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See detailEffect of restraint stess on plasma concentrations of cortisol, progesterone and pregnancy associated-glycoproteins-1 in pregnant heifers during late embryonic development.
Szenci, O.; Karen, A.; Bajcsy, A. C. et al

in Theriogenology (2011), 76(8), 1380-1385

The aim of the present study was to evaluate the effect of restraint stress, which is commonly practised in the field, on plasma concentrations of cortisol, progesterone (P4) and bovine pregnancy ... [more ▼]

The aim of the present study was to evaluate the effect of restraint stress, which is commonly practised in the field, on plasma concentrations of cortisol, progesterone (P4) and bovine pregnancy-associated glycoprotein-1 (boPAG-1) in pregnant heifers between Days 30 to 40 of gestation. Twelve Holstein-Friesian heifers between Days 30 (Day 0 of experiment) and 40 (Day 10 of experiment) of pregnancy in a Hungarian dairy farm were used in the present study. The heifers were exposed to an acute stressor consisting of immobilisation (restraint stress) in a crush for 2 h (Group 1, n = 6) on Day 2 (Hour 48) and for 2 × 2 h (Group 2, n = 6) on Days 2 and 3 (Hour 72) of the experiment. Transrectal ultrasonography (7.5 MHz linear-array rectal transducer) was performed daily from Day 0 to Day 10 of the experiment to detect embryonic heartbeat or the fate of the conceptus. Blood samples were withdrawn before each ultrasonographic examination. Additional blood samples were withdrawn by 1 and 2 h (at Hours 49 and 50 in Groups 1 and 2 and Hours 73 and 74 in Group 2) of the onset of applying the stressor. Plasma cortisol, P4 and boPAG-1 concentrations were measured by radioimmunoassay. Acute restraint stress significantly (P < 0.001) increased the plasma cortisol level in pregnant heifers at 1 h of the exposure to the stressor at Days 2 (48 h) and 3 (72 h) of the experiment. On the other hand, the restraint stress did not affect the concentration of P4 and boPAG-1 concentrations in both groups. In conclusion, restraint stress for 2 h during early pregnancy in heifers increased blood cortisol, but it did not affect the concentrations of P4 and boPAG-1 between Days 30 to 40 of gestation. [less ▲]

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See detailLate embryonic and early fetal mortalities in dairy cows: the incidence and pregnancy protein profiles.
Karen, A.; Bajcsy, A. C.; Kovacs, R. et al

in Proceedings of the 20th International Congress of Hungarian Association for Buiatrics. (2010, October 20)

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See detailAccuracy of ultrasonography and pregnancy-associated glycoprotein test for pregnancy diagnosis in buffaloes
Karen, A.; Darwish, S.; Ramoun, A. et al

in theriogenology (2007), 68(8), 1150-1155

The aims of the present study were to evaluate and compare the accuracy of transrectal ultrasonography and pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) test for diagnosis of pregnancy in ... [more ▼]

The aims of the present study were to evaluate and compare the accuracy of transrectal ultrasonography and pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) test for diagnosis of pregnancy in buffaloes. Two hundred and seventy-five buffalo cows and heifers were examined once for pregnancy diagnosis by transrectal ultrasonography using a 5 MHz linear-array transducer between Days 19 and 55 after mating. After ultrasound scanning, a blood sample was withdrawn from jugular vein of each animal for measuring pregnancy-associated glycoprotein using a heterologous double-antibody RIA. Based on palpation of the uterus per rectum at Days 75-90, 87 animals were designated pregnant and 188 as non-pregnant. The sensitivity of transrectal ultrasonography at Days 19-24 was 44.4%, reaching 100% from Day 31 after mating. The specificity of transrectal ultrasonography ranged between 92.5 and 100% from Days 19 to 55 after mating. The sensitivity of PAG-RIA test was 11.1 % at Days 19-24 and reached 100% from Day 31 after mating. The specificity of PAG-RIA test ranged from 90 to 100% from Days 19 to 55 after mating. There were no significant differences between the sensitivity and specificity of the two tests in all examined periods. In conclusion, transrectal ultrasonography and PAG-RIA test are highly accurate tests for detecting pregnant buffaloes from Day 31 after mating onwards. [less ▲]

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See detailMeasurement of ovine pregnancy-associated glycoprotein (PAG) during early pregnancy in Lacaune sheep
El Amiri, B.; Karen, A.; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2007), 42(3), 257-262

This study describes ovine pregnancy-associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi-purified ovPAG as standard, tracer ... [more ▼]

