Harmelen, Netherlands
Harmelen, Netherlands

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Sietsma S.,University Farm Animal Practice | Dijkstra T.,GD Animal Health Service | van Werven T.,University Utrecht
Journal of Dairy Science | Year: 2016

Udder cleft dermatitis (UCD) is a skin lesion in dairy cows, most often located between anterior parts of the udder and abdomen, but also found between the front quarters. A few recent studies have investigated the prevalence of UCD, but relatively little is known about its pathogenesis, clinical course, and duration. Therefore, the aim of this study was to investigate the incidence and recovery of UCD on high-prevalence herds. Five Dutch dairy herds with a UCD prevalence of at least 6% were visited weekly for 19 wk, followed by visits every other week for 26 wk. During each visit, all dry and lactating cows were inspected for the presence of UCD signs. If a UCD case was detected, the affected skin was photographed and the photo was subsequently examined by a research assistant. Cows were then classified according to the appearance of the skin into 3 categories: healthy (no photo: no signs), mild (photo: affected skin but no wound), or severe (photo: open wound). The overall mean within-herd prevalence of UCD was 38% and the overall mean incidence was 1.94 UCD episodes per 100 cow-weeks at risk. Incidence of UCD was significantly higher in cows in third or higher parity and significantly increased with DIM. Median observed duration of UCD was 16 wk. The UCD recovery was 3 times more likely for mild than for severe lesions. The probability to move from one category to another between 2 consecutive visits was very low, indicating that rapid changes in appearance did not occur. The observed incidence of UCD was rather low, and the relatively high prevalence in the selected herds was most likely due to the long duration of lesions rather than a high incidence of new UCD cases. © 2016 American Dairy Science Association.


Bradley A.J.,Quality Milk Management Services Ltd. | Bradley A.J.,University of Nottingham | De Vliegher S.,Ghent University | Green M.J.,University of Nottingham | And 9 more authors.
Journal of Dairy Science | Year: 2015

The dry period is acknowledged as playing a key role in mastitis epidemiology and yet surprisingly few studies have explored dry period infection dynamics in detail. The aim of this study was to investigate the dynamics of intramammary infection across a cohort of dairy herds in Europe. Five hundred and twenty-two cows were recruited from 12 farms in 6 European countries. All cows received antibiotic dry cow therapy but teat sealants were not used. All quarters of all cows were sampled for bacteriology at drying off and in the week immediately postcalving. Two ipsilateral quarters were also sampled for bacteriology in each cow 2 and 6 wk after drying off. Cows were body condition scored and teats assessed for cleanliness at all sampling time points and for the presence of a keratin plug during the dry period. Other cow-level parameters such as historic somatic cell counts and milk yields before drying off were collated from farm records. Univariable and multivariable analyses were undertaken to investigate the etiology, prevalence, and dynamics of infection during the dry period and associated influential factors. In summary, environmental mastitis pathogens predominated. Although gram-positive major pathogens were typically well controlled and did not increase in prevalence across the dry period, gram-negative pathogens generally increased in prevalence. There was an increase in the number of quarters that yielded no growth across the dry period, although this was driven by minor rather than major mastitis pathogen control. Other than the presence of a gram-positive or gram-negative pathogen 6 wk after drying off, the measured parameters were not influential when considering their effect on the presence of pathogens postcalving. Analysis also suggested that the early and mid dry period may be more important with respect to the timing of acquisition of infection than previously thought. We observed substantial variation in the etiology and prevalence of different pathogens on different farms with, in all cases, at least one of the 12 herds experiencing the opposite of the others with respect to increases and decreases in pathogen prevalence. Overall, this study confirms the importance of the dry period in mastitis epidemiology but highlights the importance of assessing and understanding infection dynamics on individual units. The lack of influence of the cow and quarter factors measured in this study suggests that herd and management factors may be more influential. © 2015 American Dairy Science Association.


