Monitoring the circadian rhythm of serum and salivary cortisol concentrations in the horse
; ; Beckers, Jean-François et al
in Domestic Animal Endocrinology (2013), 45(1), 38-42
Daily fluctuations of cortisol concentration in the blood or saliva have been repeatedly reported. However, several contradictions in the existing literature appear on this subject. The present study was ... [more ▼]
Daily fluctuations of cortisol concentration in the blood or saliva have been repeatedly reported. However, several contradictions in the existing literature appear on this subject. The present study was performed to definitively establish options for testing adrenocortical function. To the best of our knowledge, this is the first study to evaluate parallel circadian rhythms in salivary and serum cortisol concentrations during a 24-h period. Twenty horses were examined under the same conditions. Blood and saliva samples were taken every 2 h for 24 h to determine the daily changes in cortisol concentrations of saliva and serum at rest and to determine the relationship between salivary and serum cortisol levels. Cosinor analysis of group mean data confirmed a significant circadian component for both serum and salivary cortisol concentrations (P < 0.001 in both cases). The serum cortisol circadian rhythm had an acrophase at 10:50 AM (95% CI, 10:00 AM-11:40 AM), a MESOR of 22.67 ng/mL, and an amplitude of 11.93 ng/mL. The salivary cortisol circadian rhythm had an acrophase at 10:00 AM (95% CI, 9:00 AM-11:00 AM), a MESOR of 0.52 ng/mL, and an amplitude of 0.12 ng/mL. We found a significant but weak association between salivary and serum cortisol concentrations; the Pearson correlation coefficient was 0.32 (P < 0.001). The use of salivary cortisol level as an indicator of hypothalamic-pituitary-adrenal axis activity may be warranted. However, the salivary cortisol levels are more likely to be correlated with free plasma cortisol than with the total plasma cortisol concentration. [less ▲]Detailed reference viewed: 23 (2 ULg)
Relationship between plasma progesterone and pregnancy-associated glycoprotein concentrations during early pregnancy in dairy cows
; ; et al
in Veterinary Journal (2013)
The relationship between the concentration of plasma progesterone (P4) during embryo attachment or at recognition of pregnancy, and that of pregnancy-associated glycoprotein (PAG) was assessed in dairy ... [more ▼]
The relationship between the concentration of plasma progesterone (P4) during embryo attachment or at recognition of pregnancy, and that of pregnancy-associated glycoprotein (PAG) was assessed in dairy cows. The outcome of artificial insemination (AI) was classified as positive (AI+), negative (AIÿ), or late embryonic mortality (EM) by measuring circulating PAG concentrations and by ultrasonography. Based on P4 concentrations at either day 21 or day 15, AI+ and EM cows were classified into ‘low’ (P4 concentrations < mean) and ‘high’ (P4 concentrations > mean) P4 groups. In both experiments, the threshold of P4 concentration between the ‘low’ and ‘high’ groups was approximately 6 ng/mL. PAG concentrations were lower in the ‘low’ group only when P4 concentrations were below the threshold. The study findings suggest that a possible P4 threshold exists below which PAG secretion may be impaired [less ▲]Detailed reference viewed: 36 (7 ULg)
Placental and gastric aspartic proteinases: new insights from bovine species
Bella, Amina ; Beckers, Jean-François ; Melo de Sousa, Noelita
in Proceedings of the 2nd Scientific Meeting of the Faculty of Veterinary Medicine (2012, October 19)Detailed reference viewed: 9 (0 ULg)
Assessment of pregnancy-associated glycoprotein (PAG) concentrations in swamp buffalo samples from fetal and maternal origins by using interspecies antisera.
