Evaluation of stocking density and subtherapeutic chlortetracycline on Salmonella enterica subsp. enterica shedding in growing swine

The objective of this research was to determine the effect of stocking density and inclusion of subtherapeutic chlortetracycline in the diet on Salmonella fecal prevalence and antimicrobial resistance in growing swine. A 2 x 2 factorial design was employed on a privately owned commercial swine farm. Four finisher rooms were included in the study. Two of the rooms received 50 g/tonnes of chlortetracycline in the ration, two rooms received no antimicrobials in the feed. In each room, alternate pens were assigned to either high stocking density (0.60 m2/pig) or low stocking density (0.74 m2/pig). Pigs were placed in the finisher rooms at 10 weeks of age and followed for 6 weeks. Individual fecal samples were collected from the floors of each pen and cultured once weekly. Antimicrobial resistance phenotypes were determined. Data were analyzed using multilevel, multivariable logistic regression. Pigs fed chlortetracycline were at increased odds (OR 6.88, 95% CI 2.77-17.12) to shed Salmonellae. No other associations between treatments (CTC and stocking density) and Salmonella prevalence or reduced susceptibility to antimicrobials were identified. Variance in the odds of a fecal sample to be positive was distributed mostly at the lowest level, the individual fecal sample. The increased risk of shedding associated with inclusion of subtherapeutic chlortetracycline in swine diets is discordant with previous results by our group, suggesting farm or strain specific factors may impact this association. Understanding this risk may provide a potential intervention for controlling Salmonella pre-harvest.     

Comparison of Spring Barley Lines Produced by Single Seed Descent, Pedigree Inbreeding and Doubled Haploidy

Samples of inbred lines of Hordeum vulgare produced by pedigree inbreeding, doubled haploidy and single seed descent have been compared for a range of agronomic characters. Differences between the means of the in bred s produced by single seed descent and pedigree breeding were due to differing levels of inbreeding. The present study confirmed chat recombinant inbred families which out-perform the higher scoring parent may be produced by either method. Caution should, however, be exercised when simply inherited characters controlled by major genes are fixed in early generations. Differences between the doubled haploid and single seed descent samples for the character thousand grain weight were attributable to coupling linkages involving epistatic genes. The production and evaluation of random inbred lines should be considered as an alternative to pedigree methods of barley breeding.     

Light Weight Aggregates made from Dredged Harbour Sediments

Goal  

Annually, 400.000 m₃ harbour sediments are dredged to maintain the water depth in the harbours of Bremen and Bremerhaven. The sediment contains organic and inorganic pollutants and hence is deposited on a landfill. Because of the limited capacity of that landfill alternative treatment techniques are investigated. This study aims to evaluate the production of Light Weight Aggregates (LWA) from harbour sediments with respect to the product quality and environmental aspects of the use of the LWA.     

The effect of immunosuppression on protective immunity of turkey poults against infection with turkey coronavirus

The objective of the present study was to evaluate the protective effect of humoral and cellular immunities on turkeys infected with turkey coronavirus (TCV). Two trials were conducted with two separate hatches of turkey poults. Turkey's were experimentally immunosuppressed with cyclosporin A (CsA) or cyclophosphamide (CY) and infected with TCV. Prior to infection, treatment with CsA selectively suppressed T cell activity as revealed by 2-3 fold decreased (p < 0.1) lymphocyte proliferation responses to a T cell mitogen, concanavalin A (Con A). Treatment with CY mainly induced B cell deficiency as indicated by significant reductions (p < 0.05) in antibody responses to sheep erythrocytes 7 days after injection. Body weight gain of turkeys treated with CY was significantly lower (p < 0.05) than that of untreated turkeys at 9 days post-infection (PI). Turkeys treated with CY had 1-2 fold higher immunofluorescent antibody assay (IFA) scores for TCV antigens (p < 0.05) in the intestine than untreated turkeys at 9 or 14 days PI. These results suggested that humoral immunity against TCV infection may be important in turkeys.     

SHEEP PATHSO

The variability of some chalk pastures above the Pewsey Vale in Wiltshire was studied by recording point-quadrats two inches apart on strips across sheep paths; the results are shown diagrammatically. There were usually lines of tall grasses at the edges of the paths, with belts of shorter grass, richer in forbs, between the paths. Some species of grasses and forbs were most common on or near the paths; others were more common in the short turf. The theoretical and practical implications of this variability are briefly discussed.     

Magnetic resonance imaging features of feline intracranial neoplasia: retrospective analysis of 46 cats

The purpose of this retrospective study was to determine the magnetic resonance imaging (MRI) characteristics of feline brain tumors and to determine whether these characteristics can be used to accurately predict the histologic diagnosis. MRI scans of 46 cats with histologically confirmed brain tumors were reviewed, including 33 meningiomas, 6 lymphomas, 4 gliomas, 2 olfactory neuroblastomas, and 1 pituitary tumor. MRI features including axial origin, shape, location, signal intensity, contrast enhancement, peritumoral edema, and mass effect were reviewed and characterized for each tumor type. Tumor shape, axial origin, contrast enhancement, and degree of peritumoral edema aided in the identification of tumor type. Meningiomas were always extra-axial and were most often ovoid with marked contrast enhancement and mild peritumoral edema. Gliomas were always intra-axial with ring enhancement and generally caused more peritumoral edema than other tumors. The brain tumor was detected on MRI in 45 (98%) cats. Two blinded independent reviewers correctly identified 82% of all of the tumor types on the basis of MRI appearance alone. Thus, MRI is an excellent diagnostic tool for the detection of brain tumors in cats, and it provides important information to aid in the diagnosis of tumor type.     

Primary central nervous system B-cell lymphoma in a young dog

This report describes a primary central nervous system B-cell lymphoma in a 3-year-old intact female Maltese dog. Canine primary central nervous system lymphomas constitute about 4% of all intracranial primary neoplasms, but comprehensive histopathologic classifications have rarely been carried out. This is the first report of this disease in a young adult dog.     

Persistence and binding of DDT and gamma-HCH in a sandy loam soil under field conditions in Delhi,India

Persistence and binding capacity of [¹⁴C]p, p′-DDT and [¹⁴C]y-HCH were studied for one year in a sandy loam soil of Delhi, India, after surface treatment during monsoon, winter and summer seasons under field conditions. Both DDT and HCH dissipated more rapidly under the Indian subtropical climate than reported for temperate regions. In all three seasons, both insecticides dissipated most rapidly during the initial 60 days. However, in the final six months there was very little change in the residue levels. After one year, the final soil burden of DDT varied from 33 to 36% and of HCH from 14 to 15% of the initial concentrations in the different experiments. HCH bound more with the soil as, out of the total residues present after one year, more than 75% of HCH was in bound form compared with only 24% of DDT. The observed time for 50% initial dissipation of DDT ranged from 60 to 120 days, while in the case of HCH it varied from 30 to 45 days. However, the rate of loss of residues which persisted for more than 6 months was equivalent to a half-life of between 500 and 10000 days for DDT, and between 700 and 2000 days for HCH, thus illustrating the very long persistence of aged residues. Since degradation of both insecticides was apparently minimal, the data indicate that dissipation of DDT and HCH was largely due to volatilisation.