The objective of this cross-sectional study was to determine the prevalence of disorders in preweaned calves in 3 regions in Germany, exemplary for structural diversity in dairy farming. A farm visit was performed on a single occasion on 731 dairy farms in the northern, eastern, and southern regions of Germany between December 2016 and July 2019. Farms differed in herd size, geographical location, and management. In the northern region, the farms had a median of 90 milking cows and were often run as full-time family businesses, partly with external workers. The eastern region tended to have larger farms (a median of 251 milking cows), which were often large-scale agricultural enterprises with employees. In the southern region, the farms had a median of 39 milking cows and were often traditional family businesses, some of these being part-time businesses. Clinical examinations were performed on 14,164 preweaned dairy calves (median 12 calves per farm) by trained veterinarians. A complete data set was available for 13,656 calves. Almost half (42.0%) of the evaluated calves were classified as being affected by at least 1 of the common calf disorders. Omphalitis (O, 20.9%; n = 2,876) and diarrhea (D, 18.5%; n = 2,670) were the most frequently recorded diagnoses, whereas respiratory diseases (RD) were observed to a lesser extent (8.7%; n = 1,100). A striking feature was the fact that 7.1% (n = 987) of the calves were affected by more than 1 disorder at the same time (multimorbidity, M). The following combinations of disorders were frequently observed: O and D (n = 596), O and RD (n = 164), and D and RD (n = 140). Disorders such as O and D, as well as M, were predominantly observed in calves aged 2 wk. A gradual increase in the frequency of RD was observed with age. For all disorders except RD, male calves were more often affected than females. Omphalitis was predominantly diagnosed in the summer months, whereas RD, D, and M were more common in the fall. We detected several statistically significant differences in the prevalence of clinical signs and disorders in preweaned dairy calves between the 3 exemplary regions. The prevalence of RD was higher in the south (10.8%) than in the north (8.2%) and east (7.4%). In the north (33.2%), O was observed more frequently than in the other regions (east: 18.9%; south: 10.5%), whereas D was found less frequently in the north (13.8%) than in the east (21.6%) and south (20.0%).

Production diseases affect dairy cows predominantly during the transition period. A causal relationship is drawn between high milk yield and the occurrence of production diseases. Such a monocausal approach, however, does not reflect the real situation as production diseases are multifactorial by origin, with exogen (environmental) and endogen (animal related) factors being involved. The bovine metabolism follows the rules of a complex system as it is characterized by a great number of variables (metabolic parameters) that interact by positive as well as negative feedback mechanisms of variable intensity. Furthermore the effects of such feedback mechanisms might not occur instantaneously but with some delay in time. Negative feedback loops contribute to the stability of a complex system. Resilience with respect to animal health is defined as the capacity of animals to cope with short-term perturbations in their environments and return rapidly to their pre-challenge status. Aim of the present paper is to answer the question whether resilience does exist in dairy cows, what characteristics it shares, whether it is measurable and whether research on resilience could contribute to a decrease in the incidence rates of production diseases. Close monitoring of dairy cows by clinical examination, use of sensor technology and analysis of blood samples for metabolic parameters (NEFA, Ca, P, urea, albumin, haptoglobin,) and faecal samples in the dry period allowed Dutch researchers to identify cows on beforehand that were at risk of developing production diseases in the post partum period. Cows at risk demonstrated differences in their behaviour as well as a delayed return of selected metabolic analytes to the reference range following calving compared to cows that remained healthy during the transition period. Identification of resilient dairy cows could help breeders in their efforts to improve dairy health and allow farmers to take preventive measures whenever a cow at risk is identified in the dry period.