; ; et al
in Animal Science Journal (2012), 83(10), 683-689
Pregnancy-associated glycoproteins (PAG) constitute a large family of glycoproteins found in the outer placental epithelial cell layer of the placenta in Eutherian species. In ruminants, they are noted to ... [more ▼]
Pregnancy-associated glycoproteins (PAG) constitute a large family of glycoproteins found in the outer placental epithelial cell layer of the placenta in Eutherian species. In ruminants, they are noted to be structurally closely related among the different species. This study was designed to determine PAG concentrations in maternal and fetal plasma, allantoic and amniotic fluids in buffalo species. Antisera (AS) generated in rabbits against distinct PAG molecules were used in three RIA-PAG systems: RIA-1 (raised against bovine PAG67kDa; AS#497), RIA-2 (raised against caprine PAG55+62kDa; AS#706) or RIA-3 (raised against buffalo PAG; AS#859). Samples were collected at slaughterhouse (n = 67). PAG concentrations determined by RIA-2 gave significantly higher results in both allantoic and amniotic fluids (12.7 ± 2.1 ng/ml and 24.0 ± 7.3 ng/ml, respectively). Regarding maternal and fetal plasma, PAG concentrations obtained by RIA-2 (21.8 ± 2.4 ng/ml and 20.2 ± 2.5 ng/ml, respectively) and RIA-3 (25.0 ± 2.2 ng/mL and 21.9 ± 3.2 ng/ml, respectively) were higher than those obtained by RIA-1 (15.5 ± 1.4 ng/ml and 16.1 ± 1.8 ng/ml, respectively). The correlation among the three systems was very high. The study clearly reveals the ability of PAG-RIA systems to determine PAG concentration in swamp buffalo samples. [less ▲]Detailed reference viewed: 72 (7 ULg)
Pregnancy-associated glycoprotein, chymosin and pepsinogen immunoreactivity of proteins extracted from fetal gastric tissue in bovine species.
Bella, Amina ; Melo de Sousa, Noelita ; et al
in Research in Veterinary Science (2012), 92(3), 378-386
The objective of this work was to investigate the expression of gastric aspartic proteinases in fundic and pyloric mucosa removed from bovine fetuses. For this purpose, fractions issued from classical ... [more ▼]
The objective of this work was to investigate the expression of gastric aspartic proteinases in fundic and pyloric mucosa removed from bovine fetuses. For this purpose, fractions issued from classical biochemical protocols were analyzed by proteolytic method, by PAG-RIA and by Western blot with the use of antisera raised against both pepsinogens and PAG. A strong reaction of proteins extracted from the fundic mucosa collected at the beginning of pregnancy was revealed with both anti-bPAG-I and anti-bPAG-II antisera, suggesting the expression of pepsinogen F in bovine species. Concerning pyloric mucosa, the analysis by Western blot highlighted a very strong immunoreaction with the anti-bovine chymosin serum. Amino-terminal sequencing allowed to identify bovine fetuin and albumin in fundic extracts, chymosin in the pyloric mucosa extracts, as well as some unknown proteins in both mucosa. Despite no N-terminal microsequence corresponding to the hypothetical pepsinogen F could be identified, it cannot be excluded that an existing bovine pepsinogen F-like molecule could be degraded during the purification procedure or that co-purified proteins could be responsible for masking its N-terminal microsequence. [less ▲]Detailed reference viewed: 75 (19 ULg)
The inseminating bull and plasma pregnancy-associated glycoprotein levels were related to peripheral leukocyte counts during the late pregnancy/early postpartum period in high-producing dairy cows.
