Rüdiger Daniel Ollhoff

Treponemes Detected in Digital Dermatitis Lesions in Brazilian Dairy Cattle and Possible Host Reservoirs of Infection

ABSTRACT The main pathogenic treponemes causing bovine digital dermatitis were identified from 17 infected herds in southern Brazil for the first time in this study using PCR. We did not find a relationship between treponeme phylogroup composition and clinical classification. Treponema phagedenis was present in all lesions. Rumen fluid was implicated as a reservoir location for these pathogens.

Sensitivity and specificity of the FAMACHA© system in growing lambs

The FAMACHA© system is used for targeted selective treatment (TST) of small ruminants for the control of haemonchosis. The aim of this study was to evaluate the sensitivity and specificity of this system in growing lambs. Between 2015 and 2016, lambs aged 60-210 days on two sheep farms were evaluated at 15-day intervals using the FAMACHA© system (F1-F5), with analysis of hematocrit (Ht), counting of eggs per gram of feces, and larval culture. The sensitivity and specificity of the system were calculated according to two criteria: criterion 1, lambs classified as F4 or F5 were considered anemic (positive test) and those classified as F1, F2, or F3 were considered not anemic (negative test); and criterion 2, lambs classified as F3, F4, or F5 were considered anemic (positive test) and those classified as F1 and F2 were considered not anemic (negative test). Three gold standard Ht cutoff values were used to diagnose anemia, i.e., ≤22%, ≤18%, and ≤15%. In total, 1591 assessments were analyzed. The highest percentage of larvae in the fecal cultures was for Haemonchus spp., with an average of 78.5%. The sensitivity values found when F3 lambs were considered anemic were 13.9%, 30.8%, and 66.7%, respectively, for Ht cutoff values of ≤22%, ≤18%, and ≤15%. When F3 lambs were excluded, the maximum sensitivity was 14.9% and the specificity was 100% for all degrees of anemia using criterion 1. The FAMACHA© system had low sensitivity in growing lambs and should not be used alone for control of haemonchosis in young animals.

Immune response after rabies oral immunization in mice

The objective of this study was to formulate an anti-rabies oral vaccine from the cell culture vaccine PV TECPAR to elicit the production of antibodies against the rabies in mice. A vaccine was developed using 107.5 DL50/0.03 ml viral antigens homogenised in lanovaseline to facilitate oral administration. Mice were vaccinated two times for seroconversion. Sera of the vaccinated mice showed a higher level of antibody production than the control group. These results could be used to direct the development of an anti-rabies oral vaccine.

Detecção de corpos estranhos metálicos por meio de ferroscopia em rebanho bovino de leite de alta produção

The presence of foreign metallic bodies through abdominal metal detector examination in high yielding dairy cattle (> 9,000 kg milk/lactation) under free-stall and TMR-feeding with a mixer wagon was evaluated. The occurrence of foreign metallic bodies in the years 2005 and 2006 was, respectively, 83.67% and 51.52%, with a maximum of amperage measured during examination of 9.36 ± 7.54 µA in 49 cows in 2005 equal to 6.44 ± 7.54 µA in 66 cows in 2006. A total of 44% (33/75) of the cows presented the foreign body in the reticulum (between the fifth and seventh intercostal space) and 56% (42/75) in the rumen. The presence of foreign metallic bodies in most of the animals of the examined herd, after exclusion of other possible causes, was due to failures in the maintenance of the mixer wagon.