livestock industry for genetic improvement. Early efforts to establish AI as a tool were initiated in Russia around 1899 and since that time major advances in methods of semen collection, evaluation of male fertility, cryopreservation of sperm, sex-sorted semen, and estrous cycle control have occurred. The preceding advances not only led to the widespread use of AI, but also contributed to our fundamental understanding of ovulation control, timing of insemination, gamete biology, and cryopreservation. In regards to anestrus, our understanding of the concept of neuroendocrine control of the pituitary gland and the role of steroid feedback led to the Gonadostat Theory, which proposes that onset of puberty is due to a decrease in the negative feedback of gonadal steroids over time. Subsequent studies in prepuberal and postpartum sheep and cattle established that a short luteal phase frequently precedes the first normal length cycle that is accompanied by estrous expression. This observation led to the common practice of treating prepuberal heifers and anestrous postpartum cows with a short-term progestin treatment (e.g., Controlled Internal Drug Release) to induce normal estrous cycles. In domestic ruminants, fertilization rate is high (85% to 95%); however, significant embryonic mortality before or around the time of maternal recognition of pregnancy (MRP) reduces the pregnancy rate to a single breeding. Significant effort has been directed at determining the time of MRP, the signal for MRP, as well as elucidating the physiological, cellular, and molecular dialogue between the conceptus and uterine environment. Advancements have now led us to the ability to edit the genome to alleviate disease and possibly improve production traits. In summary, major advancements in our understanding of reproductive biology have stemmed from efforts to establish the AI and embryo transfer technique and reduce the negative impact of anestrus and embryonic mortality in domestic ruminants.
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Affiliation(s)
- Michael F Smith
- Division of Animal Science, University of Missouri, Columbia, MO
| | - Rodney D Geisert
- Division of Animal Science, University of Missouri, Columbia, MO
| | - John J Parrish
- Department of Animal Science, University of Wisconsin, Madison, WI
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Pohler KG, Green JA, Moley LA, Gunewardena S, Hung WT, Payton RR, Hong X, Christenson LK, Geary TW, Smith MF. Circulating microRNA as candidates for early embryonic viability in cattle. Mol Reprod Dev 2018. [PMID: 28643872 DOI: 10.1002/mrd.22856] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Blood-borne extracellular vesicles (i.e., exosomes and microvesicles) carrying microRNAs (miRNAs) could make excellent biomarkers of disease and different physiologic states, including pregnancy status. We tested the hypothesis that circulating extracellular vesicle-derived miRNAs might differentiate the pregnancy status of cows that had maintained pregnancy to Day 30 from non-pregnant cows or from those that exhibited embryonic mortality between Days 17 and 30 of gestation. Cows were randomly assigned for artificial insemination with fertile semen (n = 36) or dead semen (n = 8; control group) on Day 0 (day of estrus). Blood was collected from all animals on Day 0 and on Days 17 and 24 after artificial insemination. Cows receiving live sperm were retrospectively classified as pregnant on Day 30 (n = 17) or exhibiting embryonic mortality between Days 17 and 30 (n = 19). Extracellular vesicles from Day 17 and 24 samples were isolated from serum using ultra-centrifugation, and their presence was confirmed by nanoparticle tracking and Western blot analyses (for CD81) prior to RNA extraction. MicroRNA sequencing was performed on pregnant, embryonic-mortality, and control cows (n = 4 per day), for a total of 24 independent reactions. In total, 214 miRNAs were identified in serum, 40 of which were novel. Based on differential abundance parameters, we identified 32 differentially abundant loci, representing 27 differentially abundant mature miRNA. At Days 17 and 24, specific miRNAs (e.g., miR-25, -16b, and -3596) were identified that differentiated the pregnancy status. In summary, we identified several circulating extracellular vesicles derived miRNAs that differ in abundance between embryonic mortality and pregnant cows.
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Affiliation(s)
- Ky G Pohler
- Department of Animal Science, University of Tennessee, Knoxville, Tennessee
| | - Jonathan A Green
- Division of Animal Sciences, University of Missouri, Columbia, Missouri
| | - Laura A Moley
- Division of Animal Sciences, University of Missouri, Columbia, Missouri
| | | | - Wei-Ting Hung
- University of Kansas Medical Center, Kansas City, Kansas
| | - Rebecca R Payton
- Department of Animal Science, University of Tennessee, Knoxville, Tennessee
| | - Xiaoman Hong
- University of Kansas Medical Center, Kansas City, Kansas
| | | | - Tom W Geary
- USDA-ARS, Fort Keogh Livestock and Range Research Laboratory, Miles City, Montana
| | - Michael F Smith
- Division of Animal Sciences, University of Missouri, Columbia, Missouri
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Montes-Quiroz GL, Sánchez-Dávila F, Grizelj J, Bernal-Barragán H, Vazquez-Armijo JF, Bosque-González ASD, Luna-Palomera C, González Gómez A, Ledezma-Torres RA. The reinsertion of controlled internal drug release devices in goats does not increase the pregnancy rate after short oestrus synchronization protocol at the beginning of the breeding season. JOURNAL OF APPLIED ANIMAL RESEARCH 2017. [DOI: 10.1080/09712119.2017.1386109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | | | - Juraj Grizelj
- Facultad de Medicina Veterinaria, Universidad de Zagreb, Zagreb, Croatia
| | - Hugo Bernal-Barragán
- Facultad de Agronomía, Universidad Autonoma de Nuevo León, Laboratorio de Nutrición y calidad de los alimentos, Campus de ciencias agropecuarias, General Escobedo, México
| | | | | | - Carlos Luna-Palomera
- División de Ciencias Agropecuarias 86280, Universidad Autónoma de Juárez de Tabasco, Villahermosa, México
| | - Adán González Gómez
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, México
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20
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Wiltbank MC, Baez GM, Garcia-Guerra A, Toledo MZ, Monteiro PL, Melo LF, Ochoa JC, Santos JE, Sartori R. Pivotal periods for pregnancy loss during the first trimester of gestation in lactating dairy cows. Theriogenology 2016; 86:239-53. [DOI: 10.1016/j.theriogenology.2016.04.037] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 02/02/2016] [Accepted: 03/14/2016] [Indexed: 12/16/2022]
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21
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Pohler K, Peres R, Green J, Graff H, Martins T, Vasconcelos J, Smith M. Use of bovine pregnancy-associated glycoproteins to predict late embryonic mortality in postpartum Nelore beef cows. Theriogenology 2016; 85:1652-1659. [DOI: 10.1016/j.theriogenology.2016.01.026] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/12/2016] [Accepted: 01/27/2016] [Indexed: 01/22/2023]
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