The present study aimed at analysis of the effects of polyunsaturated fatty acid (PUFA), linoleic acid (LA, C18:2n − 6) and linolenic acid (LNA, C18:3n − 3) on bovine peripheral blood mononuclear cells (PBMC) in vitro. Both mitogen (ConA)-induced proliferative lymphocyte responsiveness during 4 days of culture and eicosanoid (prostaglandin E2 (PGE2) and leukotriene B4 (LTB4)) production during 36 h were determined in relation to the absence or presence of various concentrations of LA and LNA (0, 1, 5, 25, 125 and 250 μM). Mitogen-driven proliferative responses of lymphocytes tended to be uninfluenced in the presence of lower concentrations of LA, whereas significant inhibition was observed at the higher concentrations of LA (125 and 250 μM). However, increasing amounts of LNA did not affect the proliferation. ConA stimulation induced a clear PGE2 response, which significantly decreased in the presence of 250 μM of LA. In addition, increasing amounts of LNA, but not LA, led to a significant decrease in LTB4 levels. However, The production of LTB4 did not alter due to mitogenic stimulation. In conclusion, the present study shows that bovine mononuclear cells may functionally be influenced by the presence of PUFA in their environment. Further studies need to be conducted to clarify in vivo consequences of these findings in a situation of PUFA enriched rations in ruminants.

Dexamethasone is a potent therapeutic for treatment of the fatty liver syndrome or primary ketosis in post partum dairy cows. Reservations exist, however, among practitioners with respect to the risk of immunosuppression induced by corticosteroids. The aim of this study was to investigate the effect of a single injection of dexamethasone-21-isonicotinate on distinct immune functions of postpartum dairy cows because only scarce information is available on the effects of corticosteroid preparations when administered at a dosage and frequency for treatment of the fatty liver syndrome or primary ketosis. Sixteen Swedish red-pied dairy cows, between days 9 and 15 post partum, were allotted to either a control group (n = 8) or a treatment group (n = 8). The cows in the treatment group received a single intramuscular injection of a dexamethasone-21-isonicotinate suspension at a dosage of 0.02 mg/kg i.m. at the start of the experiment. White blood cell counts and selected lymphocyte functions (lymphocyte proliferation, expression of lymphocyte markers and the b2 and a4 chain of adhesion molecules belonging to the integrin family) and some parameters of the energy metabolism (glucose, insulin) were determined before the administration of corticosteroids (day 0) and subsequently at days 2, 4, 7 and 9 of the experiment. Changes in glucose and insulin were within the target range for treatment of the fatty liver syndrome or primary ketosis. Significant (P < 0.05) increases in the number of circulating white blood cells were observed in treated cows on the second day following treatment which was exclusively caused by an increase in the number of circulating neutrophils. Lymphocyte blastogenesis in response to ConA and the percentages of lymphocytes positive for CD2, CD4, CD8, CD49d and CD18 as well as the intensity of CD49d expression did not differ between the treatment and control groups. There was, however, a significant reduction (P < 0.01) in the intensity of CD18 expression on lymphocytes in the treated animals on the fourth day after treatment. In conclusion, a single administration of dexamethasone-21-isonicotinate in a dosage of 0.02 mg/kg i.m. at two weeks post partum in healthy cows had a significant but highly transient effect on CD18 expression on lymphocytes and the number of peripheral blood neutrophils, but did not affect lymphocyte blastogenesis or lymphocyte subpopulation patterns in peripheral blood.

Eight Swedish crossbred heifers, about two-and-a-half years old, were given a single intramuscular dose of dexamethasone-21-isonicotinate between nine and 15 days after they had calved and eight similar heifers were left untreated. The treatment had no significant effects on the lipolytic activity of the heifers' fat tissues, and no effect on the concentrations of non-esterified fatty acids and beta-hydroxybutyrate in blood or the triacylglycerol content of the liver. However, there were significant increases in plasma glucose concentrations two days after the injection and in plasma insulin concentrations two and four days after the injection.

