Genetic relatedness and netB prevalence among environmental Clostridium perfringens strains associated with a broiler flock affected by mild necrotic enteritis     

Engström BE  Johansson A  Aspan A  Kaldhusdal M 《Veterinary microbiology》2012,159(1-2):260-264

In a previous study we investigated pulsed-field gel electrophoresis (PFGE) genotype diversity and prevalence of the netB toxin gene in Clostridium perfringens (CP) isolates recovered from a broiler flock (flock 1) affected by necrotic enteritis (NE). In this follow-up work, we examined samples collected before placement of flock 1, to see if NE during rearing could be traced back to the cleaned and empty building or the day-old chicks. Litter from the next flock in the same building (flock 2) was also examined. We detected 25 different PFGE genotypes, five of which were found only in litter from flock 2. Six genotypes which had been found in flock 1 during rearing were detected in samples collected before placement. NetB positive isolates belonging to two of these genotypes had been recovered from NE lesions during rearing, suggesting that virulent strains were transmitted from the cleaned and disinfected broiler house. NetB frequency among isolates from the empty building was 45%, indicating that netB positive strains were prevalent in a building that previously had housed a healthy flock offered in-feed narasin (flock 0). NetB frequency among isolates from litter used by flock 2 was 22%, indicating that netB positive strains were present in the environment of a 14-days-old healthy flock offered in-feed narasin. Two prevalent genotypes were consistently either netB negative or netB positive. However, the presence of genotypes represented by both negative and positive isolates may suggest that the gene can spread horizontally among different CP strains.  相似文献   

Greenhouse gas emissions from Silphium perfoliatum and silage maize cropping on Stagnosols     

Björn Kemmann  Thorsten Ruf  Reinhard Well  Christoph Emmerling  Roland Fuß 《植物养料与土壤学杂志》2023,186(1):79-94

Background

The sustainability of bioenergy is strongly affected by direct field-derived greenhouse gas (GHG) emissions and indirect emissions form land-use change. Marginal land in low mountain ranges is suitable for feedstock production due to small impact on indirect land-use change. However, these sites are vulnerable to high N₂O emissions because of their fine soil texture and hydrology.

Aims

The perennial cup plant (Silphium perfoliatum L.) might outperform silage maize (Zea mays L.) on cold, wet low mountain ranges sites regarding yield and ecosystem services. The aim of this study was to assess whether the cultivation of cup plant also provides GHG mitigation potential compared to the cultivation of maize.

Methods

A t-year field experiment was conducted in a low mountain range region in western Germany to compare area and yield-scaled GHG emissions from cup plant and maize fields. GHG emissions were quantified using the closed chamber method.

Results

Cup plant fields emitted an average of 3.6 ± 4.3 kg N₂O-N ha^–1 year^–1 (–85%) less than maize fields. This corresponded to 74.0 ± 94.1 g CO_2-eq kWh^–1 (–78%) less emissions per produced electrical power. However, cup plant had a significantly lower productivity per hectare (–34%) and per unit of applied nitrogen (–32%) than maize.

Conclusion

Cup plant as a feedstock reduces direct field-derived GHG emissions compared to maize but, due to lower yields cup plant, likely increases emissions associated with land-use changes. Therefore, the increased sustainability of bioenergy from biogas by replacing maize with cup plant is heavily dependent on the performance of maize at these sites and on the ecosystem services of cup plant in addition to GHG savings.  相似文献   

Neospora caninum and bovine virus diarrhoea virus infections in Swedish dairy cows in relation to abortion     

Björkman C  Alenius S  Manuelsson U  Uggla A 《Veterinary journal (London, England : 1997)》2000,159(2):201-206

The protozoan parasite Neospora caninum and bovine virus diarrhoea virus (BVDV) are recognized as important causes of bovine abortion and congenital disease worldwide. In this study, serological investigations were performed to estimate the prevalence of N. caninum infection in Swedish dairy cattle, to assess to what extent it may affect abortion rates, and to determine possible effects of coinfection with BVDV. The overall N. caninum seroprevalence in Swedish dairy cows was estimated at 2% (16/780), and the BVDV seroprevalence was 32% (249/780). Among aborting cows from herds with abortion problems, 7% (26/378) had antibodies to N. caninum and 42% (153/378) to BVDV. Seventeen of the N. caninum positive animals also had antibodies to BVDV. There was a statistically significant (P = 0.013) association between presence of antibodies to N. caninum and BVDV. In a case-control study comprising sera from cows in herds without recognized abortion problems, 6% (5/89) and 1% (1/89) of sera from aborting and non-aborting cows, respectively, had antibodies to N. caninum. Two of the N. caninum seropositive aborting cows also had antibodies to BVDV. These results confirm that N. caninum infection is associated with bovine abortion in Sweden and also indicate that there might be concurrent effects of N. caninum and BVDV. It is concluded that Swedish dairy cows have a low prevalence of N. caninum infection which is favourable in relation to possible future control programmes.  相似文献   

Intervertebral disc degeneration in the dog. Part 1: Anatomy and physiology of the intervertebral disc and characteristics of intervertebral disc degeneration     