; ; et al
in Theriogenology (2012), 77(7), 1390-1397
The interest in the immunology and endocrinology aspects of the peripartum in dairy cows has been increasing in the last years, since the animal status during the pre- and postpartum period determines the ... [more ▼]
The interest in the immunology and endocrinology aspects of the peripartum in dairy cows has been increasing in the last years, since the animal status during the pre- and postpartum period determines the subsequent productive and reproductive performance of the animal. At parturition, a drop in the immune functions of the peripheral blood polymorph-nuclear cells (PMN) was observed after a peak of Pregnancy-Associated Glycoproteins (PAGs) and recently, the inseminating bull was found to affect the plasma levels of bovine Pregnancy-Associated Glycoproteins (bovine PAGs) in the pregnant Holstein-Friesian dairy cows. The present work was aimed to determine whether changes in leukocyte counts during the peripartum, indicative of the animal immune status, could be related to the inseminating bull and to the levels of plasma pregnancy-associated glycoproteins (PAGs). Ninety six clinically healthy, single pregnant cows were selected in a commercial dairy herd. Six blood samples (four prepartum and two postpartum) were obtained every two weeks, and total and differential blood cell counts were analyzed. Based on procedures of General Linear Model analysis of variance for repeated measures, the inseminating bull affected counts of total leukocytes and lymphocytes (P<0.001; between-subject effects) throughout the peripartum period. In addition, cows with high plasma levels of PAGs (>900 ρg/µL) on Day 262-268 of gestation had higher numbers of total leukocytes and neutrophils throughout the peripartum period (P<0.001; between-subject effects). Young animals (≤ 1 lactation) had higher total leukocyte and lymphocytes counts than older cows (two or more lactations) throughout the study period. These results showed a clear relationship between the inseminating bull and plasma PAG levels and peripheral leukocyte counts during the peripartum period of dairy cows. [less ▲]Detailed reference viewed: 37 (5 ULg)
Investigations sur les protéines placentaires extraites des cotylédons fœtaux du Cervus elaphus
; ; et al
Poster (2012, February)Detailed reference viewed: 18 (2 ULg)
Fractionnement et immunoréactivité de type PAG (Pregnancy-Associated Glycoprotein) des protéines extraites des caroncules maternelles chez les cervidés (Cervus elaphus)
; ; et al
Poster (2012, February)Detailed reference viewed: 33 (7 ULg)
Étude de la cyclicité en relation avec le poids vif et l’état corporel chez les agnelles Ouled Djellal nées en automne dans la région Est de l’Algérie
; ; et al
in Annales de Médecine Vétérinaire (2012), 156
The objective of the present work was to describe the cyclicity of Ouled Djellal ewes born one year before regarding their live weight and body condition score, during the autumn season. The study has ... [more ▼]
The objective of the present work was to describe the cyclicity of Ouled Djellal ewes born one year before regarding their live weight and body condition score, during the autumn season. The study has been driven in the region of Guelma, East of Algeria, on 104 ewes belonging to two farms. At the beginning of the study, ewes from farms A and B had similar ages but differed in live weight and body condition scores. The concentration of progesterone wasdetermined by radioimmunoassay. The level of spontaneous cyclicity, as well as the plasmatic level of the progesterone, were influenced significantly by both live weight and body condition score (P<0.0001). If the first was in favor of ewes with high body weight and body condition score, the second seemed to be higher in slim cyclic ewes. The body fatness appears to influence positively the age of puberty. [less ▲]Detailed reference viewed: 32 (3 ULg)
Effect of restraint stess on plasma concentrations of cortisol, progesterone and pregnancy associated-glycoproteins-1 in pregnant heifers during late embryonic development.
; ; 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 ▲]Detailed reference viewed: 31 (3 ULg)
Placental and gastric arpartic proteinases: new insights from bovine species.
Beckers, Jean-François ; Bella, Amina ; Melo de Sousa, Noelita
Conference (2011, September 24)Detailed reference viewed: 22 (5 ULg)
Development of a new radioimmunoassay by using antiserum against pregnancy-associated glycoprotein II : concentrations in holstein dairy cattle .
