Search

For blood plasma copper concentrations in Dutch sheep, reference values, clinical cut-off values, seasonal variation and within flock variation are partly unknown. To determine the clinical significance of blood plasma copper concentration in sheep, a study was conducted with the aims (1) to determine the reference values for copper concentrations in blood plasma, (2) quantify the difference in copper concentrations between sheep suspected of mineral disbalance and sheep unsuspected of mineral disbalance and identify clinical cut-off values for copper intoxication or deficiency, (3) describe the seasonal variation of copper concentrations, and (4) describe the variation in copper values within Dutch sheep flocks. In this cross-sectional study, 1,698 blood plasma samples of Dutch sheep were obtained through convenience sampling, of which 1,270 samples were sent in with a suspicion of a mineral disbalance. The samples were sent in between 1999 and 2012. A mixture model was used to determine clinical cut-off values. The 95 % reference interval for copper concentration in blood plasma of Dutch sheep in this study was 3.6 µmol/L – 21 µmol/L. Sheep suspected of a mineral disbalance had significantly higher copper values in blood plasma than sheep unsuspected of a mineral disbalance. In April and June, significantly higher copper values in blood plasma were found compared to the other months of the year (p < 0.05). The within-farm variation in copper values was greater than 10.0 µmol/L. No clinical cut-off values could be obtained through the mixture model. Altogether, these findings suggest there is some value in measuring the copper concentration in sheep, but when interpreting these results, season should be taken into account, and multiple samples should be taken within a flock in order to validly assess the copper status of the flock as a whole.

Online somatic cell count (SCC) measurement is widely used in dairy herds milked with automatic milking systems (AMS) and gives the opportunity to closely monitor individual cow udder health. Using automated SCC data, we observed cows displaying a remarkably regularly fluctuating SCC (rfSCC) pattern, which is described in this study. We aimed to (1) estimate the prevalence of rfSCC in cows milked by AMS, (2) characterize the rfSCC pattern, and (3) identify factors potentially associated with the rfSCC pattern. We analyzed 30-d episodes of composite SCC recordings of 1,000 cows from 55 dairy herds from 6 countries using an AMS with automated SCC measurement, and we identified the rfSCC pattern in 4.7% (95% CI: 3.5–6.2%) of these episodes. The rfSCC episodes had a median SCC of 701 × 1,000 cells/mL (2.5–97.5% quantile: 539–1,162), a median amplitude of 552 × 1,000 cells/mL (2.5–97.5% quantile: 409–886), and a median cycle length of 4.1 d (2.5–97.5% quantile: 3.7–4.9). Bacteriological culture data from quarter-milk samples collected every 2 wk in 1 Dutch AMS herd were analyzed, yielding no clear association between pathogen species and the rfSCC pattern found in that herd. Altogether, we described an intriguing phenomenon, present in almost 5% of the cows during a 1-mo study period. Further work is needed to quantify its importance in terms of udder health, but also to elucidate the mechanism behind this remarkable SCC pattern.

Mastitis is one of the major causes for antimicrobial use on dairy cattle farms. On farms with an automatic milking system (AMS), diagnostics differ from those with a conventional milking system (CMS), with potentially a different attitude toward mastitis treatment. This may result in differences in antimicrobial usage (AMU) between these 2 types of farms. The aims of this study were (1) to compare AMU between AMS and CMS farms, (2) to identify variables associated with AMU in both types of herds, and (3) to describe the distribution of mastitis-causing pathogens and their antimicrobial resistance patterns. Data on AMU was collected for 42 AMS and 254 CMS farms in the Netherlands and was expressed as animal-defined daily dose (ADDD). The ADDD variables were total usage (ADDDTOTAL), intramammary usage during lactation (ADDDIMM), usage for dry cow therapy (ADDDDCT), and usage by injection (ADDDINJ). Eighteen AMS farms and 24 CMS farms participated in a survey on factors potentially related to AMU. These farmers collected 5 quarter milk samples from quarters with clinical mastitis or high somatic cell count, which were subjected to bacteriological culture and antimicrobial susceptibility testing. In addition, routinely collected udder health data of these farms were used in the analysis. Nonlinear principal component analysis (NLPCA) was used to explore associations between AMU, udder health, and questionnaire variables. The ADDDTOTAL and ADDDDCT were comparable between AMS and CMS farms, whereas ADDDIMM tended to be lower and ADDDINJ higher on AMS farms than on CMS farms. The NLPCA yielded 3 principal components (PC) that explained 48% of the variation in all these variables. The AMS farms were not distinguished from CMS farms in the principal component space. The 3 PC represented different aspects of udder health, ADDDTOTAL, and treatment strategy. Differences in treatment strategy were unrelated to total antimicrobial usage or overall udder health. The distributi

