Dry cow therapy and early lactation udder health problems-Associations and risk factors.

Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015-2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers' questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ≥ 200 000 cells/mL) on the first test-day within 5-45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (× 1000 cells/mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.

Dry-off and dairy cow udder health and welfare: Effects of different milk cessation methods.

The cessation of milking at the end of lactation is a routine management practice in dairy herds, and the importance of the dry period for milk production and udder health, has long been recognized. Among countries and herds, drying-off practices differ and include various milk cessation methods, such as changes in milking frequency and in feeding, the use of antibiotic dry cow therapy and teat sealants, and changes in housing. Published studies reporting methods of stopping milk production are scarce, and there are no uniform recommendations on optimal procedures to dry cows off for good udder health, cow welfare, and milk production. This review describes methods to stop mik production to prepare cows for the dry period and their effects on mammary involution, udder health, and dairy cow welfare. Milk yield at dry-off (the final milking at the end of lactation) is important for rapid involution, which stimulates the immune system and promotes good udder health and cow welfare. Based on the findings of this review, gradual cessation of milking over several days before the final milking can effectively reduce milk yield at dry-off and accelerate mammary gland involution while maximizing cow comfort and welfare. Data from this review indicate a target production level of 15 kg/day of milk or less at dry-off.

Antibiotic dry cow therapy, somatic cell count, and milk production: Retrospective analysis of the associations in dairy herd recording data using multilevel growth models.

Antibiotic dry cow therapy (DCT) is an important part of most mastitis control programs. Updating DCT recommendations is an ongoing topic due to the global problem of antimicrobial resistance. Finland, along with other Nordic countries, has implemented selective DCT for decades. Our study analyzed Dairy Herd Improvement (DHI) information from 241 Finnish farmers who participated in a survey about their drying-off practices. The aim was to evaluate herd-level associations between milk somatic cell count (SCC), milk production, and various antimicrobial DCT approaches both cross-sectionally in 2016 and longitudinally in 2012-2016. The three DCT approaches in the study were selective, blanket, and no DCT use. An additional aim was to evaluate whether dynamic changes occurred in herd-average SCC and annual milk production over five years, and whether these potential changes differed between different DCT approaches. The method for the longitudinal analyses was growth modeling with random coefficient models. Differences in SCC and milk production between farms with different DCT approaches were minor. Regardless of the farm's DCT approach, annual milk production increased over the years, while average SCC was reasonably constant. The variability in SCC and milk production across all DCT groups was low between years, and most of the variability was between farms. Compared to other milking systems, farms with automatic milking system (AMS) had higher SCC, and in 2016 higher milk production. The results of this study suggest that it is possible to maintain low herd-average SCC and good milk production when using selective DCT and following the guidelines for prudent antimicrobial use. Average SCC and milk production varied across the herds, suggesting that advice on DCT practices should be herd-specific. The methodology of growth modeling using random coefficient models was applicable in analyzing longitudinal data, in which the time frame was relatively short and the number of herds was limited.

Short communication: Drying-off practices and use of dry cow therapy in Finnish dairy herds.

The objective of this study was to survey drying-off practices and use of dry cow therapy (DCT) in Finland through an online questionnaire. The questionnaire was accessible to all dairy farmers of the Finnish dairy herd recording system in 2016 (approximately 5,400 farms). In total, 715 dairy producers across the country, representative of the Finnish dairy industry, participated in the survey. Cows were dried off gradually in most of the farms. Most farms (78%) reported using selective DCT, whereas 9% of farms did not use any DCT, and 13% of farms applied blanket DCT. A significant trend was observed with increasing herd size and proportion of farms using blanket DCT. Percentage of farms using blanket DCT was also higher in farms with automatic milking system. Farmer's own experience was the most commonly reported reason for choosing a particular approach to DCT. Microbiological testing of milk samples at dry-off was the preferred method of selecting cows for DCT; 82 and 64% of farms using selective and blanket DCT approach, respectively, reported testing milk samples before treatment. The second most common criteria for using antibiotic DCT were clinical mastitis history and high somatic cell count. A high number of farms using selective DCT reported treating only up to one-fourth of their cows at dry-off. Information acquired on drying-off practices in Finland allows for future monitoring of prudent antimicrobial usage at dry-off.

