Spatial risk assessment of herd sero-status of Aujeszky's disease in a county in Hungary

A Geographic Information System (VetEpiGIS) was used to analyze the ADV (Aujeszky's disease virus) sero-status in large-scale pig units regarding certain geographical features in a county of southern Hungary. The ADV sero-statuses were collected from all swine units in Csongrád county in 1998-2000. The units' coordinates were combined with a vector graphical digital map of the county, with a resolution of 1:100,000. Logistic regression tested the associations between sero-status of large-scale units and presence of topographical features, other units and villages in the neighborhood. "Neighborhood" was defined by circular zones with radius 1-10km around the unit (in 1km increments; one logistic regression for each radius). The following topographical features showed significant positive association with the ADV seropositivity: lake (3km OR: 5.7; 5km OR: 7.5; 6km OR: 6.1; 10km OR: 5.4) and highway (5km OR: 4.2; 6km OR: 5.3). Other features had negative association with ADV seropositivity: forest (3km OR: 0.13; 4km OR: 0.15; 5km OR: 0.15; 6km OR: 0.10; 7km OR: 0.10; 8km OR: 0.23) and uninfected large-scale unit (4km OR: 0.07; 5km OR: 0.27; 6km OR: 0.32; 7km OR: 0.31).     

Changes in Some Red Blood Cell and Clinical Laboratory Parameters in Young and Old Beagle Dogs

Routine laboratory and lipid peroxidase parameters in the blood of Beagle dogs under 1 year of age (7 males, 7 females) and over 9 years of age (7 males, 7 females) were compared. The mean corpuscular haemoglobin (MCH) and haemoglobin (Hb) values, plasma total protein (TP) and globulin concentrations in the older dogs were significantly higher than in the younger ones by 13%, 6%, 10% and 15%, respectively. The plasma inorganic phosphate concentration, however, was 30% lower in the older dogs than in the young ones. The concentration of malondialdehyde (MDA) was 30% higher, while the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities were around twice as high in the older dogs as in the young ones. However, in the older males the concentration of reduced glutathione (GSH) was 43% and in the older females 9% less than in the young ones. Extremely high levels of MDA and low levels of GSH were only found in the older males. GSH-Px and SOD activities were significantly higher in the older male dogs than in the young ones. The activities of these enzymes were highest in the older females. From our results, we suspect that old dogs, especially males, are particularly exposed to the harmful effects of free radicals and lipid peroxidation.     

Effect of enteral feeding on gallbladder function in dogs

Nutritional support in critically ill patients is a fundamental principle of patient care. Little is known about gallbladder motility during the interdigestive phase and in response to enteral feeding. The objective of this study was to investigate the effect of enteral feeding on gallbladder function in dogs. The cholagogue meal (Lipofundin infusion) was applied in four anatomical positions (jejunum, duodenojejunal junction, descending duodenum, stomach) in five healthy Beagle dogs. Gallbladder volume (GBV) was monitored by ultrasonography. Lipofundin infusion given through the feeding tube caused a maximal gallbladder contraction of 9.2% (range 3.7-13.9%) in the jejunum, 16.5% (9.1-22.1%) at the duodenojejunal junction and 26.3% (22.8-29.5%) in the descending duodenum. When the cholagogue meal was given through the mouth, it caused a mean 33.8% (28.6-46.5%) maximum gallbladder contraction in the same animals. In conclusion, we can establish that the ultrasound-guided gallbladder emptying method proved to be a useful technique for monitoring the cholagogue effect of Lipofundin meal applied in different anatomical positions of the intestine. The deeper the position of application, the smaller and shorter gallbladder contraction was evoked.     

Overwintering of winter cereals in Hungary in the case of global warming

Summary Under phytotronic conditions investigations were made on the effect of important environmental factors, such as temperature, water and an increasing concentration of atmospheric CO₂, on the hardening of young cereal plants.In all the varieties derived from the major wheat growing regions of the world the hardening process was favourably influenced by a doubling of atmospheric CO₂ content, so that a significantly larger number of plants survived the frost test than for plants of the same variety raised under normal conditions.A reduction in freezing temperature and an increase in soil moisture content caused a slight reduction in survival % for varieties with excellent frost resistance and a great reduction for those with medium or poor frost resistance.Predictions suggest that in Central Europe, as the result of global climatic changes, there will be a reduction in the quantity of winter precipitation, a considerable rise in winter temperatures and an increase in atmospheric CO₂ concentration. Judging by the experimental results, these changes could improve the overwintering of winter cereals; at the same time, however, a number of factors (mainly the reduction of precipitation) leading to yield losses must be expected during the vegetation period.     

Tree-Based Methods as an Alternative to Logistic Regression in Revealing Risk Factors of Crib-Biting in Horses

Determining the risk factors might help in designing prevention of crib-biting. Logistic regression is a commonly used statistical method for finding risk factors, but tree-based methods are also getting more popular. An important difference between these two statistical approaches is that logistic regression makes a number of assumptions about the underlying data, whereas tree-based methods do not. Another difference is that logistic regression can be used to derive odds ratios for the significant risk factors, whereas tree-based methods create a tree where the ramifications represent the risk factors. The probability of occurrence is assigned to each end of branch in the tree. Data of horses used for noncompetition purposes were analyzed with three statistical approaches: logistic regression, classification tree, and conditional inference tree methods. By this, we compared the advantages and disadvantages of these statistical methods. No difference was found between the two tree-based methods regarding the structure and prediction accuracy of the trees. Compared to them, logistic regression revealed fewer risk factors, and also the number of the stereotypic horses classified correctly by the model was less. The representation of the tree-based methods is closer to medical reasoning and also high-order interaction of the risk-factors can easily be visualized. Our results suggest that tree-based methods can be a new alternative in revealing risk factors, even if used alone or together with logistic regression.