This study describes ovine pregnancy-associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi-purified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG(57+59kDa)) and R805 (against ovPAG5(58+61kDa)) were used respectively in RIA-780 and RIA-805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n = 17) than in non-pregnant ones (n = 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA-780 and 14 900 Ci/mmol in RIA-805. The minimal detection limits for RIA-780 and RIA-805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra-assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA-780 and 8%, 9% and 5% for RIA-805. The inter-assay CV in the same samples were 13%, 12% and 7% for RIA-780 and 13%, 11% and 5% for RIA-805. The recovery was higher than 95% in both assays. No cross-reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA-780 and RIA-805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding. [less ▲]

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See detailComparison of accuracy of transabdominal ultrasonography, progesterone and pregnancy-associated glycoproteins tests for discrimination between single and multiple pregnancy in sheep
Karen, A.; El Amiri, B.; Beckers, Jean-François ULg et al

in Theriogenology (2006), 66(2), 314-322

The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests ... [more ▼]

The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests for the discrimination between single and multiple pregnancy in sheep. One hundred pregnant Awassi x Merino ewes were scanned by transabdominal ultrasonography (3.5 MHz linear-array transducer) at Days 43-56 and 81 of these ewes were scanned at Days 76-87 of gestation. The ewes were scanned in dorsal recumbency at the bare area of the inguinal regions (without pre-scanning shaving of the ventral abdominal wall). After each scan, blood samples were withdrawn from the jugular vein to estimate the levels of P4 and ovPAG by radioimmumoassay. At lambing, 61 ewes gave birth to single lambs and 39 ewes gave birth to multiples. The sensitivity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying multiples was 54, 64.1 and 64.1% at Days 43-56. At Days 76-87 of gestation these accuracies were 60.0, 66.7 and 76.6% for the US, P4-RIA and PAG-RIA tests, respectively. The specificity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying singles, was 78.6, 60.7 and 62.3% at Days 43-56 and 78.4, 64.7 and 70.6% at Days 76-87 of gestation, respectively. It is concluded that the accuracy of transabdominal ultrasonographic (without pre-scanning shaving of the ventral abdominal wall), the P4- and the ovPAG-RIA tests for determination of the fetal numbers in Awassi x Merino crossbred ewes is too low to be used in the field. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailPlasma urea nitrogen and phosphorus in relation to pregnancy rate in dairy sheep
Karen, A.; Kovacs, P.; Beckers, Jean-François ULg et al

in Proceedings of the 24th World Buiatrics Congress (2006)

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See detailEffect of GnRH day 12 after artificial insemination on pregnancy rate in the cow
Szenci, O.; Perényi, Z.; Karen, A. et al

in Proceedings: 23rd World Buiatrics Congress, Québec, Canada (2004)

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See detailAz energiaegyensúly zavarának hatása a méh involúciójára és a ciklikus petefészek működésére tejhasznú tehenekben]
Könyves, L.; Brydl, E.; Jurkovich, V. et al

in Proceedings: 5th Middle-European Buiatrics Congress (2004)

The aim of the study was to evaluate the effect of energy imbalance (manifested increased blood NEFA) on reactivation of the ovaries, uterine involution and the incidence of retained placenta and ... [more ▼]

The aim of the study was to evaluate the effect of energy imbalance (manifested increased blood NEFA) on reactivation of the ovaries, uterine involution and the incidence of retained placenta and endometritis [less ▲]

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See detailA juhok korai vemhességének megállapítása
Karen, A.; Beckers, Jean-François ULg; Sulon, J. et al

in Proceedings: The 5th Middle-European Buiatrics Congress (2004)

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See detailDiagnostic et suivi de gestation chez la chèvre et la brebis
Melo de Sousa, Noelita ULg; Gonzalez, F.; Karen, A. et al

Scientific conference (2004)

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See detailProsztaglandin kezelések hatasa az ovulacio bekövezkeztére szarvasmarhakban
Répasi, A; Beckers, Jean-François ULg; Sulon, J et al

in Proceeding of prosztaglandin kezelések hatasa az ovulacio bekövezkeztére szarvasmarhakban (2003, October)

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See detailEarly pregnancy diagnosis in sheep by progesterone and pregnancy-associated glycoprotein tests
Karen, A.; Beckers, Jean-François ULg; Sulon, Joseph ULg et al

in Theriogenology (2003), 59(9), 1941-1948

The aim of this study was to compare the accuracy of the progesterone (P4) and pregnancy associated glycoprotein (PAG) tests for determination of early pregnancy in sheep. Estrus was synchronized in 182 ... [more ▼]

