Evaluation of the antibody response of two local Saudi lines and commercial chickens vaccinated against Newcastle diseases virus and infectious bursal disease virus

الملخص EN

Two lines of local Saudi chicken, Hajar-l and Hajar-2, were developed by researchers in King Faisal University.

Their physiological and immunological performances are still under investigation.

The aim of this study is to evaluate the immunological response of vaccinated and non-vaccinated chicks against Newcastle and infectious bursal diseases in the Saudi lines compared with commercial line.

One hundred-eighty one-day-old chicks were divided into three equal groups; Hajarl, Hajar2 and commercial Hisex.

Each group was further subdivided into two equal subgroups, vaccinated and non-vaccinated.

Blood samples were collected from all chicks at weekly interval starting from the second week of age for four weeks.

Indirect enzyme-linked immunosorbent assay (ELISA) technique was used to assess the antibody titer against Newcastle and Infectious bursal disease viruses in addition to measuring weekly body weight.

The results of this study showed that both local Saudi chicken lines had the same body weight gain like the commercial one (p > 0.05).

Concerning vaccinated groups, Hisex chicken breed showed significant higher antibody titer (p < 0.05) against Newcastle and Infectious bursal disease viruses in the second and third weeks samples compared to Hajar-1 and Hajar-2.

However, Non-vaccinated local Saudi lines Hajar-1 and Hajar-2 showed better immunity at four weeks old against the two major viral threads compared to the commercial line (Hisex).

It could be concluded that non-vaccinated Hajar-1 and Hajar-2 lines high immunity at older age indicates the potential breeding advantage of these lines as possible source of immunity under non- vaccination condition