Reduced Milk Production in Udder Quarters with Subclinical Mastitis and Associated Economic Losses in Crossbred Dairy Cows in Ethiopia

The objective of the study was to estimate the losses associated with subclinical mastitis (SCM) in crossbred dairy cows in the Central Highlands of Ethiopia. A split udder investigation was performed with 30 cows to determine production losses associated with SCM. Each quarter of the study cows was examined using the California Mastitis Test (CMT) and quarter milk production was measured over a period of 8 days. Production losses were determined for different CMT scores by comparing production of quarters with CMT score 0 to quarters with CMT scores trace, 1, 2 and 3, respectively. Using data from a recently published study, economic losses were determined for different farm sizes and production subsystems by multiplying the prevalence of the respective CMT scores with the production losses associated with these CMT scores. Mean quarter milk production was 0.82 + 0.40 kg per milking in the split udder trial. Milk production was reduced by 1.2%, 6.3%, and 33% in quarters with CMT scores 1+, 2+, and 3+, respectively. Using data from the published study, a quarter with SCM lost an average of 17.2% of its milk production. Production losses associated with SCM were estimated at 5.6% for the Addis Ababa Milk Shed. Stratified losses were highest (9.3%) in urban dairy farms (UDF) and small-scale farms (6.3%). The estimates of the financial losses ranged from US$29.1 in dairy herds in secondary towns (DHIST) to US$66.6 in UDF. A total loss of US$38 was estimated for each cow per lactation. Reducing mastitis in UDF (highest prevalence) to the level of DHIST (lowest prevalence) could reduce the loss by US$35. As this does not include costs associated with treatment or culling of diseased cows, this figure probably underestimates the possible benefits of control measures.     

Morphological, histological, and ultrastructural studies of the ovary of the cattle-tick Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae)

This study presents the morphology of the ovary, as well as the dynamics of the vitellogenesis process in oocytes of the cattle-tick Boophilus microplus. The ovary of these individuals is of the panoistic type; therefore, it lacks nurse cells. This organ consists of a single tubular structure, continuous, and composed of a lumen delimitated by a wall of small epithelial cells with rounded nuclei. In this tick species, the oocytes were classified into six stages varying from I to VI and according to: cytoplasm appearance and presence of the germ vesicle, yolk granules, and chorion. Oocytes of various sizes and at different developmental stages remain attached to the ovary through a cellular pedicel until completing stage V. Afterwards, they are liberated into the lumen and from there to the exterior. Some oocytes (classified as type VI) showed an atypical appearance indicating that some of the cellular components would be undergoing a degenerative process and/or reabsorption.     

Use of alkaline phosphatase staining to differentiate canine osteosarcoma from other vimentin-positive tumors

Aspiration of lytic bone lesions is an excellent diagnostic test in the initial evaluation of primary bone neoplasia. However, cytologically, it can be difficult to differentiate osteosarcoma (OSA) from other bone neoplasms, including fibrosarcoma, chondrosarcoma, synovial cell sarcoma, and plasma cell myeloma. The purpose of this study is to determine the sensitivity and specificity of alkaline phosphatase (ALP) staining to differentiate OSA from other tumors that express vimentin by immunocytochemistry or immunohistochemistry. ALP is a hydrolytic enzyme present in multiple tissues including liver, kidney, intestine, placenta, and bone. Hypothetically, neoplasms actively producing bone should be specifically positive for ALP staining. Unstained, cytologic specimens were incubated for 8-10 minutes with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase substrate. A positive reaction stains the membrane of the cells gray to black. Samples were counterstained with a Romanowsky's stain to determine whether the sample was of representative cellularity. A total of 61 vimentin-positive neoplasms have been evaluated and confirmed histopathologically. Tumors that expressed vimentin and were positive for ALP included 33 OSAs, one multi-lobular tumor of bone, one amelanotic melanoma, and one chondrosarcoma. Tumors that expressed vimentin and were negative for ALP included chondrosarcomas (three of four), multiple fibrosarcomas, and multiple synovial cell sarcomas. The sensitivity is 100%, and the specificity is 89%. In conclusion, ALP appears to be a highly sensitive and fairly specific marker in the diagnosis of OSA.     

A critical role of interleukin-10 in the response of bovine macrophages to infection by Mycobacterium avium subsp paratuberculosis

OBJECTIVES: To evaluate the role of interleukin (IL)-10 in the inability of monocyte-derived bovine macrophages to kill Mycobacterium avium subsp paratuberculosis organisms in vitro. SAMPLE POPULATION: Monocytes were obtained from healthy adult Holstein dairy cows that had negative results when tested for infection with M avium subsp paratuberculosis. PROCEDURE: Monocyte-derived macrophages were incubated with M avium subsp paratuberculosis for 2, 6, 24, 72, or 96 hours with or without addition of saturating concentrations of a goat anti-human IL-10 that has been documented to neutralize bovine IL-10 activity. Variables assessed included ingestion and killing of M avium subsp paratuberculosis; expression of tumor necrosis factor (TNF)-alpha, IL-12, IL-8, major histocompatability (MHC) class II, vacuolar H+ ATPase, and B cell CLL/lymphoma 2 (BCL-2); production of nitric oxide; acidification of phagosomes; and apoptosis of macrophages. RESULTS: Neutralization of IL-10 enabled macrophages to kill 57% of M avium subsp paratuberculosis organisms within 96 hours. It also resulted in an increase in expression of TNF-alpha, IL-12, IL-8, MHC class II, and vacuolar H+ ATPase; decrease in expression of BCL-2; increase in acidification of phagosomes; apoptosis of macrophages; and production of nitric oxide. CONCLUSIONS AND CLINICAL RELEVANCE: The capacity of M avium subsp paratuberculosis to induce IL-10 expression may be a major determinant of virulence for this organism.     

Hyoscyamus niger,a useful local lesion host for a mosaic virus in Hippeastrum

Samenvatting Bladeren vanHyoscyamus niger planten vertoonden chlorotische lokale lesies 7 dagen na inoculatie met sap van mozaïekziekeHippeastrum-planten. Met sap vanHippeastrum-planten zonder mozaïeksymptomen werd geen reactie verkregen. In dooppreparaten gemaakt van chlorotische lesies inHyoscyamus-bladeren en van bladeren vanHippeastrum planten met mozaïeksymptomen werden draadvormige virusdeeltjes van 648–772 nm aangetroffen. Het virus kon met sap geperst uit geïnoculeerdeHyoscyamus-planten weer op gezondeHippeastrum-planten worden overgebracht.