The aim of this study was to compare the accuracy of the progesterone (P4) and pregnancy associated glycoprotein (PAG) tests for determination of early pregnancy in sheep. Estrus was synchronized in 182 Awassi x Merino ewes and blood samples were collected at Days 0 (day of the insemination), 18, 22, 29, 36, and 50 after artificial insemination (AI). Plasma P4 concentrations at Days 0 and 18 were determined by double antibody radioimmunoassay, while PAG concentrations at Days 22, 29, 36 and 50 were determined by a heterologous, double-antibody radioimmunoassay (RIA) using the bovine PAG 67 kDa subunit as tracer and standard and rabbit antiserum raised against a mixture of caprine 55 and 59 kDa PAG subunits as the first antibody. The discriminatory value for diagnosis of pregnancy by the P4 and the PAG-RIA tests was greater than or equal to1 ng/ml. Based on lambing data, the accuracy for diagnosing pregnant (sensitivity) and non-pregnant ewes (specificity) and predictivity of both tests were calculated. The sensitivity, specificity, positive and negative predictive values for P4 and PAG tests were 100, 95.4, 81.6, and 100% at Day 18 (P4) and 93.5, 100, 100 and 98.7% at Day 22 (PAG), respectively. For diagnosis of non-pregnant ewes the PAG test had significantly higher specificity than the P4 test (P < 0.05). It is concluded that ovine pregnancy can be reliably diagnosed at Day 22 after AI by using a heterologous radioimmunoassay of PAG. [less ▲]

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See detailValidation of two homologous radioimmunoassays for measuring pregnancy-associated glycoprotein in ewes.
El Amiri, B.; Karen, A.; Sulon, J. et al

in Reproduction in Domestic Animals (2003), 38(4), 358

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See detailEvaluation of false transrectal ultrasonographic pregnancy diagnoses in sheep by measuring the plasma level of pregnancy-associated glycoproteins
Karen, A.; Beckers, Jean-François ULg; Sulon, Joseph ULg et al

in Reproduction Nutrition Development (2003), 43(6, NOV-DEC), 577-586

The present study was undertaken to investigate to what extent pregnancy diagnoses made by transrectal ultrasonography could be confirmed by measurements of plasma concentration of ovine pregnancy ... [more ▼]

The present study was undertaken to investigate to what extent pregnancy diagnoses made by transrectal ultrasonography could be confirmed by measurements of plasma concentration of ovine pregnancy-associated glycoproteins (ovPAG). A total of 424 Awassi x Merino ewes were synchronized for estrus and examined by transrectal ultrasonography. In Experiment 1, the ewes (n = 156) were repeatedly scanned in a standing position on d 29, 36 and 50 of gestation. Similarly, the ewes (n = 268) in Experiment 2 were scanned on d 24, 29 and 34 of gestation, but these ewes were fasted for 12 h prior to the examination and the abdominal wall of each animal was lifted up by the hands of the assistant during the scanning. Blood samples were withdrawn after each transrectal ultrasonographic examination in both experiments. Ovine PAG concentrations were measured in plasma by a heterologous radioimmunoassay and the cut-off value for pregnancy was greater than or equal to 1 ng.mL(-1). Based on the lambing performance, in Experiment 1, altogether 47 false negative and 38 false positive diagnoses were made by transrectal ultrasonography in 24 and 33 ewes, respectively between d 29 and 50 of gestation. In Experiment 2, altogether 8 false negative and 13 false positive diagnoses both were made in 7 ewes between d 24 and 34 of gestation. In both experiments, all ewes with false negative diagnoses had ovPAG concentrations higher than the threshold level for pregnancy diagnosis and all ewes with false positive diagnoses had ovPAG concentrations lower than the threshold of pregnancy. Furthermore, by the PAG-RIA test all lambed or aborted ewes (n = 63) were correctly diagnosed as pregnant and with three exceptions, all non-lambed ewes (n = 361) were correctly diagnosed as non-pregnant during the examined periods of both experiments. [less ▲]

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See detailEvaluation of transrectal ultrasonography for determination of pregnancy in sheep
Karen, A; Szabados, K; Beckers, Jean-François ULg et al

in Proceeding of evaluation of transrectal ultrasonography for determination of pregnancy in sheep (2002, October 10)

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See detailPlazma urea-N koncentracio és a vemhesülés közötti összefüggés vizsgalata egy holstein-fris tehenészetben
Szenci, O; Simonsen, E.I; Karen, A et al

in Proceeding of effect of plasma urea-N concentration on fertility in a Holstein-friesian dairy herd (2002, October 10)

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See detailEarly pregnancy diagnosis in sheep by progesterone and pregnancy-associated glycoprotein tests.
Karen, A.; Beckers, Jean-François ULg; Sulon, J. et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2002), 6(1), 8

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