1
|
Chen F, Hou Y, Zhu X, Mei C, Guo R, Shi Z. Impact of Accessory Corpus Luteum Induced by Gonadotropin-Releasing Hormone or Human Chorionic Gonadotropin on Pregnancy Rates of Dairy Cattle following Embryo Transfer: A META-Analysis. Vet Sci 2023; 10:vetsci10050309. [PMID: 37235391 DOI: 10.3390/vetsci10050309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/07/2023] [Accepted: 04/17/2023] [Indexed: 05/28/2023] Open
Abstract
The circulation of progesterone (P4) concentrations of recipients has positive correlations with embryo survival and pregnancy success of embryo transfer (ET) in dairy cows. One strategy to improve P4 concentration is the administration of gonadotropin-releasing hormone (GnRH) or human chorionic gonadotropin (hCG), thereby inducing the formation of accessory corpus luteum (CL). This study aimed at determining the efficacy of GnRH or hCG treatment regarding embryo transfer (ET) and providing a better clinical veterinary practice guidance. A meta-analysis was conducted on the data from 2048 treated recipient cows and 1546 untreated cows. By inducing the formation of accessory CL with GnRH (100 µg), GnRH analogue Buserelin (8-10 µg), or hCG (≥1500 IU) 5-11 days after synchronized ovulation, hCG alone achieved an improvement (RR = 1.39, p < 0.05), while GnRH and GnRH analogue did not result in significant changes (RR = 1.04, p = 0.26). Treatment with GnRH or hCG 5-7 days after synchronized ovulation was associated with increased chances of pregnancy compared with later treatment (11-14 days). Owing to the treatment, the pregnancy rate of cows with very poor fertility (<40%) was improved, while that of cows with good fertility (≥40%) was not affected. Treatment with GnRH or hCG greatly improved pregnancy rates of parous lactating cows (RR = 1.32, p < 0.05) compared with heifers (RR = 1.02, p > 0.05). Additionally, as indicated by pregnancy loss analysis, the treatment had no benefit on late embryo/early fetus survival at days 28-81. In conclusion, the induction of accessory CL with GnRH or hCG may benefit fertility and have important implications for the management of reproductive performance in the dairy industry.
Collapse
Affiliation(s)
- Fang Chen
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yi'an Hou
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xiaoqing Zhu
- Science and Technology Industry Development Center, Chongqing Medical and Pharmaceutical College, Chongqing 401331, China
| | - Cheng Mei
- Dongying Austasia Modern Dairy Farm Co., Ltd., Dongying 257345, China
| | - Rihong Guo
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- Key Laboratory of Crop and Animal Integrated Farming, Ministry of Agriculture, Nanjing 210014, China
| | - Zhendan Shi
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| |
Collapse
|
2
|
McCoski SR, Cockrum RR, Ealy AD. Short Communication: Maternal obesity alters ovine endometrial gene expression during peri-implantation development. J Anim Sci 2022; 100:skac090. [PMID: 35772750 PMCID: PMC9246656 DOI: 10.1093/jas/skac090] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Exposure to maternal obesity in utero is associated with marked developmental effects in offspring that may not be evident until adulthood. Mechanisms regulating the programming effects of maternal obesity on fetal development have been reported, but little is known about how maternal obesity affects the earliest periods of embryonic development. This work explored how obesity influences endometrial gene expression during the peri-implantation period using a sheep model. Ewes were assigned randomly to diets that produced an obese state or maintained a lean state. After 4 mo, obese and lean ewes were bred and then euthanized at day 14 post-breeding. The uterus was excised, conceptuses were flushed, and endometrial tissue was collected. Isolated RNA from endometrial tissues (n = 6 ewes/treatment) were sequenced using an Illumina-based platform. Reads were mapped to the Ovis aries genome (Oar_4.0). Differential gene expression was determined, and results were filtered (false discovery rate ≤ 0.05 and ≥2-fold change, ≥0.2 reads/kilobase/million reads). Differentially expressed genes (DEGs) were identified (n = 699), with 171 downregulated and 498 upregulated in obese vs. lean endometrium, respectively. The most pronounced gene ontology categories identified were cellular process, metabolic process, and biological regulation. Enrichments were detected within the DEGs for genes involved with immune system processes, negative regulation of apoptosis, cell growth, and cell adhesion. A literature search revealed that 125 DEGs were associated with either the trophoblast lineage or the placenta. Genes within this grouping were involved with wingless/integrated signaling, angiogenesis, and integrin signaling. In summary, these data indicate that the peri-implantation endometrium is responsive to maternal obesity. Transcript profile analyses suggest that the endometrial immune response, adhesion, and angiogenesis may be especially susceptible to obesity. Thus, alterations in uterine transcript profiles during early embryogenesis may be a mechanism responsible for developmental programming following maternal obesity exposure in utero.
