H. Schobesberger

Evaluation of pressure distribution under an English saddle at walk, trot and canter

REASONS FOR PERFORMING STUDYnBasic information about the influence of a rider on the equine back is currently lacking.nnnHYPOTHESISnThat pressure distribution under a saddle is different between the walk, trot and canter.nnnMETHODSnTwelve horses without clinical signs of back pain were ridden. At least 6 motion cycles at walk, trot and canter were measured kinematically. Using a saddle pad, the pressure distribution was recorded. The maximum overall force (MOF) and centre of pressure (COP) were calculated. The range of back movement was determined from a marker placed on the withers.nnnRESULTSnMOF and COP showed a consistent time pattern in each gait. MOF was 12.1 +/- 1.2 and 243 +/- 4.6 N/kg at walk and trot, respectively, in the ridden horse. In the unridden horse MOF was 172.7 +/- 11.8 N (walk) and 302.4 +/- 33.9 N (trot). At ridden canter, MOF was 27.2 +/- 4.4 N/kg. The range of motion of the back of the ridden horse was significantly lower compared to the unridden, saddled horse.nnnCONCLUSIONS AND POTENTIAL RELEVANCEnAnalyses may help quantitative and objective evaluation of the interaction between rider and horse as mediated through the saddle. The information presented is therefore of importance to riders, saddlers and equine clinicians. With the technique used in this study, style, skill and training level of different riders can be quantified, which would give the opportunity to detect potentially harmful influences and create opportunities for improvement.

Motion pattern analysis of gait in horseback riding by means of Principal Component Analysis

As a consequence of the three interacting systems of horse, saddle, and rider, horseback riding is a very complex movement that is difficult to characterize by a limited number of biomechanical parameters or characteristic curves. Principal Component Analysis (PCA) is a technique for reducing multidimensional datasets to a minimal (i.e., optimally economic) set of dimensions. To apply PCA to horseback riding data, a pattern vector composed of the horizontal velocities of a set of body markers was determined. PCA was used to identify the major dynamic constituents of the three natural gaits of the horse: walk, trot, and canter. It was found that the trot is characterized by only one major component accounting for about 90% of the datas variance. Based on a study involving 13 horses with the same rider, additional phase plane analyses of the order parameter dynamics revealed a potential influence of the saddle type on movement coordination for the majority of horses.

Determination of the stiffness of the equine spine.

REASONS FOR PERFORMING STUDYnMechanical properties of the equine back are the bases for realistic modelling of the back, which is recognised as an important step towards improved understanding of the pathogenesis of equine back conditions.nnnHYPOTHESISnThe stiffness of the equine back depends on the direction of the applied force and on the position of the spine.nnnMETHODSnFourteen dissected spines were tested in a tensile testing machine. In 3 different positions, simulating dorsoventral, laterolateral and dorsoventral-30 degree rotated movement, force was applied on the dorsal spinous process of T12 to reach an excursion of 4 cm in each direction. The normal distribution of the stiffness coefficients was tested with a Kolmogorov-Smirnov test and the stiffness coefficients were compared with paired t tests.nnnRESULTSnMean +/- s.d. dorsoventral stiffness was 2093 +/- 611 N/m for the nonrotated spine and 2182 +/- 459 N/m for the 30 degree rotated spine. Mean laterolateral stiffness was significantly lower than dorsoventral stiffness at 1454 +/- 156 N/m.nnnCONCLUSIONSnThe stiffness of the spine depends on the direction of loading.nnnPOTENTIAL RELEVANCEnThe stiffness of the spine under loading may be a relevant factor in the development of back disorders.

Influence of the load of a rider or of a region with increased stiffness on the equine back: a modelling study

REASONS FOR PERFORMING STUDYnKnowledge of load effects is crucial for the understanding of the aetiology and pathogenesis of equine back problems.nnnOBJECTIVEnTo investigate different load scenarios of the equine back, such as being ridden or increased muscle tone, using biomechanical simulations.nnnMETHODSnKinetic and kinematic data of 15 sound horses and the electromyelograph of their long back muscles were recorded. A biomechanical simulation model was used for simulations under different biomechanical scenarios (ridden/unridden, localised increased stiffness) using ADAMS.nnnRESULTSnThe vertical forces acting through a rider were: walk 3.83 N/kg, trot 5.18 N/kg and gallop 5.60 N/kg. No significant changes in transversal forces were found between ridden and unridden horses. Profound changes were seen in the torques at the segment following a region of increased stiffness: in walk, lateral peak torques increased from 342 to 1723 Nm, and in trot from 393 to 1004 Nm, and dorsoventral from 386 to 3705 Nm (walk) and 458 to 4340 Nm (trot).nnnCONCLUSIONS AND POTENTIAL RELEVANCEnThe simulation shows that the stress of a rider is lower than that of pathological processes such as partial increased stiffness of the back. Study of revised models with improved anatomical realism might help to raise the plausibility of model results.

Red Deer as Maintenance Host for Bovine Tuberculosis, Alpine Region

To estimate the prevalence of bovine tuberculosis in the Alpine region, we studied the epidemiology of Mycobacterium caprae in wildlife during the 2009–2012 hunting seasons. Free-ranging red deer (Cervus elaphus) were a maintenance host in a hot-spot area, mainly located in Austria.

