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101.
Clostridium (C.) difficile, or its cytoxin, was demonstrated in faecal samples from 10 of 25 (40%) mature horses investigated with acute colitis treated primarily with antibiotics for disorders other than diarrhoea. C. difficile was not found in faecal samples from 140 horses without signs of enteric disorders, from 21 nondiarrhoeic horses treated with antibiotics, nor from 22 horses with colitis untreated with antibiotics. Except for C. difficile neither Salmonella nor any other investigated intestinal pathogen was isolated in any of the diarrhoeic horses. The findings strongly support some earlier reports that C. difficile is associated with acute colitis in mature horses treated with antibiotics. Of the 10 horses, 4 proved positive for C. difficile both in culture and in the cytotoxin test, 4 in culture only and 2 only in the cytotoxin test. Eight of 10 horses positive for C. difficile were or had recently been hospitalised, indicating that C. difficile may be a nosocomial infection in horses. All horses positive for C. difficile were treated with beta-lactam antibiotics.  相似文献   
102.

Introduction

Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds.

Objective

To investigate potential interbreed variation in serum 5-HT in healthy dogs.

Animals

483 healthy dogs of nine breeds aged 1–7 years.

Methods

Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA).

Results

Median 5-HT concentration was 252.5 (interquartile range = 145.5–390.6) ng/mL. Overall breed difference was found (p<0.0001), and 42% of pairwise breed comparisons were significant. Univariate regression analysis showed association between serum 5-HT concentration and breed, center of examination, storage time, and sex, with higher 5-HT in females. In multiple regression analysis, the final model had an adjusted R2 of 0.27 with breed (p<0.0001), center (p<0.0001), and storage time (p=0.014) remaining significant. Within centers, overall breed differences were found at 3/5 centers (p≤0.028), and pairwise comparisons within those centers showed breed differences in 42% of comparisons. Among the included breeds, Newfoundlands, Belgian Shepherds and CKCSs had highest 5-HT concentrations.