Collapse
Affiliation(s)
- Sarah R McCoski
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT, USA
| | | | - Alan D Ealy
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA
| |
Collapse
|
3
|
Stenhouse C, Halloran KM, Hoskins EC, Newton MG, Moses RM, Seo H, Dunlap KA, Satterfield MC, Gaddy D, Johnson GA, Wu G, Suva LJ, Bazer FW. Effects of exogenous progesterone on the expression of mineral regulatory molecules by ovine endometrium and placentomes†. Biol Reprod 2022; 106:1126-1142. [PMID: 35191486 DOI: 10.1093/biolre/ioac042] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
This study aimed to determine whether the acceleration of conceptus development induced by the administration of exogenous progesterone (P4) during the preimplantation period of pregnancy alters calcium, phosphate, and vitamin D signaling at the maternal-conceptus interface. Suffolk ewes (n = 48) were mated to fertile rams and received daily intramuscular injections of either corn oil (CO) vehicle or 25 mg of progesterone in CO (P4) for the first 8 days of pregnancy and hysterectomized on either Day 9 (CO, n = 5; P4, n = 6), 12 (CO, n = 9; P4, n = 4) or 125 (CO, n = 14; P4, n = 10) of gestation. The expression of S100A12 (P < 0.05) and fibroblast growth factor receptor (FGFR2) (P < 0.01) messenger RNAs (mRNAs) was lower in endometria from P4-treated ewes on Day 12. The expression of ADAM10 (P < 0.05) mRNA was greater in endometria from P4-treated ewes on Day 125. The expression of ADAM10 (P < 0.01), FGFR2 (P < 0.05), solute carrier (SLC)20A1 (P < 0.05), TRPV5 (P < 0.05), and TRPV6 (P < 0.01) mRNAs was greater, but KL mRNA expression was lower (P < 0.05) in placentomes from P4-treated ewes at Day 125. There was lower endometrial and greater placentomal expression of mRNAs involved in mineral metabolism and transport in twin compared to singleton pregnancies. Further, the expression of mRNAs involved in mineral metabolism and transport was greater in P4-treated twin placentomes. KL, FGF23, vitamin D receptor (VDR), S100A9, S100A12, S100G, and CYP27B1 proteins were immunolocalized in endometria and placentomes. Exogenous P4 in early pregnancy altered the expression of regulators of calcium, phosphate, and vitamin D on Day 125 of pregnancy indicating a novel effect of P4 on mineral transport at the maternal-conceptus interface.
Collapse
Affiliation(s)
- Claire Stenhouse
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | | | - Emily C Hoskins
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Makenzie G Newton
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Robyn M Moses
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Heewon Seo
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Kathrin A Dunlap
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | | | - Dana Gaddy
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Gregory A Johnson
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Larry J Suva
- Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas USA
| | - Fuller W Bazer
- Department of Animal Science, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
4
|
Su Y, Li Q, Zhang Q, Li Z, Yao X, Guo Y, Xiao L, Wang X, Ni H. Exosomes derived from placental trophoblast cells regulate endometrial epithelial receptivity in dairy cows during pregnancy. J Reprod Dev 2021; 68:21-29. [PMID: 34690214 PMCID: PMC8872746 DOI: 10.1262/jrd.2021-077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inadequate fetomaternal interactions could directly lead to pregnancy failure in dairy cows. Exosomes are widely involved in endometrial matrix remodeling, immune function changes,
placental development, and other processes of embryo implantation and pregnancy in dairy cows. However, the role of exosomes derived from placental trophoblast cells in regulating the
receptivity of endometrial cells and facilitating fetomaternal interaction remains unclear. In this study, bovine trophoblast cells (BTCs) were obtained from bovine placenta and immortalized
by transfection with telomerase reverse transcriptase (TERT). Immortalized BTCs still possess the basic and key properties of primary BTCs without exhibiting any neoplastic transformation
signs. Subsequently, the effect of trophoblast-derived exosomes (TDEs) on endometrial receptivity in endometrial epithelial cells (EECs) was determined, and the mechanism whereby TDEs and
their proteins participate in the fetomaternal interaction during bovine pregnancy were explored. EECs were co-cultured with the exosomes derived from BTCs treated with progesterone (P4).
