Echinacea purpurea（cone flower）:an immunomodulatory agent in Newcastle disease infected broiler chicks
摘要：Vaccination nowadays is the utmost reliable approach to reduce the fatality rate due to Newcastle disease virus（NDV）. In spite of vaccination and biosecurity, Newcastle disease（ND） is still prevalent globally in poultry. Various drugs shield the poultry birds for short period of time, while immune modulators work for longer duration against infection. The present study was planned to examine the immunomodulatory effects of Echinacea purpurea（E.purpurea） dried extracts against NDV infection. For the present trial, a flock of 120 day old broiler chicks were randomly distributed into 4 equal groups A, B, C and D with 30 birds per replicate. Experimental shed was properly cleaned and disinfected with 4% formalin solution a day before the arrival of chicks. Fresh water was available for chicks ad libitum. All chicks were vaccinated against infectious bursal disease（IBD）, NDV and hydropericardium syndrome（HPS） according to routine schedule. Group Aserved as control negative received no treatment and E.purpurea treatment was offered at 2.5 g/kg to group C and D in feed till 40 th day of age. At day 19 th of trial, the chicks of control positive group B were challenged with velogenic NDV strain. Anticoagulant added blood was collected at day 26 th, 33 rd and 39 th day post infection（DPI） for haemagglutination（HA） and haemagglutination inhibition（HI） assay against NDV and sheep red blood cells（SRBCs）. The Duncan multiple range test results concluded that body weight was significantly higher in group C from 3 rd week onward as compared to control negative group. Geometric mean titers log2 against NDV was higher in control positive group B & treatment group D as compared to control groups at 26 th, 33 rd and 39 th DPI. Cellular immunity and phagocytic index; lymphoproliferative response（LPR） against avian tuberculin was higher significantly at 24 th and 48 th hour post inoculation in group D while carbon clearance assay（CCA） was higher in treatment group C at 0,3 rd & 15 th minute. In conclusion, the present study revealed that use of Echinacea purpurea at 2.5 g/kg in feed enhanced the overall performance and immune response of broiler birds against NDV.
2017 International Conference on Agricultural and Food Science （ICAFS 2017）