References of "Hanzen, Christian"
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See detailUN NOUVEAU SYNDROME HÉMORRAGIQUE INEXPLIQUÉ CHEZ LE BOVIN – LA PANCYTOPÉNIE NÉONATALE BOVINE
Theron, Léonard ULg; Vogin, Nathalie; Moreaux, Emeline et al

in Antibiothérapies : Santé animale et santé publique (2010, May)

For several decades, the bovine was subject to various hemorrhagic syndromes which causes have historically been found. Since the mid-2000s, a new hemorrhagic syndrome seems to emerge with a significant ... [more ▼]

For several decades, the bovine was subject to various hemorrhagic syndromes which causes have historically been found. Since the mid-2000s, a new hemorrhagic syndrome seems to emerge with a significant epidemiological consistency, suggesting a common etiology, although unknown at present. The affected animals were calves of less than 30 days, of all races born to mothers without specific parity. We noticed a very sporadic disease (1/10.000) but lethal to 99%. The characteristic lesions are multifocal hemorrhages, hyperthermia, melena, we noted medullar aplasia systematically. These calves are vironegative for BTV, enzootic bovine leukosis and BVDV. No viral or bacterial agent could be isolated. It seems that most of these calves were born from dams vaccinated against BVDV. The track of an immune dysfunction is the most serious for the moment. [less ▲]

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See detailPancytopénie néonatale : nouveau syndrome hémorragique chez le bovin
Theron, Léonard ULg; Vogin, Nathalie; Moreau, Emeline et al

in Point Vétérinaire (2010), 41(Numéro spécial), 79-86

For 30 years, many haemorrhagic syndromes were observed in cattle. The recent observation in Europe of a new entity hemorrhagic highlights a consistent set of clinical cases in calves of all breeds under ... [more ▼]

For 30 years, many haemorrhagic syndromes were observed in cattle. The recent observation in Europe of a new entity hemorrhagic highlights a consistent set of clinical cases in calves of all breeds under 30 days of age, with pancytopenic haemorrhagic purpura. Calves are vironegative for BVD and BTV, most are seropositive for both viruses antibodies. No specific etiology has been highlighted, but it seems that the syndrome is linked to the ingestion of colostrum immunized against cells of the calf. The syndrome is sporadic, with a prevalence ranging between 1:10,000 and 1:100,000 cattle under one year of age, causing a lethality of 99%. The origin of the pancytopenia is a medullar aplasia. [less ▲]

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See detailWhen is a cow in estrus? Clinical and practical aspects.
Roelofs, Judith; Lopez-Gatius, Fernando; Hunter, R. H. F. et al

in Theriogenology (2010)

Good detection of estrus is critically important in dairy husbandry. Incorrect detection of estrus is related to loss of profit due to extended calving intervals, milk loss, veterinary costs, etc ... [more ▼]

Good detection of estrus is critically important in dairy husbandry. Incorrect detection of estrus is related to loss of profit due to extended calving intervals, milk loss, veterinary costs, etc. Detection of estrus remains a major problem despites enormous progress in the knowledge of reproductive physiology of the cow and in development of estrus detection aids. To achieve good estrus detection, many factors have to be taken into account. On one hand a cow has to express estrus and on the other hand the farmer has to detect it. Combined action of several hormones causes physiological changes that lead to ovulation and an environment in the uterus that allows sperm to fertilize the egg. Besides these internal actions, a number of external changes can be observed. When using visual observations, time of the day and time spend on observation have a great impact on detection rates. Many devices are available to aid in estrus detection, such as pedometers, mount devices, temperature, and hormone measurements. Expression of estrus can be influenced by many factors. Heritability, number of days postpartum, lactation number, milk production, and health are known to influence estrus expression. Environmental factors like nutrition, season, housing, herd size, etc. also play a role in estrus expression. To evaluate estrus detection, record keeping is very important; a number of formulas can be used to assess detection efficiency. Besides the farmer, the veterinarian and inseminator can play an important role in estrus confirmation and good insemination strategy. In the end, the time of ovulation and the age of the egg at sperm penetration is critical for conception. Therefore, emphasis in research needs to be on the timing of insemination relative to ovulation, and thus on the detection of ovulation [less ▲]

