Reducing lameness in dairy herds--overcoming some barriers.

Incomplete detection, high tolerance of lameness, and shortage of time and labour have been identified as barriers to reducing lameness in dairy herds. The effects of farmer participation in a project aimed at reducing lameness in dairy cattle on these factors were investigated. Over the course of the project farmers' detection of lameness improved and tolerance decreased. On farms entering the study with lameness prevalence below the median of 35%, improved detection was correlated with a reduction in lameness prevalence, but this was not the case for farms entering above the median prevalence. Lowered tolerance of lameness was correlated with reduced lameness regardless of initial prevalence. A greater importance given to lack of time as an initial barrier to progress was correlated with a greater reduction in lameness over the course of the project, suggesting that farmers who recognised limited time as a barrier were able to overcome this to some extent.

Evaluating an intervention to reduce lameness in dairy cattle.

Lameness in dairy cattle remains a significant welfare concern for the UK dairy industry. Farms were recruited into a 3-yr study evaluating novel intervention approaches designed to encourage farmers to implement husbandry changes targeted toward reducing lameness. All farms completing the study were visited at least annually and received either monitoring only (MO, n=72) or monitoring and additional support (MS, n = 117) from the research team. The additional support included traditional technical advice on farm-specific solutions, facilitation techniques to encourage farmer participation, and application of social marketing principles to promote implementation of change. Lameness prevalence was lower in the MO (27.0 ± 1.94 SEM) and MS (21.4 ± 1.28) farms at the final visit compared with the same MO (38.9 ± 2.06) and MS (33.3 ± 1.76) farms on the initial visit. After accounting for initial lameness, intervention group status, and year of visit within a multilevel model, we observed an interaction between year and provision of support, with the reduction in lameness over time being greater in the MS group compared with the MO group. Farms in the MS group made a greater number of changes to their husbandry practices over the duration of the project (8.2 ± 0.39) compared with those farms in the MO group (6.5 ± 0.54). Because the lameness prevalence was lower in the MS group than the MO group at the start of the study, the contribution of the additional support was difficult to define. Lameness can be reduced on UK dairy farms although further work is needed to identify the optimum approaches.

The aetiological agent of cat scratch disease.

A highly pleomorphic, gram-positive bacterium was cultured from an excised lymph node of a patient with cat scratch disease (CSD). The organism had morphological forms similar to those of the bacterium observed in Warthin-Starry stains of lymph node sections from CSD patients and may be the aetiological agent of this disease. Electron microscopic examination of lymph node sections from another patient with CSD showed organisms with morphological forms similar to those of the isolated bacterium. Biochemical and physiological analyses of this isolate suggested that it is not a commonly recognised contaminant or human pathogen and that it may be a member of the genus Rothia. This organism appears to resemble the bacterium that was identified as the aetiological agent of Parinaud's oculoglandular syndrome, a specific form of CSD, over 70 years ago.

Rapid quantitative microenzyme-linked immunosorbent assay for tetanus antibodies.

A rapid quantitative microenzyme-linked immunosorbent assay for the detection of immunoglobulin G antibodies to tetanus toxoid is described. The assay is performed in 2.5 h and detects antibody levels of between 0.1 and 6 U/ml. Quantitation of the antibody concentration is unique in that multiple serum dilutions are tested on a single patient, the results are plotted as an antibody dilution curve, and the area under the curve is integrated for a final concentration. Tests for immune status on sera from 77 individuals demonstrated tetanus antibody concentrations of greater than or equal to 0.1 U/ml in 92% of a pediatric group and 62% of an adult group. The microenzyme-linked immunosorbent assay procedure is reproducible and is useful for the determination of immune status and immunization response.

Identification of Legionella pneumophila by latex agglutination.

A latex agglutination test for the identification of Legionella pneumophila serogroups 1 through 6 is described. The reagent is specific for L. pneumophila and enables the ready identification of L. pneumophila colonies on agar plates. Preliminary evidence suggests that latex agglutination enables the detection of soluble L. pneumophila antigens in respiratory secretions of patients suspected of having legionellosis.