Dutch Udder Health Center

AA, Netherlands

Dutch Udder Health Center

AA, Netherlands

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van den Borne B.H.P.,University Utrecht | van Schaik G.,GD Animal Health Service | Lam T.J.G.M.,GD Animal Health Service | Lam T.J.G.M.,Dutch Udder Health Center | Nielen M.,University Utrecht
Journal of Dairy Science | Year: 2010

Two linked randomized field trials were performed on 39 herds in the Netherlands to 1) determine therapeutic effects of antimicrobial treatment of recently acquired subclinical mastitis (RASCM) during lactation, 2) evaluate the effect of duration of subclinical mastitis on therapeutic outcome, and 3) identify factors related to the therapeutic success of RASCM. Cows with a first elevated composite somatic cell count (CSCC) after 2 consecutive low CSCC measurements were eligible for enrollment in trial 1 (treatment at the first elevated CSCC). Quarter milk samples were collected to determine bacteriological status for major pathogens and coagulase-negative staphylococci. Cows with one or more culture-positive quarters with a quarter somatic cell count (QSCC) ≥100,000 cells/mL were defined to have RASCM and were randomly assigned treatment or control (no treatment). Untreated cows from trial 1 that had a second elevated CSCC at the next milk recording were eligible for enrollment in trial 2 (treatment at the second elevated CSCC). In trial 2, staphylococci-positive cows (Staphylococcus aureus and coagulase-negative staphylococci) were randomly assigned to treatment or control. Farmers used their own treatment protocols to treat quarters in both trials. Bacteriological cure was defined as absence of the pathogen identified pre-intervention in 2 samples post-intervention; QSCC, CSCC, and milk yield were also analyzed. Hierarchical logistic and linear models were used to determine therapeutic effects and to identify factors related to therapy outcome. Treated quarters had a higher bacteriological cure rate than control quarters for all pathogens in both trials. Treatment resulted in lower QSCC and CSCC, whereas milk yield was not affected by treatment. Bacteriological cure of RASCM was better in quarters with a low QSCC pre-intervention and in coagulase-negative staphylococci-positive quarters. Control quarters with a single culture-positive sample pre-intervention also had a higher bacteriological cure than control quarters with ≥2 culture-positive samples. Time of antimicrobial treatment affected bacteriological cure for penicillin-sensitive Staph. aureus. Bacteriological cure tended to be higher for Staph. aureus after treatment at the first elevated CSCC compared with treatment at the second elevated CSCC. Thus, early treatment of Staph. aureus might be more effective than later treatment. © 2010 American Dairy Science Association.


van den Borne B.H.P.,University Utrecht | Nielen M.,University Utrecht | van Schaik G.,GD Animal Health Service | Melchior M.B.,Wageningen University | And 4 more authors.
Journal of Dairy Science | Year: 2010

Staphylococcus aureus causes a wide range of diseases in multiple species. Some sequence types (ST) are observed in a variety of hosts, whereas other strains are mainly associated with bovine mastitis, suggesting host adaptation. We propose that host adaptation of Staph. aureus may influence bacteriological cure of bovine subclinical mastitis after antimicrobial treatment. To test this hypothesis, multilocus sequence typing was performed on Staph. aureus isolates from 60 treated and 79 untreated control quarters that were obtained from well-defined cohorts of dairy cows from a recently conducted randomized field trial on early treatment of subclinical mastitis. Bovine-associated ST were distinguished from non-bovine-associated ST based on the literature and public databases. The association between host adaptation and bacteriological cure was investigated using population-averaged logistic regression models. Thirteen ST were identified, with approximately 80% of isolates belonging to bovine-associated ST. The odds for cure were around 2.5 times as high for non-bovine-associated ST as for bovine ST in treated quarters, whereas no difference in spontaneous cure was observed in untreated control quarters. In addition, host adaptation was related to known predictors of cure, such as penicillin susceptibility and somatic cell count. All isolates belonging to non-bovine-associated ST were resistant to penicillin, whereas the majority of isolates belonging to bovine-associated ST were penicillin susceptible. Penicillin-resistant bovine-associated strains were associated with high somatic cell counts compared with other strains. The correlation between penicillin resistance, cell counts, and host adaptation may affect the association between host adaptation and cure. For diagnostic purposes, a simple and fast alternative to multilocus sequence typing of Staph. aureus to determine host adaptation may be valuable. © 2010 American Dairy Science Association.