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See detailDescribing an emerging disease: A case of thrombocytopenic syndrome of the newborn calf
Theron, Léonard ULg; Vogin, Nathalie; Bayrou, Calixte ULg et al

in Maillard, R.; Navetat, H. (Eds.) European buiatrics forum 2009 (2009, December 03)

Since the last 5 years, a specific hemorrhagic syndrome of unknown etiology was described in young calves. This disease has a low incidence but a very high mortality rate. No etiology has been found yet ... [more ▼]

Since the last 5 years, a specific hemorrhagic syndrome of unknown etiology was described in young calves. This disease has a low incidence but a very high mortality rate. No etiology has been found yet, though many labs have already gathered lots of cases around Europe. For example, more than 200 cases in 170 farms in Germany, 60 cases in 40 farms were described in Gent’s veterinary faculty in Belgium. In France and in the United Kingdom, several cases have been recorded yet, in multiple different locations. As far as we know, the disease concern young calves aging between 10 and 30 days, from different breeds. Most calves present a purpura on multiple sites on skin, gums, eye sclera and ears. Hematology indicates severe anemia, thrombocytopenia, neutropenia with or without leukopenia. Necropsy indicates multiple hemorrhages in serous membranes on every abdominal viscera. Alfort’s veterinary faculty has described acute necrotizing hepatitis on one case in France. Those calves are BVDV and BTV negative both on antigen tests. In Liege’s veterinary faculty one live case was examined, from a modern farm with 160 calvings, and less than 5% of calf mortality per year. The farm had 3 hemorrhagic fatal cases during July 2009, of very quick evolution. From those, 2 were autopsied and diagnosed BVDV negative. The 20 days old calf had hyperthermia in the morning, received oxytetracycline in the farm and began bleeding at noon. As many of the described cases, the calf presented mild depression with hyperthermia and tachypnoea. Skin and ear purpura, gum hematoma, melena, hematuria and hemoglobinuria were noticed. Hematology revealed a severe anemia with decreased hematocrite due to a profound thrombocytopenia (4.79*109/l). Leukocytes formula also shown neutropenia (0.10*109/l) and a monocytosis (1.32*109/l). It resulted in a mild leukopenia (3.59*109/l). We also noticed hypogammaglobulinemia (2.92 g/l and 6.8% of total protein). This calf received an immune-suppressive treatment with a high dose of dexamethasone (0.64mg/kg), and a cover antimicrobial therapy (Enrofloxacine). A good evolution of the symptoms on day 2 was observed. Leukocyte formula had a normal answer to dexamethasone concerning the lymphocytes and neutrophils population. On day 6, blood formula was already stabilized, with increasing hematocrite from 12% on day 3 to 15%. Thrombocytes count has also increased to 58.20*109/l; leukocytes count was also back to normal with normal formula. Flow cytometric measures on the lymphocytes subpopulations indicated a subnormal Gamma-Delta and Natural Killer population, and a high number of apoptotic cells 12 hours after sampling. This syndrome can be linked to idiopathic thrombocytopenia in human newborn both regarding symptomatology and treatment answer. Though this data helps in the understanding of this pathology, it concerns only one animal and needs to be confirmed through further experiment on live cases. [less ▲]

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See detailIdentification and Ranking of risk factors for somatic cell count economic penalty in 349 southern Belgium dairy farms
Theron, Léonard ULg; Humblet, Marie-France ULg; Delfosse, C. et al

in Maillard, R.; Navetat, H. (Eds.) European buiatrics forum 2009 (2009, December 02)

In Belgium, the main economic penalty accounted for bovine milk quality is the bulk milk somatic cell count geometric mean over 3 months reaching more than 400,000 cells/ml. Yet, it is still difficult to ... [more ▼]