Niklas Bergknut  Lucas A. Smolders  Guy C.M. Grinwis  Ragnvi Hagman  Anne-Sofie Lagerstedt  Herman A.W. Hazewinkel  Marianna A. Tryfonidou  Björn P. Meij 《Veterinary journal (London, England : 1997)》2013,195(3):282-291

Intervertebral disc (IVD) degeneration is common in dogs and can give rise to a number of diseases, such as IVD herniation, cervical spondylomyelopathy, and degenerative lumbosacral stenosis. Although there have been many reports and reviews on the clinical aspects of canine IVD disease, few reports have discussed and reviewed the process of IVD degeneration. In this first part of a two-part review, the anatomy, physiology, histopathology, and biochemical and biomechanical characteristics of the healthy and degenerated IVD are described. In Part 2, the aspects of IVD degeneration in chondrodystrophic and non-chondrodystrophic dog breeds are discussed in depth.  相似文献   

Responses to Selection against Clinical Mastitis in the Norwegian Cattle Population     

Bjørg Heringstad  Gunnar Klemetsdal  John Ruane 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):155-160

The genetic trend for clinical mastitis was estimated for Norwegian Cattle, a population in which mastitis resistance has been included in the breeding programme since 1978. More than 1.2 million first-lactation daughters, with clinical mastitis records registered from 1978 to 1995, bred by 2043 sires, were analysed with a linear sire model. For bulls born from 1974 to 1990 a flat genetic trend for clinical mastitis was found. However, bull sires born from 1983 onwards, selected on a breeding goal with increased weight on mastitis relative to milk production, showed consistently larger and favourable selection differentials for mastitis relative to bull sires born earlier, which had an average selection differential of approximately zero. This will influence genetic trend in the population through their sons, which were born from 1990 onwards.  相似文献   

Topiramate as an add‐on antiepileptic drug in treating refractory canine idiopathic epilepsy     

A.‐M. Kiviranta  O. Laitinen‐Vapaavuori  A. Hielm‐Björkman  T. Jokinen 《The Journal of small animal practice》2013,54(10):512-520

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Incidence of mastitis and bacterial findings at clinical mastitis in Swedish primiparous cows- influence of breed and stage of lactation     

Persson Waller K  Bengtsson B  Lindberg A  Nyman A  Ericsson Unnerstad H 《Veterinary microbiology》2009,134(1-2):89-94

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Pesticide contamination of the upper Elbe River and an adjacent floodplain area     

Karlsson  Anneli S.  Lesch  Michael  Weihermüller  Lutz  Thiele  Björn  Disko  Ulrich  Hofmann  Diana  Vereecken  Harry  Spielvogel  Sandra 《Journal of Soils and Sediments》2020,20(4):2067-2081

Journal of Soils and Sediments - Pesticide contamination of river waters is a global problem, and therefore, authorities regularly monitor the water quality status. Especially, flood events might...  相似文献   

Report of the 3rd Havemeyer workshop on allergic diseases of the Horse, Hólar, Iceland, June 2007     

Marti E  Gerber V  Wilson AD  Lavoie JP  Horohov D  Crameri R  Lunn DP  Antczak D  Björnsdóttir S  Björnsdóttir TS  Cunningham F  Dérer M  Frey R  Hamza E  Horin P  Heimann M  Kolm-Stark G  Olafsdóttir G  Ramery E  Russell C  Schaffartzik A  Svansson V  Torsteinsdóttir S  Wagner B 《Veterinary immunology and immunopathology》2008,126(3-4):351-361

Allergic diseases occur in most mammals, although some species such as humans, dogs and horses seem to be more prone to develop allergies than others. In horses, insect bite hypersensitivity (IBH), an allergic dermatitis caused by bites of midges, and recurrent airway obstruction (RAO), a hyperreactivity to stable born dust and allergens, are the two most prevalent allergic diseases. Allergic diseases involve the interaction of three major factors: (i) genetic constitution, (ii) exposure to allergens, and (iii) a dysregulation of the immune response determined by (i) and (ii). However, other environmental factors such as infectious diseases, contact with endotoxin and degree of infestation with endoparasites have been shown to influence the prevalence of allergic diseases in humans. How these factors may impact upon allergic disease in the horse is unknown at this time. The 3rd workshop on Allergic Diseases of the Horse, with major sponsorship from the Havemeyer Foundation, was held in Hólar, Iceland, in June 2007 and focussed on immunological and genetic aspects of IBH and RAO. This particular venue was chosen because of the prevalence of IBH in exported Icelandic horses. The incidence of IBH is significantly different between Icelandic horses born in Europe or North America and those born in Iceland and exported as adults. Although the genetic factors and allergens are the same, exported adult horses show a greater incidence of IBH. This suggests that environmental or epigenetic factors may contribute to this response. This report summarizes the present state of knowledge and summarizes important issues discussed at the workshop.  相似文献   

How does the veterinarian keep his back straight?     

Weijtens M  Siebinga JT  Eussen B  Cleton N 《Tijdschrift voor diergeneeskunde》2008,133(14-15):632-633

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