Effect of different passages, times and routes of inoculation on humoral immune response induced by attenuated fowl adenovirus in broiler chickens

Lee, Shin Jye (2020) Effect of different passages, times and routes of inoculation on humoral immune response induced by attenuated fowl adenovirus in broiler chickens. [Project Paper] (Submitted)

Text lp FPV 2020 13.pdf Download (2MB)

Abstract

Fowl adenovirus (FAdV) infection may lead to disease outbreak t1n(i huge economy loss in the poultry industry. The objectives of the study were to determine the effect of different passages, times and routes of inoculation on humoral immune responses induced by attenuated FAdV isolate (UPMl 142) in broiler chickens. Seventy-six, day-old chicks were divided into five groups, namely Groups A, B, C, D and E. The Groups A, B, C and D each consisted of 16 chicks each and further divided into 3 subgroups namely Groups A1, BI, CI and DI; A2, B2, C2 and D2, and A3, B3, C3 and D3. The Groups A and C were inoculated with attenuated FAdV UPMl 142 isolate (1 x 106·5 TCID50 per mL) passaged 20 (P20) subcutaneously and orally, respectively. The Groups Band D were inoculated with the attenuated FAdV (1 x 105·7 TCID50 per mL) passaged 15 (P15) subcutaneously and orally, respectively, while Group E acted as control group and remain un-inoculated. The chickens were given feed and water ad-libitum and monitored for abnormal clinical signs twice daily One one day of age or day O post-inoculation (pi), chickens in Groups A1, B1, C1, D1, A2, B2, C2 and D2 were inoculated with the virus accordingly. Four chicks from Group E were sacrificed by cervical dislocation for sampling. Body weight and blood samples were taken prior to necropsy. Gross lesion of liver and liver weight were recorded during necropsy. The liver samples were collected and fixed in 10% buffered formalin for histological examination, while FAdV antibody titer was detected from the blood samples using ELISA techniques. On day 7 pi, four chicks from Groups A1, B1, C1, DI and E were sacrificed for sampling, while Groups A2, B2, C2, D2, A3, 83, C3 and D3 were inoculated with the virus accordingly. On day 21 pi, all the rest of the chickens were sacrificed for sampling. TJ.-i:,·,;.u:..iy revealed that neither abnormal clinical signs nor gross and histological le£ions were recorded throughout the trial. There was no significant difference (p>0.05) in body weight in all groups of chickens, except the Group E recorded the lowest (p<0.05) body weight (964±23.51) compared to the Groups Cl, C2, C3, DI, D2 and D3 on day 21 pi. The chickens in all groups showed no significant differences (p>0.05) in their liver weight and liver to body weight ratio. The Group Cl had the highest antibody titer (1557±528) compared to groups Al (380±99), Bl (771±289), DI (895±506) and E (1256±730) on day 7 pi. On day 21pi, Group B2 that inoculated twice with P15 attenuated FAdV subcutaneously had the highest antibody titer (1956±916) among other groups. Overall the FAdV antibody titer induced showed no significant differences (p>0.05) across all groups. In conclusion, the study suggests that attenuated FAdV at passage 15 and inoculated twice subcutaneously at day old and 7 of age able to induce higher antibody response when compared to the other groups. Attenuated FAdV is safe to use in commercial broiler chickens.

Item Type:	Project Paper
Faculty:	Faculty of Veterinary Medicine
Depositing User:	Ms. Nordeena Abdul Aziz
Date Deposited:	18 Oct 2023 04:28
Last Modified:	18 Oct 2023 04:28
URI:	http://psaspb.upm.edu.my/id/eprint/1450

Actions (login required)

View Item