Such treatment enhanced the expression of the endometrial receptivity factors, integrin αv, β3, Wnt7a, and MUC1 by changing the extracellular environment, metabolism, and redox balance in
EECs via proteome alignment, compared with no treatment according to the DIA quantitation analysis. Our study demonstrated that trophoblast-derived exosome proteins are one of the most
critical elements in fetomaternal interaction, and their changes may act as a key signal in altering endometrial receptivity and provide a potential target for improving fertility.
Collapse
Affiliation(s)
- Yue Su
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Qianru Li
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Qiaochu Zhang
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Zhiming Li
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Xinxin Yao
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Yong Guo
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Longfei Xiao
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Xiangguo Wang
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| | - Hemin Ni
- Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China
| |
Collapse
|
5
|
Endometrial Inflammation at the Time of Insemination and Its Effect on Subsequent Fertility of Dairy Cows. Animals (Basel) 2021; 11:ani11071858. [PMID: 34206536 PMCID: PMC8300153 DOI: 10.3390/ani11071858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary A detailed understanding of cellular and molecular mechanisms in the bovine uterus is crucial to explain and avoid subfertility in dairy cows. Therefore, we examined the effect of inflammation in the bovine uterus in cows with no clinical signs of disease at the time of artificial insemination (AI) on subsequent pregnancy outcome. In a total of 71 healthy dairy cows, uterine cytology samples were collected by cytobrush technique within 10 min after insemination. Endometrial inflammation was investigated at the cellular and mRNA expression levels. All factors with a significant effect on fertility in our study were related to uterine polymorphonuclear neutrophil (PMN) migration, i.e., the first line of uterine defense. Cows with a proportion of ≥1% PMN had a 1.8-fold increased chance of pregnancy within 150 days postpartum compared to cows with fewer PMNs. From our results, we conclude that a certain level of inflammation at the molecular and cellular levels before the stimulus of AI might be favorable for cows’ fertility. Abstract Our objective was to investigate the level of endometrial immune response at artificial insemination (AI) and to relate it to subsequent fertility. From 71 healthy cows, endometrial cytobrush samples were taken at the first AI for cytological and mRNA analyses. Total RNA isolated from the cytobrushes was used for reverse transcription qPCR for selected transcripts. Animals were grouped into pregnant (PREG; n = 32) and non-pregnant (non-PREG; n = 39) cows following their first AI. The mRNA abundance of the neutrophil-related factor CEACAM1 and the chemokine CXCL5 was 1.2- (p = 0.03) and 2.0-fold (p = 0.04) greater in PREG than in non-PREG cows, respectively. Animals were further subdivided according to the number of inseminations until pregnancy (PREG1, n = 32; PREG2-3, n = 19) and in repeat breeder cows (RBC, n = 13). CEACAM1 and CXCL8 mRNA expression was 1.7- (p = 0.01) and 2.3-fold (p = 0.03) greater in PREG1 than in RBC, respectively. Cox regression showed that cows with PMN ≥ 1% had a 1.8-fold increased chance of pregnancy within 150 days postpartum compared with cows with fewer PMNs. We conclude that a certain level of inflammation before the stimulus of AI might be beneficial for subsequent fertility.
Collapse
|
6
|
Campanile G, Baruselli PS, Limone A, D'Occhio MJ. Local action of cytokines and immune cells in communication between the conceptus and uterus during the critical period of early embryo development, attachment and implantation - Implications for embryo survival in cattle: A review. Theriogenology 2021; 167:1-12. [PMID: 33743503 DOI: 10.1016/j.theriogenology.2021.02.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/15/2021] [Accepted: 02/24/2021] [Indexed: 12/16/2022]
Abstract
Early embryo development, implantation and pregnancy involve a complex dialogue between the embryo and mother. In cattle this dialogue starts as early as days 3-4 when the embryo is still in the oviduct, and it continues to implantation. Immunological processes involving cytokines, mast cells and macrophages form an important part of this dialogue. Amongst the cytokines, interleukin-6 (Il-6) and leukemia inhibitory factor (LIF) are secreted by both the embryo and uterine endometrium and form part of an ongoing and reciprocating dialogue. Mast cells and macrophages populate the uterine endometrium during embryo development and are involved in achieving the correct balance between inflammatory and anti-inflammatory reactions at the uterus that are associated with embryo attachment and implantation. Embryo loss is the major cause of reproductive wastage in cattle, and livestock generally. A deeper understanding of immunological processes during early embryo development will help to achieve the next step change in the efficiency of natural and assisted breeding.
