References of "Guyot, Hugues"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailNutritional markers course after oral supplementation with different forms of iodine in Holstein non-lactating cows
Guyot, Hugues ULg; VanParijs, Sandrine; Uyttenhoef, Aude et al

Poster (2009)

Iodine (I) deficiency is commonly reported in cattle around the world and is often associated with clinical or sub-clinical diseases. As most of clinical signs are not pathognomonic, diagnosis has to be ... [more ▼]

Iodine (I) deficiency is commonly reported in cattle around the world and is often associated with clinical or sub-clinical diseases. As most of clinical signs are not pathognomonic, diagnosis has to be confirmed by biochemical analyses such as plasmatic inorganic iodine (PII) or urinary I. Different oral mineral forms of I are available in Europe for cattle. The aim of the study was to compare the kinetic of I in blood and urine in non-lactating cows, following oral administration of different forms of I. Five groups of 6 non-lactating cows (aged 6 ± 2 years, weight 604 ± 89 kg), receiving the same ration (11 kg dry matter) and housed in the same conditions (tied-stall and straw) underwent a double-blinded trial during 2 months. Excepting in Group A (Control), all cows received a daily oral supplementation of I equal to 5 ppm, in the form of Ca(IO3)2 (Group B), KI (Group C), organic form of I 1 (Group D) and organic form of I 2 (Group E). Formulas of the organic forms of I are not public and coverable by patent. Supplementation was stopped at T45. Blood and urine samples were taken at T0, T15, T30 and T60. Thyroxine (T4) was measured at T0, T30 and T60 while PII and urinary I were measured at the 4 times of the trial. Student-t test and multiple comparisons of means (mix crossed model) were used to compare I and T4 concentrations between groups and times. All characteristics about the cows and I levels in blood or urine were not significantly different at T0 (p>0.1). There was no significant difference (p>0.1) between groups B, C, D, E at the different times of the trial. PII and urinary I in Group A were significantly lower than in other groups (p<0.01) at T15 and T30. Highest concentrations of I (PII up to 242 ± 30 µg/L and urinary I up to 2326 ± 439 µg/L) were reached at T15 for groups B, D and E. At T60, PII (19 ± 4 µg/L) and urinary I (110 ± 29 µg/L) of all groups reached the basal level. A good correlation was found between PII and urinary I (r² = 0.77). No significant differences were found about T4 (67 ± 10 nmol/L) in all groups and times (p>0.1). PII and urinary I are good markers to assess I nutritional status. No difference was found between either inorganic or organic forms of I, nor between them. Concerning the mineral forms of I, Ca(IO3)2 might be preferably used because of its higher stability in the mineral complexes. [less ▲]

Detailed reference viewed: 34 (6 ULg)
Full Text
See detailSerum cardiac troponin I concentrations as a diagnostic aid of pericarditis in cattle
Guyot, Hugues ULg; Sartelet, Arnaud ULg; Leidinger, K. et al

Poster (2008, July 10)

Detailed reference viewed: 47 (12 ULg)
Full Text
See detailWhole blood viscosity and viscoelasticity in healthy dairy cows
Sandersen, Charlotte ULg; Dringenberg, B.; Vandeputte, Sébastien ULg et al

Poster (2008, July 10)

Detailed reference viewed: 50 (11 ULg)
Full Text
Peer Reviewed
See detailVegetative endocarditis in the horse: retrospective study
Porter, Sarah ULg; Saegerman, Claude ULg; Van Galen, Gaby ULg et al

in Journal of Veterinary Internal Medicine (2008), 22(6), 1411-1416

Detailed reference viewed: 20 (6 ULg)
Full Text
Peer Reviewed
See detailBluetongue in captive yaks.
Mauroy, Axel ULg; Guyot, Hugues ULg; De Clercq, Kris et al

in Emerging Infectious Diseases (2008), 14(4), 675-6

In August 2006, several Northern European countries including Belgium reported their first cases of bluetongue (BT). Surprisingly, it was the first time that BT was diagnosed so far in the northern ... [more ▼]

In August 2006, several Northern European countries including Belgium reported their first cases of bluetongue (BT). Surprisingly, it was the first time that BT was diagnosed so far in the northern hemisphere (1). BT is a non contagious, arthropod borne animal disease. The causal virus belongs to the genus Orbivirus in the family Reoviridae. The genome of the bluetongue virus (BTV) consists of 10 segments of double-stranded RNA and 24 serotypes have been reported (2). Serotype 8 (BTV-8) was implied in the emergence in Belgium (3). All ruminant species are thought to be susceptible to BT (2) but lack of data remains for certain species. We report here laboratory confirmed clinical cases of BT in yaks. [less ▲]