Mastitis is one of the most common and costly problems in the dairy industry, and is caused by intramammary infections (IMI). IMI can be diagnosed by measuring somatic cell counts (SCC) as values increase during mastitis. Upon the emergence of automatic milking systems (AMS) SCC can be monitored daily. Results of this monitoring showed daily fluctuating SCC patterns in some cows that were associated with persistent infections. These fluctuating patterns have not been evaluated before. hypothesized is that fluctuating bacterial concentrations in the milk over time may explain the fluctuating SCC response. Therefore, the aim of this study was to evaluate whether the SCC is associated with bacterial concentrations in the milk. In addition, differences in mean log10 SCC of the identified bacteria species were also investigated. During the study, 9 cows in different stages of lactation were sampled for 19 days, and the SCC of each individual quarter was determined daily. Bacterial colonies, if present, were counted and identified in each sample. The means of the log10 SCCs of all identified bacteria species were compared to the culture-negative samples by a t.test. All pathogens except from Bacillus spp. and some Streptococcus spp. showed an increased mean log10 SCC in comparison to the culture-negative samples. The mean log10 SCC of major mastitis pathogens were compared the mean log10 SCC of minor mastitis species, showing a higher mean log10 SCC in major pathogens. The quarters were subdivided into three groups: quarters with a fluctuating SCC pattern, stable high values and stable low values. The mean log10 SCC of the quarters with fluctuating patterns and stable high values were significantly higher than the mean log10 SCC of the low SCC quarters. Random effect regression models showed no significant association of the SCC with bacterial count (BC) in any of the three groups. The results suggest that there was no relationship between the SCC and the BC in the cows .

© 2019 Elsevier B.V. We study identifying restrictions that allow news and noise shocks to be recovered empirically within a Bayesian structural VARMA framework. In population, the identification scheme we consider exactly recovers news and noise shocks. Monte Carlo evidence further demonstrates its excellent performance, as it recovers the key features of the postulated data-generation process—the real-business cycle model of Barsky and Sims (2011) augmented with noise shocks about future total factor productivity (TFP)—with great precision. In an empirical application, evidence suggests that TFP noise shocks play a minor role in macroeconomic fluctuations.

© 2020 John Wiley & Sons, Ltd. Adding multivariate stochastic volatility of a flexible form to large vector autoregressions (VARs) involving over 100 variables has proved challenging owing to computational considerations and overparametrization concerns. The existing literature works with either homoskedastic models or smaller models with restrictive forms for the stochastic volatility. In this paper, we develop composite likelihood methods for large VARs with multivariate stochastic volatility. These involve estimating large numbers of parsimonious models and then taking a weighted average across these models. We discuss various schemes for choosing the weights. In our empirical work involving VARs of up to 196 variables, we show that composite likelihood methods forecast much better than the most popular large VAR approach, which is computationally practical in very high dimensions: the homoskedastic VAR with Minnesota prior. We also compare our methods to various popular approaches that allow for stochastic volatility using medium and small VARs involving up to 20 variables. We find our methods to forecast appreciably better than these as well.

Veel melkgeitenhouders kampen met hoge kiemgetallen in de tankmelk. Vooral in het voorjaar, rondom het lammeren, zien veel veehouders het aantal bacteriën per ml tankmelk stijgen tot soms boven de boetegrens. Een onderzoek dat nu een aantal maanden loopt, probeert oplossingen te vinden.