Distribution and genetic characterization of Enterovirus G and Sapelovirus A in six Spanish swine herds.

The prevalence of Enterovirus G (EV-G) and Sapelovirus A (PSV-1) was investigated in Spanish swine herds by means of cross-sectional studies. Faecal samples from clinically healthy pigs were collected from six farms, and analysed by RT-PCR. The results indicated a high prevalence of EV-G detected in nearly all the animals older than 3 weeks of age. Otherwise, PSV-1 was only detected in 3-week-old piglets from one of the farms. Genetic analyses performed in the VP1 region of the EV-G indicated circulation of diverse strains in the same farm, related to genotypes G1, G2, G3, G4, G6, G9, G12, G13 and G14. Moreover, co-infection of several PSV-1 variants in the same animal was evident, typical of viral quasispecies. Evolutionary pressure analysis indicated that microevolution of PSV-1 seems to be driven by negative selection. This study gives further insights in the epidemiology of EV-G and PSV-1.

Bayesian Estimation of the True Prevalence and of the Diagnostic Test Sensitivity and Specificity of Enteropathogenic Yersinia in Finnish Pig Serum Samples.

Bayesian analysis was used to estimate the pig's and herd's true prevalence of enteropathogenic Yersinia in serum samples collected from Finnish pig farms. The sensitivity and specificity of the diagnostic test were also estimated for the commercially available ELISA which is used for antibody detection against enteropathogenic Yersinia. The Bayesian analysis was performed in two steps; the first step estimated the prior true prevalence of enteropathogenic Yersinia with data obtained from a systematic review of the literature. In the second step, data of the apparent prevalence (cross-sectional study data), prior true prevalence (first step), and estimated sensitivity and specificity of the diagnostic methods were used for building the Bayesian model. The true prevalence of Yersinia in slaughter-age pigs was 67.5% (95% PI 63.2-70.9). The true prevalence of Yersinia in sows was 74.0% (95% PI 57.3-82.4). The estimates of sensitivity and specificity values of the ELISA were 79.5% and 96.9%.

Bayesian modelling to identify the risk factors for Yersinia enterocolitica contamination of pork carcasses and pluck sets in slaughterhouses.

The probability of contamination by pathogenic Yersinia enterocolitica of carcasses and pluck sets at slaughterhouse was determined by means of a Bayesian analysis. Prior information of the prevalence of Y. enterocolitica in faeces and the seroprevalence of Yersinia in serum of pigs collected at farms were obtained from previous studies and introduced in the models as beta prior informative distributions. Samples of intestinal content, tonsils, and swabs of carcasses and pluck set surfaces were collected at slaughterhouses. The posterior probabilities, odds ratio (OR) and their probability interval (PI) were calculated by means of a generalized linear model constructed in WinBugs. Occurrence of Y. enterocolitica in intestinal content (OR: 35.6, 95%PI 2.8-8285), tonsils (OR: 38.4, 95%PI 5.0-854), and pluck set (OR: 16.6, 95%PI 1.9-1111) was a risk for the contamination of pork carcasses, and an increased risk of contaminated pluck set was observed when Y. enterocolitica was isolated in intestinal content (OR: 40.6, 95%PI 2.1-10510) and tonsils (OR: 17.6, 95%PI 3.4-230.6). This increased risk indicated a potential cross-contamination at the slaughterhouse.

Comparison of bovine cysticercosis prevalence detected by antigen ELISA and visual inspection in the North East of Spain.

