Validation of tDNA-intergenic spacer PCR for species level identification of bovine coagulase-negative staphylococci

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Udder cleft dermatitis (UCD) is a well-known disorder in dairy cows. Veterinary literature about this subject, however, is scarce. The objectives of this study were to define a clinical scoring system for UCD, estimate the within-herd prevalence of UCD, and identify potential risk factors of UCD at cow and herd level. On 20 randomly selected dairy farms in the Netherlands, each lactating cow was photographed from a ventral, lateral, and caudal position. A scoring system with 6 categories of severity of UCD was proposed based on the ventral photographs. Cow measures such as udder width and depth, and front quarter attachment were determined from the lateral and caudal photographs. A questionnaire was conducted on each farm during farm visits. Udder cleft dermatitis, defined as a score 3 or higher, was detected in 5.2% of the 948 cows involved in this study. Within-herd prevalences of UCD ranged between 0 and 15% and UCD was found in 16 (80%) of the participating farms. Cows with a deep udder (relative to the hock), large front quarters, and a small angle between udder and abdominal wall were more likely to develop UCD. Production level and use of a footbath were identified as being positively associated with herd-level UCD prevalence. Herd size and average bulk milk somatic cell count did not seem to be associated with UCD prevalence. Because of the small herd sample size, no firm conclusions were drawn on herd-level risk factors. However, results from this study can be used in designing a future longitudinal UCD study. The prevalences of UCD found in the present study illustrate the current UCD situation in the Netherlands. Our results demonstrate that multiple potential risk factors of UCD could be identified at both the cow and herd level

Betrouwbaar naar gezonde uiers: ontrafelen celgetalgegevens levert uiergezondheidsindex met 85 procent betrouwbaarheid

Fokken op uiergezondheid kan betrouwbaarder, zo luidt de conclusie van nieuw onderzoek. Door de celgetalgegevens dieper te analyseren ontstaat een index met 85 % betrouwbaarheid, vergelijkbaar met fokwaarden in de zo geroemde Scandinavische landen. Stieren zullen op z'n vroegst in april 2009 een vernieuwde fokwaarde krijge

Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus chromogenes in dairy heifers

Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus chromogenes strain originating from a persistent intramammary infection (S. chromogenes IM) and a S. chromogenes strain isolated from a heifer's teat apex (S. chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 x 10(6) colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii-inoculated quarters, although the strain was eliminated within 12 h. The two S. chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. chromogenes IM than with S. chromogenes TA. In conclusion, these results suggest that S. chromogenes might be better adapted to the mammary gland than S. fleurettii. Furthermore, not all S. chromogenes strains induce the same local host response

Bacteriological etiology and treatment of mastitis in Finnish dairy herds

Background: The Finnish dairy herd recording system maintains production and health records of cows and herds. Veterinarians and farmers register veterinary treatments in the system. Milk samples for microbiological analysis are routinely taken from mastitic cows. The laboratory of the largest dairy company in Finland, Valio Ltd., analyzes most samples using real-time PCR. This study addressed pathogen-specific microbiological data and treatment and culling records, in combination with cow and herd characteristics, from the Finnish dairy herd recording system during 2010-2012. Results: The data derived from 240,067 quarter milk samples from 93,529 dairy cows with mastitis; 238,235 cows from the same herds served as the control group. No target pathogen DNA was detected in 12% of the samples. In 49% of the positive samples, only one target species and in 19%, two species with one dominant species were present. The most common species in the samples with a single species only were coagulase-negative staphylococci (CNS) (43%), followed by Staphylococcus aureus (21%), Streptococcus uberis (9%), Streptococcus dysgalactiae (8%), Corynebacterium bovis (7%), and Escherichia coli (5%). On average, 36% of the study cows and 6% of the control cows had recorded mastitis treatments during lactation. The corresponding proportions were 16 and 6% at drying-off. For more than 75% of the treatments during lactation, diagnosis was acute clinical mastitis. In the milk samples from cows with a recorded mastitis treatment during lactation, CNS and S. aureus were most common, followed by streptococci. Altogether, 48% of the cows were culled during the study. Mastitis was reported as the most common reason to cull; 49% of study cows and 18% of control cows were culled because of mastitis. Culling was most likely if S. aureus was detected in the milk sample submitted during the culling year. Conclusions: The PCR test has proven to be an applicable method also for large-scale use in bacterial diagnostics. In the present study, microbiological diagnosis was unequivocal in the great majority of samples where a single species or two species with one dominating were detected. Coagulase-negative staphylococci and S. aureus were the most common species. S. aureus was also the most common pathogen among the culled cows, which emphasizes the importance of preventive measures.Peer reviewe

Celgetal goed bruikbaar voor opsporen chronische celgetalproblemen

Veel melkveehouders hebben een abonnement op het celgetalprogramma van het NRS. Dit betekent dat bij een proefmelking niet alleen de standaardmetingen gedaan worden, maar dat ook het aantal cellen in de melk gemeten wordt. Koeien worden op basis van een te hoog celgetal geattendeerd. Ook is het mogelijk met het celgetal-B.O. programma bacteriologisch onderzoek (B.O.) uit te voeren bij koeien met attenties. De resultaten van dit programma zijn beoordeeld op twee bedrijven: een bedrijf met een laag tankmelkcelgetal en een bedrijf met een hoog tankmelkcelgetal. Het bleek dat dat celgetalprogramma op beide bedrijven de meeste koeien met chronische celgetalproblemen attendeerde. De resultaten van het celgetal-B.O. programma vonden op beide bedrijven de belangrijkste bacteriën. Op een bedrijf met een laag celgetal waren echter meer melkmonsters negatief

Gebruik droogzetters op basis van bedrijfsinformatie

De kans op een zieke koe bij droogzetten is te voorspellen uit het celgetal bij droogzetten, een stijgend of dalend celgetal in de laatste drie melkcontroles voor droogzetten, en de lengte van de droogstand. Het gebruik van antibiotica bij droogzetten had altijd effect op de hoogte van het celgetal en het voorkomen van kiemen in de melk na het afkalven. Van de niet met antibiotica drooggezette kwartieren kreeg 3,3 % binnen 7 dagen na afkalven klinische mastitis. Van de wel met antibiotica drooggezette kwartieren was dat 1,3%