Contagious bovine pleuropneumonia--a nearly forgotten disease?

Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) is a notifiable disease and has to be reported to the World Organisation for Animal Health (Office International des Epizooties, OIE, http://www.oie.int). Despite the fact that the last reported cases in Germany date back to 1926, the risk of introduction through clinically inconspicuous animals from countries where the disease is still endemic is rising. This is due mainly to an increase in international trade of live cattle and the failure to contain CBPP in many parts of Africa and elsewhere. To detect and eliminate this highly contagious infectious disease of the bovine respiratory tract, it is necessary to recognize matching clinical symptoms as soon as possible, as well as to have efficient methods for its detection on hand. In the present paper, we describe clinical manifestations and review state-of-the-art research, as well as currently used detection methods.     

The bovine pituitary‐adrenocortical axis and milk yield

Summary

A review is given of the available literature concerning the relationship between the bovine pituitary‐adrenocortical axis and milk yield in dairy cattle. A severe drop in milk yield (more than 50%) can be induced by a single or repeated intramuscular injection of at least 200 IU ACTH or by a single intramuscular injection of 14.6 mg dexamethasone. Sixty minutes after an intravenous injection, both 200 IU ACTH and 100 mg cortisol are equivalent to a plasma cortisol concentration of at least 31 ng/ml. Thus the decrease in milk yield after an intramuscular injection of more than 200 IU ACTH can hardly be induced by cortisol only. The fact that bovine plasma hardly binds any dexamethasone, in sharp contrast with bovine mammary epithelial tissue, is a possible explanation of the special part which dexamethasone plays in milk yield.     

La mammillite herpétique bovine au Québec

Bovine herpetic mammillitis in Quebec     

Horse anti‐bovine lymphocyte serum. Its effect in calves

Summary

Anti‐bovine lymphocyte serum (ABLS) had been prepared in horses with calf thymocytes as antigen and its effects in calves following parenteral administration were studied. The optimal dose was found to be one ml/kg body weight. The A BLS suppressed both the T and B cell functions. The former was indicated by the disturbed response to sheep erythrocytes injections, by the decreased number of spontaneous E rosette forming lymphocytes, the prolonged survival of skin allografts and the significant inhibition of the delayed hypersensibility skin reaction (tuberculination) following administration of Mycobacterium microti. The latter was based on the disturbed response to a subcutaneous dose of tetanus toxoid. The reaction of lymphocytes of ABLS treated calves to phytohemagglutinin and poke weed mitogen was also inhibited. The disturbed reactions of the T and B cells might be among others based on the strong reduction of lymphocytes in the blood circulation by ABLS (up to 10–20%).

Suggestions with regard to further applications and studies with ABLS were given.     

Does control of bovine viral diarrhoea infection make economic sense?

AIM: To provide an economic analysis of the costs of control or eradication of bovine viral diarrhoea (BVD) against the estimated costs of the disease. METHODS: A decision-tree approach was adapted to an analysis of the costs of bovine viral diarrhoea virus (BVDV) infection and that of three main control options (vaccination, test-and-cull, and increased biosecurity) and their combinations, to the dairy industry in New Zealand. The model was based on an average herd of 322 milking cows. Endemic, epidemic and sporadic effects of BVDV infection were modelled in the herd, to derive an estimate of costs. RESULTS: The cost of BVDV infection to an infected average-sized dairy herd in New Zealand was estimated to be NZ $11,334 (or NZ $35.19 per cow) per annum, and NZ $48,311 over 10 years. Based on these calculations, the estimate of the annual cost of BVDV infection to the dairy industry in New Zealand was in excess of NZ $23 million per annum. While all of the control options required financial input, the rate of return compared with the cost of BVD, when viewed over a 10-year term, was as high as 123%. CONCLUSIONS: All control options offered considerable savings compared with the cost of BVD infection, and control is economically favourable. Uncertainty over the likely efficacy of the control options under field conditions in New Zealand would not allow a firm choice of one option over another at this stage, and more work on determining the efficacy of those control options in New Zealand is needed.     

Presumptive bovine neonatal pancytopenia in a Holstein calf in Québec

An 18-day-old heifer was presented with fever, depression, tachycardia, tachypnea, and prolonged bleeding time. Blood tests revealed severe anemia, thrombocytopenia, and leucopenia. The animal was negative by PCR for bovine virus diarrhea virus antigen. The findings supported a diagnosis of bovine neonatal pancytopenia. Treatments included fresh whole blood transfusion and antibiotics. The animal recovered fully.     

