Sébastien Vandeputte

Highly effective SNP-based association mapping and management of recessive defects in livestock

The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal welfare concerns. Here we show that the availability of genome-wide, high-density SNP panels, combined with the typical structure of livestock populations, markedly accelerates the positional identification of genes and mutations that cause inherited defects. We report the fine-scale mapping of five recessive disorders in cattle and the molecular basis for three of these: congenital muscular dystony (CMD) types 1 and 2 in Belgian Blue cattle and ichthyosis fetalis in Italian Chianina cattle. Identification of these causative mutations has an immediate translation into breeding practice, allowing marker assisted selection against the defects through avoidance of at-risk matings.

Multidisciplinary and Evidence-based Method for Prioritizing Diseases of Food-producing Animals and Zoonoses

To prioritize 100 animal diseases and zoonoses in Europe, we used a multicriteria decision-making procedure based on opinions of experts and evidence-based data. Forty international experts performed intracategory and intercategory weighting of 57 prioritization criteria. Two methods (deterministic with mean of each weight and probabilistic with distribution functions of weights by using Monte Carlo simulation) were used to calculate a score for each disease. Consecutive ranking was established. Few differences were observed between each method. Compared with previous prioritization methods, our procedure is evidence based, includes a range of fields and criteria while considering uncertainty, and will be useful for analyzing diseases that affect public health.

Comparison of Four Refractometers for the Investigation of the passive transfer in Beef Calves

BACKGROUND Failure of passive transfer (FPT) in beef calves can be detected by refractometry. Nevertheless, different models of refractometers are available, and few studies compare them for the detection of FPT. OBJECTIVES To compare the accuracy of 4 different refractometers for measuring serum total protein concentrations in comparison with results obtained by the biuret method and, based on the serum IgG threshold of 1,600 mg/mL, to determine, for each refractometer, the optimal serum protein concentrations lowest threshold for successful passive transfer. ANIMALS One hundred and eight healthy beef calves, 3-8 days of age. METHODS Observational study. The concentrations of serum total proteins were determined with 4 different models of refractometers and compared with the biuret method by a Bland-Altman statistical method. The optimal serum protein concentrations lowest threshold for successful passive transfer was determined for each refractometer by receiver operating characteristic (ROC) analysis. In addition, the serum immunoglobulin G (IgG) concentration was compared with the serum gamma-glutamyl transferase (γ-GT) activity and with the total immunoglobulin concentration. RESULTS The refractometric measurements were highly correlated with those obtained by the biuret method. Serum total protein concentration threshold values of 56, 58, 54, and 56 g/L were found respectively for the Atago, Atago ATC, Wolf ATC, and digital ATC refractometers. Immunoglobulins were highly correlated with IgG, whereas γ-GT only reflected colostrum uptake by the calf. CONCLUSIONS AND CLINICAL IMPORTANCE All refractometers could be used for the assessment of passive transfer using their individual serum protein concentration threshold.

Estimating the economic impact of a possible equine and human epidemic of West Nile virus infection in Belgium.

This study aimed at estimating, in a prospective scenario, the potential economic impact of a possible epidemic of WNV infection in Belgium, based on 2012 values for the equine and human health sectors, in order to increase preparedness and help decision-makers. Modelling of risk areas, based on the habitat suitable for Culex pipiens, the main vector of the virus, allowed us to determine equine and human populations at risk. Characteristics of the different clinical forms of the disease based on past epidemics in Europe allowed morbidity among horses and humans to be estimated. The main costs for the equine sector were vaccination and replacement value of dead or euthanised horses. The choice of the vaccination strategy would have important consequences in terms of cost. Vaccination of the country’s whole population of horses, based on a worst-case scenario, would cost more than EUR 30 million; for areas at risk, the cost would be around EUR 16–17 million. Regarding the impact on human health, short-term costs and socio-economic losses were estimated for patients who developed the neuroinvasive form of the disease, as no vaccine is available yet for humans. Hospital charges of around EUR 3,600 for a case of West Nile neuroinvasive disease and EUR 4,500 for a case of acute flaccid paralysis would be the major financial consequence of an epidemic of West Nile virus infection in humans in Belgium.

Investigation of colostrum quality in beef cattle by radial immunodiffusion and brix refractometry

In cattle, ingestion of sufficient good quality colostrum during the first hours of life is essential for the future health and performance of the calf (Rauprich and others 2000). However, colostrum quality, reflected by its IgG content, can vary widely among individual cows (Gulliksen and others 2008). As the colostrum quality cannot be predicted by its physico-chemical characteristics (Maunsell and others 1999), it is crucial to assess its IgG concentration before administration to the calf. Currently, several methods exist to measure the IgG content of colostrum, both directly and indirectly, but few of them are transposable to farm conditions. The use of a brix refractometer (BR) has been described for the assessment of the colostrum quality in dairy cattle (Bielmann and others 2008, 2010, Chigerwe and others 2008, Morrill and others 2012, Quigley and others 2013). To date, no such studies have been performed in beef cows while colostrum volume and quality differ widely between dairy and beef cows. It is recognised that colostrum produced by beef breeds is frequently of higher quality than dairy breeds colostrum, even if its volume is lower (Guy and others 1994, Lorenz and others 2011). Therefore, the selection and distribution of higher colostrum quality are important to ensure the transfer of a sufficient mass of IgG to the beef calf. The aim of this study was first to assess the use of a …

Evaluation of a Bovine Concentrated Lactoserum for Preventing Neonatal Diarrhoea in Belgian Blue Calves

The purpose of this study was to evaluate, under field conditions, the efficacy of an european registered bovine concentrated lactoserum (Locatim) in 3 farms with neonatal diarrhoea in calves. A total of 117 healthy Belgian Blue (BB) calves were allocated in 2 groups. Two thirds of the calves received Locatim orally immediately after birth and maternal colostrum one hour later (treated group), while control calves only received maternal colostrum. Every day during 14 days, mental status, faeces consistency, suckling reflex and hydration status of each calf were monitored. Individual blood samples were assessed for passive transfer and specific Escherichia coli antibodies against strains F5, CS31A, F17 and F41. Faecal samples from diarrheic and non diarrheic calves were analysed for rotavirus, bovine coronavirus, Cryptosporidium parvum and Escherichia coli F5. Locatim had no significant effect on the onset, duration and incidence of diarrhoea. The mean serum IgG concentration of 23.1 ± 7.8 mg/ml indicates a good IgG transfer. Only the CS31A strain titer was significantly higher in the treated group. The major identified causative agent of diarrhoea was C. parvum. In conclusion, Locatim only has a slight effect when IgG transfer is optimal, but could be justified when specific antibodies lacking in colostrum are needed.