Sampimon O.,GD Animal Health Service | Van Den Borne B.H.,University Utrecht | Santman-Berends I.,GD Animal Health Service | Barkema H.W.,University of Calgary | And 2 more authors.
Journal of Dairy Research | Year: 2010

The effect was quantified of coagulase-negative staphylococci (CNS) intramammary infections on quarter- and cow-level somatic cell count (SCC) and on bulk milk somatic cell count (BMSCC) in different BMSCC cohorts in Dutch dairy herds. Two datasets were used for this purpose. In the first dataset, on 49 randomly selected dairy farms a total of 4220 quarter milk samples of 1072 cows were collected of all cows and heifers with a test-day SCC ≥ 250 000 and ≥ 150 000 cells/ml, respectively, and of 25% of cows and heifers below these thresholds. In the second dataset, on 39 selected dairy farms a total of 8329 quarter milk samples of 2115 cows were collected of all cows with a test-day SCC ≥ 250 000 cells/ml following two consecutive SCC <250 000 cells/ml, and of heifers using the same SCC criteria but with a threshold of 150 000 cells/ml. These cows and heifers were defined as new high SCC. In both datasets, CNS was the most frequently isolated pathogen, 11% in the first dataset and 12% in the second dataset. In both datasets, quarters with CNS IMI had a lower SCC than quarters infected with major pathogens, and a higher SCC than culture-negative quarters. The same was found for SCC at cow level. Coagulase-negative staphylococci were more often found in quarters with SCC ≥ 200 000 cells/ml in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a higher BMSCC. Prevalence of CNS in cows and heifers with a high SCC was higher in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a medium or high BMSCC: 30, 19 and 18%, respectively. This indicates that CNS IMI as a cause of subclinical mastitis is relatively more important in dairy farms with a low BMSCC and may become a point of attention in udder health management on that type of farm. © 2010 Proprietors of Journal of Dairy Research.


van den Borne B.H.P.,University Utrecht | van Schaik G.,GD Animal Health Service | Lam T.J.G.M.,GD Animal Health Service | Lam T.J.G.M.,Dutch Udder Health Center | Nielen M.,University Utrecht
Preventive Veterinary Medicine | Year: 2010

Composite somatic cell count data from the national test day recording and reported cases of farmer diagnosed clinical mastitis were used to estimate the occurrence of mastitis from July 2004 to June 2005 in primi- and multiparae in the Netherlands. Herds had to participate in the test day recording and had to have at least 50 cows. A random selection of 396 of these dairy herds provided composite somatic cell count data, while 205 dairy herds additionally reported on clinical mastitis cases. Prevalence of subclinical mastitis was calculated per herd as the proportion of cows with somatic cell count >200,000. cells/ml. The incidence rate to clinical mastitis was calculated as the number of clinical mastitis cases divided by the number of cow days at risk per herd. Negative binomial models were used to correct for overdispersion. Mean herd level subclinical mastitis prevalence was 12.8% (95% CI: 12.2-13.5%) in primi- and 27.1% (95% CI: 26.2-28.1%) in multiparae. Mean herd level clinical mastitis cases were observed 20.2 (95% CI: 18.3-22.4) and 39.6 (95% CI: 37.1-42.3) times per 100 cow-years at risk, respectively. Some herds had a high mastitis occurrence in one parity group, while it was low in the other. Parity-specific monitoring is needed to identify such herds. © 2010 Elsevier B.V.


Van den Borne B.H.P.,University Utrecht | Vernooij J.C.M.,University Utrecht | Lupindu A.M.,Wageningen University | van Schaik G.,GD Animal Health Service | And 4 more authors.
Preventive Veterinary Medicine | Year: 2011

High composite somatic cell counts (CSCC) in dairy cows may develop into clinical mastitis (CM), suggesting that prevention or intervention of high CSCC may prevent CM later in lactation. The objective of this study was to quantify the relationship between high CSCC in dairy cows and the first subsequent case of CM in the same lactation. Farmer-diagnosed cases of CM and test day CSCC measurements during 1 year of 13,917 cows in 196 randomly selected Dutch dairy herds were available for analysis. Cows were followed in 1 lactation from the first test day postpartum until CM, drying off, culling or end of study. Cox proportional hazards models with time-varying CSCC levels were used to estimate the effect of high CSCC (≥200,000. cells/ml) on the time until the first case of CM. A shared frailty effect was included to adjust for clustering of cows within herds. The proportion of cows developing CM after a CSCC measurement was 11%. Primiparae with a high CSCC had a 4-fold higher hazard for subsequent CM than primiparae with a low CSCC; multiparae with a high CSCC had a 2-fold higher hazard than multiparae with a low CSCC. Additionally, multiparae with a low CSCC had a 2-fold higher hazard for CM occurrence than primiparae with a low CSCC. Increasing the threshold for high CSCC showed that the risk for CM increased. If the last CSCC before CM was low, CSCC information of 2 preceding test days was more predictive than CSCC information from only the last test day. When the last CSCC was high, CSCC information of 2 preceding test days did not have added predictive value. This study identified that approximately 25% of first subsequent CM cases after a CSCC measurement can potentially be prevented when cows are prevented to get high CSCC or when high CSCC cows are removed from the population. This corresponded with a decrease in the proportion of lactating cows with CM after a CSCC measurement from 11% to 7%. © 2011 Elsevier B.V.


