Presence of Ureaplasma diversum in the Australian cattle population

In cattle, Ureaplasma diversum has been associated with decreased fertility, granular vulvovaginitis, endometritis, salpingitis and spontaneous abortion in cows and seminal vesiculitis, balanoposthitis and changes in bull sperm. The presence of U. diversum within the Australian cattle population has not been established. One of the aims of this study was to determine if U. diversum was present in Australian cattle, using culture and polymerase chain reaction (PCR), both of which are considered to be gold standards for bacterial identification. Of 100 samples collected from 66 male and 34 female cattle, 15 were positive for U. diversum. Therefore, Australia can no longer be considered free of U. diversum. Further studies should be conducted to ascertain the effects of U. diversum within Australian cattle herds and, if warranted, to investigate prevention, treatment and eradication protocols.     

Effect of farm management on topsoil organic carbon and aggregate stability in water: A case study from Southwest England,UK

There are few reliable data sets to inspire confidence in policymakers that soil organic carbon (SOC) can be measured on farms. We worked with farmers in the Tamar Valley region of southwest England to select sampling sites under similar conditions (soil type, aspect and slope) and management types. Topsoils (2–15 cm) were sampled in autumn 2015, and percentage soil organic matter (%SOM) was determined by loss on ignition and used to calculate %SOC. We also used the stability of macroaggregates in cold water (WSA) (‘soil slaking’) as a measure of ‘soil health’ and investigated its relationship with SOC in the clay‐rich soils. %SOM was significantly different between management types in the order woodland (11.1%) = permanent pasture (9.5%) > ley‐arable rotation (7.7%) = arable (7.3%). This related directly to SOC stocks that were larger in fields under permanent pasture and woodland compared with those under arable or ley‐arable rotation whether corrected for clay content (F = 8.500, p < .0001) or not (F = 8.516, p < .0001). WSA scores were strongly correlated with SOC content whether corrected for clay content (SOC_adj R² = .571, p < .0001) or not (SOC_unadj R² = 0.490, p = .002). Time since tillage controlled SOC stocks and WSA scores, accounting for 75.5% and 51.3% of the total variation, respectively. We conclude that (1) SOC can be reliably measured in farmed soils using accepted protocols and related to land management and (2) WSA scores can be rapidly measured in clay soils and related to SOC stocks and soil management.     

Grain yield of wheat (Triticum aestivum L.) under long‐term heat stress is sink‐limited with stronger inhibition of kernel setting than grain filling

The aim of the study was to investigate source‐sink relations of wheat under continuous heat stress and to identify bottle necks of yield formation. A pot experiment was conducted in two climatic chambers exposing wheat plants (Triticum aestivum L. cv. Thasos) either to day/night temperatures of 20/20°C (control conditions) or of 30/25°C (heat stress) during the whole vegetation period in the absence of plant water deficit. Plants were harvested at four phenological stages: three‐node stage (DC 33), start of flowering (DC 61), grain filling (DC 75) and maturity (DC 94). Heat stress shortened the development phases of the plants and caused a significant decrease in total above‐ground biomass between 19% and 41%. At grain filling and at maturity, the reductions in total shoot biomass mainly resulted from grain yield depressions by 77% and 58%, respectively. The ear number per plant was significantly higher under heat stress in comparison with the control, at maturity it was more than doubled. On the contrary, under heat stress, the kernel number per ear was strongly decreased by 83% and 75% during grain filling and at maturity, respectively. The decrease in individual kernel weight was 23% at maturity. Thus, the heat‐stressed plants were able to strongly increase the number of ear‐bearing tillers which were able to set only a small number of kernels, yet these kernels showed good grain filling. The harvest index (HI) of heat‐stressed plants was significantly reduced by 36% (control: HI = 50.1% ± 0.4, heat: HI = 32.2% ± 0.9***). The plants in the stress treatment adapted to the adverse conditions by less biomass production which presumably allowed a higher transpiration without an increase in total water consumption. Nevertheless, under heat stress, the water use efficiency (WUE_grain) was strongly decreased by 62% as a result of a small grain yield. In ears and grains, the sucrose, glucose and fructose concentrations were not significantly different between control and heat stress at start of flowering and during grain filling. Thus, the supply of assimilates was not restricted (no source limitation). Sink capacity was reduced by heat stress, as lesser and smaller kernels were produced than in the control. Concerning sink activity, the sink‐limiting step during kernel set is probably the active transport of hexoses across the plasma membrane into the developing kernels, which could also affect grain filling. This needs to be investigated in more detail in further studies.     

Filamentous Intranuclear Inclusion Bodies in Psittacine Birds. A Structural and Ultrastructural Study

This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2–3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes.     