A cross-sectional serological study on cattle less than 2 years old, using an antigen ELISA for the detection of bovine cysticercosis was carried out between November 2009 and February 2010 in 10 slaughterhouses from the Catalonia region (North-Eastern Spain). Circulating antigen was detected in 23 of 2073 animals, i.e. a sero-prevalence of 1.11% (CI95%: 0.76-1.75%). The determined sero-prevalence was about 50 times higher than the prevalence obtained by visual inspection within the same period: 19 positive animals of 90,891 slaughtered animals (0.02%) in the same slaughterhouses. None of the animals with positive result in the Ag-ELISA was detected by meat inspection.

Culicoides vectors of bluetongue virus in Chester Zoo.

On four nights in June 2008, light traps were operated for Culicoides biting midges, the vector species for bluetongue virus (BTV), at five sites in Chester Zoo in north-west England. Over 35,000 Culicoides midges, of 25 species, were captured, including high densities inside animal enclosures. Over 94 per cent of all the Culicoides trapped were females of the Obsoletus group, which is implicated as the vector of BTV serotype 8 in northern Europe. The mean catch of this group per trap per night was over 1500, suggesting a potential risk of BTV transmission if the virus is introduced to Chester Zoo in the animals or midges in the summer.

Quantitative assessment of the probability of bluetongue virus transmission by bovine semen and effectiveness of preventive measures.

Given that bluetongue (BT) may potentially be transmitted by semen, that the disease has significantly expanded in recent years, and that millions of doses of cattle semen are annually traded throughout the world, the transmission of bluetongue virus (BTV) by semen could have severe consequences in the cattle industry. The hypothesis that infected bulls could excrete BTV in their semen led to restrictions on international trade of ruminant semen and the establishment of measures to prevent BTV transmission by semen. However, neither the risk of BTV transmission by semen nor the effectiveness of these measures was estimated quantitatively. The objective of the study was to assess, in case of introduction of BTV into a bovine semen collection centre (SCC), both the risk of BTV transmission by bovine semen and the risk reduction achieved by some of the preventive measures, by means of a stochastic risk assessment model. The model was applied to different scenarios, depending on for example the type of diagnostic test and the interval between the controls (testing) of donor bulls, or the rate of BTV spread within the SCC. Enzyme-linked immunosorbant assay (ELISA) controls of donor bulls every 60 days seemed to be an ineffective method for reducing the risk of BTV transmission in contrast to polymerase chain reaction (PCR) tests every 28 days. An increase in the rate of spread within the SCC resulted in a reduced risk of BTV transmission by semen. The storage of semen for 30 days prior to dispatch seemed to be an efficient way of reducing the risk of transmission by semen. The sensitivity analysis identified the probability of BTV shedding in semen as a crucial parameter in the probability of BTV transmission by semen. However, there is a great degree of uncertainty associated with this parameter, with significant differences depending on the BTV serotype.

Seroprevalence and risk factors of swine influenza in Spain.

Swine influenza is caused by type A influenza virus. Pigs can be infected by both avian and human influenza viruses; therefore, the influenza virus infection in pigs is considered an important public health concern. The aims of present study were to asses the seroprevalence of swine influenza subtypes in Spain and explore the risk factors associated with the spread of those infections. Serum samples from 2151 pigs of 98 randomly selected farms were analyzed by an indirect ELISA for detection of antibodies against nucleoprotein A of influenza viruses and by the hemagglutination inhibition (HI) using H1N1, H1N2 and H3N2 swine influenza viruses (SIV) as antigens. Data gathered in questionnaires filled for each farm were used to explore risk factors associated with swine influenza. For that purpose, data were analyzed using the generalized estimating equations method and, in parallel by means of a logistic regression. By ELISA, 92 farms (93.9%; CI(95%): 89.1-98.7%) had at least one positive animal and, in total, 1340/2151 animals (62.3%; CI(95%): 60.2-64.3%) were seropositive. A total of 1622 animals (75.4%; CI(95%): 73.6-77.2%) were positive in at least one of the HI tests. Of the 98 farms, 91 (92.9%; CI(95%): 87.7-98.1%) had H1N1 seropositive animals; 63 (64.3%; CI(95%): 54.6-73.9%) had H1N2 seropositive pigs and 91 (92.9%; CI(95%): 87.7-98.1%) were positive to H3N2. Mixed infections were detected in 88 farms (89.8; CI(95%): 83.7-95.9%). Three risk factors were associated with seroprevalences of SIV: increased replacement rates in pregnancy units and, for fatteners, existence of open partitions between pens and uncontrolled entrance to the farm.

