Relationship between mastitis pathogen numbers in bulk tank milk and bovine udder infections in California dairy herds

Samples of bulk tank milk and cow-composite milk from 23,138 dairy cows from 50 California dairies were examined by use of microbiologic procedures. The number of colonies of mastitis pathogens isolated per milliliter of bulk tank milk (used as a predictor of the percentage of infected cows in the herd) was evaluated, using simple regression analysis and Spearman's rank correlation. Correlations between the pathogens and the percentage of cows in each herd shedding the pathogens were found for Streptococcus agalactiae (r = 0.71) and mycoplasma (r = 0.59), but were considerably lower for other pathogens. When greater than or equal to 4,000 colonies of Streptococcus agalactiae were found per milliliter of bulk tank milk, at least 7% of the cows in the herd was shedding this organism. However, a pattern was not found between the number of mycoplasma colonies per milliliter of bulk tank milk and the percentage of infected cows in the herd.     

Ovine Pulmonary Adenomatosis in Patagonia,Argentina

An outbreak of pulmonary adenomatosis (OPA) occurred in sheep in Patagonia, Argentina's southernmost region. On the affected farm, nine animals died over a 6-month period with pulmonary lesions of OPA. In all cases, the histology of the lungs was characterized by proliferation of cuboideal and prismatic cells lining the alveoli. Inflammatory exudates and accumulation of alveolar macrophages were marked in most cases, but in six of the cases there was no excess fluid in the airways. The presence of the Jaagsiekte retrovirus was demonstrated in the lungs by immunocytochemistry and PCR. To the best of our knowledge, this is the first report of OPA in Patagonia.     

Bovine herpesvirus 4-associated postpartum metritis in a Spanish dairy herd

In more than 10 Spanish dairy cows, a bovine herpesvirus 4 (BHV4) associated postpartum metritis was confirmed by virus isolation, BHV4-glycoprotein B (gB) PCR and/or serology. In this study, 12 cows with, and, at the time of sampling, 3 cows without clinical signs of acute postpartum metritis from one large dairy herd in Spain were examined for bacterial and viral infections. Blood, placenta/caruncles and uterine contents were collected between day 1 and day 20 post-calving, and examined for the presence of bacteria and for viruses by virus isolation, BHV4 DNA by BHV4-gB PCR and/or BHV4 antibody titres. Bovine herpesvirus 4 was detected in 83% of the cases with clinical signs of acute postpartum metritis by virus isolation and/or BHV4-gB PCR. An increase of BHV4 antibodies was detected in all examined postpartum metritis cows and in the 3 cows without clinical metritis. Two of these 3 cows developed severe metritis a few dayss after collecting the first blood sample. A concurrent infections of BHV4 and bacteria, mainly Arcanobacterium pyogenes and Streptococcus sp., were detected in 73% of the examined uterine contents collected from postpartum metritis affected cows. This case-report study showed a clear association between BHV4 infections and acute postpartum metritis in dairy cows. In addition, the BHV4-associated postpartum metritis appeared to be an emerging syndrome in this Spanish herd.     

Dairy cow preference for a soft track surface

Abstract

Extract

As dairy herds get larger cows have to walk further, and foot care becomes more important. Lameness from bruising of the soles of the feet is a particular hazard (Tranter and Morris 1991 Tranter, W P and Morris, RS. 1991. A case study of lameness in three dairy herds. New Zealand Veterinary Journal, 39: 88–96. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar], especially on hard tracks with loose angular stones or grit (Clackson and Ward 1991 Clackson, DA and Ward, WR. 1991. Farm tracks, stockman's herding and lameness in dairy cattle. Veterinary Record, 129: 511–512.  [Google Scholar]. One way of reducing this problem might be to provide an overlay of woodchips on top of the normal hard track. This would provide a softer grit-free surface, which could be more comfortable for the cows.     

The Neocortex of the Dog

This article describes the structural organization of the neocortex of the dog from purely morphological point of view. Series of 50 urn transverse sections were cut from the frozen right hemiencephala of adult greyhounds, stained by N issl's method, and drawn. His's method was then used to construct life-size lateral, dorsal and medial views of the hemiencephalon from 38 sections located at regular intervals. Once the cytoarchitectonic criteria to be used had been established on the basis of preliminary observations, all the sections of each hemiencephalon were examined microscopically and the cytoarchitectonic types observed in each mapped on the corresponding drawing. These maps were then projected onto lateral, dorsal and medial views of the whole hemiencephalon to produce a classical cytoarchitectonic map of the neocortex made up of 21 types, 7 of them agranular (with no inner granular layer), 2 dysgranular (with a granular layer with diffuse boundans) and the rest granular (with a well-defined layer IV). Various areas of cortex whose characteristics were intermediate between those of adjoinin areas were classified in a residual typus intermedius.     

Differential response of cull cow muscles to the hypertrophic actions of ractopamine-hydrogen chloride

Ractopamine-HCl (RAC) is a beta-adrenergic agonist with variable effects on cattle performance and carcass variables. Cull cows fed RAC (200 mg . head(-1) . d(-1)) demonstrate an increased size of type I and II muscle fibers that does not translate into a larger ribeye area. The objective of this study was to examine the dose-dependent effects of RAC on cull cow muscle morphometrics. Eighty-eight cull beef cows representing 2 breed types (n = 44 each) were fed 0, 100, 200, and 300 mg . head(-1) . d(-1) of RAC for the last 28 d of a 54-d feeding period. On d 54, cows were slaughtered, and samples of the LM and semimembranosus muscle (SM) from 16 randomly selected carcasses (n = 4 per treatment) were taken for measurement of beta (2)-adrenergic receptors and type I, IIA, and IIX myosin heavy chain (MyHC) gene expression. Twenty-four hours postmortem, LM, SM, infraspinatus (INF), and vastus lateralis samples from 40 randomly selected carcasses (n = 10 per treatment) were obtained and frozen for immunohistochemical analysis. Muscle fiber cross-sectional area and diameter, MyHC isoform expression, and fiber-associated nuclei numbers were measured. Ractopamine dosage exhibited differential effects on muscle morphometrics and MyHC gene expression. Muscle fiber cross-sectional area and diameter were increased (P < 0.05) by RAC in INF type I and IIA fibers and SM type IIA fibers. Ractopamine increased (P < 0.05) MyHC type IIX mRNA and tended to increase (P < 0.10) beta(2)-adrenergic receptors in the SM; a change in mRNA abundance was not detected for either gene in the LM. Treatment with RAC decreased (P < 0.05) fiber-associated nuclei numbers in the INF, vastus lateralis, and LM but did not affect (P > 0.05) MyHC or beta-adrenergic receptor expression. These results indicate that cull cow feeding programs may consider supplementing RAC as a means of adding value to cuts within the chuck, such as the INF.