Detailed reference viewed: 33 (8 ULg)
See detailClinical aspects of bluetongue in ruminants
Guyot, Hugues ULg; Mauroy, Axel ULg; Kirschvink, N. et al

in Bluetongue in northern Europe (2008)

Detailed reference viewed: 14 (2 ULg)
See detailDifferential diagnosis of bluetongue
Bexiga, R.; Guyot, Hugues ULg; Saegerman, Claude ULg

in Bluetongue in northern Europe (2008)

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailEvolution of the clinical expression of Bluetongue in Belgian cattle during year 2006 vs 2007
Guyot, Hugues ULg; Mauroy, Axel ULg; Rollin, Frédéric ULg et al

Conference (2008)

In August 2006, Belgium notified its first cases of Bluetongue (BT), serotype 8, in cattle and sheep. The disease was also observed at this time in the neighboring countries. The resurgence of BT was ... [more ▼]

In August 2006, Belgium notified its first cases of Bluetongue (BT), serotype 8, in cattle and sheep. The disease was also observed at this time in the neighboring countries. The resurgence of BT was observed in Northern Europe in 2007. The aim of the study was to compare clinical signs of BT observed in 2006 vs 2007 in Belgian cattle. The description of clinical signs was based on the observation of 38 and 39 cows in 2006 and 2007, respectively. BT cases were only included if they were confirmed by one or both laboratory diagnostic tests (competitive ELISA test and/or RT-qPCR). The inventory of clinical signs was made with a standardised clinical form for BT. This form is divided into general, cutaneous, locomotor, digestive, respiratory, neurological and reproductive clinical signs. Case data were summarised to determine changes in clinical presentation of BT between 2006 and 2007. A Fischer’s exact probability test was performed to compare (P<0.05) the frequency of clinical signs between the two years. Regarding general clinical signs, hyperthermia and tiredness were more often observed in 2007, compared to 2006. All clinical signs about skin and annexes were not significantly different between the two years. Locomotor signs such as prostration, incapacity to get up, reluctance to move, lameness and amyotrophy were more frequent in 2007. Loss of appetite, difficulties in grasping feed, salivation and drooling were the digestive signs more often observed in 2007. A purulent nasal discharge was the only respiratory sign more commonly observed in 2007. Apathy, generalised weakness and paresis or paralysis were more often encountered in 2007. The most important changes between the two years concerned reproduction. A higher incidence of abortion, premature calving and stillbirth was observed during 2007 outbreak. The frequency of most of the clinical signs of BT was higher in 2007 in Belgian cattle. Confirmed cases of BT in Belgian cattle were only 296 in 2006 compared to 4187 in 2007. These data do not represent the real situation of BT infection because the farmers do not notify all cases. Nevertheless, it seems that the 2007 outbreak was more severe regarding the number of cases and the frequency of clinical signs. The mild winter and wet 2007 summer might have favored the persistence of the vectors. [less ▲]

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailDevelopment and validation of a radioimmunoassay for thyrotropin in cattle
Guyot, Hugues ULg; Sulon, Joseph ULg; Beckers, Jean-François ULg et al

in Journal of Veterinary Diagnostic Investigation (2007), 19(6), 643-651

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of ... [more ▼]

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of this study was to develop and validate, under physiologic and pathologic conditions, a radioimmunoassay (RIA) for bovine TSH (bTSH). Double RIA was performed with purified bTSH and specific bovine antiserum. Laboratory validation included research of minimal detection limit, accuracy, and reproducibility. The physiologic validation included a thyrotropin-releasing hormone (TRH) challenge performed on euthyroid cows and a follow-up of bTSH concentration over a 24-hour period. Furthermore, bTSH concentration was assayed in a large population of healthy dairy and beef cows to define reference interval. The pathologic validation was made by assaying bTSH and thyroid hormones on healthy and goitrous newborn calves. The minimum detection limit (MDL) for bTSH assay was 1.3 microU/ml. The recovery was 101% to 106%. The intra- and interassay coefficients of variation (CVs) ranged from 5% to 11% and 11% to 15%, respectively. The RIA covered the whole range of physiologic bTSH values, as shown by bTSH values induced by TRH-challenge. A pulsatile secretion of bTSH was observed, accompanied by a diurnal variation with lower night values than day values. Reference intervals of bTSH ranged from 1.3 to 13.0 microU/ml for beef and dairy breeds. Finally, bTSH easily discriminated goitrous newborn calves from healthy ones, leading to the definition of a cutoff value of 35 microU/ml. The bTSH assay positively reacted to physiologic and pathologic conditions. The accuracy and precision of the RIA were satisfying. [less ▲]