Santman-Berends I.M.G.A.,GD Animal Health Service | Hage J.J.,GD Animal Health Service | Lam T.J.G.M.,GD Animal Health Service | Lam T.J.G.M.,Dutch Udder Health Center | And 2 more authors.
Journal of Dairy Science | Year: 2011

The effect of bluetongue virus serotype 8 (BTV-8) infections was quantified on milk production and udder health. From July 2008 to December 2008, 1,074 seronegative cows in 15 herds that were not vaccinated against BTV-8 were tested every 3 wk for BTV-8 antibodies. Sampling stopped when cows seroconverted. Test-day records were provided and 3 traits were defined to evaluate the effect of BTV-8 on milk production and udder health: 1) the difference between observed and predicted fat- and protein-corrected milk production; 2) the natural logarithm of the somatic cell count (lnSCC); and 3) the occurrence of a new high SCC. In the default model, the variables were assumed influenced by BTV-8 when the test-day record of the seroconverted cow was taken within 30 d before seroconversion, thus, in the period in which the cow was infected. In sensitivity analyses, the time intervals were varied in which BTV-8 was assumed to affect milk production and udder health. During the study, 185 cows (17%) had a subclinical infection and seroconverted and 77 had a test-day result within 30 d before seroconversion. In this period, in cows that seroconverted, the fat- and protein-corrected milk production was 52 (95% confidence interval: 26 to 77) kg less than in the period before and after seroconversion and was 51 (95% CI: 26 to 76) kg less than in cows that remained seronegative. When the time interval was increased to within 42 d before seroconversion, the milk production in BTV-8-seroconverted cows decreased by 61 (95% CI: 28 to 94) kg compared with the period before and after seroconversion and decreased by 59 (95% CI: 27 to 92) kg compared with cows that remained BTV-8 seronegative. No significant effect of BTV-8 was found on SCC and odds for a high SCC. Subclinical BTV-8 infection in dairy cattle results in a decreased milk production. © 2011 American Dairy Science Association.


Jansen J.,Wageningen University | van Schaik G.,GD Animal Health Service Ltd. | Renes R.J.,Wageningen University | Lam T.J.G.M.,GD Animal Health Service Ltd. | Lam T.J.G.M.,Dutch Udder Health Center
Journal of Dairy Science | Year: 2010

Over the years, much effort has been put into implementing mastitis control programs in herds. To further improve utilization of such programs, there needs to be an understanding of the attitudes, knowledge, and behavior of farmers regarding udder health, and the way this can be influenced by mastitis control programs. This study aimed to explore the effect of a national mastitis control program on Dutch farmers' attitudes, knowledge, and behavior regarding mastitis. A total of 378 dairy farmers completed a survey on attitudes, knowledge, and behavior regarding mastitis before the start of a national mastitis control program in 2004, and 204 completed a similar survey in the final year of the program (2009). Although the average annual bulk milk somatic cell count (BMSCC) remained the same, the farmers' self-reported attitudes, knowledge, and behavior changed significantly. The problem level of BMSCC decreased from 285,000 cells/mL in 2004 to 271,000 cells/mL in 2009. More farmers perceived that they had sufficient knowledge about the prevention of mastitis (34% in 2004 vs. 53% in 2009) and they more often perceived that they knew the cause of a mastitis problem (25% in 2004 vs. 37% in 2009). The use of gloves for milking increased from 15 to 46%, the use of a standardized mastitis treatment protocol increased from 7 to 34%, and freestalls were cleaned more often (2.28 vs. 2.51 times/d) in 2009 compared with 2004. Most changes in attitudes, knowledge, and behavior did not differ between groups of dairy farmers whose herds had an initially low (≤162,000 cells/mL), medium (163,000 to 205,000 cells/mL), or high (>206,000 cells/mL) BMSCC. The high BMSCC group significantly decreased their annual BMSCC level by 15,000 cells/mL. Regression analysis showed that the decrease in BMSCC was associated with a change in farmers' perceptions (e.g., increased perceived knowledge about the effect of the milking machine on mastitis) and with a change in certain management practices (e.g., disinfecting all teats after milking). The results showed that a national mastitis control program affected the attitudes, knowledge, and behavior of farmers regarding mastitis and could contribute to udder health improvement in the long term. © 2010 American Dairy Science Association.