Bella, Amina ; Melo de Sousa, Noelita ; et al
in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)
Bovine pregnancy-associated glycoproteins (boPAG) can be classified into two main subfamilies: the boPAG–1 and the boPAG–2 groups. RIA systems allow quantifying boPAG-1 molecules in pregnant cattle ... [more ▼]
Bovine pregnancy-associated glycoproteins (boPAG) can be classified into two main subfamilies: the boPAG–1 and the boPAG–2 groups. RIA systems allow quantifying boPAG-1 molecules in pregnant cattle. Concerning boPAG-2, as no radioimmunoassay was developed, its quantification in peripheral blood of pregnant cows remains to be investigated. The present work aimed to develop a new heterologous RIA allowing the measurement of boPAG-2 concentrations in bovine species. A total of 77 Holstein dairy cows were used for this study. They were bled at Days 45, 90, 120, 150, 180, 210 after AI, at parturition and at Day 30 postpartum. Polyclonal antiserum against boPAG-2 (AS438) was raised in New Zealand rabbits. Due to the instability of boPAG-2 molecule, we used boPAG-1 (67 kDa) as standard (dilutions ranging from 100 to 0.8 ng/mL) and for iodination with 125-I isotope. The optimal dilution for primary AS438 was 1:1,1500. Mean concentrations of boPAG-2 increased continuously from Day 45 of pregnancy (0.78 ± 0.07 ng/mL) reaching a peak at Day 210 (32.78 ± 3.02 ng/mL). Thereafter, they decreased until parturition (7.73 ± 0.59). Lower PAG concentrations were observed at Day 30 postpartum (3.62 ± 0.31 ng/mL). In conclusion, boPAG-2 profile differed from boPAG-1. In general, concentrations of boPAG-2 reached lower values, with no dramatic increase being observed at peripartum period. Due to the lower postpartum concentrations, it is expected that this new RIA can be available for pregnancy diagnosis of cows inseminated in early postpartum, minimizing the risk of false positive concentrations due to the previous pregnancy. [less ▲]Detailed reference viewed: 61 (11 ULg)
Concentrations of pepsinogens A and C in peripheral blood of cattle at different developmental stages.
Melo de Sousa, Noelita ; Michiels, Jean-Albert ; et al
in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)
Measurements of global proteolytic activity of pepsinogens are successfully used for diagnosis of gastric nematode parasitism in cattle. Higher pepsinogen concentrations detected in peripheral circulation ... [more ▼]
Measurements of global proteolytic activity of pepsinogens are successfully used for diagnosis of gastric nematode parasitism in cattle. Higher pepsinogen concentrations detected in peripheral circulation were found to be associated with damage in gastric mucosa The aim of the present study was to investigate the ontogenesis of PgnA and PgnC in cattle. Bovine PgnA and PgnC were isolated in our laboratory. Both antigens were labeled to 125I by using chloramine T method. Standard curves ranged from 125 to 1.0 ng/mL. Antisera were raised in rabbits: AS866 (anti-PgnA) and AS869 (anti-PgnC). The optimal dilutions for primary antisera were 1:15,000 and 1:20,000 for AS866 and AS869, respectively. In order to establish the ontogenesis of both PgnA and PgnC, samples were collected from 50 bovine fetuses (3rd to the 9th month), 18 calves and 57 adult cattle. Mean(±SEM) concentrations of PgnA were 4.6±0.7 ng/mL, 78.9±6.7 ng/mL and 133.2±17.6 ng/mL in fetuses, calves and mature cows, respectively. Concentrations of PgnC were <0.9 ng/mL, 13.5±1.1 ng/ml and 201.5±26.5 ng/ml in fetuses, calves and mature cows, respectively. The ratio PgnA/PgnC concentrations decrease from fetal age (maximal ratio due to undetectable PgnC concentrations), being 5.8 in young calves and lowest (0.7) in mature cows. In conclusion, PgnA and PgnC concentrations can be distinctly measured by specific RIA systems. Ratio PgnA/PgnC concentrations can be useful to better understand the ontogenesis of gastric aspartic proteinases in cattle. It is expected that clinical application of these assays will help vet practitioners to establish diagnosis of gastric nematode parasitism in dairy and beef herds taking into account the age of the animal. [less ▲]Detailed reference viewed: 57 (7 ULg)
Pregnancy-associated glycoprotein levels in cattle exhibiting prolonged pregnancy: case reports.