Neutrophil migration into the airways and pulmonary tissue is a common finding in bovine respiratory syncytial virus (BRSV) infections. Although neutrophil trans-endothelial migration in general depends on beta(2)-integrins, alternative integrins such as the alpha(4)-integrins have been implicated. In this study, rolling and firm adhesion of peripheral blood neutrophils isolated from healthy and BRSV-infected calves to tumour necrosis factor (TNF)-alpha activated pulmonary endothelium was investigated under flow conditions in vitro. For neutrophils obtained from healthy animals, inhibition of the beta(2)-integrin reduced firm adhesion to 63% and inhibition of alpha(4)-integrin to 73% compared with untreated controls. Inhibition of both integrins reduced firm adhesion to 25%. Rolling velocity, which is used as a parameter for integrin involvement in neutrophil rolling, increased 1.7-fold by blocking beta(2)-integrin and was significantly augmented to 2.5-fold by blocking both alpha(4)- and beta(2)-integrins. For neutrophils obtained from BRSV-infected animals, however, rolling velocities at 10 days after infection (p.i.) were not influenced by blocking adhesion of alpha(4)- and beta(2)-integrins, indicating that these integrins did not support neutrophil rolling. In addition, the inhibition of firm adhesion by blocking both alpha(4)- and beta(2)-integrins was reduced significantly 9 days post-infection, resulting in a residual 68% neutrophil binding at 9 days p.i. Non-blocked firm adherence was not reduced, indicating that binding was achieved by other mechanisms than through alpha(4)- and beta(2)-integrins. These results demonstrate an important function for alpha(4)- and beta(2)-integrins in rolling and firm adherence of bovine neutrophils, to TNF-alpha-activated endothelium and show the dynamic use of these integrins for adhesion and migration by neutrophils in the course of BRSV infection.

ABSTRACTA method is proposed to identify leukocyte subpopulations in bovine bronchoalveolar lavage fluid by dual-laser flow cytometry. The technique uses several parameters, i.e., exclusion of highly autofluorescent alveolar macrophages and inclusion of leukocytes on the basis of labeling by specific antibodies and light scatter characteristics.

During the last six weeks of the dry period, eight Holstein-Friesian cows were fed a restricted amount of grass silage; after calving, a mixture of maize silage and concentrates was offered in a feeding regimen designed to induce a displacement of the abomasum. In the first month after calving, the cows were monitored for the following variables: feed intake and composition, milk production, the position of the abomasum, and the pH and osmolality of the rumen contents. In five of the eight cows, a left displacement of the abomasum occurred between four and 21 days after calving in the absence of other diseases. The displacement was temporary, lasting between five and 36 consecutive hours and one or two days in two of the cows (floaters), and for three or more days in the other three. Before these three cows developed the displacement, their abomasum was 4.3 to 7.9 cm higher, its contents had a higher mean osmolality (+19.2 mosmol/kg), and the ratio of roughage to concentrates in their feed was lower (-0.87) than in the three cows that did not develop clinical signs of a displaced abomasum. There were no significant differences in these variables between the floaters and the healthy cows.

The aim of this study was to investigate whether dietary n-6 polyunsaturated fatty acids (PUFA) alter immune functions as lymphocyte blastogenesis, expression of lymphocyte and monocyte markers, and cell adhesion molecules of the integrin family in goats. Dutch White castrated male goats received a diet either rich in olive oil (control group, n = 4) or rich in corn oil (test group, n = 4) over a period of 3 weeks. The animals in the test group had significantly higher linoleic acid (LA, 18:2n-6) levels in plasma on days 7, 14 and 21 of the diet than control animals. This was also true for washed erythrocyte membranes at day 21. A significant reduction in the percentage of alpha-4 integrin (CD49d) expressing lymphocytes was observed in goats fed LA rich corn oil at day 21. However, no changes were observed in either lymphocyte proliferative responses to ConA and PHA or the expression of other lymphocyte/monocyte markers. In conclusion, feeding corn oil rich in LA caused significant increases in the proportion of LA in the fatty acid composition of plasma and erythrocyte membranes and was accompanied by a significant decrease of the adhesion molecule alpha-4 integrin (CD49d) on lymphocytes but not on monocytes.

