Effect of dietary flax oil and hypobaric hypoxia on pulmonary hypertension and haematological variables in broiler chickens.

1. Three experiments were conducted with broiler chickens using hypobaric chambers and control pens, feeding diets containing 25 or 50 g flax oil/kg food or control diets with equivalent amounts of animal/vegetable (A/V) blend oil for 4 weeks. The effect of these diets on haematological variables and the extent of right ventricular hypertrophy (RVH) leading to ascites was determined. 2. Overall growth rate was not consistently affected by dietary treatment, although feeding the 25 g flax oil/kg diet reduced weight gain in week 4 of one experiment. Feeding the 50 g flax oil/kg diet but not the 25 g flax oil/kg diet reduced RVH in birds exposed to hypobaric conditions compared to feeding control diets. 3. Feeding the 50 g flax oil/kg diet under hypobaric conditions reduced the haematocrit and haemoglobin content, increased the erythrocyte deformability and the proportion of unsaturated fatty acids in the erythrocyte membranes, and reduced the whole blood viscosity compared to feeding control diets. These effects were not seen when the 25 g flax oil/kg diet was fed. The ratio of n-3 to n-6 fatty acids in erythrocyte membranes was increased in the 50 g flax oil/kg treatment group compared to controls. 4. Including 50 g flax oil/kg broiler diet reduces RVH in broiler chickens. This may be attributable in part to an increase in erythrocyte deformability from an increased proportion of unsaturated fatty acids in the erythrocyte membranes.     

Tissue-specific changes in the activities of antioxidant enzymes during the development of the chicken embryo.

1. Tissue-specific profiles of the expression of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the concentrations of reduced glutathione (GSH) during the development of the chick embryo were investigated. 2. The liver, brain, yolk sac membrane (YSM), kidney, lung, heart and skeletal muscles were collected at the following days of embryo development: 10, 11, 13, 15, 17, 19, 21 and 22 (day-old chicks). 3. The different tissues of the embryo displayed distinct development strategies with regard to the acquisition of antioxidant capacity. In the liver the specific activity of SOD increased between days 10 and 11 of development, then significantly decreased up to day 15 and remained at the same value during the rest of the developmental period. GSH-Px specific activity increased through the time of development. CAT had 2 peaks of specific activity at day 10 of the development and in day-old chicks. 4. The brain was characterised by comparatively high SOD-specific activity especially during the last days of incubation. The specific activities of GSH-Px and CAT were low throughout development. 5. In the YSM maximal GSH-Px and CAT-specific activities were found on day 15 of incubation. In the kidney and heart GSH-Px-specific activity increased at hatching time. CAT-specific activity in the kidney increased just after hatching. 6. It is concluded that each tissue studied expressed a profile of antioxidant defence mechanisms to deal with oxidative stress at hatching time.     

Hemorrhagic septicemia in fallow deer (Dama dama) caused by Pasteurella multocida multocida.

Four outbreaks of hemorrhagic septicemia caused by Pasteurella multocida multocida occurred in a population of 1,800 fallow deer (Dama dama) during 1992-1996. A total of 340 fallow deer were submitted for postmortem examination. Pasteurellosis was diagnosed in 273 of 312 deer suspected of having septicemia. Pasteurella multocida was isolated from 257 animals, and the diagnosis was based on typical pathologic changes alone in the other 16 animals. Pasteurella multocida was isolated in pure culture from 219 of 248 samples of cerebrospinal fluid. Eighteen animals were observed moribund with severe depression, foamy nasal discharge, and respiratory distress, and 257 were found dead. Major clinical signs and pathologic changes included extensive swelling of the head and the neck and peracute or acute septic pneumonia, petechial and ecchymotic hemorrhages on serous membranes, and severely hemorrhagic adrenal glands and abomasum. Rhinitis and necrotic pharyngeal mucosae were common. Histologically, the most advanced lesions were in the nasal mucosa and pharynx. The swelling of the head and the neck arose from a diffuse cellulitis in the subcutaneous and intermuscular tissues. The earliest lesions in the lungs included large numbers of bacteria in the pulmonary capillaries, but various degrees of fibrinous exudation to the alveoli and infiltration with heterophils usually were observed.     

