Use of Forest Vegetation by Sheep as Recorded by Radio Telemetry

The effect of straw bedding on aggression, production and welfare in loose-housed, pregnant sows was studied in 14 commercial farms, half of them with straw bedding and the other half with a concrete floor. The herds were visited twice and agonistic behaviour was observed. Body lesions, movement disorders and production results were also recorded. There were no significant differences in aggression, body lesions or production results between herds with concrete floor and herds with straw bedding. Movement disorders were more common in herds with concrete floor than in herds with straw bedding. Herds with a high score for movement disorders tended to have a higher percentage of sows returning to oestrus than herds with a low score. Individual data showed no significant correlation between production variables and body lesion score. However, the sows that were culled had a higher mean score for body lesions than the means of both types of farms. Altogether, this study shows that straw bedding was advantageous in preventing leg problems, but the presence of straw did not affect the aggression among sows, the incidence of body lesions or the production results.     

Assessing the relationship between patch type and soil mites: A molecular approach

An urgent need exists for indicators of soil health and patch functionality in extensive rangelands that can be measured efficiently and at low cost. Soil mites are candidate indicators, but their identification and handling is so specialised and time-consuming that their inclusion in routine monitoring is unlikely. The aim of this study was to measure the relationship between patch type and mite assemblages using a conventional approach. An additional aim was to determine if a molecular approach traditionally used for soil microbes could be adapted for soil mites to overcome some of the bottlenecks associated with soil fauna diversity assessment. Soil mite species abundance and diversity were measured using conventional ecological methods in soil from patches with perennial grass and litter cover (PGL), and compared to soil from bare patches with annual grasses and/or litter cover (BAL). Soil mite assemblages were also assessed using a molecular method called terminal-restriction fragment length polymorphism (T-RFLP) analysis. The conventional data showed a relationship between patch type and mite assemblage. The Prostigmata and Oribatida were well represented in the PGL sites, particularly the Aphelacaridae (Oribatida). For T-RFLP analysis, the mite community was represented by a series of DNA fragment lengths that reflected mite sequence diversity. The T-RFLP data showed a distinct difference in the mite assemblage between the patch types. Where possible, T-RFLP peaks were matched to mite families using a reference 18S rDNA database, and the Aphelacaridae prevalent in the conventional samples at PGL sites were identified, as were prostigmatids and oribatids. We identified limits to the T-RFLP approach and this included an inability to distinguish some species whose DNA sequences were similar. Despite these limitations, the data still showed a clear difference between sites, and the molecular taxonomic inferences also compared well with the conventional ecological data. The results from this study indicated that the T-RFLP approach was effective in measuring mite assemblages in this system. The power of this technique lies in the fact that species diversity and abundance data can be obtained quickly because of the time taken to process hundreds of samples, from soil DNA extraction to data output on the gene analyser, can be as little as 4 days.     

Rapid and sensitive quantification of amino acids in soil extracts by capillary electrophoresis with laser-induced fluorescence

A growing body of research is arguing that amino acids are key components of the soil nitrogen cycle. For example, we now know that many plants can take up intact amino acids, even in competition with soil microbes. Our growing recognition of the importance of amino acids is not matched by knowledge of the amounts and type of amino acids in the soil, certainly not in comparison with our encyclopaedic knowledge of inorganic N. The primary reason that less is known about amino acids than inorganic N is that measuring the amounts of individual amino acids with conventional chromatographic techniques is slow and typically requires extensive sample clean-up if KCl extracts are analysed. The aim of this study was to develop capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) as a more rapid alternative for measuring individual amino acids in KCl extracts of soil. The CE-LIF method separated 17 common amino acids within 12 min, with detection limits between 7 and 250 nM. One molar KCl extracts could be analysed without any sample clean-up or de-salting, and spike and recovery tests indicated that the complex matrix of soil extracts did not affect quantification. Further evidence of the suitability and robustness of the method came from the repeated analysis (n=5) of the same soil KCl extract. The relative standard deviation of migration times for replicate analyses were <0.2% while relative standard deviations for peak areas were <5%. To demonstrate application of the CE-LIF method to real world problems it was used to analyse amino acids in 1 M KCl extracts from a sub-alpine grassland and a Eucalyptus regnans forest. The most abundant amino acids were Ala, Gly and Arg. Other amino acids present at smaller concentrations or in a minority of samples were Asn, Cit, GABA, Glu, His, Phe, Leu, and Lys. The proposed CE-LIF method offers significant advantages over chromatographic methods via its rapidity, reproducibility and, most importantly, its ability to analyse crude KCl extracts.     