In Belgium, the main economic penalty accounted for bovine milk quality is the bulk milk somatic cell count geometric mean over 3 months reaching more than 400,000 cells/ml. Yet, it is still difficult to make progress on udder health and milk quality because regional risks related to endemic farming practices are not broadly known. Hence, a first step in understanding specific udder health risks associated with herd management has to be a broad ecopathological survey. A random stratified sample of 349 dairy farms, representing 25% of producers registered for performance recording, was selected with a total of 16,000 cows. Thorough audits recording 400 farming practices were made in each farm by 2 different surveyors during milking. The practices were recorded across four categories: Herd structure, Housing, Milking practices and Herd Management (including Nutrition). Our chosen variable was the geometric mean of the herd composite somatic cell count from the last three months compared to the 400,000 cells/ml European threshold. The sample had a mean somatic cell count of 287,000 cells/ml following a normal distribution between 73,000 and 807,000 cells/ml. From 19 risk indicators identified through univariate logistic analysis (p<0.15), half were related to milking practices and 5 were underlined by significant odds-ratios (OR) found through multivariate logistic analysis (p<0.05). Therefore, it was found that cubicle housing had the least risk (OR= 0.59 compared with tightened stalls, OR= 0.42 compared with straw stalls); Presence of a calving pen (OR= 0.40), use of post-dipping (OR= 0.50) had a positive impact; whereas pre-dip had a negative impact in our study (OR= 3) though it was not clear if this routine was performed correctly. Stripping also had a bad impact on milk quality whether it was systematic (OR = 1.90) or occasional (OR = 2.43). It was also found that farms with poor milking liner hygiene had more trouble (OR = 2.34). The results were comparable to other ecopathological studies such as northern and southern American and European studies. This study is a prerequisite in operational veterinary advice in southern Belgium dairy farms, because it provides a cross-sectional study of dairy practices and states on major epidemiological risk factors in dairy management for this region. [less ▲]

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See detailImplementing pedagogic strategies between vets and farmers to create synergies in udder health management: Project Mammipack®
Theron, Léonard ULg; Sustronck, Bart; Bertozzi, Carlo et al

Poster (2009, December)

Udder health is usually considered as a health and economic problem for farmers. We now consider that mastitis is the result of many factors related to the environment, the pathogen and the host. What may ... [more ▼]

Udder health is usually considered as a health and economic problem for farmers. We now consider that mastitis is the result of many factors related to the environment, the pathogen and the host. What may have been forgotten in the process is the fact that nowadays, the main interface with mastitis is the farmer, and their knowledge about mastitis is very heterogeneous. This reflexion has led to the creation of a technical and pedagogical pack called “Mammipack” which contains different tools, from all actors of the dairy chain. We included small charts explaining the most important risk factors identified through epidemiology, good dairy practices and its effect on milk flow, milking machine check-up, how-to for mastitis milk sample, a how-to for performance records use for udder health management, a resume on genetic selection of sires and mastitis, charts upon nutrition factors and their main effect on udder physiology during lactation and dry-off, resume on veterinary drugs good management in the farm. Small laminated sheets upon milk sampling for bacteriology and teats evaluation were also joined in order to be use in parlors, sterile sampling tubes were also given in the pack. A mastitis record pad was designed to record the main clinical forms and the treatment chosen. Eventually, the book Udder Health® was added to have a complete modern look on that problem in dairy farms. 25 farmers were selected on a voluntary base by 12 veterinarians, and they answered to questionnaires about their main practices regarding herd structure, mastitis treatment, and southern Belgium main 19 risk factors. They had to answer basic questions concerning udder health on 15 points. They agreed to keep a record of all next mastitis cases in their farms and take milk samples for bacteriology each time at day 0 and day 21 during 3 months. The main objective is to show to a group of dairy farmers that mastitis could take several different forms from one farm to another, in term of incidence, pathogens and clinical forms. One other purpose is to show the difficulty to have bacteriological cure, even when physical cure has happened. After all, one collateral objective was to create the Mammipack®, designed for farmers and vets to increase their ability to collaborate on mastitis management through most dairy chain actors’ expertise. [less ▲]

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See detailAnomalies et traitements de la cyclicité dans l’espèce bovine
Hanzen, Christian ULg

Conference given outside the academic context (2009)