SUMMARY Neutrophil migration into the airways and pulmonary tissue is a common finding in bovine respiratory syncytial virus (BRSV) infections. Although neutrophil trans-endothelial migration in general depends on β2-integrins, alternative integrins such as the α4-integrins have been implicated. In this study, rolling and firm adhesion of peripheral blood neutrophils isolated from healthy and BRSV-infected calves to tumour necrosis factor (TNF)-α activated pulmonary endothelium was investigated under flow conditions in vitro. For neutrophils obtained from healthy animals, inhibition of the β2-integrin reduced firm adhesion to 63% and inhibition of α4-integrin to 73% compared with untreated controls. Inhibition of both integrins reduced firm adhesion to 25%. Rolling velocity, which is used as a parameter for integrin involvement in neutrophil rolling, increased 1·7-fold by blocking β2-integrin and was significantly augmented to 2·5-fold by blocking both α4- and β2-integrins. For neutrophils obtained from BRSV-infected animals, however, rolling velocities at 10 days after infection (p.i.) were not influenced by blocking adhesion of α4- and β2-integrins, indicating that these integrins did not support neutrophil rolling. In addition, the inhibition of firm adhesion by blocking both α4- and β2-integrins was reduced significantly 9 days post-infection, resulting in a residual 68% neutrophil binding at 9 days p.i. Non-blocked firm adherence was not reduced, indicating that binding was achieved by other mechanisms than through α4- and β2-integrins. These results demonstrate an important function for α4- and β2-integrins in rolling and firm adherence of bovine neutrophils, to TNF-α-activated endothelium and show the dynamic use of these integrins for adhesion and migration by neutrophils in the course of BRSV infection.

As left-displaced abomasum (LDA) often occurs in cows with high contents of fat in the liver (fatty liver), a postpartum fatty liver-inducing regimen was applied to 16 cows. The main interest of the study was whether there were productive or metabolic changes in cows prior to LDA. Therefore, feed intake and milk production were monitored and blood samples were collected from the cows. The LDA occurred in 4 out of 16 dairy cows that were included in the feeding regimen. Compared to cows not developing LDA, LDA-cows had a significantly lower feed intake, 6.5 kg/d less, and milk production, 8 kg/d less, prior to clinical diagnosis of LDA. In the 10-d period preceding clinical diagnosis of LDA, blood concentrations of calcium, glucose, and insulin were significantly lower, whereas blood concentrations of nonesterified fatty acids and beta-hydroxybutyrate, as well as aspartate aminotransferase activities were significantly elevated compared to cows not developing LDA. These preclinical changes may play an important role in the pathogenesis of LDA. It is not certain, however, whether there is a causal association between these parameters and LDA.

Neutrophil emigration from the pulmonary vasculature, is mediated by cellular adhesion molecules (CAM) expressed on the outer membranes of endothelial cells and neutrophils. Although beta(2)-integrin-dependent migration is a major mechanism of neutrophil migration, which was demonstrated by extensive invasion of neutrophils in pulmonary tissue of calves suffering from a genetic deficit in expression of beta(2)-integrins, termed bovine leukocyte adhesion deficiency (LAD), the role of alternative CAM is still unclear. We investigated whether an alternate CAM for beta(2)-integrin function, i.e. the alpha(4)-integrin, was expressed on peripheral blood neutrophils of calves. As we detected basal but significant expression, the effect of naturally acquired pulmonary infection on the expression of either integrin was determined, as an indication for its function in the migration process. In our experiments, basal expression of alpha(4)-integrins on peripheral blood neutrophils from clinically healthy calves was detected. On neutrophils of calves, experiencing field outbreaks of enzootic bronchopneumonia, higher expression of the alpha(4)-integrin was detected, which returned to normal after successful treatment of the disease. In addition, its level of expression was linearly related to plasma acute phase protein (haptoglobin) concentrations, which is a sensitive parameter for severity of respiratory inflammation. Increased expression of the alpha(4)-integrin on peripheral blood neutrophils during pulmonary inflammation indicates a role for this CAM in neutrophil migration in the lung.