Collapse
Affiliation(s)
- Giuseppe Campanile
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy.
| | - Pietro S Baruselli
- Department of Animal Reproduction, Faculty of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, Brazil.
| | - Antonio Limone
- Instituto Zooprofilattico Sperimentale Del Mezzogiorno, Portici, Naples, Italy
| | - Michael J D'Occhio
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, New South Wales, 2006, Australia
| |
Collapse
|
7
|
Hoskins EC, Halloran KM, Stenhouse C, Moses RM, Dunlap KA, Satterfield MC, Seo H, Johnson GA, Wu G, Bazer FW. Pre-implantation exogenous progesterone and pregnancy in sheep: I. polyamines, nutrient transport, and progestamedins. J Anim Sci Biotechnol 2021; 12:39. [PMID: 33663606 PMCID: PMC7934464 DOI: 10.1186/s40104-021-00554-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
Background Administration of exogenous progesterone (P4) to ewes during the pre-implantation period advances conceptus development and implantation. This study determined effects of exogenous P4 on transport of select nutrients and pathways that enhance conceptus development. Pregnant ewes (n = 38) were treated with either 25 mg P4 in 1 mL corn oil (P4, n = 18) or 1 mL corn oil alone (CO, n = 20) from day 1.5 through day 8 of pregnancy and hysterectomized on either day 9 or day 12 of pregnancy. Endometrial expression of genes encoding enzymes for synthesis of polyamines, transporters of glucose, arginine, and glycine, as well as progestamedins was determined by RT-qPCR. Results On day 12 of pregnancy, conceptuses from P4-treated ewes had elongated while those from CO-treated ewes were spherical. The mRNA expression of AZIN2, an arginine decarboxylase, was lower in endometria of P4-treated than CO-treated ewes on day 9 of pregnancy. Expression of FGF10, a progestamedin, was greater in endometria of CO and P4-treated ewes on day 12 of gestation in addition to P4-treated ewes necropsied on day 9 of gestation. Treatment with P4 down-regulated endometrial expression of amino acid transporter SLC1A4 on day 12 of pregnancy. Conclusions Results indicated that administration of exogenous P4 during the pre-implantation period advanced the expression of FGF10, which may accelerate proliferation of trophectoderm cells, but also was correlated with decreased expression of glycine and serine transporters and polyamine synthesis enzyme AZIN2. Further research with increased sample sizes may determine how differential expression affects endometrial functions and potentially embryonic loss. Supplementary Information The online version contains supplementary material available at 10.1186/s40104-021-00554-6.
Collapse
Affiliation(s)
- Emily C Hoskins
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Katherine M Halloran
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Claire Stenhouse
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Robyn M Moses
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Kathrin A Dunlap
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Michael C Satterfield
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Heewon Seo
- Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA
| | - Gregory A Johnson
- Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA
| | - Guoyao Wu
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Fuller W Bazer
- Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA.
| |
Collapse
|
8
|
D Occhio MJ, Campanile G, Baruselli PS. Transforming growth factor-β superfamily and interferon-τ in ovarian function and embryo development in female cattle: review of biology and application. Reprod Fertil Dev 2021; 32:539-552. [PMID: 32024582 DOI: 10.1071/rd19123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 09/16/2019] [Indexed: 12/21/2022] Open
Abstract
Survival of the embryo and establishment of a pregnancy is a critical period in the reproductive function of female cattle. This review examines how the transforming growth factor-β (TGFB) superfamily (i.e. bone morphogenetic protein (BMP) 15, growth differentiation factor (GDF) 9, anti-Müllerian hormone (AMH)) and interferon-τ (IFNT) affect ovarian function and embryo development. The oocyte in a primary follicle secretes BMP15 and GDF9, which, together, organise the surrounding granulosa and theca cells into the oocyte-cumulus-follicle complex. At the same time, the granulosa secretes AMH, which affects the oocyte. This autocrine-paracrine dialogue between the oocyte and somatic cells continues throughout follicle development and is fundamental in establishing the fertilisation potential and embryo developmental competency of oocytes. The early bovine embryo secretes IFNT, which acts at the uterine endometrium, corpus luteum and blood leucocytes. IFNT is involved in the maternal recognition of pregnancy and immunomodulation to prevent rejection of the embryo, and supports progesterone secretion. Manipulation of BMP15, GDF9, AMH and IFNT in both invivo and invitro studies has confirmed their importance in reproductive function in female cattle. This review makes the case that a deeper understanding of the biology of BMP15, GDF9, AMH and IFNT will lead to new strategies to increase embryo survival and improve fertility in cattle. The enhancement of oocyte quality, early embryo development and implantation is considered necessary for the next step change in the efficiency of natural and assisted reproduction in cattle.