Bradley A.J.,Quality Milk Management Services Ltd. | Bradley A.J.,University of Nottingham | De Vliegher S.,Ghent University | Green M.J.,University of Nottingham | And 10 more authors.
Journal of Dairy Science | Year: 2015

The dry period is acknowledged as playing a key role in mastitis epidemiology and yet surprisingly few studies have explored dry period infection dynamics in detail. The aim of this study was to investigate the dynamics of intramammary infection across a cohort of dairy herds in Europe. Five hundred and twenty-two cows were recruited from 12 farms in 6 European countries. All cows received antibiotic dry cow therapy but teat sealants were not used. All quarters of all cows were sampled for bacteriology at drying off and in the week immediately postcalving. Two ipsilateral quarters were also sampled for bacteriology in each cow 2 and 6 wk after drying off. Cows were body condition scored and teats assessed for cleanliness at all sampling time points and for the presence of a keratin plug during the dry period. Other cow-level parameters such as historic somatic cell counts and milk yields before drying off were collated from farm records. Univariable and multivariable analyses were undertaken to investigate the etiology, prevalence, and dynamics of infection during the dry period and associated influential factors. In summary, environmental mastitis pathogens predominated. Although gram-positive major pathogens were typically well controlled and did not increase in prevalence across the dry period, gram-negative pathogens generally increased in prevalence. There was an increase in the number of quarters that yielded no growth across the dry period, although this was driven by minor rather than major mastitis pathogen control. Other than the presence of a gram-positive or gram-negative pathogen 6 wk after drying off, the measured parameters were not influential when considering their effect on the presence of pathogens postcalving. Analysis also suggested that the early and mid dry period may be more important with respect to the timing of acquisition of infection than previously thought. We observed substantial variation in the etiology and prevalence of different pathogens on different farms with, in all cases, at least one of the 12 herds experiencing the opposite of the others with respect to increases and decreases in pathogen prevalence. Overall, this study confirms the importance of the dry period in mastitis epidemiology but highlights the importance of assessing and understanding infection dynamics on individual units. The lack of influence of the cow and quarter factors measured in this study suggests that herd and management factors may be more influential. © 2015 American Dairy Science Association.


Koop G.,University Utrecht | van Werven T.,University Utrecht | van Werven T.,University Farm Animal Practice | Roffel S.,University of Amsterdam | And 7 more authors.
Journal of Dairy Science | Year: 2015

Due to the increasing use of automated milking systems, automated detection of clinical mastitis is becoming more important. Various in- or on-line diagnostic tests are in use, but generally suffer from false mastitis alerts. In this study, we explored a new diagnostic approach based on measurement of protease activity using fluorogenic protease substrates, which can be performed on site, at high speed, and at low costs. Samples from cows with clinical mastitis submitted for bacteriological culture at the University Farm Animal Practice were collected during several months and kept at -20°C until protease activity measurement. A reference set of milk samples from clinically healthy cows were collected on 9 different farms and were tested for protease activity directly and after freezing at -20°C to allow for comparison with the samples from clinical cases. The protease activity in mastitic milk samples was significantly higher than in samples from healthy animals. Based on 71 clinical mastitis samples and 180 milk samples from clinically healthy quarters, the area under the receiver-operating characteristic curve was estimated to be between 0.88 and 0.90, and at a threshold of 38 fluorescence per minute the test had a specificity of 0.99 at a sensitivity of 0.58. Protease activity measured in fresh milk from clinically healthy cows was significantly associated with somatic cell count and parity, but not with electrical conductivity, whereas protease activity in milk that had been frozen was statistically significantly associated with all 3 parameters. This study indicates that protease activity measurement as a stand-alone test can be used for detecting mastitis samples, using milk samples that have been frozen. Because protease activity acts in part on a different biological mechanism than somatic cell count or electrical conductivity, this test may increase the accuracy of mastitis diagnosis in combination with currently available in- or on-line tests in automated milking systems. © 2015 American Dairy Science Association.