Staphylococcus aureus is an important mastitis pathogen, causing both clinical mastitis (CM) and subclinical mastitis (SCM) in small ruminants. In general, CM has a low incidence in sheep and goats but can be very severe and costly. In contrast, subclinical mastitis (SCM) is common but is associated with less cost. For both sheep and goats, S. aureus is the main cause of CM and is associated with SCM cases with a high SCC. Recently, specific lineages of S. aureus have been identified that are associated with CM rather than SCM in dairy cows. It is unknown whether specific S. aureus lineages are associated with CM in goats and sheep. The aim of this study was to compare the clonal complex (CC), staphylococcal protein A (spa) type, leukocidin lukM-lukF' presence, and potential to produce LukMF' in vitro between CM and SCM S. aureus mastitis isolates obtained from sheep and goats. Differences between isolates from different host species were also compared. Ovine (CM, n = 12; SCM, n = 29) and caprine (CM, n = 14; SCM, n = 30) isolates were obtained from 8 sheep flocks and 8 goat herds in the Netherlands. Overall, the isolates belonged to CC133 (85%), CC398 (7%), CC425 (5%), and CC45 (2%). Seventeen spa types were found, including 6 novel types; the predominant types were t2678 (34%), t544 (18%), and t3583 (18%). Although CC133 was dominant among both sheep and goat isolates, spa type CC133/t2678 was associated with ovine isolates, whereas CC133/t544 and CC133/t3583 were found mostly in goats. The presence of lukM-lukF' among the S. aureus isolates was high (87%), especially in CC133 (96%) and CC425 (100%), but the genes were absent in CC45 and CC398. In vitro-cultured lukM-lukF'-positive isolates produced LukM (71 out of 74 positive isolates tested) in the range of 0.4 to 5.0 µg/mL. Interestingly, the goat-associated lineages CC133/t544 and CC133/t3583 produced more LukM in vitro than the sheep-associated CC133/t2678. We found no difference in LukMF' production poten

Mastitis is a costly disease and in many areas of the world, these costs have been quantified to support farmers in their decision making with regard to prevention of mastitis. Although for subsaharan circumstances estimates have been made for the costs of subclinical mastitis ( SCM ), farm-specific cost estimations comprising both clinical mastitis ( CM ) and SCM are lacking. In this paper, we quantified failure costs of both CM and SCM on 150 Ethiopian market-oriented dairy farms keeping Holstein Friesian × Zebu breed cows. Data about CM were collected by face-to-face interviews and the prevalence of SCM was estimated for each farm using the California mastitis test. All other relevant information needed to calculate the failure costs, such as the consequences of mastitis and price levels, was collected during the farm visits, except for the parameter for milk production losses due to SCM, which was based on literature estimates and subjected to sensitivity analyses. The average total failure costs of mastitis was estimated to be 4 765 Ethiopian Birr ( ETB ) (1 ETB = 0.0449 USD) per farm per year of which SCM contributed 54% of the costs. The average total failure costs per lactating cow per farm per year were 1 961 ETB, with a large variation between farms (range 0 to 35 084 ETB). This large variation in failure costs between farms was mainly driven by variation in incidence of CM and prevalence of SCM. Milk production losses made the largest contribution (80%), whereas culling contributed 13% to 17% to the total failure costs. In our estimates, costs of veterinary services, drugs, discarded milk and labour made a minor contribution to the total failure costs of mastitis. Relative to the income of dairy farmers in North Western Ethiopia; the total failure costs of mastitis are high. In general, Ethiopian farmers are aware of the negative consequences of CM, but creating awareness of the high costs of SCM and showing large variation between farmers may be instrume

BACKGROUND: Staphylococcus aureus is a contagious, opportunistic pathogen that causes clinical or subclinical mastitis in dairy cattle. The genetic background and antimicrobial resistance of isolates from Ethiopian dairy farms has not been studied. Therefore, the aim of this study was to characterize S. aureus from Ethiopian hand milked dairy cows, by spa, MLST and virulence factor typing, and by assessment of antimicrobial susceptibility. A total of 79 S. aureus isolates from intramammary infections was studied. A PCR was used to detect lukM-lukF' and pvl genes encoding the bovine and human associated bi-component leukocidins, and the toxic shock syndrome toxin gene-1 (tst). Antimicrobial susceptibility was determined using the broth microdilution method.RESULTS: Twenty different spa types were identified, most isolates were t042 (58%), and the closely related t15786 (11%). The proportion of isolates positive for lukM-lukF', tst and pvl was low at 0.04, 0.10 and 0.09 respectively, with lukM-lukF' often co-occurring with tst, but not with pvl. Methicillin-resistance was not found, but resistance to penicillin/ampicillin (86%) and tetracycline (54%) was very common.CONCLUSIONS: We found a high degree of relatedness among bovine S. aureus isolates in North-Western Ethiopia, suggesting contagious within and between farm transmission of strains that are often resistant to commonly used antimicrobials. This highlights the need for effective preventive measures that aim at limiting transmission of bacteria rather than using antimicrobials to control S. aureus mastitis in Ethiopia.