Bacterial phylogenetic diversity in a constructed wetland system treating acid coal mine drainage

Microorganisms in acid mine drainage are typically acidophiles that mediate the oxidation of reduced compounds of iron and sulfur. However, microbial populations in wetland systems constructed to treat acid mine drainage are not well characterized. The purpose of this study was to analyze bacterial diversity, using cultivation-independent molecular ecological techniques, in a constructed wetland that received acid drainage from an abandoned underground coal mine. DNA was purified from Fe(III)-precipitates from the oxidized surface zone of wetland sediments and 16S rRNA gene sequences were amplified and cloned. A total of 200 clones were analyzed by restriction fragment length polymorphism (RFLP) and 77 unique RFLP patterns were obtained with four restriction enzymes. Of these patterns, 30 most dominant unique clones were selected for sequencing of their 16S rRNA genes. Half of these 30 clones could be matched with autotrophic iron- and sulfur-oxidizing bacteria (Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans). Several clones also formed a clade with heterotrophic iron-oxidizing bacteria (TRA2-10, TRA3-20, and TRA5-3) and heterotrophic bacteria (Stenotrophomas maltophilia, Bordetella spp., Alcaligenes sp., Alcaligenes faecalis, and Alcaligenes xylosoxidans). Approximately 40% and 35% of the analyzed RFLP restriction patterns were consistent with A. ferrooxidans and A. thiooxidans, respectively. The relatively high frequency of acidithiobacilli is consistent with the chemical and physical characteristics of this site—i.e., continuous, abundant supply of reduced iron and sulfur compounds, pH 3–4, ambient temperature, and limited organics originating from the coal seam and from vegetation or soil surrounding the inlet channel to the wetland. The RFLP results were consistent with our previous culture-independent PCR-DGGE and FISH study, showing relatively low bacterial diversity and predominance of mesophilic acidithiobacilli in oxic wetland sediments.     

What is your diagnosis? Biopsy impression smear of a hepatic mass in a yearling Thoroughbred filly

A 1-year-old Thoroughbred filly was presented to the Cornell University Hospital for Animals with a 10-day history of fever, diarrhea, inappetance, and hypodipsia. Clinical pathology abnormalities found by the referring veterinarian included erythrocytosis, hyperproteinemia, and increased serum gamma-glutamyltransferase and lactate dehydrogenase activities. At Cornell University, the laboratory abnormalities were confirmed and also included thrombocytosis and hypoglycemia. Erythrocytosis persisted despite vigorous fluid therapy. Ultrasound examination revealed an extremely enlarged liver with abnormal echogenicity and a 21 x 25-cm hepatic mass with varied echogenicity. Imprints of an ultrasound-guided biopsy of the mass revealed a neoplastic epithelial population of uncertain origin, although the cells did not resemble hepatocytes. Together with the presenting signs, signalment, ultrasonographic findings, and persistent erythrocytosis, the cytologic findings were considered to be most consistent with hepatoblastoma. Histopathologic examination of the mass at necropsy confirmed the diagnosis and findings also included bone marrow erythroid hyperplasia. Serum erythropoietin concentration was 28.0 mU/mL (reference interval 1.0-11.8 mU/mL), supporting erythropoietin production by the tumor and secondary inappropriate erythrocytosis. To our knowledge, this report is the first to document secondary erythrocytosis with increased erythropoietin concentration in a horse with hepatoblastoma, and also the first to describe the cytopathologic features of this rare tumor.     

