Experimental Yersinia enterocolitica placentitis in sheep.

A strain of Yersinia enterocolitica of O serogroup 6,30 isolated from the liver of an aborted ovine fetus was inoculated intravenously into a group of pregnant ewes at about 90 days gestation and produced placentitis with abortion or delivery of infected lambs about 50 days later. Y. enterocolitica of the same serogroup was recovered from the necrotic placental cotyledons and most other fetal tissues and could be isolated from vaginal discharges of the ewes for a least 2 weeks after abortion. Histological changes were consistent with an acute bacterial necrotizing placentitis and systemic infection of the fetus. Subsequent pregnancies in the ewes proceeded to term without evidence of infection.     

The Effect of Diet on the Biochemical Composition of Juvenile Artemia: Potential Formulations for Rock Lobster Aquaculture

The lipid class and fatty acid (FA) composition of juvenile Artemia fed continuously on four diets—the microalga Tetraselmis suecica , a mix of oat bran-wheat germ-lecithin (OWL), OwL-eicosapentaenoic acid (EPA), and OWL-EPA-arachidonic acid (AA)—were examined over a 9-d experiment in an attempt to approximate the FA profile of phyllosoma larvae of wild southern rock lobster Jasus edwardrii . The main difference in lipid class composition of Artemia fed the four diets was the relative level of polar lipid (PL) and triacylglycerol (TAG). By day 9, the algal-fed Artemia were highest in PL (95% of total lipid) and lowest in TAG (2%), whereas the remaining diets resulted in Artemia with 16–30% PL and 41–82% TAG. After 2 d, the relative FA composition of all Artemia treatments closely reflected those of the diets, with no marked change after further feeding (to day 9). In terms of the content of essential polyunsaturated fatty acids (PUFA), by day 5 Artemia fed: 1) with the algal diet contained 7 mg/g FA dry mass (0.3% DHA, 6.3% EPA, 3.4% AA of total FA); 2) with the OWL diet contained 3 mg/g (0.3% DHA, 0.9% EPA, 0.7% AA); 3) with the OWL-EPA diet contained 55 mg/g (6.2% DHA, 11.6% EPA, 1.1% AA); and 4) with the OWL-EPA-AA contained 83 mg/g (3.8% DHA, 7.5% EPA, 17.4% AA). The PUFA profiles of Artemia using the OWL-oil diets were similar to wild rock lobster phyllmmata, although levels of doco-sahexaenoic acid (DHA) were lower (10% DHA) than in J. edwardsii larvae. On the basis of PUFA composition data alone, the results suggest the suitability of the OWL-oil mixed diets for consideration for feeding to Artemia used in the culture of southern rock lobster larvae, particularly if the level of DHA can be further enhanced.     

Immunophenotype of pulmonary cellular infiltrates in sheep with visceral caseous lymphadenitis

Pulmonary lesions associated with Corynebacterium ovis were analyzed with an indirect immunoperoxidase staining technique using monoclonal antibodies. The predominant cells in abscess walls and surrounding lung parenchyma were large macrophages which expressed major histocompatibility complex (MHC) class II molecules on their surfaces. T lymphocytes were prominent in the same sites in the naturally occurring lesions, and SBU-T4-positive ("helper/inducer") cells were the major subset of lymphocytes (mean T4/T8 ratio = 3.5). B lymphocytes and granulocytes comprised minor populations of infiltrating cells. These results implicate activated macrophages and MHC class II-restricted T lymphocytes in the pathogenesis of established C. ovis infections in sheep.     

A potential early clinical phenotype of necrotizing meningoencephalitis in genetically at‐risk pug dogs