Introduction. Bovine paratuberculosis is caused by infection of young calves with Mycobacterium avium subsp. paratuberculosis, and results in chronic granulomatous infection of the ileum. The aim of the present study was to perform a longitudinal follow up of immunological and microbiological parameters of calves experimentally infected in the first month of life. Materials and methods, White blood cell counts and differentiation were done on whole blood samples. PBMC were isolated from bloodsamples of 20 experimentally infected calves and 10 uninfected control animals. The PBMC were phenotyped by flow cytometry using a panel of 8 monoclonal antibodies. Lymphoproliferation assays, with a panel of 6 mycobacterial antigens were used for evaluating T cell function. Fecal culture was performed to aqcuire data on the mycobacterial load.Results and conclusion. The results obtained during the first 3 years of infection indicated that minor responses in the PBMC population of infected calves can be detected within 3 months after infection, followed by an exponentially rise 1 year post infection to reach a plateau. By the end of the third year, the indications of a decrease in cell mediated immune responses became evident. The immunophenotyping of the PBMC showed differences in the gammadelta T cell and B-cell frequencies between the infected and the control group. Comparisons of lymphocyte stimulation and bacterial load in the infected group indicated a dose-response relationship. Definite conclusions on whether the observed immunological responses are the correlates of protective immunity awaits completion of this ongoing study.

Myophosphorylase deficiency in cattle is a muscle disease induced by a C-->T point mutation in codon 489 of the myophosphorylase gene, which until now has only been diagnosed in the Charolais breed. The disease seems to be inherited in an autosomal monogenic recessive manner. A calf of double muscled phenotype was suspected of suffering from myophosphorylase deficiency based on typical symptoms, i.e. brown-coloured, transparent urine, occurring after exercise; exercise intolerance; symptoms of pain; and an elevated level of plasma creatine kinase. The presence of the previously described mutation was excluded using a newly developed, improved polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure to identify easily heterozygous carriers and homozygous affected animals.

The pH value of the abomasal contents in adult cattle is normally constant and has a value of 2. Abomasal contents with pH values of 5.5 and higher could give rise to bacterial fermentation with subsequent gas production. The accumulation of gas is thought to form a key event in the pathogenesis of abomasal displacement. The aim of the present study was to determine the pH values of abomasal contents of dairy cows in the first 3 weeks after calving. The pH of the abomasal contents was, over several days. higher than the pH value of the abomasal juice in mid-lactation cows. The highest pH values were measured on day 14 after calving, thereafter the pH declined. Possible explanations for the rise in the pH value of the abomasal contents are discussed.

The position of the abomasum in six cows was examined by ultrasonography at regular intervals for six weeks after they had calved. Its position was established by determining the distance between the margin of the left side of the abomasum and the ventral midline at two sites. During the last weeks of pregnancy, the abomasum was positioned in a small region of the left ventral side of the abdominal cavity. At parturition it was positioned high on the left side and then descended. The abomasum was furthest from the midline immediately after parturition. Its position was related to the interval after calving, the cow's feed intake, and the pH and osmotic pressure of the rumen fluid. There was considerable variation between the cows in the position of the abomasum, which was in part due to analytical variation, and in individual cows it had a circadian rhythm.

Lung inflammation is often associated with sustained neutrophil migration into the lung tissue, causing undesired side effects, i.e. substantial damage of lung tissue and fibrin deposition, which hamper complete recovery. The need for additional anti-inflammatory treatment strategies focused attention on the function of cellular adhesion molecules (CAMs) on the leukocyte membrane, which guide migration of leukocytes across the endothelium to the site of inflammation. Recent data indicate that neutrophil migration in the lung is mediated by unique pathways, involving different CAM as compared to other organs. These pulmonary characteristics of neutrophil migration enable specific targeting of CAM for anti-inflammatory treatment of pneumonia. In addition, the recent interest in intracellular signaling revealed that most CAM not only function in adhesion, but also play an important role in initiation of intracellular signal transduction and vice versa may be modulated by intracellular signaling molecules (ISMs). In this review, the mechanisms of neutrophil migration in the lung and the role of ISM with respect to CAM function are described in the context of potential anti-inflammatory intervention strategies.