Application of ATP bioluminescence for evaluation of surface cleanliness of milking equipment.

The ATP bioluminescence method was used to evaluate the cleanliness of milking equipment surfaces (teat cup rubbers, teat dip containers, milk receivers, and pipeline joints) in dairy farms in Galicia (northwest Spain) with parlour, pipeline tie-stall or bucket tie-stall milking systems. The cleanest surfaces were teat cup rubbers. The use of non-chlorinated water for cleaning, and of pipeline or bucket tie-stall milking systems, was associated with high ATP bioluminescence values. However, ATP bioluminescence values only explained 12% of the variability in bulk-tank bacterial count; this is attributable to the importance of other factors (notably the correct functioning of the tank cooling system) for maintenance of low bacterial count.

Management practices associated with Mycobacterium avium subspecies paratuberculosis infection and the effects of the infection on dairy herds.

During 2004, a survey of Mycobacterium avium subspecies paratuberculosis (map) was conducted in 101 randomly selected dairy herds to investigate associations between the infection status of the herds, different management practices, and possible disease indicators, such as indices of mastitis and reproductive performance. Data were collected by means of a questionnaire through personal interviews with the farmers and veterinarians in charge of each farm. At the same time, blood samples were taken from cattle over one year old and analysed with a commercial elisa to detect antibodies to map. Statistical analyses indicated that the following management practices constituted major risk factors: utilisation of colostrum from cows with a previous positive map diagnosis, and housing replacement calves with adult cattle before they were six months old. Seropositivity to map was related to the herds' bulk tank somatic cell counts and incidence of clinical mastitis, but not to their reproductive performance.

Prevalence of and risk factors for Listeria species on dairy farms.

This cross-sectional study determined the prevalence of Listeria spp. in bulk-tank milk on dairy farms in the region of Galicia in northwest Spain. The aim was to identify management practices associated with the presence of Listeria spp. and possible effects on milk hygienic quality. A total of 98 farms was randomly selected on the basis of an expected prevalence of 6.5% for Listeria monocytogenes from 20,107 dairy farms in the region. Bulk-tank milk samples were obtained from 98 farms, fecal samples from lactating cows from 97 farms, and silage samples from 83 farms. Listeria monocytogenes was detected in 6.1, 9.3, and 6.0% of these samples, respectively. Statistical analyses confirmed the relationship between low silage quality (as indicated by high pH) and presence of Listeria spp. in silage (29.5 vs. 6.2% for pH above or below 4.5, respectively). Only milking system [tie-stall systems (28.6%) vs. parlor milking (10%)] and inadequately controlled milking order [yes (32.0%) vs. no (10.7%)] had statistically significant effects on management practices for increasing the risk of Listeria contamination of bulk-tank milk.

Estimating the incidence of systemic lupus erythematosus in a tropical region (Natal, Brazil).

