A framework for evaluation of on-farm mastitis diagnostics in Australia

Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.     

MECHANICAL TREATMENT FOR IMPROVING UPLAND GRAZING

The botanical changes in a wet ( Molinia ) and a drier ( Nardtts ) upland pasture that followed a single defoliation by a forage harvester are briefly described. Without fertilizer the bare and litter-covered areas were soon recolonized by the original dominants; with lime and fertilizer the recolonization was mainly by Agrostis spp., even when Agrostis was a minor element in the original sward. These changes were markedly accelerated by the forage-harvester treatment. The results of surface seeding after the forage-harvester treatment are compared with those obtained after rotary cultivation. Contrasting moisture regimes and competitive thresholds led to considerable differences in sward balance and in establishment of sown species, and seeding was successful only on the wetter site. Too rapid regeneration of undesirable remnants was prevalent, but this and other hazards are related to the uneven deposit of litter left by the forage harvester; thick, slowly-rotting accumulations inhibited the redevelopment of rapidly-growing species and germination on seeded areas.     

Soil and erosion features of the central plateau region of Tigrai,Ethiopia

The results of reconnaissance soil surveys covering 6,000 km² are used to describe the Central Plateau region, which lies at elevations of 2,000 to 2,800 m in northern Ethiopia. Landform and soil sequences on calcareous shales, dolerites and sandstones are described, in which the principal soil units are Lithosols, Luvisols, Cambisols, Arenosols and Vertisols. Detailed morphological and analytical data are presented for a profile representative of arable soils in each sequence.Small-scale subsistence cultivation of cereals is the dominant land use; all land which is physically cultivable is at present cultivated. Settlement patterns are closely related to soil type, nucleated settlement occurring on fine textured soils but dispersed settlement on coarser textured and more freely draining soils.Erosion and soil moisture features of the three landforms described were investigated and compared. Empirical methods and suspended sediment measurements indicate high rates of regional soil loss (17–33 t ha^?1 yr^?1), accounted for by seasonally high rates of rainfall erosivity, steep terrain and poor land use. The recent development of gully erosion is seen to be linked to the disintegration of waterfall tufas. Application of the universal soil loss equation to arable lands indicates potential annual soil losses in the range of 400 t ha^?1 on Vertisols to 200 t ha^?1 on Cambisols: differences in rates are ascribed principally to differences in crop planting dates, which affect the degree of vegetative protection during periods of high rainfall erosivity.Soil moisture is shown to be in the available range for less than three months in the year. The time at which moisture in the profile enters the available range differed between the three soils monitored and was found to be closely related to the crop planting date, thus indirectly affecting the erosion hazard.     

Aetiology and diagnosis of persistent nasal disease in the dog: a retrospective study of 42 cases

Forty-two dogs with a history of persistent nasal disease were evaluated by a combination of clinical examination, thoracic and nasal radiography, retroflexed endoscopy and biopsy, and anterograde rhinoscopy and blind nasal biopsy. A definitive diagnosis was made in 91 per cent of cases. Neoplasia was the most common diagnosis (33 per cent of cases), followed by inflammatory rhinitis (24 per cent). Other diagnoses included periodontal disease (10 per cent), aspergillosis (7 per cent) and foreign bodies (7 per cent). Adenocarcinoma was the most common tumour diagnosed. The clinical findings were found to be too variable to be used as specific diagnostic criteria. Anterograde rhinoscopy and retroflexed endoscopy had higher specificity and sensitivity than radiology for the diagnosis of neoplasia, inflammatory rhinitis, aspergillosis and foreign bodies. With a systematic approach to the investigation of persistent nasal disease, a definitive diagnosis can be successfully obtained in the vast majority of cases.     

Resolution of skin lesions and long-term survival in a dog with superficial necrolytic dermatitis and liver cirrhosis

A nine-year-old, neutered female Shetland sheepdog was presented with crusted, ulcerative skin lesions affecting the footpads, commissures of the lips and the lateral canthi of the eyes. Histopathological examination of skin biopsies revealed changes consistent with superficial necrolytic dermatitis and biochemical analysis demonstrated elevated liver enzymes. Abdominal radiography revealed a small liver which, on ultrasonography, appeared diffusely mottled and showed changes suggestive of periportal fibrosis. On exploratory laparotomy, the pancreas appeared normal, but the liver was small and had multiple nodules throughout the parenchyma. This appearance was confirmed as cirrhosis on histopathological examination. The dog was placed on a hepatic support diet and treated with colchicine, essential fatty acid supplementation and raw egg yolks. After four weeks, the skin lesions had resolved and the dog remained free of clinical signs over a 22-month follow-up period.     

Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound

Objective To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning.     

Comparative water use by dryland trees in Parklands in Senegal

Despite the clear evidence of competition for water between trees and crops, there have been very few studies comparing simultaneous water use by differing tree species in drylands. Comparative water use by dryland trees was measured in Senegal using heat balance gauges at the end of the wet season and in the dry season. Significant differences between tree species were found for maximum rates of water use per unit leaf area. Indigenous species may be better adapted to the dry environment than exotic species but the indigenous species Acacia seyal Del. used more water per unit leaf area than all other species. The exotic species Azadirachta indica Adr. Juss. consistently used less water per unit leaf area than most other species. There were significant differences in amounts of water used per unit leaf area by differing provenances of the same tree species. Water use in the dry season varied by a factor of three between two provenances of Acacia aneura F. Muell ex Benth. indicating potential to select provenances for drylands based on their water use characteristics. Absolute rates of water use as well as differences in sapflow between species were greatest when soils were moist suggesting that comparative sapflow studies will be most informative when carried out during the wet season. Water use rankings of the differing tree species were broadly maintained irrespective of season.This revised version was published online in November 2005 with corrections to the Cover Date.     

Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland,Canada

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.     

Expression of Perilipin 2 (PLIN2) in Porcine Oocytes During Maturation

Perilipins have been reported to limit the interaction of lipases with neutral lipids within the droplets, thereby regulating neutral lipid accumulation and utilization. This study aimed to identify the location and expression of PLIN1 and PLIN2 in porcine oocytes during maturation. Quantitative real‐time polymerase chain reaction (qRT‐PCR), immunostaining and Western blot methods were used to characterize the expression and distribution patterns of PLIN1 and PLIN2 in porcine oocytes. The results showed that PLIN1 was not detectable in porcine oocytes. PLIN2 and BODIPY 493/503‐detected neutral lipid droplets appeared identical distribution patterns and extensive colocalization in both GV and MII porcine oocytes. PLIN2 protein expression was higher in GV oocytes than that in MII oocytes (p < 0.05), although PLIN2 mRNA expression was similar in both groups. These findings suggested that PLIN2 was a major lipid droplet‐associated protein in porcine oocytes.