Collapse
Affiliation(s)
- Michael J D Occhio
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, 410 Werombi Road, Camden, NSW 2006, Australia
| | - Giuseppe Campanile
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, V. F. Delpino, 1 80137 Naples, Italy
| | - Pietro S Baruselli
- Department of Animal Reproduction, Faculty of Veterinary Medicine and Zootecnia, University of Sao Paulo, Sao Paulo, CEP 05508-270 Brazil; and Corresponding author.
| |
Collapse
|
9
|
Effect of estrus expression or treatment with GnRH on pregnancies per embryo transfer and pregnancy losses in beef recipients synchronized with estradiol/progesterone-based protocols. Theriogenology 2020; 157:378-387. [PMID: 32866844 DOI: 10.1016/j.theriogenology.2020.08.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 11/23/2022]
Abstract
Two experiments were designed to determine the effect of expression of estrus or GnRH treatment on pregnancies per embryo transfer (P/ET) and pregnancy losses in beef recipients that were synchronized with estradiol/progesterone based protocols for fixed-time embryo transfer (FTET). Experiment 1 evaluated the effect of expression of estrus and GnRH treatment in the absence of estrus on P/ET. Beef cows (n = 729) were treated with 2 mg estradiol benzoate (EB) and an intravaginal device containing 0.5 g of progesterone. Devices were removed 8 d later and all cows received prostaglandin F2α (PGF2α), 400 IU eCG, and 0.5 mg estradiol cypionate (ECP) at that time. Expression of estrus was determined at 48 and 56 h after device removal using tail-paint and cows that did not show positive signs of estrus by 48 h received GnRH or no treatment at random. The overall estrus rate was 76.0% (554/729); 68.0% had positive signs of estrus by 48 h after progesterone device removal and 28.0% of those not in estrus by 48 h showed estrus by 56 h. The proportion of recipients receiving in vivo-derived (IVD) or in vitro-produced (IVP) embryos and P/ET were greater in recipients that showed estrus by 48 and 56 h (94.0% and 48.4%, respectively) than in those that did not show estrus 41.0% and 29.0%, respectively; P < 0.01). However, GnRH treatment of recipients not showing estrus by 48 h did not improve P/ET. Experiment 2 evaluated the effect of expression of estrus on P/ET and pregnancy loses up to parturition in recipients synchronized with two estradiol-based protocols. Beef cows (n = 403) were divided at random to receive the same synchronization protocol as in Experiment 1 (ECP) or a J-Synch protocol (device removal on day 6 and without using estradiol cypionate to induce ovulation). In this experiment, pregnancy was determined at 30 and 60 d by ultrasonography, and all pregnant recipients were followed until parturition to determine pregnancy losses during gestation. Although the number of recipients receiving IVP embryos was greater in the ECP group (90.5% vs. 83.5%; P = 0.03), P/ET did not differ (ECP: 37.0% and J-Synch: 39.0%; P = 0.43). Overall, 88.0% (357/407) of the recipients synchronized showed estrus and a greater P/ET (P = 0.05) was found in the recipients that showed estrus (39.0%) vs. those that did not show estrus (26.0%), regardless of treatment group. Pregnancy losses were lower (P = 0.004) and the calving rate was higher (P = 0.01) in recipients that showed estrus (25.0% and 29.3%, respectively) than in those that did not (88.8% and 2.9%, respectively). In summary, expression of estrus was associated with a greater P/ET in recipients treated with two different estradiol/P4-based synchronization protocols. The expression of estrus was associated with a greater proportion of recipients receiving embryos, P/ET and calving rate. Treatment with GnRH did not improve P/ET in the recipients that did not show estrus, questioning the its use in recipients synchronized with estradiol/progesterone based FTET protocols.
Collapse
|
10
|
Graña-Baumgartner A, Meikle A, Fernández-Foren A, Neimaur K, Barrera N, Cuadro F, Santos-Neto PCD, Bosolasco D, Núñez-Olivera R, Crispo M, Menchaca A, de Brun V. Local influence of the corpus luteum on the ipsilateral oviduct and early embryo development in the ewe. Theriogenology 2020; 151:7-15. [DOI: 10.1016/j.theriogenology.2020.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/11/2020] [Accepted: 03/23/2020] [Indexed: 12/17/2022]
|