Beckers, Jean-François ; Melo de Sousa, Noelita
in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)
Prolonged gestation (PG) is a complex clinical entity which occurs in bovine species. This pathology has been described in Belgian Blue cattle. PG may require termination by cesarean section. Fetuses ... [more ▼]
Prolonged gestation (PG) is a complex clinical entity which occurs in bovine species. This pathology has been described in Belgian Blue cattle. PG may require termination by cesarean section. Fetuses often exhibit increased body weight, long hair and well erupted teeth. All calves die within minutes or hours after birth. From endocrinological point of view, PG is highly correlated to fetal adenohypophyseal aplasia. The aim of the present study was to investigate the usefulness of PAG RIA for diagnosis of prolonged gestation in Belgian Blue cattle. Blood samples were collected from five Blue Belgian cows having an abnormally long pregnancy length (10 to 15 months). PAG was measured by routine RIA with the use of antiserum AS497 as primary antibody. A purified bovine PAG preparation (boPAG67kDa) was used as standard (0.8 to 100 ng/mL) and for radio-iodination (125I). Cesarean section was used for termination of pregnancy of those cows exhibiting abnormal PAG concentrations. Morphological aspect and viability of fetuses were reported. Concentrations of PAG were very low (94.1 ng/mL, 50 ng/mL, 5 ng/mL, 110 ng/mL and 26 ng/mL) in the five females suffering of prolonged gestation. Fetuses issued from prolonged gestation exhibited long hair, well erupted teeth and died within few minutes after birth. In conclusion, PAG concentration is a good indicator of prolonged gestation in cattle. Concentrations are much lower than those expected in normal ongoing pregnancy (<120 ng/mL versus >1,000 ng/mL). [less ▲]Detailed reference viewed: 67 (13 ULg)
Prediction of stillbirth in Holstein-Friesian dairy cows by monotoring endocrine profiles in the periparturient period.
; ; et al
During the last decades, there is a declining trend in conception and calving rates in high yielding Holstein dairy cattle. At the same time, the gradual increase in stillbirth rates, especially in ... [more ▼]
During the last decades, there is a declining trend in conception and calving rates in high yielding Holstein dairy cattle. At the same time, the gradual increase in stillbirth rates, especially in Holstein heifers, has until recently received relatively little attention. Birth weight and gender of the calf, parity, age and breed of the dam, and season of calving are all factors associated with calving difficulties and stillbirths. Other causes of stillbirths not related to calving difficulties are, for example, herd size, infections (e.g. BVD), insufficient placenta development and/or function, metabolic disorders of the cow, and congenital malformations of the calf. The objective of the present study was to investigate the possible effect of hormonal disturbances on the incidence of stillbirth in dairy cows on a Holstein-Friesian dairy farm in Hungary. Dairy cows (n=173) were sampled three times during the periparturient period (at drying-off, 3 weeks prior to expected calving, and within 1 h after calving) in 2006 and two times (3 weeks prior to expected calving, and within 1 h after calving) in 2007. Dairy cows were grouped according to the incidence of stillbirth: Group 1 (control): n=165 and Group 2 (stillbirth): n=8. Hormone and pregnancy protein parameters measured by RIA were as follows: progesterone (P4), estradiol (E2), cortisol, triiodine-thyronin (T3), thyroxin (T4), insulin, insulin-like growth factor (IGF-1) and pregnancy associated glycoprotein (PAG). To determine, which of the hormones and PAG were the best predictors of the presence or absence of stillbirth at a given time (2 months and 3 weeks before calving and within 1 h after calving), a generalised linear model was used with binomial error distribution and logit link function (multivariate logistic regression). All analyses were carried out by R 2.7.2. Statistical Software. The significant level was set at P< 0.05 and an effect was considered a trend when P was between 0.05 and 0.10. The overall prevalence of stillbirth was 4.6 % (4.0% in 2006 and 5.4% in 2007). Interestingly, most calves (7 out of 8) with stillbirth were bulls, but this difference was not significant. Weight of the calves, body score condition of the cows and number of people needed to assist at calving also did not affect the presence or absence of stillbirth significantly, and there was no significant difference among the groups regarding the gestation length or parity either (P>0.100 in all cases). Regarding hormone and pregnancy protein parameters, no significant differences were found during the periparturient period (at 2 months and 3 weeks before expecting calving), however, there was a trend for lower IGF-1 values (P=0.079, OR=0.96) in stillbirth group compared to controls at dry off (2 months before expecting calving). Within one hour after calving significant differences were observed in case of P4 (P<0.001, OR= 3.06), and IGF-1 (P=0.021, OR= 0.94), resulting significantly higher values in P4 and lower values in IGF-1 in stillbirth cows compared to controls. The higher P4 values observed in stillbirth cows also resulted a higher P4/E2 ratio compared to controls (P=0.003, OR= 1.60). Changes in the IGF-1, P4 and P4/E2 ratio may be one of the reasons for stillbirth in Holstein-Friesian dairy cows however more examinations are needed to be confirmed. Other hormones (P4, cortisol, T3, T4, insulin, PAG) did not mirror dependency due to the incidence of stillbirth in dairy cows. [less ▲]Detailed reference viewed: 96 (2 ULg)
Development of a new ELISA for measurement of pregnancy-associated glycoprotein.
; Melo de Sousa, Noelita ; et al
In the present study we report the development of a new ELISA for PAG measurement (Ref. code E.G.7, CER, Maloie) in ruminant species. Purified boPAG67kDa protein was purified in our laboratory and used as ... [more ▼]
In the present study we report the development of a new ELISA for PAG measurement (Ref. code E.G.7, CER, Maloie) in ruminant species. Purified boPAG67kDa protein was purified in our laboratory and used as standard. Antiserum raised against caprine PAG 55kDa+62kDa (AS707) was used as capture antibody (1:40,000). Antiserum raised against PAG purified from buffalo placentas (AS859) was used as detection antibody (1:32,000 dilution). Avidin-HRP and TMB completed the ELISA system. Reproducibility was determined by calculating the intra- and inter-assay CV. Accuracy was determined by adding increasing concentrations of purified boPAG67kDa to bovine sera containing low PAG concentrations. Specificity was tested regarding 25 different compounds: carbohydrates, aspartic proteinases, hormones and major plasma proteins. Parallelism was assessed by serially diluting pregnant cow serum containing high PAG concentrations. Sera was collected from pregnant cows (n=4) during the whole duration of gestation. Samples were tested by both RIA and ELISA. Samples giving high PAG concentrations were serially diluted in order to fit with optical density (OD) of the ELISA standard curve. Intra-and inter-assay CV ranged from 5.5 to 9.1%. Accuracy ranged from 92.9 to 105.5%. No cross reaction was observed with almost all tested compounds excepting lactic acid at supra-physiological levels (1 mg/ml). Dilutions of bovine maternal sera were parallel to standard curve. Profiles obtained by ELISA in pregnant cows were very similar to those obtained by RIA. In conclusion, a new PAG-ELISA is available for measurement of PAG concentrations in cattle. This new test was validated in vitro and can be used for pregnancy diagnosis and follow-up of gestation in cattle. [less ▲]Detailed reference viewed: 65 (3 ULg)
Pregnancy diagnosis in cattle by using a new ELISA for pregnancy-associated glycoprotein: preliminary results.