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See detailRisks analysis of dairy practices impact on herd udder health in walloon dairy farms
Theron, Léonard ULg; Saegerman, Claude ULg; Hanzen, Christian ULg

Poster (2009, September 22)

As most of production pathologies in dairy farming, mastitis is characterized by a multifactorial aetiology. Its diagnosis and treatment requires a good knowledge of its determinant and predisposing ... [more ▼]

As most of production pathologies in dairy farming, mastitis is characterized by a multifactorial aetiology. Its diagnosis and treatment requires a good knowledge of its determinant and predisposing factors. The comparative epidemiology of 349 walloon farms registered to individual milk analysis programs led to highlight the practices used in farms whose last 3 months' herd somatic cell count was above 400.000 cells/ml. We identified the following risk indicators relative to 1) herd demography : age, composition, herd production average, percentage of high cell counts animals 2) the animal housing : use of straw as bedding stall for all classes of animals and lack of a calving pen 3) the milking machine : milking cups cleaning 4) the dairy practices : lack of washing cloth towels between 2 milkings, occasional foremilk check, stripping, lack of post-dip and 5) animal nutrition : mould on beet pulp silos and composition of the main concentrate. This descriptive and univariate analysis confirmed the risky situation of a large majority of dairy farms regarding the recommendations of good dairy practices guides. [less ▲]

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See detailL'université entre hasard et nécessité
Hanzen, Christian ULg

Speech (2009)

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See detailApplication du raisonnement clinique à l'interprétation d'un bilan de reproduction bovine
Hanzen, Christian ULg

Conference given outside the academic context (2009)

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See detailTraitement des mammites - Actualité et mises en pratique
Theron, Léonard ULg; Hanzen, Christian ULg

Conference given outside the academic context (2009)

La mammite doit être ciblée en tant que maladie de production et risque de mortalité. Sa caractérisation repose sur une bonne connaissance de ses aspects épidémiologiques à l'échelle de la région, ainsi ... [more ▼]

La mammite doit être ciblée en tant que maladie de production et risque de mortalité. Sa caractérisation repose sur une bonne connaissance de ses aspects épidémiologiques à l'échelle de la région, ainsi, à l'aide d'indicateurs épidémiologiques pertinents, la mammite peut être caractérisée par une prévalence d'environ 100.000 cas wallons par an. Soit 50% de prévalence maximale en Wallonie. Sur base des informations disponibles sur le terrain wallon, il est possible d'identifier les cibles prioritaires thérapeutiques. A travers l'étude des bases de données de l'ARSIA, nous sommes en mesure de déterminer un schéma de travail incluant : les germes prioritaires et leur sensibilité moyenne aux antibiotiques. Dans une seconde phase, les aspects pharmacologiques du traitement des mammites sont revus à la lumière des contraintes que pose la mamelle bovine. Cette phase donne lieu à une meilleure adéquation entre choix du traitement, cible thérapeutique et sensibilité des pathogènes. Puis seront abordés des exemples de thérapeutiques en fonction du germe présent dans la ferme, en s'attardant sur la posologie choisie et le type de stratégie thérapeutique en fonction du degré d'atteinte. Les mammites impliquant Streptococcus uberis, Staphylococcus aureus, les staphylocoques coagulase négatif et les mammites à coliforme sont ainsi passées en revue. Enfin, la question de la thérapie anti-inflammatoire est abordée. 2 cas pratiques issus du terrain sont abordés en fin de formation afin d'illustrer la complexité de la thérapie mammaire, et le fait que le germe et le traitement ne sont jamais les seuls facteurs à prendre en compte pour le praticien. [less ▲]

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See detailLe Système de Conseil Agricole : pour une synergie du conseil agronomique, zootechnique, économique et conditionnalité au bénéfice de l’éleveur
Gounot, G.; Hanzen, Christian ULg; Hobe, M. et al

in Recueil des journées nationales 2009 (2009, May)

Entré en vigueur en 2008, le Système de Conseil Agricole est un nouveau mode de travail dans le milieu agricole. Les exploitants agricoles ne sont plus en contact direct avec l’administration pour ... [more ▼]