Conclusions

Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1–7 years. These differences should be taken into account when designing clinical studies.  相似文献   
103.
The concept of foetal programming(FP) originated from human epidemiological studies, where foetal life nutrition was linked to health and disease status later in life. Since the proposal of this phenomenon, it has been evaluated in various animal models to gain further insights into the mechanisms underlying the foetal origins of health and disease in humans. In FP research, the sheep has been quite extensively used as a model for humans. In this paper we will review findings mainly from our Copenhagen sheep model, on the implications of late gestation malnutrition for growth, development, and metabolic and endocrine functions later in life, and discuss how these implications may depend on the diet fed to the animal in early postnatal life. Our results have indicated that negative implications of foetal malnutrition, both as a result of overnutrition and, particularly, late gestation undernutrition, can impair a wide range of endocrine functions regulating growth and presumably also reproductive traits. These implications are not readily observable early in postnatal life, but are increasingly manifested as the animal approaches adulthood. No intervention or cure is known that can reverse this programming in postnatal life. Our findings suggest that close to normal growth and slaughter results can be obtained at least until puberty in animals which have undergone adverse programming in foetal life, but manifestation of programming effects becomes increasingly evident in adult animals.Due to the risk of transfer of the adverse programming effects to future generations, it is therefore recommended that animals that are suspected to have undergone adverse FP are not used for reproduction. Unfortunately, no reliable biomarkers have as yet been identified that allow accurate identification of adversely programmed offspring at birth,except for very low or high birth weights, and, in pigs, characteristic changes in head shape(dolphin head). Future efforts should be therefore dedicated to identify reliable biomarkers and evaluate their effectiveness for alleviation/reversal of the adverse programming in postnatal life. Our sheep studies have shown that the adverse impacts of an extreme, high-fat diet in early postnatal life, but not prenatal undernutrition, can be largely reversed by dietary correction later in life. Thus, birth(at term) appears to be a critical set point for permanent programming in animals born precocial,such as sheep. Appropriate attention to the nutrition of the late pregnant dam should therefore be a priority in animal production systems.  相似文献   
104.
105.
Several studies have been published since 1990 on the economics of mastitis and mastitis management. However, hardly any of these studies has discussed the consistency of results with other studies. In the present paper, the economic factors associated with mastitis are explained, providing a framework for economic analysis. As a second step calculations of the costs of mastitis and the costs in relation to the benefits of mastitis management published since 1990 in peer-reviewed journals are extensively reviewed and analysed. The result shows a large variation in the calculated costs and benefits of mastitis and mastitis management between the different studies. Moreover, it is clear that important factors were ignored in some of the studies. The framework provided in this paper can provide a basis for analysis for future studies on the economics of mastitis and mastitis management.  相似文献   
106.
The effect of dietary protein to carbohydrate ratios (P/CH, weight percentage) of P34/CH21, P39/CH15 and P44/CH10 was studied in Atlantic salmon (Salmo salar L.) with respect to growth and feed conversion ratio (FCR) in one medium-scale experiment (Experiment 1) and to slaughter quality in two production scale experiments (Experiments 2A and 2B). The dietary fat was maintained at 290 g kg−1 whereas the protein (fish meal) was exchanged with carbohydrate (wheat). Fish grown from approximately 1 to 4 kg were fed a restricted diet (iso-energetic on gross energy basis) or to satiation. Nitrogen, fat, starch and energy digestibilities were measured in a separate experiment. There were slight tendencies for lower growth (P = 0.06) and for higher FCRs (P = 0.06) in Experiment 1, and a slight tendency for a lower dress-out percentage in Experiments 2A and 2B (P = 0.10 and 0.20 respectively) with decreasing P/CH. The P/CH had no effect on the fat concentration of fillets, flesh colour or sexual maturation. The digestibility of starch decreased from 62.1% to 46.1% and the digestibility of energy from 84.9% to 79.5% when P/CH decreased from P44/CH10 to P34/CH21. Growth per unit digestible protein increased with decreasing P/CH. Feeding to satiation improved the growth but the FCR was higher than it was for restricted feeding. The calculated starch load per kg of fish growth increased with decreasing P/CH, whereas the effluent nitrogen decreased.  相似文献   
107.
Initial analysis of needle nutrient status and visible symptoms suggested that a declining Norway spruce (Picea abies L. Karst.) stand in south Sweden was suffering from B and Cu deficiency. Effects of addition of 1000 kg ha-1 of a commercial N-free fertilizer containing macro nutrients plus B, Cu, and Zn were investigated. B concentrations and B/N ratios were increased significantly in needles from fertilized trees compared to the control, to levels well above critical levels of deficiency and optimum nutrient ratios. In contrast, the treatment did not change the low needle Cu status and there was no effect on growth measured as needle mass after one growing season. Graphical vector analysis together with the absence of change in needle mass suggested a luxury uptake of B. Application of the concepts for critical levels of deficiency and optimum nutrient ratios in relation to N suggested B and Cu deficiency were contributing factors to the observed forest damage in the area. Graphical vector analysis requires a rapid response in needle mass, in combination with improved needle nutrient status in order to identify nutrient deficiencies. The applicability of the technique appears to be limited to primarily growth-promoting nutrients.  相似文献   
108.
Integrated Water Resources Management   总被引:1,自引:0,他引:1  
  相似文献   
109.
Salmonid alphavirus (SAV) causes pancreas disease (PD) in farmed Atlantic salmon (Salmo salar L.), and exocrine pancreas tissue is a primary target of the virus. Digestive enzymes secreted by the exocrine pancreas break down macromolecules in feed into smaller molecules that can be absorbed. The effect of SAV infection on digestion has been poorly studied. In this study, longitudinal observations of PD outbreaks caused by SAV subtype 2 (SAV2) in Atlantic salmon at two commercial sea sites were performed. The development of PD was assessed by measurement of SAV2 RNA load and evaluation of histopathological lesions typical of PD. Reduced digestion of both protein and fat co‐varied with the severity of PD lesions and viral load. Also, the study found that during a PD outbreak, the pen population comprise several subpopulations, with different likelihoods of being sampled. The body length of sampled fish deviated from the expected increase or steady state over time, and the infection status in sampled fish deviated from the expected course of infection in the population. Both conditions indicate that disease status of the individual fish influenced the likelihood of being sampled, which may cause sampling bias in population studies.  相似文献   
110.
Pancreas disease (PD) caused by salmonid alphavirus (SAV) severely affects salmonid aquaculture during the seawater phase. To characterize immune cells in target tissues for SAV infection, heart, pancreas and pyloric caeca were analysed from two groups of fish adapted to seawater for 2 and 9 weeks. The sections were scored for the relative abundance of cells expressing MHC class II, IgM, CD3, CD8 or neutrophil/granulocyte markers using immuno‐histochemical techniques. In general, necrosis of tissue was more severe in fish infected at 2 weeks post‐seawater transfer (wpt) compared with those infected at 9 wpt. At 9 wpt, there were higher numbers of MHC II+ cells in heart, pancreas and pyloric caeca, IgM+ cells in heart and pancreas, and CD3+ cells in pancreas compared to those infected at 2 wpt. The majority of the immune cells infiltrating PD‐affected tissues were MHC II+ and CD3+ cells suggesting that antigen‐presenting cells and T lymphocytes are the main types of immune cells responding to SAV infection. All the investigated cell types were also observed in pyloric caeca of infected fish, suggesting that this tissue may play a role in the immune response to SAV.  相似文献   
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