Beckers, Jean-François ; Melo de Sousa, Noelita ; et al
In the present study we report the use of a new PAG-ELISA for routine pregnancy diagnosis in cattle. A total of 2777 samples were collected from pregnant or non-pregnant cows and assayed by both classical ... [more ▼]
In the present study we report the use of a new PAG-ELISA for routine pregnancy diagnosis in cattle. A total of 2777 samples were collected from pregnant or non-pregnant cows and assayed by both classical PAG RIA-497 method and newly developed PAG-ELISA (Ref. code E.G.7, CER, Maloie). Pregnancy status was determined on the basis of RIA results. Samples were assumed to be issued from pregnant cows when PAG concentrations were higher than 0.8 ng/mL. PAG concentrations <0.8 ng/mL were considered negative (non-pregnant). PAG concentrations between 0.8 and 1.0 ng/mL were considered doubtful. With regard to ELISA, concentrations below 0.6 were considered negative. Concentrations between 0.6 and 0.8 ng/mL were considered doubtful and finally concentrations under 0.8 ng/mL were assumed as positive. Sensitivity(Se), specificity(Sp) and predictive values (PV) of pregnancy diagnosis were determined. A total of 143(5.2%), 137(4.9%) and 38(1.4%) samples gave doubtful results by RIA, ELISA or both systems, respectively. These samples (318/2777=11.5%) were not used for estimation of Se, Sp, PPV and NPV because clinical confirmation of pregnancy diagnosis could not be established by an additional method (rectal palpation, ultrasound or calving). Taking into account the remaining samples (2459), Se, Sp, PPV and NPV obtained by ELISA were respectively 98.9%, 89.9%, 98.7% and 96.4%. In conclusion, PAG-ELISA can be successfully used for pregnancy diagnosis in cattle. In the near future, further investigations are to be conducted in order to compare results obtained by ELISA test with those obtained by rectal palpation and ultrasound in field conditions. [less ▲]Detailed reference viewed: 64 (5 ULg)
Clinical implications of induced twin reduction in dairy cattle
; ; et al
in Theriogenology (2011), 76(3), 512-521
Embryo reduction may prevent the negative effects of twinning in dairy cattle; however, the technique may carry an additional risk of pregnancy loss. The aim of this study was to evaluate the effect on ... [more ▼]
Embryo reduction may prevent the negative effects of twinning in dairy cattle; however, the technique may carry an additional risk of pregnancy loss. The aim of this study was to evaluate the effect on pregnancy maintenance of embryo reduction by manual amnion rupture in unilateral and bilateral twin pregnant cows. A secondary objective was to examine the dynamics of endocrine factors following the treatment. On Day 35-41 of gestation 55 cows bearing two live twin embryos (28 bilateral, 27 unilateral) were randomly assigned to a twin reduction group (n = 27; cows fitted with a progesterone releasing intra-vaginal device for 21 days after manual amnion rupture) or control group (n = 28; untreated cows). Pregnancy loss before Day 90 was recorded in nine control and eleven twin reduction cows (32.1% vs 40.7%, respectively, p = 0.508). Logistic regression models indicated that laterality was the only variable significantly affecting pregnancy loss. The pregnancy loss risk was 8.7 times higher for unilateral than for bilateral twin pregnancies (59.3% vs 14.3%, respectively, P < 0.001) yet was similar in the unilateral control and unilateral twin reduction cows (62.3% vs 53.8%, respectively, P = 0.581). In contrast, four of 14 cows with bilateral twin pregnancies undergoing twin reduction lost their pregnancies while no losses were recorded in control cows with bilateral pregnancies (P = 0.049). A rise in plasma progesterone concentration was detected on the day following treatment in the twin reduction group and concentrations remained high within the first week of treatment. Plasma pregnancy-associated glycoprotein-1 (PAG-1) concentrations fell between Day 35-41 and Day 42-48, regardless of treatment. Our findings indicate that embryo reduction by manual amnion rupture did not carry an additional risk of pregnancy loss for unilateral twin pregnancies, whereas it increased the risk of pregnancy failure in bilateral twin pregnancies. However, benefits of preventing cows from delivering twins might also be considered when assessing the success of embryo reduction in bilateral twin pregnancies. [less ▲]Detailed reference viewed: 47 (6 ULg)
Altered secretion of pregnancy-associated glycoproteins during gestation in bovine somatic clones.
