الفهرس 
introductionOnly 14 pages are availabe for public view
 |  | from | 141 |  |  |
| | | from | 141 | | |
Abstract
’Bovine viral diarrhaea virus course severs economic losses in animal herds. Neutralizing antibodies to type I and 2 bovine viral diarrhoea virus (BVDV) strains were measured by virus neutralization test in MDBK cell culture and by ELISA test. The blood samples were collected from different governorates in Egypt. A dose titration study was performed using serum samples from different species i.e. cattle, buffaloes, sheep, goats and camels. Positive control serum samples were available for diagnostic testing of both type I and 2 BVDV antibodies. There did not appear to be major differences in antibody titres among the respective type strains, regardless of biotype (cytopathic or non cytopathic). Some seronegative samples via SNT were identified as seropositive ones through ELISA test. ELISA has sensitivity comparable with serum neutralization test. Blood samples were examined for BDV antibodies in different seasons to detect the influence of weather on the virulence of the virus through the titre of antibodies. The outbreak of bovine virus diarrhoea raised markedly in summer in regard to other seasons. The maximum number of responding animals has been recognized through the titre of the antibodies. The highest and lowest antibody prevalence was depending on the herd. The mean prevalence was high, moderate, or low regarding the corresponding species cattle, buffaloes, sheep, goats and camels respectively. In the recent study, the percentage of reaction of naturally infected or vaccinated herd was different according to the age of the responding animals. The old species have less susceptibility than the young ones; the matters give attention to good rearing of the animal against infection with BVDV specially the newly- born animals.