Pro-inflammatory and pro-apoptotic responses of TNF-α stimulated bovine mammary endothelial cells

Coliform mastitis may be severe in periparturient cows due to enhanced expression of pro-inflammatory cytokines that contribute to disease pathogenesis. Tumor necrosis factor (TNF)-α is implicated with the severity of coliform mastitis by provoking inflammatory responses in affected tissues. The endothelium is an integral organ in regulating inflammatory responses and loss of endothelial integrity may be fatal. Studies in humans suggest that endothelial cell apoptosis may be a consequence of TNF-α exposure and contributes to the development of sepsis, however, its impact on bovine mammary endothelial cells (BMEC) is unknown. We sought to determine the inflammatory and apoptotic responses of primary BMEC exposed to TNF-α in vitro. Stimulation of endothelial monolayers with TNF-α resulted in significant increase of toll-like receptor 4, interleukin-6 and -8, and intercellular adhesion molecule-1 and vascular cellular adhesion molecule-1 gene expression in a time-dependent manner. Caspase-8 and caspase-3 mRNA expression, as well as caspase enzyme activity, also increased significantly following TNF-α stimulation. Cell viability assessed by ATP activity and BMEC apoptosis determined by flow cytometry revealed no significant changes across time with TNF-α stimulation. Results suggest that TNF-α stimulation, at the dose used in this study, can elicit a pro-inflammatory response in BMEC, but not induce apoptosis. The impact of TNF-α on mammary vascular function and the subsequent impact on the pathophysiology of severe coliform mastitis warrant further investigation.     

Detection and characterisation of bovine rotavirus in Ireland from 2006–2008

Background

Worldwide, Group A bovine rotavirus (RVA boRV) is one of the main causes of neonatal calf diarrhoea. Currently, limited epidemiological and sequence data exists on the RVA disease in bovines in Southern Ireland only. The aim of the study was to generate epidemiological and sequence data of RVA boRV distributed over a wide geographical area in Ireland.

Findings

272 stool samples were obtained from symptomatic calves and analysed to identify the prevalent G and P genotypes. Viral type combinations including G6P[5], G6P[11] and G10P[11] genotype were the most frequently identified. The G6P[5] combination was predominant throughtout the study, accounting for 70% (n = 191). Sequence analysis of the VP7 gene revealed that Irish G6 strains fell within Lineage IV, similiar to previous reports in Ireland.

Conclusion

The detection of unusual G and P combinations may have an impact on rotavirus control programmes and current vaccines may need to incorporate new strains, as the current vaccine available may not offer protection against all of these circulating types.     

Is poly(ADP-ribose) polymerase involved in bovine placental retention?

Poly(ADP-ribose) polymerase (PARP) is the enzyme which utilises NAD to synthesise poly(ADP-ribose) polymers. This process appears in response to DNA lesions. Oxidative stress, which might be involved in bovine placental retention, is the reason for oxidative DNA injury. In this mini-review, the relationship between PARP activity and bovine placental retention is discussed. The results of our experiments on PARP activity in placental tissues showed that the enzyme of 113 kDa and its cleavage products were present in retained as well as released fetal membranes. Western blotting technique showed different intensities in the staining of bands which might suggest different activities of the enzyme.     

Zilpaterol hydrochloride alters abundance of β-adrenergic receptors in bovine muscle cells but has little effect on de novo fatty acid biosynthesis in bovine subcutaneous adipose tissue explants

We predicted that zilpaterol hydrochloride (ZH), a β-adrenergic receptor (AR) agonist, would depress mRNA and protein abundance of β-AR in bovine satellite cells. We also predicted that ZH would decrease total lipid synthesis in bovine adipose tissue. Bovine satellite cells isolated from the semimembranosus muscle were plated on tissue culture plates coated with reduced growth factor matrigel or collagen. Real-time quantitative PCR was used to measure specific gene expression after 48 h of ZH exposure in proliferating satellite cells and fused myoblasts. There was no effect of ZH dose on [(3)H]thymidine incorporation into DNA in proliferating myoblasts. Zilpaterol hydrochloride at 1 μM decreased (P < 0.05) β1-AR mRNA, and 0.01 and 1 μM ZH decreased (P < 0.05) β2-AR and β3-AR mRNA in myoblasts. The expression of IGF-I mRNA tended to increase (P = 0.07) with 1 μM ZH. There was no effect (P > 0.10) of ZH on the β-AR or IGF-I gene expression in fused myotube cultures at 192 h or on fusion percentage. The β2-AR antagonist ICI-118, 551 at 0.1 μM attenuated (P < 0.05) the effect of 0.1 μM ZH to reduce expression of β1- and β2-AR mRNA. The combination of 0.01 μM ZH and 0.1 μM ICI-118, 551 caused an increase (P < 0.05) in β1-AR gene expression. There was no effect (P > 0.10) of ICI-118, 551 or ZH on β3-AR or IGF-I. Western blot analysis revealed that the protein content of β2-AR in ZH-treated myotube cultures decreased (P < 0.05) relative to control. Total lipid synthesis from acetate was increased by ZH in bovine subcutaneous adipose tissue explants in the absence of theophylline but was decreased by ZH when theophylline was included in the incubation medium. These data indicate that ZH alters mRNA and protein concentrations of β-AR in satellite cell cultures, which in turn could affect responsiveness of cells to prolonged ZH exposure in vivo. Similar to other β-adrenergic agonists, ZH had only modest effects on lipid metabolism in adipose tissue explants.     

