Bulk milk-estimated seroprevalence of Fasciola hepatica in dairy herds and collecting of risk factor data in East Frisia, northern Germany.

The liver fluke Fasciola (F) hepatica is one of the most important trematodes in cattle farming worldwide. Fasciolosis in dairy cows is leading to production losses due to decreased milk yield, liver condemnation and impaired reproduction. The treatment of dairy cows is unsatisfactory, because available drugs are either effective against adult flukes only or have long withdrawal times or in some countries may not be used at all. In the present study the prevalence of F. hepatica in dairy farms located in East Frisia, which is part of the federal state Lower Saxony, was investigated. East Frisia is considered a high risk area for Fasciola hepatica infections, because of its coastal location, high precipitation and moist pastures. About 750 bulk milk samples were collected in January and November 2006 and analysed for F. hepatica antibodies using the Pourquier ELISA. In addition, questionnaires, which were answered by 260 of the participating farmers, were evaluated to analyse management-related factors associated with fasciolosis. In January and November, 52.1% and 53.6% of the bulk milk samples, respectively, showed positive results. Thereby, 88.1% of the examined farms showed an unchanged infection status, whereas 6.2% of the farms became seropositive during the grazing season and 5.8% of the dairy herds turned seronegative. Statistical analysis revealed a significant negative association between average annual milk production and the frequency of infections with F. hepatica.

Kuerpick B ，Fiedor C ，von Samson-Himmelstjerna G ，Schnieder T ，Strube C ... -  《BERLINER UND MUNCHENER TIERARZTLICHE WOCHENSCHRIFT》

Seroprevalence and GIS-supported risk factor analysis of Fasciola hepatica infections in dairy herds in Germany.

Kuerpick B ，Conraths FJ ，Staubach C ，Fröhlich A ，Schnieder T ，Strube C ... -  《-》

Seasonal pattern of Fasciola hepatica antibodies in dairy herds in Northern Germany.

Kuerpick B ，Schnieder T ，Strube C 《-》

Farm-level risk factors for Fasciola hepatica infection in Danish dairy cattle as evaluated by two diagnostic methods.

The prevalence of bovine fasciolosis in Denmark is increasing but appropriate guidelines for control are currently lacking. In order to help develop a control strategy for liver fluke, a risk factor study of farm management factors was conducted and the utility of bulk tank milk (BTM ELISA) as a tool for diagnosis in Danish dairy cattle farms was assessed. This case-control study aimed to identify farm-level risk factors for fasciolosis in Danish dairy farms (> 50 animals slaughtered in 2013) using two diagnostic methods: recordings of liver condemnation at slaughter, and farm-level Fasciola hepatica antibody levels in BTM. A case farm was defined as having a minimum of 3 incidents of liver condemnation due to liver fluke at slaughter (in any age group) during 2013, and control farms were located within 10 km of at least one case farm and had no history of liver condemnation due to liver fluke during 2011-2013. The selected farmers were interviewed over telephone about grazing and control practices, and BTM from these farms was collected and analysed by ELISA in 2014. The final complete dataset consisting of 131 case and 63 control farms was analysed using logistic regression. Heifers grazing on wet pastures, dry cows grazing on wet pastures, herd size, breed and concurrent beef cattle production were identified as risk factors associated with being classified as a case farm. With the categorised BTM ELISA result as the response variable, heifers grazing on wet pastures, dry cows grazing on wet pastures, and purchase of cows were identified as risk factors. Within the case and control groups, 74.8 and 12.7% of farms were positive for fasciolosis on BTM ELISA, respectively. The differences are likely to be related to the detection limit of the farm-level prevalence by the BTM ELISA test, time span between slaughter data and BTM, and the relatively low sensitivity of liver inspection at slaughter. Control of bovine fasciolosis in Denmark should target heifers and dry cows through grazing management and appropriate anthelmintic treatment, and BTM ELISA can be a useful diagnostic tool for fasciolosis in Danish dairy farms.

Takeuchi-Storm N ，Denwood M ，Hansen TVA ，Halasa T ，Rattenborg E ，Boes J ，Enemark HL ，Thamsborg SM ... -  《Parasites & Vectors》

Fasciola hepatica seroprevalence in Northern German dairy herds and associations with milk production parameters and milk ketone bodies.

Infections with the liver fluke Fasciola hepatica remain a serious problem in dairy herds causing significant production losses. In sheep, a strong relationship between F. hepatica infections and an increase in serum ketone bodies due to reduced feed intake and liver damage was demonstrated. We hypothesized that F. hepatica infections might contribute to an increase in milk ketone bodies in dairy herds. Thus, the objective of the study was to estimate the association between F. hepatica bulk tank milk (BTM) antibodies and milk production parameters (milk yield, milk protein, fat yield), somatic cell count (SCC) and the milk ketone bodies ß-hydroxybutyrate (BHB) and acetone, inferred from Fourier transform infrared (FTIR) spectrometry, via linear mixed model analysis. A further aim was to follow up the F. hepatica seroprevalence in dairy herds in the northern German region East Frisia. We collected BTM samples between October and December from 1022 herds in 2017 and 1318 herds in 2018. Overall, 33.1 % of the herds tested positive in 2017 and 37.0 % in 2018, showing decreased F. hepatica seroprevalences compared to prior seroprevalence studies in the same region in 2010, 2008 and 2006 (> 45 % positive herds). We estimated a significant negative association (P < 0.001) between herd F. hepatica infection category and average milk yield with a loss of -1.62 kg per cow per day in strongly infected herds compared to BTM ELISA negative herds. Moreover, F. hepatica infection category had a significant effect on herd average milk protein and fat yield (P < 0.001), showing a decrease of 0.06 kg for both parameters from BTM ELISA negative herds to strongly infected herds. No significant association with milk SCC was found (P = 0.664). Regarding ketone bodies, we estimated significant higher average BHB values in strongly infected herds compared to the other three infection categories in the model analysis (P = 0.002). The association between F. hepatica infection category and acetone values was not significant (P = 0.079). Besides primary ketosis, fasciolosis should be considered as differential diagnosis in dairy herds with increased BHB values.

May K ，Bohlsen E ，König S ，Strube C ... -  《-》