van Werven T.,University Farm Animal Practice | van Werven T.,University Utrecht | Waldeck F.,University Farm Animal Practice | Souza A.H.,CEVA Sante Animale | And 2 more authors.
Animal Reproduction Science | Year: 2013

Objectives were to compare circulating progesterone (P4) profile and pregnancies per AI (P/AI) of two commercial intravaginal P4 devices (PRID-Delta® vs CIDR®). In Experiment 1, ovariectomized dairy cows (PRID-Delta, n=6 vs CIDR, n=6) were sampled throughout 7 days to measure circulating P4. In Experiment 2 (PRID-Delta, n=399 vs CIDR, n=375), cows were assigned to treatments, as follows: D0, an intravaginal P4 device containing 1.38g of P4 (CIDR) or 1.55g of P4 (PRID-Delta); D6: 25mg PGF2α (Dinoprost) and P4 devices were removed 24h later. Insemination was performed at 56h after P4 removal. Cows visually detected in estrus between days 18 and 24 after 1st synchronized AI were re-inseminated. PRID-Delta produced greater circulating P4 compared to CIDR, particularly within 4 days after insertion (P<0.01). The logistic regression analysis indicated a tendency for improved P/AI at 1st AI in PRID-Delta cows compared to CIDR (36% vs 31%, P=0.10). More cows were detected in estrus in the following cycle nearly 21d after 1st AI when treated with PRID-Delta (28% vs 16%), but P/AI in the returning-natural estrus breedings did not differ (PRID-Delta=56% vs CIDR=55%; P=0.91). As a result, final cumulative P/AI was greater in cows receiving PRID-Delta (46% vs 37%, P=0.02). These results indicate that PRID-Delta seem to maintain greater circulating P4 levels as compared to CIDR in non-lactating dairy cows. This might explain potential benefits in fertility of dairy cows found in Experiment 2. Underlying physiological consequence of greater circulating P4 during synchronization programs in lactating cows in terms of oocyte quality and other reproductive structures warrants further investigation. © 2013 Elsevier B.V..


PubMed | University Farm Animal Practice
Type: Comparative Study | Journal: Animal reproduction science | Year: 2013

Objectives were to compare circulating progesterone (P4) profile and pregnancies per AI (P/AI) of two commercial intravaginal P4 devices (PRID-Delta() vs CIDR()). In Experiment 1, ovariectomized dairy cows (PRID-Delta, n=6 vs CIDR, n=6) were sampled throughout 7 days to measure circulating P4. In Experiment 2 (PRID-Delta, n=399 vs CIDR, n=375), cows were assigned to treatments, as follows: D0, an intravaginal P4 device containing 1.38g of P4 (CIDR) or 1.55g of P4 (PRID-Delta); D6: 25mg PGF2 (Dinoprost) and P4 devices were removed 24h later. Insemination was performed at 56h after P4 removal. Cows visually detected in estrus between days 18 and 24 after 1st synchronized AI were re-inseminated. PRID-Delta produced greater circulating P4 compared to CIDR, particularly within 4 days after insertion (P<0.01). The logistic regression analysis indicated a tendency for improved P/AI at 1st AI in PRID-Delta cows compared to CIDR (36% vs 31%, P=0.10). More cows were detected in estrus in the following cycle nearly 21d after 1st AI when treated with PRID-Delta (28% vs 16%), but P/AI in the returning-natural estrus breedings did not differ (PRID-Delta=56% vs CIDR=55%; P=0.91). As a result, final cumulative P/AI was greater in cows receiving PRID-Delta (46% vs 37%, P=0.02). These results indicate that PRID-Delta seem to maintain greater circulating P4 levels as compared to CIDR in non-lactating dairy cows. This might explain potential benefits in fertility of dairy cows found in Experiment 2. Underlying physiological consequence of greater circulating P4 during synchronization programs in lactating cows in terms of oocyte quality and other reproductive structures warrants further investigation.

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