Buletin Veteriner Udayana Volume 14 No. 4: 425-432 pISSN: 2085-2495; eISSN: 2477-2712 Agustus 2022 Online pada: http://ojs.unud.ac.id/index.php/buletinvet DOI: 10.24843/bulvet.2022.v14.i04.p16 Terakreditasi Nasional Sinta 4, berdasarkan Keputusan Direktur Jenderal Pendidikan Tinggi, Riset, dan Teknologi No. 158/E/KPT/2021 425 Seroprevalensi dan Profil Antibodi Anti-Virus Newcastle Disease Pasca Vaksinasi pada Ayam Kampung di Kabupaten Bobonaro Timor-Leste (SEROPREVALENCE AND PROFILE ANTI-VIRUS OF NEWCASTLE DISEASE POST- VACCINATION ON LOCAL CHICKEN IN BOBONARO DISTRICT TIMOR-LESTE) Alberto Agustinho Pereira Da Costa Joao 1 , I Nyoman Mantik Astawa 2 *, Anak Agung Ayu Mirah Adi 3 1 Departamento de Saúde Animal, Faculdade de Agricultura Universidade Nacional Timor Lorosa’e, Timor Leste; 2 Laboratorium Virologi, Fakultas Kedokteran Hewan, Universitas Udayana, Jl. PB. Sudirman Denpasar, Bali; 3 Laboratorium Patologi, Fakultas Kedokteran Hewan Universitas Udayana, Jl. PB. Sudirman Denpasar, Bali. *Email: mantik.astawa@unud.ac.id Abstrak Penelitian ini bertujuan untuk mengetahui titer antibodi prevaksinasi maupun pascavaksinasi terhadap penyakit Newcastle disease (ND) pada ayam kampung di desa Lahomean, Odomau Raifun dan Ritabou Kabupaten Bobonaro Timor-Leste. Sampel serum prevaksinasi sebanyak 80 sampel dan pascavaksinasi sebanyak 79 sampel diambil dari ayam kampung yang diternakan secara ekstensif di keempat desa tersebut. Penentuan sampel penelitian dilakukan dengan teknik simple random dan purposive sampling untuk memilih subjek berdasarkan kriteria yang telah ditentukan. Titer antibodi anti-virus ND diperiksa dengan uji hemaglutinasi (HA) dan uji hambatan hemaglutinasi (HI). Data yang diperoleh dari penelitian ini disajikan secara deskriptif. Hasil penelitian menunjukkan bahwa dari 80 sampel serum prevaksinasi, 53 sampel (66,25%) menunjukkan seronegatif dengan titer antibodi < 2 3 (2 1 – 2 3 ) HI unit dan 27 sampel (33.75%) menunjukkan seropostif dengan titer antibodi 2 4 – 2 10 HI unit. Sementara itu, dari 79 sampel serum pasca-vaksinasi 46 (57%) sampel menunjukkan seronegatif dengan titer antibodi 2 1 – 2 3 HI dan 33 (43%) menunjukkan seropositif dengan titer antibodi 2 4 – 2 11 HI unit. Hasil tersebut menunjukkan bahwa sebagian kecil ayam yang belum divaksin pernah terpapar virus Newcastle disease secara alami dan vaksinasi dapat meningkatkan titer dan jumlah ayam yang seropostif terhadap virus ND. Kata kunci: Ayam kampung; uji HA; uji HI; virus Newcastle Disease Abstract The objective of this study was to determine anti-Newcastle disease virus (NDV) antibody titres in sera samples of pre-vaccinated and post-vaccinated local chickens in the villages of Lahomean, Odomau Raifun and Ritabou, Bobonaro District Timor-Leste. Eighty sera samples of pre-vaccinated and 79 samples of post-vaccinated chickens were collected from village chicken farms bred extensively in all four villages. The sampling techniques adopted were simple random and purposive sampling methods to select subjects based on predetermined criteria. Antibody titers against NDV in serum samples were examined by using hemagglutination test (HA) and hemagglutination inhibition test (HI). The data obtained in this studi were presented descriptively. The results showed that of 80 sera samples collected from pre-vaccinated chickens, 53 (66.25%) sera samples were seronegative with the antibody titers of < 2 3 (2 1 – 2 3 ) HI units and 27 (33,75%) sera samples were seropositive with antibody titers of 2 4 – 2 10 HI units. As for 79 sera samples collected from post-vaccinated chickens, 46 (57%) samples were seronegaitive with the antibody titers of 2 1 – 2 3 HI and 33 (43%) sera samples were seropositive with antibody titer of 2 4 – 2 11 HI units. The results showed that presence of anti-NDV antibody in prevaccinated chickens was very likely due to the natural infection and vaccination increased the titers and the number of seropositive chickens. Keywords: HA test; HI test; local chicken; Newcastle Disease virus