Epidemiology and control of an outbreak of classical swine fever in wild boar in Switzerland

An outbreak of classical swine fever in wild boar in the southern part of Switzerland (Canton of Ticino) was investigated after the implementation of control measures in a defined infected area (the risk zone), and in a surrounding surveillance zone (the non-risk zone). After the disease had been detected, hunting was not allowed in the risk zone for over six months, during which the disease was left to run its course, but hunting was continued in the non-risk zone for one month. After seven months, a hunting strategy targeted at young animals was implemented in both zones. Between May 1998 and January 2000,1294 wild boar were shot or found dead, and diagnostic and biological data were collected and analysed. Only one animal from the non-risk zone was found to be seropositive for antibodies to the virus, whereas 179 of 528 wild boar from the risk zone were virus positive and 162 were seropositive. The proportion of virus-positive animals decreased from 62.7 per cent to zero over one year. During the first hunting season, seropositive animals were found in all age groups, but 12 months later only animals more than one year old had antibodies against the virus.     

Selected topics in pediatric gastroenterology.

This article discusses some of the more common gastrointestinal problems encountered in pediatric patients. Topics include infectious and endoparasitic disorders, congenital esophageal and hepatic disorders, and acute or chronic intestinal diseases. Diagnostic criteria as well as treatment guidelines are presented.     

Short fallows of Tithonia diversifolia and Crotalaria grahamiana for soil fertility improvement in western Kenya

Managed short-duration fallows may have the potential to replace longer fallows in regions where population density no longer permits slow natural fallow successions. The purpose of fallows is not only to improve subsequent crop performance but also to restore soil fertility and organic matter content for the long term. We therefore evaluated the soil organic matter and nutrient flows and fractions in a short fallow experiment managed in the western Kenya highlands, and also compared the experimental area with a 9–12-yr-oldadjacent natural bush fallow. The factorial agroforestry field experiment with four land-use and two P fertilizer treatments on a Kandiudalfic Eutrudox showed that 31-wk managed fallows with Tithonia diversifolia(Hemsley) A. Gray and Crotalaria grahamiana Wight &Arn. improved soil fertility and organic matter content above those of a natural weed fallow and continuous maize (Zea mays L.). Post-fallow maize yields were also improved, although cumulative three-season increases in yield were small (0–1.2 Mg ha⁻¹) when the yield foregone during the fallow season was accounted for. Improvements in yield and soil quality could be traced to quantity or quality of biomass recycled by the managed fallows. The non-woody recycled biomass produced by the continuous maize, weed fallow, and tithonia treatments was near 2Mg ha⁻¹, whereas crotalaria produced three times more recyclable biomass and associated N and P. Increases in topsoil N due to the fallows may have been attributable in part to deep acquisition and recycling of N by the fallows. Particulate macro-organic matter produced by the fallows contained sufficient N(30–50 kg ha⁻¹) to contribute substantially to maize production. Organic Paccumulation (29 kg ha⁻¹) similarly may play a significant role in crop nutrition upon subsequent mineralization. The effect of the P fertilizer application on soil properties and maize yield was constant for all land-use systems (i.e., no land-use system × P fertilizer interactions occurred). There was an indication that tithonia may have stimulated infestation of Striga hermonthica (Del.) Benth., and care must be taken to evaluate the full effects of managed fallows over several seasons. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of photoperiod, stocking density and diet on growth in young spotted wolffish (Anarhichas minor olafsen)

Full scale experiments in tanks were conducted to elucidate the effect of photoperiod regime, dietary fat level and stocking density on growth in spotted wolffish. The study showed that continuous light (LD24:0) did not give a higher final mean weight or faster overall growth rate in spotted wolffish compared to constant 8 h light and 16 h darkness (LD8:16). However, there were indications that the fish needed time to adapt to a new photoperiod regime. The feeding experiment indicated a negative relation between dietary fat level and growth, where fish given 15% fat in the diet had a 13% higher final mean weight compared to fish on a diet with 20% fat. However, no conclusions could be made. The final mean weight was 10% higher at 25 kg/m² compared to 40 kg/m², indicating a negative impact of high stocking density on spotted wolffish.     

Digestive capacity, intestinal morphology, and microflora of 1-year and 2-year old Atlantic cod (Gadus morhua) fed standard or bioprocessed soybean meal