Detailed reference viewed: 109 (3 ULg)
Full Text
See detailContribution au diagnostic et à la correction des carences en iode et sélénium chez les bovins
Guyot, Hugues ULg

Doctoral thesis (2007)

Deficiencies of selenium (Se) and iodine (I) are widespread in livestock all over Europe. They have an impact on the animals’ health. Since the clinical signs of the deficiencies are rarely pathognomic ... [more ▼]

Deficiencies of selenium (Se) and iodine (I) are widespread in livestock all over Europe. They have an impact on the animals’ health. Since the clinical signs of the deficiencies are rarely pathognomic, auxiliary exams, based on blood and milk samples are needed for the confirmation of the diagnosis. To evaluate the Se and I status, the plasmatic Se content, the erythrocytic glutathione peroxydase activity (GPX), and the inorganic plasmatic I (IIP) content are measured routinely. Other analyses, like e.g. the dosage of tri-iodothyronine (T3) or thyrotropine (bTSH) can be used. Once the deficiency is diagnosed, it can be corrected by several methods. The first aim of the study was to evaluate the zinc, copper, Se, and I status of Wallonian dairy and beef herds and to correlate their trace element status to their health. The trace element status of the herds with pathologies was less good than that of healthy herds. Further, more herds with pathologies had deficiencies when compared to healthy ones. Dairy herds had a better trace element status than beef herds. Se and I deficiencies are among the most important ones and have the most severe sequels. Therefore, the subsequent parts of the study focussed on these two trace elements. The second aim was the establishment of a technique for the dosage of bTSH and of reference values in healthy cattle. Reference ranges for bTSH and for thyroxine (T4) have been determined in healthy adult cows and in healthy calves. Thereafter, the next aim was to compare the concentration of bTSH in newborn calves with goitre to those obtained in healthy calves, in order to validate a diagnostic test for this pathology. The bTSH allowed the discrimination of the two groups and to approve the diagnosis of hypothyroidism in some of the calves. The threshold value of bTSH for the diagnosis of hypothyroidism in the newborn calf has been fixed at 35 µU/ml. The fourth aim was to compare the I (IIP) and Se (plasmatic Se, GPX) status as well as the thyroid status (bTSH, T4, T3, rT3) in dried pregnant cows and their calves and in non-pregnant cows, that received normal diet and a diet enriched in Se and I. In those receiving a Se and I enriched diet, the T4 and the bTSH decreased while the IIP, the T3, and the GPX activity increased. In the group that received a diet with normal Se and I contents, only the GPX activity increased. At birth, calves from mothers receiving the Se and I enriched diet, had a higher IPP content and GPX activity, and a lower bTSH concentration than calves from the other group. The last aim was to compare the effects of two different forms of Se (sodium selenite versus seleno-methionine) and two different doses of Se (0.1 versus 0.5 ppm) on the health and the Se status of Se deficient Belgian Blue cows and their calves. The first two groups of cows received a ration with 0.1 and 0.5 ppm, respectively, of Se in the form of sodium selenite (Na-Se 0.1 and Na-Se 0.5), while the third group received 0.5 ppm of Se in the form of seleno-methionine (Y-Se 0.5). The Se content of plasma, colostrum, and milk was higher in the cows of group Y-Se 0.5 when compared to the two other groups. The Se content of the plasma was higher in calves from group Y-Se 0.5 when compared to the two other groups. The daily weight gain of the Y-Se 0.5 group was higher than those of the group Na-Se 0.1. The incidence of diarrhoea among calves in group Na-Se 0.1 was higher than in group Y-Se 0.5. In conclusion, trace elements deficiencies are common in Wallonia and often they are multiple. They play a major role in the aetiology of multifactorial diseases diagnosed in the cattle herds. Deficiencies in Se and in I are most commonly implicated in clinical problems. The diagnosis of these deficiencies is determined by blood analyses. Therefore, the tests need to be differentiated according to their capacity to test the nutritional or the thyroid status. A simultaneous supplementation with I and Se, as well as the form of the supplemented Se, may modify the interpretation of the nutritional and the thyroid status. Better reproduction performances and a better health have been observed in herds with a normal trace element status. Furthermore, the advantage of the supplementation with Se in the form of seleno-methionine has been demonstrated in comparison to sodium selenite in deficient Belgian Blue cattle. This study opened numerous perspectives. The measurement of bTSH should be implemented in laboratories in order to offer it as a routine analysis to the practitioning veterinarian, who could use this tool in the framework of many diseases other than goitre. From a fundamental point of view, the dosage of deiodinases would allow the understanding of the regulation and of the synthesis of the thyroid hormones in bovines, and identifying the role of Se and I in this process. Finally, following the discoveries concerning the seleno-methionine, the effect of organic forms of other trace elements in bovine supplementation should be investigated. [less ▲]