; ; et al
in Theriogenology (2011), 76(6), 1006-1021
Somatic nuclear transfer (NT) in cattle is often accompanied by severe placental anomalies, hypertrophy, and hydrallantois, which induce a high rate of pregnancy losses throughout gestation. These ... [more ▼]
Somatic nuclear transfer (NT) in cattle is often accompanied by severe placental anomalies, hypertrophy, and hydrallantois, which induce a high rate of pregnancy losses throughout gestation. These placental deficits are associated with an abnormal increase of the maternal plasma levels of pregnancy-associated glycoprotein (PAG), produced by the trophoblastic binucleate cells (BNC) of the placenta. The objective of this study was to analyze the origin of the abnormally elevated PAG concentrations in the peripheral circulation of NT recipients during pathological pregnancies. Concentrations of PAG were measured both in maternal blood, in chorionic and cotyledonary tissular extracts from control recipients (after artificial insemination, AI, or in vitro fertilization, IVF) and clone recipients on Day 32, Day 62, and during the third trimester of gestation. Three different radioimmunoassay (RIA) systems were used. One homologous RIA for PSP60, similar to bovine PAG-1 (PAG(67kDa)), and two heterologous RIA with PAG(67kDa) as standard and tracer, and antisera anti-caprine PAG (AS#706 and AS#708). Circulating and tissular concentrations of bovine placental lactogen (bPL), a glycoprotein also produced by BNC, were determined by RIA at the same stages. The number of BNC in the placental tissues was determined by cell counting after immunostaining with anti PSP60 antibody on tissue sections from control and NT pregnancies. Maternal plasma PAG concentrations were not different among groups on Day 32, but they were significantly higher in NT than in control pregnancies on Day 62 with all three RIA and during the third trimester with two RIA (RIA-PSP60 and RIA with AS#708). Circulating bPL concentrations were undetectable on Days 32 and 62 and were not different in the third trimester between NT and control pregnancies. Tissular amounts of PAG on total proteins were not different between the two groups at all stages studied. No difference was determined in the percentage of PSP60-positive BNC in placental tissues between controls and NT on Day 62 and during the third trimester of pregnancy. Western blots of tissular extracts from placenta showed no major molecular weight changes of PAG in NT pregnancies compared to controls. No differences in maternal circulation concentrations or tissular content of bPL were observed between control and NT pregnancies. In conclusion, the specific increase of PAG in maternal plasma concentrations during abnormal NT pregnancies do not result from a higher proportion of BNC, or an increased protein expression of PAG and could be due to changes in the composition of terminal glycosylation which result into a clearance decrease of PAG from the circulation. [less ▲]Detailed reference viewed: 27 (6 ULg)
Accuracy of transrectal palpation for early pregnancy diagnosis in Egyptian buffaloes.
; ; et al
in Tropical Animal Health & Production (2011), 43(1), 5-7
The present study was undertaken to evaluate the accuracy of transrectal palpation (TRP) for diagnosing early pregnancy in buffaloes and the false diagnoses of the TRP test by using the pregnancy ... [more ▼]
The present study was undertaken to evaluate the accuracy of transrectal palpation (TRP) for diagnosing early pregnancy in buffaloes and the false diagnoses of the TRP test by using the pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) test. Pregnancy was diagnosed in 168 buffalo-cows once by TRP and PAG-RIA test between days 31 and 55 after breeding. The sensitivity of TRP for detecting pregnant buffalo-cows was 37.5% at days 31-35, increased to 93.8% at days 46-50 and reached 100% at days 51-55 (P < 0.01). All cases of false negative diagnoses (n = 10) had PAG concentration higher than the threshold (>/=1.8 ng/mL) for diagnosing pregnancy. The specificity of TRP for detecting non-pregnant buffalo cows ranged between 90.9%, and 100% between days 31 and 55. All cases of false positive diagnoses (n = 5) made by TRP had PAG concentrations lower than the threshold for diagnosing pregnancy. It could be concluded that TRP is an accurate method for diagnosing pregnant and non-pregnant buffalo cows from day 46 after breeding. [less ▲]Detailed reference viewed: 53 (3 ULg)