الملخص الإنجليزي
Goats are the main source of meat in Oman as their meat is the most preferred by the local population. Infectious diseases such as Foot and Mouth disease (FMD) constitute a major impediment to animal production and are considered to be an important limiting factor in the maintenance of livestock such as goats. FMD is considered to be endemic in all regions of Oman. In order to control and prevent disease outbreaks a trivalent killed vaccine containing types O, A and Asial FMD virus is used for vaccination in the Sultanate. To ascertain the effectiveness of FMD vaccine the present study highlights the serological response of 4 breeds of goats to FMD vaccine containing FMD virus types O, A and Asial. Twenty goats from four breeds, (Jabal Akhdar, Sharqia, Shami and Crossbreed between Shami and Sharqia) four months of age of both sexes which had not been previously vaccinated against FMD were selected and maintained together. All animals were screened for antibodies against types Asia 1, A and O monisia. Thereafter, each animal was vaccinated with 1 ml of the inactivated FMD vaccine, A dose of 1 ml contained 5.08 PDso, 4.28 PDso, 4.95 PDso of O, A and Asial FMDV antigens respectively. Blood samples were collected from each goat on days 7, 14, 21, 28, 60, 90, 120, 150, 180, 210, 240 and 270 post vaccination. A liquid phase blocking ELISA was performed. The assay is based on the specific blocking of a defined amount of FMDV antigen by antibodies in the test sample during the liquid phase. The results of the study demonstrated that the FMD vaccine, presently used in Oman for goats does not give adequate protection for 6 months as indicated by the manufacturer. Also the antibody response against FMDV type A was the least protective of the three serotypes. An acceptable level of protection for all three types was only for 4 months. The genetic background of the animals appears to have an effect on the serological response. A significantly better response was observed in Jabal Akhdar goats in comparison to the other 3 groups against type O, A and Asial. The reasons for these apparent breed differences need further investigation. Furthermore, alternative FMD vaccine and vaccination strategy need to be explored for Omani goats