Detailed reference viewed: 60 (21 ULg)
Full Text
Peer Reviewed
See detailClinical differentiation of malignant catarrhal fever, mucosal disease and bluetongue.
Bexiga, R.; Guyot, Hugues ULg; Saegerman, Claude ULg et al

in Veterinary Record : Journal of the British Veterinary Association (2007), 161(25), 858-9

Detailed reference viewed: 46 (18 ULg)
Full Text
Peer Reviewed
See detailDescription clinique des cas de FCO survenus au Nord de l'Europe durant l'été et l'automne 2006
Guyot, Hugues ULg; Mauroy, Axel ULg; Thiry, Etienne ULg et al

in Bulletin des Groupements Techniques Vétérinaires (2007), 39(avril), 89-96

La fièvre catarrhale ovine (FCO) a été identifiée au Nord de l’Europe <br />le 14 août 2006. L’Allemagne, la Belgique, les Pays-Bas et, dans une <br />moindre mesure, le Grand-Duché de Luxembourg et la ... [more ▼]

La fièvre catarrhale ovine (FCO) a été identifiée au Nord de l’Europe <br />le 14 août 2006. L’Allemagne, la Belgique, les Pays-Bas et, dans une <br />moindre mesure, le Grand-Duché de Luxembourg et la France ont été <br />affectés. Le sérotype 8 du virus de la FCO (exotique) a rapidement été <br />identifié ainsi qu’un vecteur, Culicoides dewulfi, une espèce indigène du <br />Nord de l’Europe. La maladie s’est rapidement développée et au 1er <br />février 2007, on recensait 2137 foyers de FCO, toutes espèces de <br />ruminants confondues. Globalement, la maladie a affecté davantage les <br />bovins (54 %) que les ovins (46 %). Les signes cliniques les plus <br />fréquemment observés chez les bovins étaient des lésions sur le museau <br />et la cavité buccale (ulcérations/croûtes), de la salivation et des boiteries <br />chez des animaux adultes. La morbidité et la mortalité animales étaient <br />respectivement de maximum 5 % et 1 %. Les principaux signes cliniques <br />rencontrés chez le mouton étaient également des lésions sur le museau <br />et la cavité buccale (ulcérations/croûtes), de l’amaigrissement et des <br />boiteries. La morbidité et la mortalité animales étaient respectivement <br />de maximum 12 % et 6 %. Les signes cliniques n’étant pas <br />pathognomoniques et le diagnostic différentiel relativement vaste, seul <br />un examen de laboratoire permet d’établir un diagnostic de certitude. [less ▲]

Detailed reference viewed: 51 (7 ULg)
Full Text
Peer Reviewed
See detailThyrotropin in newborn calves as a tool for diagnosing hypothyroidism
Guyot, Hugues ULg; Lebreton, Pascal; Alves de Oliveira, Laurent et al

in Cattle Practice (2007), 15(Part 3), 271-275

The hypothalamic-pituitary-thyroid axis is of particular importance for the adaptation of mammals to their environment. Hypothyroidism is the most common type of thyroid disorders in cattle. Thyrotropin ... [more ▼]