Immunophenotypic and histological characterisation of 109 cases of feline lymphosarcoma

OBJECTIVE: To determine and analyse the immunophenotype and histological appearance of naturally occurring cases of lymphosarcoma in Australian cats. DESIGN: A prospective multi-institutional study of naturally occurring feline lymphosarcoma. METHODS: One hundred and eighteen cats were referred for diagnosis and/or management of suspected lymphosarcoma. Tissue samples for histopathological analysis and immunophenotyping were collected as biopsies or at necropsy from 109 cases. Histological classification of the neoplasms followed the Working Formulation Classification System. Four multi-species cross-reactive antibodies were used to classify tumours as having a B or T cell phenotype. RESULTS: Seventy-six (70%) cases were B cell tumours and 28 (26%) were T cell tumours. The remaining 5 (4%) specimens failed to stain with the four antibodies. Histologically, 11 (10%) cases were classified as low-grade, 72 (66%) were medium-grade and 26 (24%) were high-grade tumours. There were no significant associations between age and either histological grade or immunophenotype. Mediastinal and leukaemic cases were significantly more likely to be T cell tumours (P < 0.001 and P < 0.001, respectively). CONCLUSIONS: In contrast to previously documented studies in the cat, the majority of cases of lymphosarcoma were of B cell phenotype and intermediate histological grade. Based on our data, the histological phenotype of lymphosarcoma is unlikely to predict immunotype, nor are cases of certain immunotypes likely to be of specific histological subtype. Considered in relation to previous reports, the findings suggest that epidemiological factors operating in these cats to produce lymphosarcoma may be different to those operating in North American and UK cat populations.     

From science to application: field demonstrations to enhance sustainable rice production in the north of Vietnam—lessons from the LEGATO project

Two major human-made problems in rice production systems in the north of Vietnam concern the low plant-available silicon content of soils and the low biodiversity. The results of the LEGATO project suggest a change to an environmentally friendly rice production system that will help to recover biodiversity. We propose here a framework for a demonstration and dissemination model that will be exemplary for the farmers once it has been successfully realized. We advocate local-option models in different districts to demonstrate to farmers. The methods should be adapted to local and ecoregional differences in climate and land-use tradition, and they explicitly take into account soil care, organic fertilizer, manual weeding, native nectar-rich plant bunds, manual pest snail collection, hymenopteran nesting aids, and biodiversity and yield monitoring.     

Nutritional muscular dystrophy in a four-day-old Connemara foal

This report describes a four-day-old, full-term Connemara colt, presented for the evaluation of a progressive inability to rise unassisted. A diagnosis of nutritional muscular dystrophy was made based on muscular weakness, elevated muscle enzymes and low vitamin E, selenium and glutathione peroxidase activity. The foal was treated with intramuscular vitamin E-selenium and made a full recovery.     

Cytopathological and histopathological diagnosis of canine splenic disorders

Objectives To determine (1) the common types of canine splenic disorders, and the breeds affected, that are diagnosed by cytopathological and histopathological examination in Sydney, Australia and (2) the accuracy of cytopathological examination compared with histopathological examination for the diagnosis of canine splenic disorders. Design 69 cytopathological and 51 histopathological diagnoses of canine splenic disorders presented to the Veterinary Pathology Diagnostic Services, The University of Sydney during 2006 and 2007 were tabulated and analysed; 17 cases examined both cytopathologically and histopathologically during 2001–07 were also analysed. Results The most common cytopathological diagnoses were benign disorders of growth, vascular disturbances and necrosis (29%), followed by no abnormalities detectable (28%), malignant neoplasms (20%), equivocal diagnoses (20%) and inflammatory disorders (3%). The most common breeds were Kelpie crosses and mixed breeds. The most common histopathological diagnoses were benign disorders of growth, vascular disturbances and necrosis (49%), followed by malignant neoplasms (43%) and inflammatory disorders (8%). The most common breeds were German Shepherd Dogs, Boxers and Maltese Terriers. Cytopathological and histopathological diagnoses were in complete agreement in 59% of cases, partial agreement in 29% and disagreement in 12%. Conclusion Benign disorders of growth, vascular disturbances and necrosis were the most commonly diagnosed canine splenic disorders, both cytopathologically and histopathologically. Kelpie crosses presented most frequently for cytopathological examination. German Shepherd Dogs were the most common breed diagnosed histopathologically with haemangiosarcoma. Although cytopathological and histopathological splenic examinations are complementary for diagnosis, this study has shown a high correlation for complete and partial agreement between the two.     

The bioavailability of arsenic in floodplain soils: a simulation of water saturation

The soils of the floodplains of the German rivers Elbe, Mulde and Saale are often contaminated with arsenic (As). The total As concentration in soil is, however, not related to As concentration in the plant biomass and thus is unsuitable for evaluating the risk of As transfer into the food chain. The aim of the present study was to establish a method that assesses the bioavailability of As in floodplain soils and takes possible changes in the mobility of As with changing redox potential into account. Samples from the floodplain of the river Mulde were saturated with water for 34 days. A soil solution was sampled every second day and the concentrations of As species and total iron (Fe) were determined. The redox potential was measured in situ . Lepidium sativum L. (garden cress) was cultured in cylinders to assess the availability of As to the plant. In addition, extraction methods were used to define operationally different As-binding forms. Arsenic in the soil samples was predominantly bound to poorly crystalline (hydr)oxides. These (hydr)oxides are likely to be affected by changing redox conditions. On saturation, 18 soil samples could be divided into two groups based on the temporary changes in redox potential and subsequent changes in the As concentration of the soil solution. Water-extractable organic carbon was identified as the reason for the differences between the two groups. As the field site is periodically flooded, it is likely that the samples that exhibit decreasing redox potential in the experimental system will also pass through redox cycles more frequently in the field. The frequency of redox cycles, in turn, strongly affects the Fe (hydr)oxide phase and the binding of As. In the present study these differences between the two groups were reflected in the different relationships between NH₄ oxalate-extractable Fe (Fe_o) and As (As_o).