The objectives of this work were to evaluate how dietary soybean meal (SBM) or a soy meal made by bioprocessing the SBM (BPSBM) to remove anti-nutritional factors affected hydrolytic capacity, amino acid absorption, intestinal morphology, and microflora along the intestinal tract of Atlantic cod at two life stages. Three fish meal based standard cod diets were formulated to contain no soy (FM control), 25% SBM, or 22% BPSBM. Prior to sampling the diets were fed to duplicate groups of 0.5 kg (1-year old) and 1.7 kg (2-year old) cod for a period of 3 months, and the groups reached 0.9 and 2.5 kg, respectively. Digesta was then sampled from different intestinal sections for analyses of trypsin and amylase activity as well as absorption of amino acids, nitrogen, and sulphur. Gastrointestinal sections were sampled for measurements of relative weight (kg^− 1 body weight), and tissues from these sections were sampled for analyses of brush border enzyme (alkaline phosphatase (ALP), leucine aminopeptidase (LAP), and maltase) activity and histological examination. Microflora was sampled from both digesta and the intestinal wall. The SBM diet stimulated relative growth of all gastrointestinal sections except the distal intestine in both age classes. Relative growth of the pyloric intestine was also stimulated by BPSBM. The pyloric caeca and the upper mid intestine were found to be the major sites for enzymatic hydrolysis of protein and starch and for amino acid absorption. Dietary SBM and BPSBM did not alter the activity of trypsin and LAP, but the activity of these enzymes in the proximal intestine was affected by age, being higher in 1-year old than in 2-year old cod. The rate of amino acid, nitrogen, and sulphur absorption along the gastrointestinal tract was not affected by SBM, but was slowed by BPSBM. Dietary SBM or BPSBM did not alter the morphology of the intestinal mucosa in any sections of the cod intestine. The distal-most structure of the intestine, a compartment with inlet and outlet (anus) valves, showed very high microbial colonisation in the mucosal brush border. Inclusion of SBM in the diet changed the intestinal microflora, increasing the population level of transient bacteria in the pyloric and mid intestine, but reducing the population level of adherent bacteria throughout the intestine. To conclude, Atlantic cod appeared to have a robust and flexible digestive system able to adjust to high dietary levels of soy protein meals.     

Effects of acute temperature decreases on turbot fry and juveniles

Turbot fry (10–20 mm) and juveniles (85–110 mm) were transferred directly from 16.0–16.5 C to 1.0 C, 2.5 C, 5.5 C or 8.0 C seawater. The fry were more sensitive to cold water than juveniles. The fry survived for 1 week at 8.0 C but not at 5.5 C, whereas juveniles survived at 5.5 C but not at 2.5 C. Transfer of juveniles to 1.0 C and 2.5 C seawater caused a high mortality, a marked increase in plasma Cl^- concentration, decrease in muscle water content, and hyperglycaemia. Acclimation to 5.5 C (juveniles) or 8.0 C (fry and juveniles) markedly reduced the sensitivity to 1.0 C exposure.     

Hepatic neoplasia

The clinicopathologic features of hepatic neoplasms such as hepatocellular adenomas, hepatocellular carcinomas, bile duct carcinomas, and hepatic carcinoids are presented. The authors also discuss the diagnostic and therapeutic approaches to hepatic neoplasia.     

A retrospective study on salmonella infection in Danish broiler flocks

A retrospective longitudinal study was conducted to identify risk factors associated with Salmonella enterica infection in Danish broiler production. The study was based on information in the antemortem database (AM database) where data were available for all broiler flocks slaughtered over the 2-year period from 1992 to 1993 in Denmark. The AM database contains information collected by the ante-mortem veterinarians, from the slaughterhouses, and from the salmonella examinations carried out at the National Veterinary Laboratory. The epidemiological unit was the individual broiler flock. The salmonella status of the flock was determined by examining the caecal tonsils from 16 3-week-old chickens from each flock. This procedure would detect a salmonella-infected flock, with a probability above 95%, if the prevalence is above 20%. Furthermore, the structure and quality of the collected data have been evaluated.

Fourteen variables were selected for analysis by multivariable logistic regression. An increased risk of salmonella infection in the broiler flocks was associated with the biggest hatcheries and feedmill, with an increasing number of houses on the farm, if the preceding flock was infected, and if the flock was reared in the autumn. Additionally, the main variables of the model were analysed by including a random effect at the house level. This resulted only in minor changes of the parameter estimates.     

Effect of acepromazine, diazepam, fentanyl-droperidol, and oxymorphone on gastroesophageal sphincter pressure in healthy dogs

Treatment of healthy dogs with 4 commonly used psychotropic or analgesic agents significantly decreased resting gastroesophageal sphincter pressure (GESP). Acepromazine decreased GESP by 35% (P = 0.02); oxymorphone decreased GESP by 38% (P less than 0.005); diazepam decreased GESP by 42% (P = 0.005); and fentanyl-droperidol decreased GESP by 40% (P = 0.03). Therefore, esophageal manometric evaluation of gastroesophageal sphincter function should not be preceded by administration of these drugs.     

Lymphoid follicles in the gastric mucosa of dogs. Distribution and lymphocyte phenotypes

The occurrence and distribution of lymphoid follicles within the stomachs of 36 dogs that dis not have macroscopic gastric lesions are presented. The dogs ranged in age from less than 1 year to over 13 years. The number of follicles varied between the different regions of the stomach, being most numerous (15.6 follicles cm⁻²) and uniform in size (about 1 mm in diameter) in the fundus. The number and size of follicles in the antrum varied widely between dogs. Age-related changes in the distribution of follicles were not found following simple linear regression analysis. The phenotypes of lymphocytes in gastric lymphoid follicles of nine dogs aged from less than 1 year to 5 years were determined using monoclonal antibodies specific for canine leucocyte antigens and an indirect immunoperoxidase technique. The follicles had an organized distribution of lymphocytes subsets in that a predominantly B cell area contained some CD4+ cells and very few CD8+ cells and was adjacent to an area containing mostly T cells. Computer-assisted morphometric analysis was used to quantify the overall presence of the various lymphocyte subpopulations. Follicles in the fundus and body regions possessed similar percentages of lymphocytes averaging 42%, 22% and 3% of the area occupied by B cells, CD4+ and CD8+ cells, respectively. It is concluded that lymphoid follicles are a normal constituent of the canine gastric mucosa and possess a lymphocyte composition similar to that reported by others for solitary intestinal follicles.