The hypothalamic-pituitary-thyroid axis is of particular importance for the adaptation of mammals to their environment. Hypothyroidism is the most common type of thyroid disorders in cattle. Thyrotropin (TSH) is used in several mammalian species for the diagnosis of primary hypothyroidism. Currently in cattle, thyroid hormone assays are used to diagnose such disease. The aim of the study was to compare different tools for diagnosing hypothyroidism in newborn calves. Twelve goitrous newborn calves from two beef herds were studied as well as 45 healthy newborn calves. Bovine TSH, thyroxine (T4), tri-iodothyronine (T3), reverse-T3 (rT3), plasmatic inorganic iodine (PII) and glutathione peroxidase in erythrocytes (GPXe) were assayed in these calves during the first day of life. T4/T3 and T4/TSH ratio were calculated. Furthermore, TSH, T4, PII and GPXe were also assayed in their dams at calving. Results were analysed using Wilcoxon rank sum test and Spearman's rank correlation coefficient. A significant higher value (P < 0.01) of TSH was seen for the group of goitrous calves compared to healthy calves. There was no difference between healthy and goitrous calves for GPXe (P > 0.1) and PII (P > 0.05). Significantly higher values were seen for healthy calves compared to goitrous calves concerning T4, T4/T3 ratio, T4/TSH ratio, rT3 (P < 0.0 1) and T3 (P < 0.05). Regarding the group of goitrous calves, those that had larger goitre at palpation and were hairless (n=8) died within the first day of life while the four other with moderate goitre and normal hair stayed alive. Goitrous-dead calves had higher TSH values than goitrous-alive ones (P < 0.01), lower T4, T3, T4/TSH (P < 0.0 1) and rT3 (P < 0.05) but similar T4/T3 ratio (P > 0.1). Furthermore, it appeared that T4 and rT3 values in goitrous-alive calves were not different compared to healthy calves (P > 0.1). Regarding TSH (rho=0.44), T4 (rho=-0.44), PII (rho=0.70) and GPXe (rho=0.87), there was a correlation between healthy calves and their dams, with significantly higher values being found in the calves (P < 0.01). There was no correlation between values of TSH and T4 in goitrous calves and their dams (P > 0.1). However, for these animals there was a strong relationship in the values of PH (rho=0.82) and GPXe (rho=0.94) (P < 0.01). TSH, PII and GPXe were significantly higher in goitrous calves compared to their dams (P < 0.01). Regarding T4, only goitrous-dead calves showed significantly lower values than their dams (P < 0.01). Dams with goitrous calves had higher TSH (P < 0.01) and PII (P < 0.05) compared to dams with healthy calves but similar T4 and GPXe (P > 0.1). This study revealed that TSH alone is a good marker for hypothyroidism in newborn calves. In the absence of TSH assay, the T4/T3 ratio may be used to diagnose hypothyroidism in newborn calves. In our study, although T4/T3 ratio was helpful in identifying goitrous calves, it did not allow to discriminate goitrous-dead from goitrous-alive calves, contrary to TSH. In our study, the presence of a goitre in newborn calves could not be explained by the iodine (PII) and thyroid (via T4) status of their dams. [less ▲]

Detailed reference viewed: 213 (14 ULg)
Full Text
Peer Reviewed
See detailComparative responses to sodium selenite and organic selenium supplements in Belgian Blue cows and calves
Guyot, Hugues ULg; Spring, P.; Andrieu, S. et al

in Livestock Science (2007), 111(3), 259-263

Belgian Blue (BB) beef cattle is particularly prone to selenium (Se) deficiency due to the poor Se content of soil and roughages on rearing farms and the higher requirements of this hypermuscled breed ... [more ▼]

Belgian Blue (BB) beef cattle is particularly prone to selenium (Se) deficiency due to the poor Se content of soil and roughages on rearing farms and the higher requirements of this hypermuscled breed. The goal of this trial was to compare the effects of different forms and concentrations of Se supplementation on Se status, health and performance in 60 pregnant Se-deficient BB cows. Cows were allocated to 3 experimental groups receiving selenized-yeast at 0.5 ppm Se on total ration (Y-Se 0.5), Na-selenite at 0.5 ppm Se on total ration (Na-Se 0.5) and Na-selenite at 0.1 ppm Se on total ration (Na-Se 0.1), respectively. Cows were supplemented from 2 months before calving until 2 months after calving. Data on performance, health and Se status of the dams and their calves were analyzed using a linear model, least squares means and logistic regression. At the end of the study, plasmatic Se (pSe) was significantly higher (P<0.01) in cows receiving Y-Se than in cows from other groups. Glutathion-peroxidase in erythrocytes (GSH-pxe) was higher in Y-Se and Na-Se 0.5 than Na-Se 0.1 group (P<0.01). Se content in colostrum and milk was significantly higher (P< 0.01) in Y-Se than other groups. At birth, Se status of calves from group Y-Se was significantly higher than those of other groups (P<0.01). Plasmatic Se in calves remained higher for 75 days after birth in Y-Se compared to other groups (P<0.01). Diarrhoea was the most commonly observed disease in the calves and, during the first 15 days of life, diarrhoea occurred in 6%, 21% and 35% of calves from groups Y-Se, Na-Se 0.5 and Na-Se 0.1, respectively. Over the whole 75 days trial period, incidence of diarrhoea was 19, 29 and 65%, respectively. Average daily gain (ADG) in calves born from Y-Se group of cows tended to be higher than in Na-Se 0.5 (P=0.06) and Na-Se 0.1 (P<0.05) but there was no difference between Na-Se 0.5 and Na-Se 0.1 (P>0.1). At the same dosage, Y-Se conferred better Se status in both dams and their calves than did Na-Se. Requirement of 0.1 ppm Se seems to be insufficient in BB to optimise health and performance. Regarding health status and ADG in calves, Y-Se seems also to result in better performance. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 163 (5 ULg)