Entré en vigueur en 2008, le Système de Conseil Agricole est un nouveau mode de travail dans le milieu agricole. Les exploitants agricoles ne sont plus en contact direct avec l’administration pour l’application des règles de conditionnalité des aides, mais sont conseillés par des organismes aux compétences multiples. Ces derniers doivent être capables d’apporter les appuis techniques et économiques nécessaires, répondant aux critères imposés par l’administration. On assiste donc à un transfert de compétences et de responsabilité de l’administration vers les SCA. Le fonctionnement des SCA est décrit dans cet article, avec l’exemple d’un réseau de compétences mis en place en Bretagne [less ▲]

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See detail100 zile pentru reusita perioadei postpartum (langue roumaine)
Hanzen, Christian ULg

Scientific conference (2009, March)

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See detailFournir un lait de qualité et diminuer ses mammites
Theron, Léonard ULg; Hanzen, Christian ULg

Conference given outside the academic context (2009)

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See detailOvarialzysten beim Rind
Hanzen, Christian ULg

Scientific conference (2009, January)

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See detailInfections utérines : définition, symptômes et diagnostic.
Hanzen, Christian ULg; Theron, Léonard ULg; Simon, Annik ULg et al

in Point Vétérinaire (2009), 40(299), 41-46

Le contexte du sujet est introduit par les trois critères de choix d’une méthode diagnostique ainsi que par les caractéristiques symptomatologiques des quatre types d’infections utérines actuellement ... [more ▼]

Le contexte du sujet est introduit par les trois critères de choix d’une méthode diagnostique ainsi que par les caractéristiques symptomatologiques des quatre types d’infections utérines actuellement définies. Sont ensuite passées systématiquement en revue les avantages et inconvénients des méthodes de diagnostic. L’anamnèse pourtant indispensable s’avère être une méthode peu sensible tout comme d’ailleurs la palpation manuelle. L’intérêt de la prise de température est souligné dans le cadre d’un examen général. L’examen vaginal demeure un examen de choix quelle que soit la méthode employée. Le diagnostic des endométrites subcliniques implique la détermination de la concentration en polymorphonucléaires dans un prélèvement utérin réalisé par drainage ou au moyen d’une cytobrosse. . L’intérêt du diagnostic échographique mériterait d’être affiné. Les examens bactériologique, anatomopathologique et biochimique présentent un intérêt pratique plus limité. [less ▲]

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See detailNon-Invasive Methods to Predict Breast Muscle Weight in Slow-Growing Chickens
Larivière, Jean-Marc ULg; Michaux, Charles ULg; Verleyen, Vincent ULg et al

in International Journal of Poultry Sciences (2009), 8(7), 689-691

This experiment aims to compare in vivo breast morphometric and ultrasound measurements, as well as live body weight to predict breast meat weight in slow-growing chickens. Traits included Thoracic ... [more ▼]

This experiment aims to compare in vivo breast morphometric and ultrasound measurements, as well as live body weight to predict breast meat weight in slow-growing chickens. Traits included Thoracic Circumference (TC), Chest Width (CW), Keel Length (KL) and angle (KA), Live Weight (LW), thickness of muscle determined by sonography (TM) and Breast Meat Weight (BMW). Birds were then slaughtered and total breast muscles (Pectoralis major and Pectoralis minor) were dissected and weighed. A linear model including sex effect and the different predictor measurements, as covariates, were adjusted to the data. Homogeneity test of slopes between sexes showed no difference. Means of the traits were 115.58g (±19.72) for BMW, 1031 g (±163.44) for LW, 68.65o (±6.89) for KA, 26.81 cm (±1.57) for TC, 10.40 cm (±0.62) for KL, 4.67 cm (±0.47) for CW and 11.52 mm (±1.11) for TM. All traits were highly correlated to BMW: TC (0.85), LW (0.84), KL (0.81) and TM (0.79), except for KA (0.28) and CW (0.19). Finally, TC, LW, KL and TM appear to be valuable indicators for estimating BMW in slow-growing chickens but KA and CW remain poor predictors [less ▲]

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