BackgroundNecrotizing meningoencephalitis (NME) in the pug dogs is a fatal neuroinflammatory disease associated with rapid progression and poor response to conventional immunosuppressive therapy. Diagnosis is typically made after severe neurological abnormalities have manifested.Hypothesis/ObjectivePug dogs at genetic risk for NME might manifest neurological abnormalities before developing pathognomonic clinical signs of NME.AnimalsThirty‐six pug dogs less than 4 years of age asymptomatic for NME.MethodsProspective observational cohort study with germline genome‐wide genotyping. Neurological examinations were performed 4 weeks apart to document reproducible findings of central nervous system disease. Magnetic resonance imaging, cerebrospinal fluid analysis, and testing for infectious diseases were performed in all pugs with reproducible abnormalities detected on neurological examination.ResultsThe overall risk allele frequency in this cohort was 40%; 5 (14%) dogs were high risk, 19 (53%) dogs were medium risk, and 12 (33%) dogs were low genetic risk for NME. Reproducible abnormalities detected on neurological examination were identified in 8/24 (33%) genetically at‐risk dogs and 0/12 (0%) low risk dogs. Clinical abnormalities included multifocal spinal pain in 8/8, reduced menace response in 5/8, and lateralizing postural reaction deficits in 5/8 pugs. There was a strong association between genotype risk and the presence of this clinical phenotype (P = .03).Conclusions and Clinical ImportanceOur findings suggest the presence of a novel early clinical phenotype of NME in apparently asymptomatic genetically at‐risk pugs which might be used to plan early diagnostic and therapeutic clinical trials.     

Micromorphology of soils in soliflucted materials,Okstindan, Northern Norway

The micromorphology of two soil profiles developed on turf-banked solifluction lobes and a third profile formed on a larger turf-banked solifluction terrace is described. Four elements common to the three profiles are identified.In the horizontal plane the apparent long axes of detrital grains show preferred orientation parallel to the azimuth of the line of greatest slope, and in slides cut in the vertical plane aligned with the slope direction a somewhat stronger preferred orientation (or apparent dip of the grains) is observed parallel, or sub-parallel to the ground surface gradient. Secondly, coatings of matrix material are observed on the upper surfaces of detrital grains at depths greater than 50 cm. Above this depth similar coatings also appear on the sides and lower surfaces of detrital grains. Roughly horizontal flattened patches of matrix enrichment are also observed in the three profiles. These become more frequent with depth, producing a banded pattern of matrix concentrations separated by detrital grains. Finally, large rounded pores, or vesicles, are observed in the upper 25 cm of the three profiles.These micromorphological elements are described, and suggestions are made as to their origins.     

THE POTENTIAL OF LOTUS spp. FOR HILL LAND IN WALES

Thirty-four introductions of Lotus corniculatus and L. uliginosus , obtained from Europe, North America and New Zealand, were grown in plots with Aberystwyth S23 ryegrass at three centres in Wales (230–400 m a. s. 1.) to assess their potential as legumes for poor acid hill soils. The control white clover varieties were generally successful in these difficult conditions, whereas all the Lotus introductions were poor in two experiments and in the third experiment gave way to volunteer white clover by the third harvest year. These results indicate that none of the numerous Lotus varieties tested would be a useful addition to pasture seeds mixtures for hill lands in Wales.     

The characteristics of European,Mediterranean and other populations of white clover (Trifolium repens L.)

Indigenous populations of white clover (Trifolium repens L) collected from Europe, the Mediterranean area, as well as other parts of the world have been grown as spaced plants at Aberystwyth. Data were collected on various morphological characters, green weight and leaf marks.Leaflet length, width, area, plant height and green weight were all strongly correlated, but not the flowering date or leaflet shape (= ratio length/width).The mean leaflet size of Mediterranean populations (the supposed centre of origin) was very variable, and decreased northwards. All British populations were uniformly small leaved.Most of the populations were much less vigorous than the bred control varieties and only a few equalled them. Nevertheless some of the introductions exhibited seasonal growth patterns, especially growth into the autumn, and large leaves that could be usefully incorporated in improved varieties. Populations originating one step back towards the centre of origin will probably be the most useful when immediate adaptation is the aim.     

THE YIELDS AND COMPOSITION OF LUCERNE, GRASS AND CLOVER UNDER DIFFERENT SYSTEMS OF MANAGEMENT

The mean yields of 4 varieties of lucerne were compared under 5 methods of growing: broadcast with and without grass; drills 2 ft apart; alternate lucerne/grass drills 1 ft apart; spaced plants. One cut was harvested in the sowing year and 3 cuts a year for the next 3 years.
The alternate lucerne/grass drills yielded 20% less dry matter than the comparable broadcast plots. Broadcasting and sowing in alternate drills had the same effect on the pattern of lucerne/grass competition. The meadow fescue companion produced its highest yield at the first cut and there was a marked drop during each year and from year to year. There was little evidence of nitrogen transfer from the lucerne to the grass.