The objective of the study was to evaluate the incidence of Systemic Lupus Erythematosus (SLE) in a tropical urban community (Natal city, Brazil). Only patients living in Natal, a city in the northeastern area of Brazil, older than 15 years, and who fulfilled at least four of the American College of Rheumatology criteria between 1 January 2000 and 31 December 2000, were included. Four sources were used to identify new cases of SLE: (1) the University Hospital; (2) 'health units' and hospitals of the public health network; (3) specialists at private hospitals and outpatient clinics; and (4) three laboratories performing antinuclear antibody (ANA) determination. Census data from 2000 for Brazilian population was used to calculate incidence rate. The standardized mortality ratio (SMR) method and 95% confidence intervals (95% CI) were calculated. Forty-three patients were diagnosed as new SLE cases in 2000. The calculated incidence was 8.7/100,000/year (95% CI 6.3-11.7). Thirty-eight patients were female 14.1/100,000/year (95% CI 10.0-19.3) and five were male 2.2/100,000/year (95% CI 0.7-5.2). The mean age of new SLE cases was 31.8 years old. (95% CI 27.8-35.8). The mean age for females was 31.4 and for males was 35.0 years old. The median of disease duration (time between onset of the first ACR criterion for SLE and diagnosis) was 10 months (1-72 months). This study demonstrated a high incidence of SLE in Natal, apparently higher than reported in other places. The mean age at diagnosis seems lower than referred by other studies. The observed differences may be due to ethnic and/or environmental factors.

Renal abnormalities in ankylosing spondylitis.

Renal abnormalities have been reported in Ankylosing Spondylitis (AS) patients. Possible mechanisms include the effects of nonsteroidal anti-inflammatory drugs (NSAIDs), an increased incidence of glomerulonephritis, particularly the ones associated with deposition of IgA-containing immune complexes and the renal deposition of amyloid. These observations prompted us to evaluate in detail the frequency and severity of renal dysfunction in 40 AS patients, consecutively selected attending the rheumatology disease unit outpatient clinic at Escola Paulista de Medicina, using sensitive tests of glomerular and tubular function. Fourteen of the 40 patients presented one or more signs of renal involvement: microscopic hematuria (9 patients), microalbuminuria (4 patients), decreased renal function assessed by serum creatinine (2 patients), and creatinine clearance (4 patients). None of the patients presented increased urinary excretion of retinol binding protein (RBP). The finding of renal abnormalities in 35% of our patients suggests that in this illness evidence of renal involvement should be actively investigated.

Evaluation of the European Spondylarthropathy Study Group (ESSG) preliminary classification criteria in Brazilian patients.

OBJECTIVE: To evaluate the sensitivity and specificity of the ESSG criteria when applied to Brazilian patients with SpA and control patients with other rheumatic diseases. METHODS: Seventy patients with spondylarthropathies and 62 patients with other rheumatic diseases were interviewed, examined and had their charts reviewed. The diagnoses of the diseases were based on published diagnostic guidelines or classification criteria. Data were also collected according to the ESSG criteria. RESULTS: The sensitivity and specificity of the ESSG classification criteria were 98.5% and 88.7%, respectively. The sensitivities of the criteria in the different subgroups of SpA ranged from a low of 97.7% in AS to a high of 100% in other SpA studied. CONCLUSION: Despite differences in the socio-cultural and geographic characteristics and in individual disease frequencies, the ESSG preliminary classification criteria performed well when applied to Brazilian patients.

The use of focus group interview in the evaluation of patients with ankylosing spondylitis.

The purpose of this study was to develop some of the focus group discussion (FGD) potentialities in order to provide information on patients' understanding of the origin and management of their medical condition. Fifteen ankylosing spondylitis (AS) patients (mean age = 32.6 yr and mean disease duration = 13.4 yr) were selected from the Rheumatic Disease Unit (RDU) out-patient clinic at Escola Paulista de Medicina, São Paulo, Brazil, to take part in this study. The FGD constituted two sessions, with eight patients in the first and seven in the second. The moderator raised specific questions about the patients' understanding of the pathology, the treatment and how the illness affected their quality of life. It was observed through the FGD that patients believed that their illness onset was due to some physical trauma. Clinicians should inquire about this tissue to be sure that their individual patients do not have this false belief. Also, it is necessary to improve the methods for early diagnosis and to develop further studies to determine and assess the parameters of disease activity. And finally, FGD may be of use in establishing a self-help group for individuals with chronic diseases, such as AS. In conclusion the FGD is an available technique that should be used more frequently in medicine to gather global qualitative data.