Determination of Normal Values Using an Automated Coagulation Timer for Activated Coagulation Time and its Application in Dogs with Hemophilia

The present study was performed to determine normal values for the Medtronic HemoTec automated activated coagulation time (ACT) analyzer (Medtronic HemoTec Inc, Parker, CO, distributed in Switzerland by Convergenza AG, Vaduz, Liechtenstein), and to evaluate its ability to detect dogs with hemophilia. ACT was measured in 43 healthy dogs presented to the Companion Animal Hospital, University of Bern, Bern, Switzerland, with the Medtronic HemoTec ACT analyzer to determine normal values. The mean +/- 2 standard deviations (SDs) of the values obtained was defined as the normal range. ACT was measured 8-10 times on the same day in 6 dogs to determine repeatability. ACT also was measured in 11 dogs with hemophilia and compared with a conventional visual ACT measurement test and with the activated partial thromboplastin time (APTT). ACT values of the 43 dogs used to determine normal values ranged from 66.5 to 97.0 seconds (mean, 79.3 seconds; SD, 7.35 seconds; median, 78.5 seconds). A range of 64-95 seconds (mean +/- 2 SDs) was defined as the normal range for the tested device. Repeatability was poor (r = 0.256). ACT values measured with the automated device did not correlate with ACT values measured with a conventional visual test or with APTT Sensitivity of the test was 90.9%, specificity was 98.0%, and accuracy was 96.7%. Variability in the test results was large and may lead to incorrect results. The automated measurement device was not superior to the conventional visual method in evaluating dogs with hemophilia.     

Development of a polymerase chain reaction to detect Vietnamese isolates of duck virus enteritis.

A polymerase chain reaction (PCR) method for the detection of duck virus enteritis (DVE) virus in tissues of infected and affected ducks, and in cell culture was developed. This required us to obtain specific nucleotide sequence information as we could not find any specific data about the genome of the virus. We found the assay to be highly effective in detecting the virus under experimental conditions and to be easily transferred to laboratories in Vietnam where it is being used in studies on the epidemiology of the disease. We have applied this simple and rapid diagnostic method to the detection of DVE isolates grown in cell culture and tissues from infected birds. The assay was also able to differentiate DVE from other avian herpesviruses, such as Marek's disease, infectious laryngotracheitis virus and goose herpesvirus.     

Estimation of Neospora caninum seroprevalence in dairy cattle from Normandy, France.

An epidemiological study was conducted in Orne (France) on randomly selected dairy herds (42 herds including 1,924 cows and heifers, which were at least 15 months old). The aim was primarily to estimate the seroprevalence of Neospora caninum infection from two blood samples per cow, using an enzyme-linked immunosorbent assay (ELISA) for N. caninum (one positive result indicating infection). The second aim was to test the association between some individual and herd factors and N. caninum seropositivity with a logistic model including a random term effect. The prevalence was estimated at 5.6% (107 seropositive animals). At least 27 of the 42 herds had one seropositive cow or heifer. The intra-herd seroprevalence varied from 1.1 to 8% for 18 positive herds (66.7%). Dogs were present in 36 farms and 104 of the 107 seropositive animals were exposed to them. The factors associated with individual seropositivity were the presence of cats (OR = 0.17; P < 0.001), dogs (OR = 4.35; P = 0.02), rabbits and/or ducks (OR = 2.10; P = 0.04), long calving periods (12 months) (OR = 0.44; P = 0.007), tethered housing (OR = 2.50; P = 0.01), somatic cell counts (200-400 x 10(3) cells/mL) (OR = 0.24; P < 0.001) and pond water supply (OR = 2.43; P = 0.04). In conclusion, the animal and intra-herd seroprevalences were low in dairy cows from Normandy, France.     

Effects of hemolysis on plasma electrolyte and chemistry values in the common green iguana (Iguana iguana).