Geographical Spread of Highly Pathogenic Avian Influenza Virus H5N1 during the 2006 Outbreak in Austria

ABSTRACT In spring 2006, highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 was detected in Austria in 119 dead wild birds. The hemagglutinin cleavage site showed that the amino acid sequence motif was identical to that of the Qinghai lineage. For detailed analysis, the hemagglutinin (HA) and neuraminidase (NA) genes of 27 selected Austrian H5N1 viruses originating from different regions and wild bird species were analyzed phylogenetically, which revealed two clearly separated Austrian subclusters, both belonging to European cluster EMA-1. Subcluster South (SCS) contains virus isolates from the south of Austria as well as from Slovenia, Turkey, Egypt, and Nigeria. The second subcluster, Northwest (SCN), covered a larger group of viruses originating from different locations and wild bird species in the northern and very western parts of Austria, as well as from Bavaria and Switzerland. Surprisingly, virus isolates originating from two mute swans and one wild duck found on the north side of the Alps did not cluster with SCN but with SCS. Together with isolates from Bavarian, the Czech Republic, Italy, and Slovakia, they form a genuine subgroup, named subgroup Bavaria (SGB). This subgroup forms a link to SCN, indicating a spread of the virus from south to north. There has been a general assumption that the generic HPAI introduction route into Europe was from Russia to north Germany, introducing cluster EMA-2 into Europe. Interestingly, our findings support the assumption of an alternative introduction of the HPAI H5N1 virus from Turkey to central Europe, where it spread as cluster EMA-1 during the outbreak of 2006.

Influence of porcine circovirus type 2 vaccination on the probability and severity of pneumonia detected postmortem

To evaluate the influence of porcine circovirus type 2 vaccination (PCV-2) on the probability and severity of pneumonia, postmortem findings of 247,505 pigs slaughtered between 2008 and 2011 were analysed by applying a cumulative link mixed model. Three major effects could be observed: (1) PCV-2 vaccination significantly (P<0.01) reduced the odds (coefficient: −0.05) of postmortem findings of mild, moderate and severe pneumonia for vaccinated pigs. (2) Pigs from fattening farms were less likely (coefficient: −0.44; P<0.05) to exhibit signs of pneumonia at slaughter than pigs from farrow-to-finish farms. (3) When vaccinated, the odds of detecting postmortem signs showed an even more pronounced reduction (coefficient: −0.19; P<0.001) for pigs from fattening farms. Combining PCV-2 vaccination, farm type and interaction effects between these two factors, a pig vaccinated against PCV-2 from a fattening farm had only half the chance (OR 0.51) of pneumonia being detected at postmortem than a non-vaccinated pig from a farrow-to-finish farm. The study demonstrates the benefit of a vaccination programme against PCV-2 as an important tool to reduce the risk of postmortem pneumonia findings and the severity of pneumonia in pigs at slaughter.

Antimicrobial consumption on Austrian dairy farms: an observational study of udder disease treatments based on veterinary medication records

Background Antimicrobial use in livestock production is an important contemporary issue, which is of public interest worldwide. Antimicrobials are not freely available to Austrian farmers and can only be administered to livestock by veterinarians, or by farmers who are trained members of the Animal Health Service. Since 2015, veterinarians have been required by law to report antimicrobials dispensed to farmers for use in food-producing animals. The study presented here went further than the statutory framework, and collected data on antimicrobials dispensed to farmers and those administered by veterinarians. Methods Seventeen veterinary practices were enrolled in the study via convenience sampling. These veterinarians were asked to contact interested dairy farmers regarding participation in the study (respondent-driven sampling). Data were collected from veterinary practice software between 1st October 2015 and 30th September 2016. Electronic data (89.4%) were transferred via an online interface and paper records (10.6%) were entered by the authors. Antimicrobial treatments with respect to udder disease were analysed by number of defined daily doses per cow and year (nDDDvet/cow/year), based on the European Medicines Agency technical unit, Defined Daily Dose for animals (DDDvet). Descriptive statistics and the Wilcoxon rank sum test were used to analyse the results. Results Antimicrobial use data from a total of 248 dairy farms were collected during the study, 232 of these farms treated cows with antibiotics; dry cow therapy was excluded from the current analysis. The mean number of DDDvet/cow/year for the antimicrobial treatment of all udder disease was 1.33 DDDvet/cow/year. Of these treatments, 0.73 DDDvet/cow/year were classed as highest priority critically important antimicrobials (HPCIAs), according to the World Health Organization (WHO) definition. The Wilcoxon rank sum test determined a statistically significant difference between the median number of DDDvet/cow/year for acute and chronic mastitis treatment (W = 10,734, p < 0.001). The most commonly administered antimicrobial class for the treatment of acute mastitis was beta-lactams. Intramammary penicillin was used at a mean of 0.63 DDDvet/cow/year, followed by the third generation cephalosporin, cefoperazone, (a HPCIA) at 0.60 DDDvet/cow/year. Systemic antimicrobial treatments were used at a lower overall level than intramammary treatments for acute mastitis. Discussion This study demonstrated that Austrian dairy cows in the study population were treated with antimicrobial substances for udder diseases at a relatively low frequency, however, a substantial proportion of these treatments were with substances considered critically important for human health. While it is vital that sick cows are treated, reductions in the overall use of antimicrobials, and critically important substances in particular, are still possible.

MODELLIERUNG DER RÜCKENBEWEGUNG DES PFERDES IN VERSCHIEDENEN GANGARTEN

s l !l R Y 1 1 · .um öl this study is to shovv different . Mrn.mos hke heilig ruldcn or inereased muscle (oiu · » t ( · ci|inne hack. Hiomcchanical sinuilations are .in l A ^ v l l e n t tool to mvestigate potcntially difficult to « • h l , H M me.isurements in vivo. I « > d i l t e r e n t biomechameal modells of the equine back .m· uwd lo explore various stress scenarios. I 1 u* N i m u L i i i o n s show that the load of a rider is ofminor impoiuikv compared to the torques developed by an mvKMsed ih j id i ty of back. Rspecially secondary effects i i u l ( h e i r rekitionslups to certain back diseases can be Jv-uvied and described quantitatively without nevvss i ta tmL pa in fu l procedure to the horse.