Efficacy of ELISA for measurement of protective newcastle disease antibody level in broilers |
Jong-Nyeo Kim1, won Heo2, In-Pil Mo1 |
1Research Institute of Veterinary Medicine/College of Veterinary Medicine, Chungbuk National University 2Daessung Microbiological Labs. Co. Ltd. |
육계의 뉴켓슬병 방어역가 측정에 있어서 ELISA 검사법의 효용성 |
김종녀1, 허원2, 모인필1 |
1충북대학교 수의과대학 2(주)대성미생물연구소 |
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Abstract |
Newcastle disease (ND) is a highly contagious disease of poultry that can cause severe economic losses throughout the world. Vaccination has been used for a long time and proved as one of the most effective method to reduce the economic loss due to ND virus infection, The measurement of antibody titer such as hamagglutination-inhibition (Hl) test with sera has been used as a useful method to evaluate the immunity leve of host. However, Hl test is gradually being replaced by the enzyme linked-immunosorbent assay (ELISA), To evaluate the efficacy of ELISA in the chickens vaccinated with different procedure, present study has been performed. After SPF chicks and commercial broilers were vaccinated with different kinds of live vaccines such as V4, VG/GA and/or Bl at various time, the antibody level has been measured using both HI test and ELISA. Challenge test with velogenic viscerotropic NDV was also performed to measure the protective level of antibody. In the SPF chickens, the mean ELISA titer after vaccination and survival rate after challenge was increased and correlated with days post inoculation. More than 80% of chickens with higher than 1,000 ELISA titer after vaccination were survived after challenge with velogenic ND virus and had good correlation between survival rate and antibody titier. In commercial broiler chickens, most of them at market age had low level of ELISA titer regardless of the number of vaccination, and had a low correlation between survival rate and ELISA titer. However, the ELISA titer of remaining birds after challenge was increased. This result indicated that ELISA titer had good response against velogenic NOV infection compared to Hl titer. |
Key Words:
Newcastle disease, Hl, ELISA, challenge infection |
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