Relationship between Variation in Conceptus Development and Differences in Estrous Cycle Duration in Ewes1

Nephew, Kenneth P.; McClure, K. E.; Ott, Troy L.; Dubois, Daniel H.; Bazer, Fuller W.; Pope, W. F.

doi:10.1095/biolreprod44.3.536

Cited by 72 publications

(34 citation statements)

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“…During early luteal phase, inadequate or low progesterone levels generally cause to strike against embryonic development (Nephew et al 1991). For this reason, progesterone from corpus luteum is needed for embryonic implantation and development in uterus (Thatcher et al 2001) or exogenous progesterone applications may be needed to continue these vital processes for embryo (Davies and Beck 1992;Nephew et al 1994;Rostami et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Effect of double GnRH injections on reproductive parameters in Awassi ewes receiving long-term progesterone

Zonturlu

Kaçar

Kaya

et al. 2018

Journal of Applied Animal Research

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The aim of this study was to investigate the effect of single or double Gonadotropin releasing hormone (GnRH) injections at the time of mating and following on day 9 on pregnancy rates and litter size in ewes. Oestrus was synchronized in 130 adult ewes using intravaginal sponges containing 20 mg of fluorogestone acetate for 14 days. All ewes received 10 IU/kg of pregnant mare serum gonadotropin (PMSG) at the sponge withdrawal. Then animals were divided into three groups. Ewes in group 1 (G1; Control, n = 68) received 1 ml placebo injection. In group 2 (G2; n = 30), ewes in oestrus were treated with 1 ml GnRH (4 μg/ml) at the time of mating. In group 3 (G3; n = 32), ewes were injected 1 ml GnRH not only at the time of mating but also on day 9 post-mating. There was significantly higher in duration of oestrus G1 compared with the G2 and G3. Pregnancy rate was found to be higher in G3 (96.0%) than in G1 (72.7%) and G2 (83.3%). The litter size was significantly higher for G3 (1.26 ± 0.14) in comparison with the G1 (1.18 ± 0.07) and G2 (1.22 ± 0.10). In conclusion, Post-mating GnRH injection enhanced the pregnancy rate and litter size, because of its beneficial effects on embriyo viability by increasing luteal formations. ARTICLE HISTORY

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Section: Introductionmentioning

confidence: 99%

Effect of double GnRH injections on reproductive parameters in Awassi ewes receiving long-term progesterone

Zonturlu

Kaçar

Kaya

et al. 2018

Journal of Applied Animal Research

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“…The postovulatory rise in circulating P4 during early pregnancy clearly affects blastocyst growth in cattle (60). Increasing concentrations of P4 during metestrus and early diestrus enhanced blastocyst development and size by days [13][14][15][16] in heifers and cows (12,23,59), while animals with lower concentrations of P4 in the early luteal phase had retarded embryonic development (61,66) and conceptuses produced less IFNT (61). Studies of both sheep and cattle are beginning to identify pregnancy and P4-responsive genes in the endometrium that potentially regulate blastocyst elongation and implantation of the conceptus (see Refs.…”

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confidence: 99%

Discovery of candidate genes and pathways in the endometrium regulating ovine blastocyst growth and conceptus elongation

Satterfield

Song

Kochan

et al. 2009

Physiological Genomics

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Establishment of pregnancy in ruminants requires blastocyst growth to form an elongated conceptus that produces interferon tau, the pregnancy recognition signal, and initiates implantation. Blastocyst growth and development requires secretions from the uterine endometrium. An early increase in circulating concentrations of progesterone (P4) stimulates blastocyst growth and elongation in ruminants. This study utilized sheep as a model to identify candidate genes and regulatory networks in the endometrium that govern preimplantation blastocyst growth and development. Ewes were treated daily with either P4 or corn oil vehicle from day 1.5 after mating to either day 9 or day 12 of pregnancy when endometrium was obtained by hysterectomy. Microarray analyses revealed many differentially expressed genes in the endometria affected by day of pregnancy and early P4 treatment. In situ hybridization analyses revealed that many differentially expressed genes were expressed in a cell-specific manner within the endometrium. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was used to identify functional groups of genes and biological processes in the endometrium that are associated with growth and development of preimplantation blastocysts. Notably, biological processes affected by day of pregnancy and/or early P4 treatment included lipid biosynthesis and metabolism, angiogenesis, transport, extracellular space, defense and inflammatory response, proteolysis, amino acid transport and metabolism, and hormone metabolism. This transcriptomic data provides novel insights into the biology of endometrial function and preimplantation blastocyst growth and development in sheep.

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“…In ewes, low blood progesterone concentrations at ovulation increase markedly during the luteal phase (between days 2 and 10 of oestrous cycle), and during the next follicular phase (between days 16 to18 of oestrous cycle) they decrease again (Gonzales Reyna et al 1987;Peeters et al 1989;R h odes et al 1990;G onzales Reyna et al 1991;Nephew et al 1991). Differences in serum progesterone levels between the pregnant and cycling ewes appear between days 14 and 18 after oestrus, i.e.…”

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confidence: 99%

Faecal Gestagen, Serum and Milk Progesterone Concentrations in Ewes of the Jezersko-Solchava Breed

Čebulj‐Kadunc¹,

Snoj²,

Cestnik³

2000

Acta Vet. Brno

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The aim of the study was to obtain information about the characteristics of the serum progesterone, faecal gestagen and milk progesterone patterns in the ewes during oestrous cycle, pregnancy and postpartum period. The study was performed in seven adult ewes of the JezerskoSolchava breed. The faecal gestagens were extracted by methanol and hormone concentrations determined by EIA. During the oestrous cycle, lasting 16 days in average, low serum progesterone and faecal gestagen values were found in the follicular ( 4.77 nmol/L and 1.4 nmol/g, respectively) and high values in the luteal phase (31.34 nmol/L and 3.26 nmol/g respectively). They remained high during pregnancy with the mean duration of 145 days, decreased abruptly at parturition and remained low during the early postpartum period. Significant positive correlations were established between the serum progesterone and faecal gestagen concentrations during the oestrous cycle (r = 0.8848, P < 0.001), pregnancy (r = 0.9129, P < 0.001) and postpartum period (r = 0.6861, P <0.01). During the postpartum period significant positive correlation existed among the serum and milk progesterone and faecal gestagen concentrations as well. The results of our study show a positive correlation between the serum progesterone and faecal gestagen concentrations in ewes. Therefore we conclude that faecal gestagen determination is a suitable non-invasive method for the estimation of ovarial activity in ewes.

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Relationship between Variation in Conceptus Development and Differences in Estrous Cycle Duration in Ewes1

Cited by 72 publications

References 0 publications

Effect of double GnRH injections on reproductive parameters in Awassi ewes receiving long-term progesterone

Effect of double GnRH injections on reproductive parameters in Awassi ewes receiving long-term progesterone

Discovery of candidate genes and pathways in the endometrium regulating ovine blastocyst growth and conceptus elongation

Faecal Gestagen, Serum and Milk Progesterone Concentrations in Ewes of the Jezersko-Solchava Breed

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