Ploegaert T.C.W.,Wageningen University | Wijga S.,Wageningen University | Tijhaar E.,Wageningen University | van der Poel J.J.,Wageningen University | And 4 more authors.
Journal of Dairy Science | Year: 2010

Defense mechanisms of dairy cows against diseases partly rest on their naturally present disease resistance capacity. Natural antibodies (NAb) form a soluble part of the innate immune system, being defined as antibodies circulating in animals without prior intentional antigenic stimulation. Genetic selection on NAb titers in milk, therefore, might improve disease resistance. We estimated genetic parameters of NAb titers binding lipopolysaccharide, lipoteichoic acid (LTA), peptidoglycan, and keyhole limpet hemocyanin, and titers of the NAb isotypes IgG1, IgM, and IgA binding LTA in milk of Dutch Holstein-Friesian heifers. Natural antibody titers were measured in 1 milk sample from each of 1,939 Holstein-Friesian heifers and used for estimating genetic parameters of NAb titers. The data show that phenotypic variation exists among heifers in NAb titers binding lipopolysaccharide, LTA, peptidoglycan, and keyhole limpet hemocyanin, and the NAb isotypes IgG1, IgM, and IgA binding LTA in milk. High genetic correlations among NAb (ranging from 0.45 to 0.99) indicated a common genetic basis for the levels of different NAb in bovine milk. Intra-herd heritability estimates for NAb ranged from 0.10 to 0.53. The results indicated that NAb levels have potential for genetic selection. © 2010 American Dairy Science Association.


PubMed | Dutch Udder Health Center
Type: | Journal: Irish veterinary journal | Year: 2011

In this paper a review is given of frequently used mastitis diagnostic methods in modern dairy practice. Methods used at the quarter, cow, herd and regional or national level are discussed, including their usability for performance monitoring in udder health. Future developments, such as systems in which milk-derived parameters are combined with modern analytical techniques, are discussed. It is concluded that, although much knowledge is available and science is still developing and much knowledge is available, it is not always fully exploited in practice.


PubMed | Dutch Udder Health Center
Type: Journal Article | Journal: Journal of dairy science | Year: 2013

Because of increasing bulk milk somatic cell counts and continuous clinical mastitis problems in a substantial number of herds, a national mastitis control program was started in 2005 to improve udder health in the Netherlands. The program started with founding the Dutch Udder Health Centre (UGCN), which had the task to coordinate the program. The program consisted of 2 parts: a research part and a knowledge-transfer part, which were integrated as much as possible. The knowledge-transfer part comprised 2 communication strategies: a central and a peripheral approach. The central approach was based on educating farmers using comprehensive science-based and rational argumentation about mastitis prevention and included on-farm study group meetings. Comprehensive education materials were developed for farmers that were internally motivated to improve udder health. In the peripheral approach it was tried to motivate farmers to implement certain management measures using nontechnical arguments. Mass media campaigns were used that focused on one single aspect of mastitis prevention. These communication strategies, as well as an integrated approach between various stakeholders and different scientific disciplines were used to reach as many farmers as possible. It should be noted that, because this intervention took place at a national level, no control group was available, as it would be impossible to isolate farmers from all forms of communication for 5 years. Based on several studies executed during and after the program, however, the results suggest that udder health seemed to have improved on a national level during the course of the program from 2005 to 2010. Within a cohort of dairy herds monitored during the program, the prevalence of subclinical mastitis did not change significantly (23.0 in 2004 vs. 22.2 in 2009). The incidence rate of clinical mastitis, however, decreased significantly, from 33.5 to 28.1 quarter cases per 100 cow years at risk. The most important elements of the farmers mindset toward mastitis control also changed favorably. The simulated costs of mastitis per farm were reduced compared with a situation in which the mastitis would not have changed, with 400 per year. When this amount is extrapolated to all Dutch farms, the sector as a whole reduced the total costs of mastitis by 8 million per year. It is difficult to assign the improved udder health completely to the efforts of the program due to the lack of a control group. Nevertheless, investing 8 million by the Dutch dairy industry in a 5-yr national mastitis control program likely improved udder health and seemed to pay for itself financially.

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