A role for the Clostridium perfringens beta2 toxin in bovine enterotoxaemia?

Non-enterotoxigenic type A Clostridium perfringens are associated with bovine enterotoxaemia, but the alpha toxin is not regarded as responsible for the production of typical lesions of necrotic and haemorrhagic enteritis. The purpose of this study was to investigate the putative role of the more recently described beta2 toxin. Seven hundred and fourteen non-enterotoxigenic type A C. perfringens isolated from 133 calves with lesions of enterotoxaemia and high clostridial cell counts (study population) and 386 isolated from a control population of 87 calves were tested by a colony hybridisation assay for the beta2 toxin. Two hundred and eighteen (31%) C. perfringens isolated from 83 calves (62%) of the study population and 113 (29%) C. perfringens isolated from 51 calves (59%) of the control population tested positive with the beta2 probe. Pure and mixed cultures of four C. perfringens (one alpha+beta2+, one alpha+enterotoxin+ and two alpha+) were tested in the ligated loop assay in one calf. Macroscopic haemorrhages of the intestinal wall, necrosis and haemorrhages of the intestinal content, and microscopic lesions of necrosis and polymorphonuclear and mononuclear cell infiltration of the intestinal villi were more pronounced in loops inoculated with the alpha and beta2-toxigenic C. perfringens isolate. These results suggest in vivo synergistic role of the alpha and beta2 toxins in the production of necrotic and haemorrhagic lesions of the small intestine in cases of bovine enterotoxaemia. However, isolation of beta2-toxigenic C. perfringens does not confirm the clinical diagnosis of bovine enterotoxaemia and a clostridial cell counts must still be performed.     

Undifferentiated bovine respiratory disease (shipping fever): Is it communicable?

A study was conducted on 6–8-month old calves entering 2-research facility feedlots in 1983–1985, to examine if the occurrence of undifferentiated bovine respiratory disease (BRD) clustered within pens. For the purposes of analysis, 12 different groups of cattle were formed based on the source of cattle within year and/or year of arrival.The morbidity rates of BRD ranged from 5.7 to 64% and varied significantly from group to group (i.e., source to source) within year and from year to year. In all groups except one, the secondary attack (morbidity) rates were lower than the morbidity rates.An algorithm to examine for extra-binomial variation was used to formally examine for pen effects (clustering of disease within pen). In all models, a simple binomial model was sufficient to describe the data, i.e., the usual binomial parameter was estimated to describe the mean level of BRD by group, no additional parameter estimates were required to describe pen effects within group.Thus, although BRD has important pathogens as part of its sufficient causes, there is no evidence that clinical disease in one individual increases the risk of disease for other cattle in the same pen.     

Spatial seroprevalence of bovine brucellosis in India—A large random sampling survey

Brucellosis caused by Brucella spp. is an important zoonosis and constitutes a serious public health hazard. In India, the disease is increasingly prevalent among bovine population with high zoonotic potential and negative impact on national economy. The investigation was conducted to study seroprevalence of brucellosis through random sample survey using survey tool box software. A total of 12,054 [cattle-9236, buffaloes-2818] bovine serum samples sourced from 15 states of India were tested by protein G indirect ELISA. The true prevalences of brucellosis observed in cattle and buffaloes were 8.3% and 3.6%, respectively. The highest prevalence of brucellosis was observed in the state of Punjab in both cattle and buffaloes (23.51 and 10.2%). Comparatively higher prevalence was recorded in cattle than the buffaloes in all the states except Manipur. The true prevalence greater than 5% was recorded in 8 and 3 states for cattle and buffaloes, respectively [(cattle- Punjab, Maharashtra, Rajasthan, Karnataka, Madhya Pradesh, Tamil Nadu, Gujarat and Kerala) and (buffaloes-Punjab, Gujarat and Manipur)] indicating wider prevalence of brucellosis. This study conclusively highlighted the seroprevalence of bovine brucellosis at state level which might be useful for prioritizing regions for vaccination, designing control strategies and improvisation of clinical surveillance system.     

Prototheca zopfii genotype 2: the causative agent of bovine protothecal mastitis?

In order to clarify the epidemiology of bovine protothecal mastitis, 30 Prototheca zopfii mastitis isolates were genetically investigated. Based on the 18S rDNA, which allows a differentiation of the former species P. zopfii in two distinct P. zopfii genotypes and Prototheca blaschkeae sp. nov., newly developed genotype-specific PCR-assays as well as RFLP-assays were applied.

All mastitis isolates investigated could be assigned to P. zopfii genotype 2 suggesting that this genotype is the aetiological agent of bovine Prototheca mastitis.