Isolation and characterization of porcine circovirus type-2 from sera of stillborn fetuses

In order to examine an association between porcine circovirus type-2 (PCV2) infection and reproductive failure in pigs, sera (n = 171) from stillborn fetuses were collected from 3 different farms with prolonged histories of reproductive problems. These sera were tested for the presence of antibodies to PCV2 using an immunoperoxidase monolayer assay. Of the 171 sera tested, 28 had PCV2 antibody titers of ≥ 1:16. When these 28 samples were tested by a polymerase chain reaction assay, 13 were found to contain PCV2 viral DNA. Of these 13 samples containing both PCV2 antibodies and viral DNA, 9 yielded PCV2 on virus isolation. Amino acid sequences comprising open reading frame 2 of PCV2 from 2 of these isolates were compared to PCV2 isolates from cases of post-weaning multi-systemic wasting syndrome (PMWS). The amino acid sequences of the 2 isolates from stillborn pigs were shown to be nearly identical to each other, as well as to other PCV2 isolates associated with reproductive failure. When compared with PMWS isolates, the isolates from the stillborn fetuses showed differences of at least 2 amino acids. These results confirm previous findings that transplacental infection of PCV2 occurs in the field and that stillbirths in pigs may be associated with PCV2 infections. At present, the significance of minor differences in amino acid sequences is not known.     

Effect of dietary α -tocopherol concentration on performance and some immune responses in broiler chickens fed on diets containing oils from different sources

1. An investigation was carried out into the effects of dietary α-tocopherol (α-T) concentration and source of supplemental oil on performance, activity of anti-oxidative enzymes and some immune responses in broilers from day-old to 41 d of age. 2. Three dietary concentrations of α-T (10, 50 and 100 mg/kg) with three sources of supplemental oil (sunflower - SFO, palm - PMO and safflower - SAO) were provided using a 3 × 3 experimental design. 3. Body weight gain and food conversion efficiency were not affected by either interaction or concentrations of α-T and sources of oil in diet. 4. Concentrations of total protein, globulin, triglycerides and cholesterol in sera increased significantly with dietary α-T concentration irrespective of the source of oil. Significantly higher concentration of serum albumin was evident in broilers fed on the SFO-based diet and the concentration of globulin was higher in groups fed on those diets containing PMO and SAO. 5. The lipid peroxidation (LP), measured as MDA release, decreased with the concentration of α-T in a dose-related manner with SFO- and SAO-based diets, although not with the PMO-based diet. With different oil sources, LP was significantly lower with the PMO-based diet compared to the others. Activities of glutathione peroxidase and RBC catalase increased and heterophil: lymphocyte ratio was reduced with concentration of α-T for each source of oil tested. 6. Assays for humoral and cell-mediated immune responses indicated no effect of the source of dietary supplemental oil or interaction, although an increasing concentration of dietary α-T improved cell-mediated immune responses. 7. It is concluded that sunflower oil, palm oil and safflower oil can be used as sources of oil for broiler diets without having any effect on performance, immune responses or the activity of anti-oxidizing enzymes. Higher concentrations of dietary α-tocopherol (50 or 100 mg/kg) reduced lipid peroxidation activity and enhanced activities of anti-oxidative enzymes, they also improved the cell-mediated immune responses in commercial broilers.     

Tagging and mapping a second resistance gene for <Emphasis Type="Italic">Fusarium</Emphasis> wilt race 0 in chickpea

A second gene conferring resistance to the chickpea wilt pathogen, Fusarium oxysporum f. sp ciceris race 0, has been mapped to linkage group 2 (LG2) of the chickpea genetic map. Resistance to race 0 is controlled by two genes which segregate independently; one present in accession JG62 (Foc0 ₁ /foc0 ₁ ) and mapping to LG5 and the second present in accession CA2139 (Foc0 ₂ /foc0 ₂ ) but remaining unmapped. Both genes separately confer complete resistance to race 0 of the wilt pathogen. Using a Recombinant Inbred Line (RIL) population that segregated for both genes (CA2139 × JG62) and the genotypic information provided by two markers flanking Foc0 ₁ /foc0 ₁ ten resistant lines containing the resistant allele Foc0 ₂ /foc0 ₂ were selected. Genotypic analysis using these ten resistant lines paired with ten susceptible RILs, selected in the same population, revealed that sequence tagged microsatellite sites (STMS) markers sited on LG2 were strongly associated with Foc0 ₂ /foc0 ₂ . Linkage analysis, using data from two mapping populations (CA2139/JG62 and CA2156/JG62), located Foc0 ₂ /foc0 ₂ in a region where genes for resistance to wilt races 1, 2, 3, 4 and 5 have previously been reported and which is highly saturated with tightly-linked STMS markers that could be used in marker-assisted selection (MAS).     

The Impact of Animal Disease on Human Health and Welfare

Animal diseases are of considerable importance to human welfare both as a cause of illness in man and as a factor in reducing the food potential of the world. Perhaps the most important factor affecting the less developed areas is malnutrition and, while explosive epidemics among animals are of great importance, the most important sources of losses are the chronic, sub-acute or sub-clinical infections, especially those caused by the parasitic worms.     

Factors Associated with Survival in Septicemic Foals: 65 Cases (1988–1995)

In order to identify variables obtained at admission that could be used to predict survival in septicemic foals, medical records of 65 foals diagnosed with septicemia were reviewed. Initially, variables were analyzed independently (univariate analysis) for association with survival. Of the physical examination and historical data examined using univariate analysis, the ability to stand at admission, respiratory rate ≥ 60 breaths per minute (bpm), and normal-appearing mucous membranes were significantly associated with survival. Foals with history of induced parturition were significantly less likely to survive. The following hematologic and serum biochemical variables determined at admission were significantly associated with survival: white blood cell count a 6,000 cells/μL, neutrophil count <4,000 cells/μL, serum albumin concentration <2.2 g/dL, serum glucose concentration <120 mg/ dL, blood pH ≥ 7.35, and positive base excess. The administration of plasma at admission was significantly associated with survival. Stepwise multiple logistic regression analysis was performed to evaluate the association between survival and variables identified as significantly associated with survival in bivariate analysis. The final multivariate model selected included the variables standing, duration of clinical signs (24-hour intervals) prior to admission, respiratory rate a 60 bpm, neutropenia (> 4,000 cells/μL), and neonatal age category. The probability of survival was significantly increased for foals that were standing, had a respiratory rate a 60 bpm, and that had a neutrophil count <4,000 cells/μL at admission. Probability of survival was significantly decreased for foals that had a longer duration of clinical signs prior to admission. For each 24 hours of duration, the estimated risk of death was increased by 5.8-fold.