This study was conducted to describe variation in treatment policy between automatic milking system (AMS) and conventional milking system (CMS) farmers, and identify associations between treatment policy, antimicrobial use and udder health on these farms. In total 42 farmers participated (AMS = 18 and CMS = 24) and gave their consent to use their Dairy Herd Improvement records and antimicrobial usage for this study. The farmers were interviewed about their mastitis treatment policy by telephone, using a questionnaire. The results of this study revealed that AMS and CMS farmers are remarkably similar in their treatment policy, antimicrobial use and mastitis situation. No significant differences are found about: Grading the mastitis, treating the cows, which kind of antibiotics farmers use. Still, AMS and CMS farmers differed in their definition of clinical mastitis and in how farmers diagnose clinical mastitis.

© 2018 The Ohio State University This paper develops a bivariate model of inflation and a survey-based long-run forecast of inflation that allows for the estimation of the link between trend inflation and the long-run forecast. Thus, our model allows for the possibilities that long-run forecasts taken from surveys can be equated with trend inflation, that the two are completely unrelated, or anything in between. Using a variety of inflation measures and survey-based forecasts for several countries, we find that long-run forecasts can provide substantial help in refining estimates and fitting and forecasting inflation. It is less helpful to simply equate trend inflation with the long-run forecasts.

Voor een laag kiemgetal zijn een goede reiniging van de melkmachine en melktank, hygiënisch melken en snelle koeling van de melk van belang. Maar op een flink aantal bedrijven zien we ook hoge kiemgetallen, terwijl deze factoren allemaal in orde zijn. Er zijn dan aanwijzingen dat de geiten zelf de oorzaak zijn van het hoge kiemgetal. Een onderzoek moet uitsluitsel geven.

Knowledge of mastitis pathogens and their predominance as well as understanding of risk factors are prerequisites to improve udder health in a herd, region or country. In Ethiopia, such information is scarce, despite the fact that mastitis is an important cattle disease in the country. A cross-sectional study that describes prevalence and causative agents of subclinical mastitis (SCM) as well as risk factors at cow and herd level was conducted on 167 dairy farms in North-West Ethiopia. On average, 33% of the quarters and 62% of the cows were California Mastitis Test (CMT) positive, but the within herd quarter level prevalence ranged between 0 and 100%. A total of 1543 milk samples, being 27 quarters that showed signs of CM, 606 CMT positive quarters and 910 CMT negative quarters were cultured, respectively 40%, 67% and 47% was positive on bacteriological culture. Coagulase negative staphylococci (CNS) (31%) followed by Staphylococcus aureus (9%) were the pathogens most frequently isolated. Based on face-to-face questionnaire data, 35 herd level and 13 cow level factors were evaluated for their association with SCM (based on CMT) and with a positive culture for any bacteria, CNS or S. aureus. Cows with a history of CM, of higher parity, >150days in milk (DIM) and herds with owners that have >10th grade level of education had higher odds of SCM. The odds of being culture positive for any bacteria was higher in cows with ≥25% Holstein Friesian blood level (HBL), >150 DIM, housed on cemented floors, and milked by squeezing rather than stripping. Similarly, the odds of culturing CNS was higher in cows with 25-50% HBL, >150 DIM, and milked by squeezing. Staphylococcus aureus was more often found in cows with a history of CM and in larger herds. Checking the udder for mastitis, feeding cows according to their requirements and allowing calves to suckle the cows were negatively associated with SCM, with culturing any bacteria and with culturing CNS, respective

Contains fulltext : 177770.pdf (publisher's version ) (Open Access), Bicomponent pore-forming leukocidins are a family of potent toxins secreted by Staphylococcus aureus, which target white blood cells preferentially and consist of an S- and an F-component. The S-component recognizes a receptor on the host cell, enabling high-affinity binding to the cell surface, after which the toxins form a pore that penetrates the cell lipid bilayer. Until now, six different leukocidins have been described, some of which are host and cell specific. Here, we identify and characterise a novel S. aureus leukocidin; LukPQ. LukPQ is encoded on a 45 kb prophage (PhiSaeq1) found in six different clonal lineages, almost exclusively in strains cultured from equids. We show that LukPQ is a potent and specific killer of equine neutrophils and identify equine-CXCRA and CXCR2 as its target receptors. Although the S-component (LukP) is highly similar to the S-component of LukED, the species specificity of LukPQ and LukED differs. By forming non-canonical toxin pairs, we identify that the F-component contributes to the observed host tropism of LukPQ, thereby challenging the current paradigm that leukocidin specificity is driven solely by the S-component.