Cutaneous papillomatosis and carcinomatosis in the Western barred bandicoot (Perameles bougainville)

A progressive wart-like syndrome in both captive and wild populations of the Western barred bandicoot (WBB) is hindering conservation efforts to prevent the extinction of this endangered marsupial. In this study, 42 WBBs exhibiting the papillomatosis and carcinomatosis syndrome were examined. The disease was characterized by multicentric proliferative lesions involving cutaneous and mucosal surfaces, which were seen clinically to increase in size with time. Grossly and histologically the smaller skin lesions resembled papillomas, whereas the larger lesions were most commonly observed to be squamous cell carcinomas. Large amphophilic intranuclear inclusion bodies were observed in hyperplastic conjunctival lesions of 8 WBBs under light microscopy. Conjunctival lesions from 2 WBBs examined using transmission electron microscopy contained a crystalline array of spherical electron-dense particles of 45-nm diameter, within the nucleus of conjunctival epithelial cells, consistent with a papillomavirus or polyomavirus. Conjunctival samples from 3 bandicoots that contained intranuclear inclusion bodies also demonstrated a positive immunohistochemical reaction after indirect immunohistochemistry for papillomavirus structural antigens. Ultrastructural and/or immunohistochemical evidence of an etiologic agent was not identified in the nonconjunctival lesions examined. Here we describe the gross, histopathologic, ultrastructural, and immunohistochemical findings of a papillomatosis and carcinomatosis syndrome recently identified in the WBB.     

Pulmonary Mycobacterium tuberculosis (Beijing strain) infection in a stray dog

Mycobacterium tuberculosis infection in dogs is rarely reported and has not previously been documented in South Africa. A case of a stray Maltese crossbreed dog with extensive multifocal pulmonary tuberculosis due to M. tuberculosis is described. Pulmonary granulomas in this case were poorly encapsulated and contained large numbers of acid-fast bacteria, highlighting the potential for infected companion animals to excrete the pathogen. Treatment of canine tuberculosis is generally not advised, and for this reason, euthanasia of diseased animals must be advocated in most instances. Physicians and veterinarians must be aware that companion animals with active disease caused by M. tuberculosis could act as a potential source of infection.     

Hepatic intranuclear glycogen inclusions in western barred bandicoots (Perameles bougainville).

The western barred bandicoot, Perameles bougainville, is an endangered Australian marsupial species. Routine histology of liver samples collected at necropsy from 19 of 20 (95%) western barred bandicoots revealed the sporadic to common occurrence of abnormal hepatocyte nuclei characterized by margination of chromatin and concomitant central pallor. Some abnormal hepatocyte nuclei were mildly to markedly enlarged and irregularly shaped. Periodic acid-Schiff reagent stained 131 of 142 (92%) of these abnormal hepatocyte nuclei. Positive staining was completely eliminated by diastase pretreatment. Transmission electron microscopy revealed that abnormal hepatocyte nuclei with marginated chromatin did not contain viral particles. Rather, glycogen beta-particles and alpha-rosettes were identified within some abnormal hepatocyte nuclei. Glycogen intranuclear inclusions were an incidental finding in western barred bandicoot hepatocytes.     

Nutritional management of recurrent colic and colonic impactions

Although diagnosis and treatment of horses with colic have improved in the last 30 years, horses with recurrent colic can be a diagnostic and management challenge for both owners and veterinarians, and colic remains a high priority health concern of owners (Mellor et al. 2001 ). Nutritional management of these cases is often based on previous experience combined with recommendations from the evidence‐based literature. This review will briefly summarise the aetiologies of recurrent colic and primarily focus on evidence‐based nutritional management of colonic impactions, sand enteropathy, inflammatory bowel disease, and idiopathic recurrent colic, which is limited. Additional topics to be covered elsewhere in this series that are relevant to this topic include nutritional management of gastric ulceration, liver disease, colitis, geriatric horses, and feeding the horse pre‐ and post surgery.     

Ranking State Environmental Outputs: Evidence from Panel Data

This paper uses state‐level pollution data from 1986–1997 to construct two indices that rank U.S. states according to environmental outputs. A major finding is that marginal performers in other indices, such as Wyoming, garner top spots in these ranking systems. The paper also presents findings from fixed and random effects models of panel data that imply state income levels are positively associated with environmental outputs after a threshold level of income is obtained.