Hemolysis of serum and plasma samples is a common problem in veterinary diagnostic laboratories. We measured the effects of hemolysis on nine plasma analytes in 10 clinically normal common green iguanas (Iguana iguana). Blood samples with moderate and marked hemolysis were produced from each iguana by freezing, centrifuging, and decanting plasma from a portion of each blood sample, and combining the nonhemolyzed plasma with different amounts of hemolyzed plasma from the same individual. Moderate hemolysis significantly increased plasma phosphorus levels. Marked hemolysis significantly increased plasma values of potassium, phosphorus, total protein, and aspartate aminotransferase. The severity of hemolysis must be considered when interpreting values for these analytes in iguana plasma.     

Isolation and characterization of the eighth component of the bovine complement system

OBJECTIVE: To isolate and characterize the eighth component of the complement system (C8) in cattle. SAMPLE POPULATION: Fresh plasma obtained from beef cattle. PROCEDURES: Plasma samples were fractionated, using sequential precipitation and ion-exchange and gel-filtration chromatography, to yield C8. The protein was identified throughout the procedure on the basis of its hemolytic function. Electrophoresis in polyacrylamide gels was used to determine molecular weight and composition of polypeptide chains. Reconstitution of classical and alternative complement pathways was used to characterize the hemolytic function of bovine C8. RESULTS: The bovine C8 protein consisted of a disulfide-bonded alpha-gamma heterodimer that was noncovalently associated with a beta chain. Apparent molecular weight of the alpha, beta, and gamma chains under reducing conditions were 66, 61, and 23 kd, respectively. In the classical pathway of activation, bovine C8 and the ninth component of the complement system (C9) had species incompatibility with human C8 and C9 on sheep erythrocyte target cells. CONCLUSIONS: A simple 4-step fractionation procedure provided good yield of bovine C8 from plasma. The isolated protein was structurally comparable to C8 from other species. Purified bovine C8 may be useful in functional hemolytic assays to investigate the roles of complement-mediated lysis in the pathogenesis of inflammatory diseases and the killing of susceptible microorganisms.     

Structures and possibilities of herd management on the example of respiratory enzootic infection of calves

With the keeping of cattle in bigger herds problems arise, which require a modified veterinary approach. In stead of and in addition to the treatment of individual animals improvement of hygiene, intensification of prophylaxis, fast recognition (herd diagnostics) and interregional comparability have to be established. Beside the conventional field veterinarian, who is consulted on request primarily for the treatment of single animals, specialists in team practices as an alternative, permanently employed veterinarians or firm contracts with a health service up to integrated herd control are thinkable. The clarification and control of infectious diseases of the respiratory tract in cattle operations require an exact analysis of the environmental conditions and the identification of etiologic agents. Special attention has to be drawn to the evaluation of the barn climate and the respective taking of samples concerning the actual disease situation.     

Use of protected methionine (Mepron M 85) in cattle

The ruminal stability of Mepron M 85 and the effect of supplementation with Mepron M 85 on free methionine level of blood were studied in rumen-fistulated cows and rumen- and duodenum-fistulated growing bulls. In five rumen-fistulated cows in situ 69.5% and 64.6% of the methionine content of Mepron M 85 was found after ruminal incubation of 16 h and 24 h, respectively. Daily rations of the rumen-fistulated cows were supplemented with 15.0 g DL-methionine and 17.7 g Mepron M 85, which increased the free methionine level of blood from 13.64 mumol/L to 15.35 and 20.46 mumol/L, respectively, three hours after feeding. In the four rumen- and duodenum-fistulated growing bulls, supplementation with 15.0 g DL-methionine and 17.7 g Mepron M 85 increased the total methionine getting into the duodenum during 24 h from 14.99 g to 16.84 and 20.84 g, respectively. The influence of Mepron M 85 on milk production was studied in 35 pairs of Hungarian Fleckvieh x Holstein-Friesian cows. The animals were coupled on the basis of the number of finished lactations, milk production in the previous lactation, and the date of calving. Daily supplementation of 18.0 g Mepron M 85 increased daily milk production significantly (p < 0.05), by 1.24 litres. Milk fat content also increased significantly (from 3.10% to 3.19%, p < 0.05) in the experimental group. The supplementation did not influence milk protein content.